.
This commit is contained in:
Ross
+50
-129
@@ -1,132 +1,53 @@
|
||||
{
|
||||
"8f740fe23a1f9a45b36059b689e856ceb3c10b43ee55b78be2aac5303c595c96": "docs_md/external/https-appstatdxcom_app.statdx.com__68c940ff_20251017T211704Z.meta.md",
|
||||
"6783fbb02e973ac24cca6f83e9d137b370d2156f2236b9b4e6062e7ccad4f5ea": "docs_md/external/https-appstatdxcom-document-09ca9b54-a3d9-43fd-a9cc-4c0212b578a1-media_app.statdx.com_document_09ca9b54-a3d9-43fd-a9cc-4c0212b578a1_media_7fa3f9a1_20251014T204901Z.meta.md",
|
||||
"559b1f5d3eba1b9750d68db3326a16df2fa079813b29f76ed9f5824022b4b6b1": "docs_md/external/https-appstatdxcom-document-12b32579-c99b-41c0-95fd-f2ad1fc4a4fd-media_app.statdx.com_document_12b32579-c99b-41c0-95fd-f2ad1fc4a4fd_media_2ef2abb7_20251014T202907Z.meta.md",
|
||||
"132a6246376a8cc9e69228766db9c4a196cc7248c9ca86ea059483e6d4cda881": "docs_md/external/https-appstatdxcom-document-23de52b7-d9bd-441c-a18c-95c8afccb470-media_app.statdx.com_document_23de52b7-d9bd-441c-a18c-95c8afccb470_media_640e8e45_20251014T204657Z.meta.md",
|
||||
"82ee80c12711edc70ffc31ebf506d82f756be2b84e718f69e951c61e7c2360ac": "docs_md/external/https-appstatdxcom-document-23de52b7-d9bd-441c-a18c-95c8afccb470-tables_app.statdx.com_document_23de52b7-d9bd-441c-a18c-95c8afccb470_tables_a484b4c4_20251014T204657Z.meta.md",
|
||||
"aacaa46dfe4f51f6302099d5e6d3b853a75942f5418ed4fb2f830ee64b446309": "docs_md/external/https-appstatdxcom-document-24559f7a-ed5a-4ab6-90ba-769f0b5c1197-media_app.statdx.com_document_24559f7a-ed5a-4ab6-90ba-769f0b5c1197_media_68d0cff6_20251014T195936Z.meta.md",
|
||||
"b37c794f3641c894fb2c8660747ada1559fc9a5e1b32836510f65589357c9361": "docs_md/external/https-appstatdxcom-document-2aad3ac4-44fd-43e5-8e50-a86987483af3-media_app.statdx.com_document_2aad3ac4-44fd-43e5-8e50-a86987483af3_media_93b3c006_20251014T193414Z.meta.md",
|
||||
"2bc150a35fca859fcd8be1e211e74508f9e93a7f5d7c89310b796e8413d3f33f": "docs_md/external/https-appstatdxcom-document-2b99b31a-ec1a-4dce-bb63-2a101fe9f044-media_app.statdx.com_document_2b99b31a-ec1a-4dce-bb63-2a101fe9f044_media_c76d4e9f_20251014T193525Z.meta.md",
|
||||
"75b9de4f6f835bc8051888cdd61df85158949eb123cf704f0c60f8fba75ce6c0": "docs_md/external/https-appstatdxcom-document-39a0d2d1-1439-4558-8f5d-86a2a6d93e3a-media_app.statdx.com_document_39a0d2d1-1439-4558-8f5d-86a2a6d93e3a_media_9cb0e971_20251014T204947Z.meta.md",
|
||||
"cd77be566fab4b1d14b3c0ea43e67530d0260b46b6912db17561e36999678d88": "docs_md/external/https-appstatdxcom-document-4778fafe-9873-4c28-8f4f-299c00c72b50-media_app.statdx.com_document_4778fafe-9873-4c28-8f4f-299c00c72b50_media_ff79514f_20251014T204704Z.meta.md",
|
||||
"82a71486da6df4ff81e77161cb35fe2fb563f297a55a71bd67ecfbe892c31bf3": "docs_md/external/https-appstatdxcom-document-49510d0e-acf7-45cb-9eb1-53f8193b0b6d-media_app.statdx.com_document_49510d0e-acf7-45cb-9eb1-53f8193b0b6d_media_00a64790_20251014T204710Z.meta.md",
|
||||
"9c6e2263738e59593a52304ab0a67371b5464c947582ef980f12ed0bf7f26d38": "docs_md/external/https-appstatdxcom-document-49510d0e-acf7-45cb-9eb1-53f8193b0b6d-tables_app.statdx.com_document_49510d0e-acf7-45cb-9eb1-53f8193b0b6d_tables_19dabcac_20251014T204710Z.meta.md",
|
||||
"1d48e82de0f4352714943824207c81f6bb59e2272c18c48c9622e99615f4f19e": "docs_md/external/https-appstatdxcom-document-5813a554-06a4-4696-af71-7ce50693039d-media_app.statdx.com_document_5813a554-06a4-4696-af71-7ce50693039d_media_0b54d39d_20251017T212345Z.meta.md",
|
||||
"7babfed03c49edde5d00443c1783838a267c32d880406fde5b3ba176d7ee5802": "docs_md/external/https-appstatdxcom-document-6cb71737-f574-4121-a8fb-02eeada9f9f7-media_app.statdx.com_document_6cb71737-f574-4121-a8fb-02eeada9f9f7_media_a7fbcf7b_20251014T195847Z.meta.md",
|
||||
"cc70569e8c4ecd1c18b5f6b008a4c1c20b86b63ec77125dbefa0042a0e34f616": "docs_md/external/https-appstatdxcom-document-78257543-6d52-4879-84b1-445f3611d996-media_app.statdx.com_document_78257543-6d52-4879-84b1-445f3611d996_media_2f9e2bbb_20251014T204752Z.meta.md",
|
||||
"a863f5fa5e19d6b83c76506567103d4acc160428ec313917ff7f041b4e931fbd": "docs_md/external/https-appstatdxcom-document-7d64f5fb-c62c-4861-8ff4-654a12074605-media_app.statdx.com_document_7d64f5fb-c62c-4861-8ff4-654a12074605_media_44ed5888_20251014T202430Z.meta.md",
|
||||
"213a241699c1efa5cd3b558e806ae96e169f6ead79a16f19d3aa7faf1cc951a9": "docs_md/external/https-appstatdxcom-document-7f85487f-9497-44a9-b884-b98e50d41018-media_app.statdx.com_document_7f85487f-9497-44a9-b884-b98e50d41018_media_f2029cbd_20251014T204849Z.meta.md",
|
||||
"19821bf3e438c87c30551ba78fd40b80a2313ab946078f2c262efc592ccb4996": "docs_md/external/https-appstatdxcom-document-840ed321-c0ab-4069-a07e-ad416232f916-media_app.statdx.com_document_840ed321-c0ab-4069-a07e-ad416232f916_media_6c4131be_20251014T204602Z.meta.md",
|
||||
"e0ddb24025036cf14ab45719650731dee26e1ef76daafffb10a31818852f6a1e": "docs_md/external/https-appstatdxcom-document-8bfa943b-c158-4a3b-9d43-e6ef057f45d4-media_app.statdx.com_document_8bfa943b-c158-4a3b-9d43-e6ef057f45d4_media_08746c1e_20251014T204445Z.meta.md",
|
||||
"fb86e9b6bdec86b3e3307a3647c5c59987872be307824aa5e335fa74eadaf59f": "docs_md/external/https-appstatdxcom-document-8e3465d1-d058-48d8-863c-1fd85cc6caee-media_app.statdx.com_document_8e3465d1-d058-48d8-863c-1fd85cc6caee_media_079e5a6e_20251014T204533Z.meta.md",
|
||||
"e11e8d088231e2fd34e20100bb5ad2adebe1ea99ab3059ffe2d9db3b4fc8458a": "docs_md/external/https-appstatdxcom-document-8f1561f7-92a7-485c-a0ae-2e2d5c8c1628-media_app.statdx.com_document_8f1561f7-92a7-485c-a0ae-2e2d5c8c1628_media_a2353309_20251014T204923Z.meta.md",
|
||||
"509bdb49d64628cd4ed0dfc17757322592692cd5f3f5f9756db1708a7cd9b44e": "docs_md/external/https-appstatdxcom-document-9f9eda8c-7e3c-4292-9861-4b8abc2c6474-media_app.statdx.com_document_9f9eda8c-7e3c-4292-9861-4b8abc2c6474_media_23f69ac7_20251014T193351Z.meta.md",
|
||||
"470aa453ed96f8620233a55268a23df09affa7ad67a1174764209da1bcb7f17b": "docs_md/external/https-appstatdxcom-document-a342e5b5-5b98-4003-a437-6d42a483b40e-media_app.statdx.com_document_a342e5b5-5b98-4003-a437-6d42a483b40e_media_e5d69417_20251014T204358Z.meta.md",
|
||||
"ab7682a6cae98f509ced3f10a99c90f486bda4074878c81406eac88abf9d2be3": "docs_md/external/https-appstatdxcom-document-aa473236-a733-4f9b-8d92-267ab8d4bcd9-media_app.statdx.com_document_aa473236-a733-4f9b-8d92-267ab8d4bcd9_media_6a74a397_20251014T204510Z.meta.md",
|
||||
"ed03db0d85cd49cee77b748d1e23fed73d3487ee7f11d604dd42f3ff16007e3b": "docs_md/external/https-appstatdxcom-document-c1e384b3-3c6e-4f67-bf79-5187bd6a1b86-media_app.statdx.com_document_c1e384b3-3c6e-4f67-bf79-5187bd6a1b86_media_f6ae7fb0_20251014T204642Z.meta.md",
|
||||
"a4d8bfa4a9b9147632c7e8bd3ff14b72b04c14fb148ae8a0ccb13274466aba10": "docs_md/external/https-appstatdxcom-document-c5d717a3-3d6e-4e86-9efe-1ad0ec14740f-media_app.statdx.com_document_c5d717a3-3d6e-4e86-9efe-1ad0ec14740f_media_ad9f4f3c_20251017T212541Z.meta.md",
|
||||
"d7f0687cf97e1acbabf128b56fcb5c262d27a290b871b7bbc85bf56d94d27a92": "docs_md/articles/craniopharyngioma_00e66680-6731-4287-b5a1-3f0b3f09053b.md",
|
||||
"0a0984979937bf4f0b37e656d58fbba6713a94793456a8ff4a5a1618e976ad21": "docs_md/external/https-appstatdxcom-document-content-00e66680-6731-4287-b5a1-3f0b3f09053b_app.statdx.com_document_content_00e66680-6731-4287-b5a1-3f0b3f09053b_ff7f86be_20251014T205219Z.meta.md",
|
||||
"c404c030c29e9f6b9dce68b4c4129ca396c3a71bb836bbc1d694812c1d8e9f0e": "docs_md/articles/adrenal_082ca43c-db5c-4770-aeed-0c6ea317e8fc.md",
|
||||
"799574ced4cf2f0c1d5a3ea81f5f36e00d4a326a80cdc705bf1a20b993f3cbb1": "docs_md/external/https-appstatdxcom-document-content-082ca43c-db5c-4770-aeed-0c6ea317e8fc_app.statdx.com_document_content_082ca43c-db5c-4770-aeed-0c6ea317e8fc_79cc786d_20251017T212319Z.meta.md",
|
||||
"941f2a3d2dd1349831c680dc843ef55cbe26fc3fffd2820cc13f6c4c57ebe30d": "docs_md/articles/pituitary-anomalies_09ca9b54-a3d9-43fd-a9cc-4c0212b578a1.md",
|
||||
"8b4ff977853904917992b7b83b0a9eabd20d998ced657a02ecb36714606c84da": "docs_md/external/https-appstatdxcom-document-content-09ca9b54-a3d9-43fd-a9cc-4c0212b578a1_app.statdx.com_document_content_09ca9b54-a3d9-43fd-a9cc-4c0212b578a1_38ef7db5_20251014T204902Z.meta.md",
|
||||
"1f3f5992a94f12ce80bbeb02780b34f25a79b35bbd93dcc5b7afa468b14c5804": "docs_md/articles/brain-tumor-in-newborn-infant_12b32579-c99b-41c0-95fd-f2ad1fc4a4fd.md",
|
||||
"70105df6bfabf1f02393b025ac8f59fcc9ea6cb448ee3a36a0f162e7545f2135": "docs_md/external/https-appstatdxcom-document-content-12b32579-c99b-41c0-95fd-f2ad1fc4a4fd_app.statdx.com_document_content_12b32579-c99b-41c0-95fd-f2ad1fc4a4fd_d27108e0_20251014T202907Z.meta.md",
|
||||
"b35301d123342f032e80a89cb636b59b9c7f7ed2e51012ab010a0dd522be84f7": "docs_md/articles/amyotrophic-lateral-sclerosis-als_23de52b7-d9bd-441c-a18c-95c8afccb470.md",
|
||||
"707fe0aa2c588cbd8f4961319c09ca37f4ee8907a2e335e4b19edc962ca207d9": "docs_md/external/https-appstatdxcom-document-content-23de52b7-d9bd-441c-a18c-95c8afccb470_app.statdx.com_document_content_23de52b7-d9bd-441c-a18c-95c8afccb470_43cf20f0_20251014T204657Z.meta.md",
|
||||
"3fc2e5bd0e1fd66e55160ab2a1436812110d477e37848a140d012212b7d494ed": "docs_md/articles/csf-like-parenchymal-lesions_24559f7a-ed5a-4ab6-90ba-769f0b5c1197.md",
|
||||
"81d0b69c9d00fa582a4a992b721b01930ecd1611e7aa0dcf91049eb752ee3e22": "docs_md/external/https-appstatdxcom-document-content-24559f7a-ed5a-4ab6-90ba-769f0b5c1197_app.statdx.com_document_content_24559f7a-ed5a-4ab6-90ba-769f0b5c1197_0b5c5cd9_20251014T195936Z.meta.md",
|
||||
"b215beb1d68b7c0b92309ace2e43e00b8dd77ae5210634a95282f19c9d123855": "docs_md/articles/normal-aging-brain_2a315550-b2ea-4afe-a2ef-f93a2209f276.md",
|
||||
"c51f31c8c91f8341d3ae0703fbf3bdf6b2f316d3efff0f4a61bee2a5aee525a7": "docs_md/external/https-appstatdxcom-document-content-2a315550-b2ea-4afe-a2ef-f93a2209f276_app.statdx.com_document_content_2a315550-b2ea-4afe-a2ef-f93a2209f276_6955e903_20251014T204549Z.meta.md",
|
||||
"43b33e02a14c9f3b70f2fb1d92a45a406538806704d644428f8da00e37b3b312": "docs_md/articles/alzheimer-disease_2aad3ac4-44fd-43e5-8e50-a86987483af3.md",
|
||||
"7d682ac0983afdfffaa2fb4d2d47c1824b2992df52eebed2cae6f2a5a1d1517a": "docs_md/external/https-appstatdxcom-document-content-2aad3ac4-44fd-43e5-8e50-a86987483af3_app.statdx.com_document_content_2aad3ac4-44fd-43e5-8e50-a86987483af3_430ffae3_20251014T193414Z.meta.md",
|
||||
"8d0d986e6b608b6afd02c3892aaf9127d8425450c7c95e6575878342247cdd52": "docs_md/articles/parkinsonian-syndromes_2b99b31a-ec1a-4dce-bb63-2a101fe9f044.md",
|
||||
"d3cf45ff401705f94cd7d2b928c484681a7772a35b0534f531ecdf47cceaeb80": "docs_md/external/https-appstatdxcom-document-content-2b99b31a-ec1a-4dce-bb63-2a101fe9f044_app.statdx.com_document_content_2b99b31a-ec1a-4dce-bb63-2a101fe9f044_dc973ded_20251014T193525Z.meta.md",
|
||||
"987e2ddc170b19041c457797cd55da626bada0603d899a5c3ca419afd597b813": "docs_md/articles/multiinfarct-dementia_3823c4d4-5e98-46da-a717-892fef54b382.md",
|
||||
"f1cfbeb100ec82283e429185bc5506685033b421b72efeb9c0795b85f85c4001": "docs_md/external/https-appstatdxcom-document-content-3823c4d4-5e98-46da-a717-892fef54b382_app.statdx.com_document_content_3823c4d4-5e98-46da-a717-892fef54b382_68f10467_20251014T185335Z.meta.md",
|
||||
"bb46c2dd5375afe6a748b59b2050a326fc85778e2427c9c3e6c7999230e74cf8": "docs_md/articles/empty-sella_39a0d2d1-1439-4558-8f5d-86a2a6d93e3a.md",
|
||||
"237051a26c6d3b2d7f5e28554066b041880234080bbcb982114f1eb8d76354fc": "docs_md/external/https-appstatdxcom-document-content-39a0d2d1-1439-4558-8f5d-86a2a6d93e3a_app.statdx.com_document_content_39a0d2d1-1439-4558-8f5d-86a2a6d93e3a_a6956072_20251014T204947Z.meta.md",
|
||||
"3dc97a3d7cf72ddaba23b5d7565487dbf99e9074550594b07929797afcd912a3": "docs_md/articles/fragile-x-associated-tremor-ataxia-fxtas_4778fafe-9873-4c28-8f4f-299c00c72b50.md",
|
||||
"bfe782cb38462deca0ce3abb8163a2f838190e6a710d4e4d7d20f718e499988b": "docs_md/external/https-appstatdxcom-document-content-4778fafe-9873-4c28-8f4f-299c00c72b50_app.statdx.com_document_content_4778fafe-9873-4c28-8f4f-299c00c72b50_07ed0854_20251014T204705Z.meta.md",
|
||||
"d71409edc61ca994e3c107a3313e2019e5f5aea83bf722657766b24d231819a1": "docs_md/articles/frontotemporal-lobar-degeneration_49510d0e-acf7-45cb-9eb1-53f8193b0b6d.md",
|
||||
"3167df8bcd04bb2dae9f46e34ca21351080b076713d1bf930c4db6e208509e50": "docs_md/external/https-appstatdxcom-document-content-49510d0e-acf7-45cb-9eb1-53f8193b0b6d_app.statdx.com_document_content_49510d0e-acf7-45cb-9eb1-53f8193b0b6d_364eb97f_20251014T193509Z.meta.md",
|
||||
"4d0a5dece865b5a5239b5e10098d22b24c8d92b4beaf178a7b2c925d57a56129": "docs_md/articles/adrenal-myelolipoma_5813a554-06a4-4696-af71-7ce50693039d.md",
|
||||
"e7e446865027f72f4aef0fdb11213f807c58a875703dfa03a234aadd99e7c998": "docs_md/external/https-appstatdxcom-document-content-5813a554-06a4-4696-af71-7ce50693039d_app.statdx.com_document_content_5813a554-06a4-4696-af71-7ce50693039d_83b20d1e_20251017T212346Z.meta.md",
|
||||
"3b4cc19ff41d84c202fcb6a327198497e6a5bc392b928933bf375acacb5d4fa9": "docs_md/articles/primary-progressive-aphasia_5dca11fe-b5ee-404c-b22e-4008b7571844.md",
|
||||
"96820c46f137231086b71ee6df91f50ee24ed0ece5c2f0f076670b3466689e60": "docs_md/external/https-appstatdxcom-document-content-5dca11fe-b5ee-404c-b22e-4008b7571844_app.statdx.com_document_content_5dca11fe-b5ee-404c-b22e-4008b7571844_3b5d482e_20251014T193517Z.meta.md",
|
||||
"3db04de725b13e7671b0b964179a612e2b1a0d8e86c498b21cf2c39087f834bd": "docs_md/articles/cyst-with-nodule_6cb71737-f574-4121-a8fb-02eeada9f9f7.md",
|
||||
"54a859320782ca42eac0fa3dcf55935b660b9130ffa8f853c134c1700e59544b": "docs_md/external/https-appstatdxcom-document-content-6cb71737-f574-4121-a8fb-02eeada9f9f7_app.statdx.com_document_content_6cb71737-f574-4121-a8fb-02eeada9f9f7_47a28ee9_20251014T195847Z.meta.md",
|
||||
"4e8c6502b0c28a8c57467aa7c729b45590b1ddda0d6a7ddd99f6a2f3d4f89094": "docs_md/articles/hypertrophic-olivary-degeneration_78257543-6d52-4879-84b1-445f3611d996.md",
|
||||
"79049cd6b95768c6df548f3874fe37e252e7c685f22829582b8cf5ccbff2134b": "docs_md/external/https-appstatdxcom-document-content-78257543-6d52-4879-84b1-445f3611d996_app.statdx.com_document_content_78257543-6d52-4879-84b1-445f3611d996_2670b622_20251014T204719Z.meta.md",
|
||||
"3da7367704165834fe003b5a0556ac4c8a7eb7133cf2098dfa29686c98cab4b2": "docs_md/articles/brain-tumor-in-child-1-year_7d64f5fb-c62c-4861-8ff4-654a12074605.md",
|
||||
"920821e8878c4e6d862742da5013227bfaa78def85f30c33abef5ecd7550584e": "docs_md/external/https-appstatdxcom-document-content-7d64f5fb-c62c-4861-8ff4-654a12074605_app.statdx.com_document_content_7d64f5fb-c62c-4861-8ff4-654a12074605_55889b6f_20251014T200552Z.meta.md",
|
||||
"36f102948b48a74527454d6aee7c0411ff65721ff62d54c1cd2cfc0c3a695d9b": "docs_md/articles/hypothalamic-hamartoma_7f85487f-9497-44a9-b884-b98e50d41018.md",
|
||||
"1b030bfd5edcfb959ee76ef3da96d0d5cc759ef1d87b304ed66029fd9bb6a09e": "docs_md/external/https-appstatdxcom-document-content-7f85487f-9497-44a9-b884-b98e50d41018_app.statdx.com_document_content_7f85487f-9497-44a9-b884-b98e50d41018_a7972d2d_20251014T204850Z.meta.md",
|
||||
"9e712c0cfe3ecda560cf69fb7b3a993c36ee9c6787b963941eaf5410c6214958": "docs_md/articles/normal-pressure-hydrocephalus_834ccc3e-2116-4295-8408-0ac9a06bd2ff.md",
|
||||
"5b38b4481f5cc5db9164d0ea3d67543fc2c52224ba3d953605e847e60dc83924": "docs_md/external/https-appstatdxcom-document-content-834ccc3e-2116-4295-8408-0ac9a06bd2ff_app.statdx.com_document_content_834ccc3e-2116-4295-8408-0ac9a06bd2ff_2e001e66_20251014T193450Z.meta.md",
|
||||
"12b6e0b330f32131f5f3f0d4c2548e45247c2c0b24cc9d3b126e78ed0dd655d9": "docs_md/articles/progressive-supranuclear-palsy_840ed321-c0ab-4069-a07e-ad416232f916.md",
|
||||
"56d98a595a67960a1f5540ef057a506138ded9c559f132369cf5a3ac04c0f0b1": "docs_md/external/https-appstatdxcom-document-content-840ed321-c0ab-4069-a07e-ad416232f916_app.statdx.com_document_content_840ed321-c0ab-4069-a07e-ad416232f916_254e1757_20251014T204728Z.meta.md",
|
||||
"1a7e20dd9ec7d90e75b1bb12c5cde610518faa1228152f4c0d6f17eff8ff7da4": "docs_md/articles/solitary-cystic-parenchymal-mass-general_8bfa943b-c158-4a3b-9d43-e6ef057f45d4.md",
|
||||
"544f72bc3fd6897035ea0b09c5615b128a707615a31599127fac2d5fecfc3748": "docs_md/external/https-appstatdxcom-document-content-8bfa943b-c158-4a3b-9d43-e6ef057f45d4_app.statdx.com_document_content_8bfa943b-c158-4a3b-9d43-e6ef057f45d4_377dc90d_20251014T204445Z.meta.md",
|
||||
"843d8ce3d6e5ffeb675a307dac794f66cd0a838c622f45ac867f520986577c0d": "docs_md/articles/neurodegeneration-with-brain-iron-accumulation-nbia_8e3465d1-d058-48d8-863c-1fd85cc6caee.md",
|
||||
"fb7a00879f3bac38cbc841c3eb593fcb08500b0a4a1719f1118094dbfb54a830": "docs_md/external/https-appstatdxcom-document-content-8e3465d1-d058-48d8-863c-1fd85cc6caee_app.statdx.com_document_content_8e3465d1-d058-48d8-863c-1fd85cc6caee_14a615d6_20251014T204533Z.meta.md",
|
||||
"c6bd32a15b4f59e8fad4e9feff4056b1e8ea5a3b6830c6cad0966a2fe99aa939": "docs_md/articles/rathke-cleft-cyst_8f1561f7-92a7-485c-a0ae-2e2d5c8c1628.md",
|
||||
"381f113c0c468347066f6b10ba9f876f3429bfd7fc71430b1851106421714db8": "docs_md/external/https-appstatdxcom-document-content-8f1561f7-92a7-485c-a0ae-2e2d5c8c1628_app.statdx.com_document_content_8f1561f7-92a7-485c-a0ae-2e2d5c8c1628_f8845a9c_20251014T204923Z.meta.md",
|
||||
"7e32629a3a5f04e77c3c70c7f8354bc91e99f516d6d1eb00acde3979fd8d3973": "docs_md/articles/pituitary-hyperplasia_9696bc9e-f00b-4fa7-aa67-f039efd8fbed.md",
|
||||
"cd884013efd0f5cca0f44a1cdedacefc3ec00b42f22070453729760193e19376": "docs_md/external/https-appstatdxcom-document-content-9696bc9e-f00b-4fa7-aa67-f039efd8fbed_app.statdx.com_document_content_9696bc9e-f00b-4fa7-aa67-f039efd8fbed_8805ff5a_20251014T205140Z.meta.md",
|
||||
"ca7df50d8ed5af7ca3be105ccf73f24a4d26817b378fae1871e3eae5a0827ffb": "docs_md/articles/frontotemporal-dementia_9f9eda8c-7e3c-4292-9861-4b8abc2c6474.md",
|
||||
"2bcd626928260fdd931f3877bda4307d59015517bbca1bc72765d592107deef2": "docs_md/external/https-appstatdxcom-document-content-9f9eda8c-7e3c-4292-9861-4b8abc2c6474_app.statdx.com_document_content_9f9eda8c-7e3c-4292-9861-4b8abc2c6474_2dde52e4_20251014T185357Z.meta.md",
|
||||
"1f56ba43275d457af490b6ade459a8b45638a68c7756ef6a39ac650de8e0301d": "docs_md/articles/attention-control-network_a1bedda5-6478-40b2-98e7-6c5f5363b06f.md",
|
||||
"7e65a279ef25c534bfcee49415e3476f6828a24b163f94c9f04b92fa1cb6a733": "docs_md/external/https-appstatdxcom-document-content-a1bedda5-6478-40b2-98e7-6c5f5363b06f_app.statdx.com_document_content_a1bedda5-6478-40b2-98e7-6c5f5363b06f_068cbfb3_20251014T185127Z.meta.md",
|
||||
"32fff07a347799f5143b7decd56cab2256d1e86aa475258469407a5b10852deb": "docs_md/articles/epilepsy-child_a342e5b5-5b98-4003-a437-6d42a483b40e.md",
|
||||
"d46a8bf3e5da6860e331a56de27852970466cf7cfe9823a4af47c985755e2e5f": "docs_md/external/https-appstatdxcom-document-content-a342e5b5-5b98-4003-a437-6d42a483b40e_app.statdx.com_document_content_a342e5b5-5b98-4003-a437-6d42a483b40e_939c8569_20251014T204358Z.meta.md",
|
||||
"d2fcf019f5973764e6c3f2f8ba848d56efb2253d2007aa8695c59ae0d9880402": "docs_md/articles/pkan_aa473236-a733-4f9b-8d92-267ab8d4bcd9.md",
|
||||
"13e4edd55e99a2183f16649f2426d4b80c082a0a05430f3dfab53dea97dbe766": "docs_md/external/https-appstatdxcom-document-content-aa473236-a733-4f9b-8d92-267ab8d4bcd9_app.statdx.com_document_content_aa473236-a733-4f9b-8d92-267ab8d4bcd9_f344beea_20251014T204510Z.meta.md",
|
||||
"9dc070ceacdcbd53c5a41da046f438cdd8e6e76bc608821afe5599f2ed090375": "docs_md/articles/crossed-cerebellar-diaschisis_c1e384b3-3c6e-4f67-bf79-5187bd6a1b86.md",
|
||||
"4f6c975ff6e60238c482e989b73121b679f2f2c9243b45f9ab806cd5e5b0092b": "docs_md/external/https-appstatdxcom-document-content-c1e384b3-3c6e-4f67-bf79-5187bd6a1b86_app.statdx.com_document_content_c1e384b3-3c6e-4f67-bf79-5187bd6a1b86_74517038_20251014T204643Z.meta.md",
|
||||
"433a086e59f60bb3610b0448ba6b34e61baa4828b946b1a410fe2a7258f6d0e1": "docs_md/articles/adrenal-cyst_c5d717a3-3d6e-4e86-9efe-1ad0ec14740f.md",
|
||||
"a190df3a8ed59c2edc942ad7c9155c712180686efc4bb82423cae85df86b2cce": "docs_md/external/https-appstatdxcom-document-content-c5d717a3-3d6e-4e86-9efe-1ad0ec14740f_app.statdx.com_document_content_c5d717a3-3d6e-4e86-9efe-1ad0ec14740f_1172170b_20251017T212337Z.meta.md",
|
||||
"82056b9e81ac92096c445680426e5c125b2cc2afbc749e7dca94986ea05a2433": "docs_md/articles/epilepsy-adult_c936f9e1-b6c6-4c4a-afc6-f2e1a968a7b0.md",
|
||||
"b6dea1bee258dc90ddc4915e01e2422aa33f24598c16769c58b05380dccbadab": "docs_md/external/https-appstatdxcom-document-content-c936f9e1-b6c6-4c4a-afc6-f2e1a968a7b0_app.statdx.com_document_content_c936f9e1-b6c6-4c4a-afc6-f2e1a968a7b0_6ab4623e_20251014T204348Z.meta.md",
|
||||
"26a6ce4b6e174212cea3f4de4f601f6bea2735b3cca53dc236242d1d014a0a24": "docs_md/articles/granular-cell-tumor_da976b04-85a3-4bf8-ac81-e579f081293e.md",
|
||||
"491eb47d85e2ad071dccbfee1649f9c6d0b9a8e24bd9a81fb382dd9239543b6d": "docs_md/external/https-appstatdxcom-document-content-da976b04-85a3-4bf8-ac81-e579f081293e_app.statdx.com_document_content_da976b04-85a3-4bf8-ac81-e579f081293e_c381b3d7_20251014T205304Z.meta.md",
|
||||
"93cf9b0021c0ddc71335a193d408536e94baa6ac8f09d50024a42baf650dfd9e": "docs_md/articles/spinocerbellar-ataxia_df64565a-5c8c-4387-879b-b341b655e478.md",
|
||||
"540d680d534cc0998e086b6f629b91a2dadcae74c3a422476f8a7715ca79ed4a": "docs_md/external/https-appstatdxcom-document-content-df64565a-5c8c-4387-879b-b341b655e478_app.statdx.com_document_content_df64565a-5c8c-4387-879b-b341b655e478_2178f1d4_20251014T204610Z.meta.md",
|
||||
"8855f0e94f69fff63493debf9b905180696299b57166957f5b55660555587d1c": "docs_md/articles/creutzfeldt-jakob-disease-cjd_e1b27954-6591-4bb0-a659-b13790492620.md",
|
||||
"745e41378795a828444ed93b1f6874187dda9eff670941f0032e7789bf3a1bf2": "docs_md/external/https-appstatdxcom-document-content-e1b27954-6591-4bb0-a659-b13790492620_app.statdx.com_document_content_e1b27954-6591-4bb0-a659-b13790492620_22d67a60_20251014T204650Z.meta.md",
|
||||
"49ff1dc0241d5f6f854ddd53394e6bb830c4f3b05f6c3c317f4acb83fe668dcd": "docs_md/articles/adrenal-adenoma_e2916d86-5f9f-4dd3-9576-1a7b89d8dda0.md",
|
||||
"18a9b5738b4e9977e65b9473ae7e2b48603a9680c8132a46e48cb2abc7d9d42b": "docs_md/external/https-appstatdxcom-document-content-e2916d86-5f9f-4dd3-9576-1a7b89d8dda0_app.statdx.com_document_content_e2916d86-5f9f-4dd3-9576-1a7b89d8dda0_553d0dda_20251017T212330Z.meta.md",
|
||||
"573773d132fe5d3d5ff6655f15ee5f3d69d73a858abbc41f27f8983ccfd766c8": "docs_md/articles/wallerian-degeneration_e4bb682d-6534-4176-9d39-34c1a42f3771.md",
|
||||
"749c70c544da5afbca891b1ebf31603f7b230bd64ad29a870d339afab9708ec3": "docs_md/external/https-appstatdxcom-document-content-e4bb682d-6534-4176-9d39-34c1a42f3771_app.statdx.com_document_content_e4bb682d-6534-4176-9d39-34c1a42f3771_ded98aae_20251014T204626Z.meta.md",
|
||||
"88d035bc3265b6478d0e2bd4b2d421e0313ace59b941927ce9d4201381165ac4": "docs_md/articles/dementia-with-lewy-bodies_e8e46d1d-46d2-4e5a-880f-f025a84c5871.md",
|
||||
"a7f5724c8e1f4a657212b317c2d801b3112b2be3515c246ad7c1754ddf3b227d": "docs_md/external/https-appstatdxcom-document-content-e8e46d1d-46d2-4e5a-880f-f025a84c5871_app.statdx.com_document_content_e8e46d1d-46d2-4e5a-880f-f025a84c5871_01610362_20251014T193405Z.meta.md",
|
||||
"412dd21efc8e036a5d93b713f557f36ff8f13a0a3e0f71a21f65258b00e2f689": "docs_md/articles/lymphocytic-hypophysitis_f30774c3-cbd0-4ab3-b3d1-e0574106db1f.md",
|
||||
"f079a3fb2928243685d408e16b599a7998701c23d969223e4eedaeee6d20e77c": "docs_md/external/https-appstatdxcom-document-content-f30774c3-cbd0-4ab3-b3d1-e0574106db1f_app.statdx.com_document_content_f30774c3-cbd0-4ab3-b3d1-e0574106db1f_63615b1f_20251014T204954Z.meta.md",
|
||||
"a909f462bee40a74aeaa8456f8ab1d4d87f6c4efb08a64253e909f85bc93fa8b": "docs_md/articles/vascular-dementia_f59dab57-c511-4369-8fcc-592421a4b8d1.md",
|
||||
"560f9312f26896ee62881d086ed5cfa74ca41ec027e4e13a60a5b56ec5a5f182": "docs_md/external/https-appstatdxcom-document-content-f59dab57-c511-4369-8fcc-592421a4b8d1_app.statdx.com_document_content_f59dab57-c511-4369-8fcc-592421a4b8d1_05e6592c_20251014T185346Z.meta.md",
|
||||
"e241f3c3a865486be3d53d872fcc526b52fe608e4ef4ce0f0a6d83b55f1d91b6": "docs_md/articles/lewy-body-dementia_f6a4382b-f0f7-4582-a703-7f695c65656f.md",
|
||||
"f9047d3410af409df29a434c7a4e59c45428024ca211df6425c5aecb6bec98ee": "docs_md/external/https-appstatdxcom-document-content-f6a4382b-f0f7-4582-a703-7f695c65656f_app.statdx.com_document_content_f6a4382b-f0f7-4582-a703-7f695c65656f_17f89880_20251014T185404Z.meta.md",
|
||||
"669126848cfb0dda10d8613b56e46ce1adf045fdf906d8264c4ae1a28e655636": "docs_md/articles/alzheimer-disease_f71f5cf5-b1af-4c6d-b145-b4c10eec7b58.md",
|
||||
"9c6c289a9518e5a3ddcab29c00d6704b3c4865e89c030fbc9455050a60f1dbba": "docs_md/external/https-appstatdxcom-document-content-f71f5cf5-b1af-4c6d-b145-b4c10eec7b58_app.statdx.com_document_content_f71f5cf5-b1af-4c6d-b145-b4c10eec7b58_3bf23d8b_20251014T193423Z.meta.md",
|
||||
"c7702914a2b5b37501f471289a9787c72403bacd557fcd1519fba54c3faf26ce": "docs_md/external/https-appstatdxcom-document-csf-like-parenchymal-lesions-24559f7a-ed5a-4ab6-90ba_app.statdx.com_document_csf-like-parenchymal-lesions_24559f7a-ed5a-4ab6-90ba-769f0b5c1197_f7d84241_20251014T200033Z.meta.md",
|
||||
"2e8e0273208aae11c09794f79ef0d283ec314a09532d5879c38a3488adb648d0": "docs_md/external/https-appstatdxcom-document-da976b04-85a3-4bf8-ac81-e579f081293e-media_app.statdx.com_document_da976b04-85a3-4bf8-ac81-e579f081293e_media_642ff061_20251014T205303Z.meta.md",
|
||||
"3fd13afe72616012e9b8f3cadcaa171314862a8c188e01e71b6d95ccd30afa53": "docs_md/external/https-appstatdxcom-document-e1b27954-6591-4bb0-a659-b13790492620-media_app.statdx.com_document_e1b27954-6591-4bb0-a659-b13790492620_media_203f5935_20251014T204650Z.meta.md",
|
||||
"7ac23e0c647137a63b89759d7da1b34bfa43bb8d6b4271e8b58acfa3a115ccd1": "docs_md/external/https-appstatdxcom-document-e1b27954-6591-4bb0-a659-b13790492620-tables_app.statdx.com_document_e1b27954-6591-4bb0-a659-b13790492620_tables_817c9ec4_20251014T193440Z.meta.md",
|
||||
"42610ac4e00ef45311e9aceafa9a2844ce8a01abbf93da88bca2734cf450a632": "docs_md/external/https-appstatdxcom-document-e2916d86-5f9f-4dd3-9576-1a7b89d8dda0-media_app.statdx.com_document_e2916d86-5f9f-4dd3-9576-1a7b89d8dda0_media_b0ad9ef2_20251017T212537Z.meta.md",
|
||||
"955be7b0036216e66dd365a24355d349181298e119abfa48b75ec8388034907b": "docs_md/external/https-appstatdxcom-document-e2916d86-5f9f-4dd3-9576-1a7b89d8dda0-tables_app.statdx.com_document_e2916d86-5f9f-4dd3-9576-1a7b89d8dda0_tables_6a891e54_20251017T212537Z.meta.md",
|
||||
"3a57091748bce8df43af1073fb6d1d5379a8ecdd0583e5ac204f8739d916d74d": "docs_md/external/https-appstatdxcom-document-e4bb682d-6534-4176-9d39-34c1a42f3771-media_app.statdx.com_document_e4bb682d-6534-4176-9d39-34c1a42f3771_media_51992643_20251014T204626Z.meta.md",
|
||||
"7cdf1b931490a1b19d9940e6f57aa6d6d061ef59ff9725ac2129e5f507dff7fe": "docs_md/external/https-appstatdxcom-document-e8e46d1d-46d2-4e5a-880f-f025a84c5871-media_app.statdx.com_document_e8e46d1d-46d2-4e5a-880f-f025a84c5871_media_541fbd43_20251014T193405Z.meta.md",
|
||||
"540f41ed78a5eff7166591fc50b09706f55673335b50ea93afdd60c3b2bcb9fc": "docs_md/external/https-appstatdxcom-document-f30774c3-cbd0-4ab3-b3d1-e0574106db1f-media_app.statdx.com_document_f30774c3-cbd0-4ab3-b3d1-e0574106db1f_media_616f3ce9_20251014T204954Z.meta.md",
|
||||
"abcb5346f4a53edbc5649bc8d49b6c37b7adf7000fbfc4ced8bff2e0b607de5c": "docs_md/external/https-appstatdxcom-document-f59dab57-c511-4369-8fcc-592421a4b8d1-media_app.statdx.com_document_f59dab57-c511-4369-8fcc-592421a4b8d1_media_0f9fed25_20251014T204618Z.meta.md",
|
||||
"a390c974122d032d8a580f277e9719d56175d429ba079827d78c6d567823c759": "docs_md/external/https-appstatdxcom-document-f71f5cf5-b1af-4c6d-b145-b4c10eec7b58-media_app.statdx.com_document_f71f5cf5-b1af-4c6d-b145-b4c10eec7b58_media_c350e39c_20251014T193422Z.meta.md",
|
||||
"5c3bf156bfd2f9e4b7bf01ee5fd72b6f9fd21ab1960a3301297f9ad68a5173cb": "docs_md/external/https-appstatdxcom-main_app.statdx.com_main_00e71309_20251017T212307Z.meta.md",
|
||||
"aefa196a21aedc8854a27dc293031b83828d7e355b0647527d923304c97e3a33": "docs_md/external/https-appstatdxcom-timetracking-start-csf-like20parenchymal20lesions-brain-ddx_app.statdx.com_timetracking_start_CSF-Like_20Parenchymal_20Lesion_s__Brain_DDX_e3812c4f_20251014T200033Z.meta.md",
|
||||
"0493eeae819b99984603e64f4fa23031f5d37b10e5be95c268605624668b8d50": "docs_md/external/https-appstatdxcom-tree-brain-6d8829f1-14d7-45af-8675-255189aa526a_app.statdx.com_tree_brain_6d8829f1-14d7-45af-8675-255189aa526a_179a579f_20251014T204842Z.meta.md",
|
||||
"efec45ee8dc4278fbe64ab80f93dcc4fe377fe844171367e892969cf9946232d": "docs_md/external/https-appstatdxcom-tree-genitourinary-bd0eb4fe-d465-4faa-a3b7-526e8f01802d_app.statdx.com_tree_genitourinary_bd0eb4fe-d465-4faa-a3b7-526e8f01802d_13437510_20251017T212316Z.meta.md",
|
||||
"b023b4da267f20a646577bcf508f8114a610d9b1273e78c99fc50d2397d8706a": "docs_md/external/https-appstatdxcom_app.statdx.com__6f54ae03_20251018T064206Z.meta.md",
|
||||
"3cfe50ff59fc6a01ea580afa8c21f0034f09f5365cfe4177f3129af2672780c1": "docs_md/external/https-appstatdxcom-document-25c1fd77-52ff-4a56-b5c4-6ee1335ba369-media_app.statdx.com_document_25c1fd77-52ff-4a56-b5c4-6ee1335ba369_media_021e17ed_20251018T064726Z.meta.md",
|
||||
"c0ef8678d2f6a70fdc486e95bd8e7cc6108baa1eba2ef87b2cd2bd7123cf87b7": "docs_md/articles/ahle_0ec0bca6-abee-4931-a6ed-43541b626261.md",
|
||||
"4b702b7b71df0322fc9a7950fe4bce671a7c35cccd1de7cc03233df76e72143c": "docs_md/articles/tracheal-dilatation_25c1fd77-52ff-4a56-b5c4-6ee1335ba369.md",
|
||||
"5fd4726279563d4f392b9067271e0b9d0640ffd9b6697f0814bcc7039b2b1e2c": "docs_md/external/https-appstatdxcom-document-content-25c1fd77-52ff-4a56-b5c4-6ee1335ba369_app.statdx.com_document_content_25c1fd77-52ff-4a56-b5c4-6ee1335ba369_e73cb09e_20251018T064726Z.meta.md",
|
||||
"bf8e1280227b526a53f9c4a1879214ce4941b1ae10fd5665c0095e7dcc693ac3": "docs_md/articles/finger-in-glove-sign_81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a.md"
|
||||
"930799d92ceb1ed43738f1acd846f56f15bc3cab49b39cca4c33d86b1f95450d": "docs_md/articles/abdominal-lymph-nodes_3ca98d42-20ef-48fe-9265-ebfe570ba54b.md",
|
||||
"bf8e1280227b526a53f9c4a1879214ce4941b1ae10fd5665c0095e7dcc693ac3": "docs_md/articles/finger-in-glove-sign_81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a.md",
|
||||
"7e1a136408e5d59032c4a49ef26f0535225e4a8b1b4964ee6be6d0bc7f327c02": "docs_md/articles/adem_a3fafeb7-5861-4364-beb8-c0e30220564e.md",
|
||||
"ecd5ffbd64a26f5a865fcf0145ae2b5b802825d48b8bfadd96e807bf5561b12b": "docs_md/articles/abdominal-wall_e708af38-508f-4404-b7c5-6b8c7d75804f.md",
|
||||
"fe503197ae432041e9d3a77ccb4cdc3480a70f8f7ff17d67c9964d4294dcefc8": "docs_md/articles/dolichoectasia_31d50b93-b057-4da3-86b5-4cc8fb0bc806.md",
|
||||
"007a7f5b5eaf15a84ff1a4af6ec5c355d93b7ca40fec5c8d358b33dd6ac0f858": "docs_md/articles/ahle_0ec0bca6-abee-4931-a6ed-43541b626261.md",
|
||||
"f237567ef0c946beb98d0ed2e3f3aaf5d9cc5ecc6f4c80960690544784861df9": "docs_md/articles/tracheal-dilatation_25c1fd77-52ff-4a56-b5c4-6ee1335ba369.md",
|
||||
"5e0ba9ab728acff2caed32f5459961372ba404fc05ecdc0f3d2227acc4a6e4ea": "docs_md/articles/dolichoectasia_31d50b93-b057-4da3-86b5-4cc8fb0bc806.md",
|
||||
"533b0af86400a62be523f3c6020ea4353e108b701d5c3292280584acafa47ed3": "docs_md/articles/abdominal-lymph-nodes_3ca98d42-20ef-48fe-9265-ebfe570ba54b.md",
|
||||
"abaeae5a7f9e589ccb0c11931a70c1ef78c2ec9af6cd42fe2bc1275bfb5a7a99": "docs_md/articles/finger-in-glove-sign_81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a.md",
|
||||
"f6a1d5ccb075178f1458039b19493dbab4f8e69052b25918896bd2f766fc5200": "docs_md/articles/adem_a3fafeb7-5861-4364-beb8-c0e30220564e.md",
|
||||
"d8cb2432042db6d41c8de45802e005f2f43a059cedae4929bd557cf4ddafcb35": "docs_md/articles/abdominal-wall_e708af38-508f-4404-b7c5-6b8c7d75804f.md",
|
||||
"35d8e7beb0d77e432ae4feb32fc46f75c73c200d027027120eb9dfa28e957a63": "docs_md/articles/ahle_0ec0bca6-abee-4931-a6ed-43541b626261.md",
|
||||
"b0f5ddf980d311d8d171b47ee3baae5e4f254e063a3e403788bcb99bd5b6d9fe": "docs_md/articles/cidp_12e4033c-edc8-46ff-8081-3acc433cda78.md",
|
||||
"52d8ee27f22ab9cc9a6e74dbdaad09f3bcabce958791b6c58de6e3bd6e58e51b": "docs_md/articles/tracheal-dilatation_25c1fd77-52ff-4a56-b5c4-6ee1335ba369.md",
|
||||
"5fdc1158e1eeab114d6d7da864f8b846f021bd93673d9f97116f2c92130c8845": "docs_md/articles/dolichoectasia_31d50b93-b057-4da3-86b5-4cc8fb0bc806.md",
|
||||
"3cf39199aa9a3c99252f085ac23d56ddfd6350d19450c6fc2a0d3a7df1d04034": "docs_md/articles/abdominal-lymph-nodes_3ca98d42-20ef-48fe-9265-ebfe570ba54b.md",
|
||||
"a3f3f6d586bddbad09878b6aac5f06a92ddf5503f1ed45afecf018e7b010a743": "docs_md/articles/neuromyelitis-optica-spectrum-disorders_54d4a8bc-9267-4df6-98c1-f22aae051d01.md",
|
||||
"3d9cdc8e3aa0979b9f2556983c6ef8e871958034dd7611dfd41435ab931433de": "docs_md/articles/autoimmune-encephalitis_6eb3d5d6-7f6a-4367-a792-b5d4b19675da.md",
|
||||
"3250a63d747ee185c59c04bff2da3b9f5c7ccd5d0239fad2e80c20c1f423f8a9": "docs_md/articles/multiple-sclerosis_7892b2a2-f52a-4d7f-9858-a326f2b7ab04.md",
|
||||
"87a9b3fe9e479d0ac801f67d94207c7a7baf815bfd0ccf525f16590fb2593cb9": "docs_md/articles/finger-in-glove-sign_81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a.md",
|
||||
"f8d96970661428d554ffc066566ee6c1c1856f433ab222ed94caffeb51a9452b": "docs_md/articles/adem_a3fafeb7-5861-4364-beb8-c0e30220564e.md",
|
||||
"730b3fcced67f5f1e84ef47553750a5155458c81b9a71d04244aa9d9684e9ff1": "docs_md/articles/clippers_ba394f3b-bbff-4128-90b5-3e1c07564c5f.md",
|
||||
"642439c7b0f722afdd9d01747b2913906d6db8d44a2cbb90e61b63661556d224": "docs_md/articles/guillain-barr-spectrum-disorders_c1f52a65-920e-4e28-8a75-07dfa208f290.md",
|
||||
"4895a9821bf569aa57b7c316648423e4fd26f81906b8301a99a9ef234682dd18": "docs_md/articles/abdominal-wall_e708af38-508f-4404-b7c5-6b8c7d75804f.md",
|
||||
"33414c3bf812f710afc95a87c4614bb13f981f584fed9c4158fd65ab01f80f9b": "docs_md/articles/aging-brain-normal_f8dc8f27-f256-480d-9393-7ec3495a3d27.md",
|
||||
"2c869913f2c97cae216ff184643be76ad3f8b5cf8fc08a7228f9294fb69b565c": "docs_md/articles/aging-brain-normal_f8dc8f27-f256-480d-9393-7ec3495a3d27.md",
|
||||
"61fab3267490da1d71612c2d07e1cca4235286e52166d7aaa1c150cca4d6446a": "docs_md/articles/aging-brain-normal_f8dc8f27-f256-480d-9393-7ec3495a3d27.md",
|
||||
"5a4127917eb59f5570a3856dd704649461e62318ae3c8fa9faa40d0be6e3525b": "docs_md/articles/fusiform-arterial-enlargement_31d50b93-b057-4da3-86b5-4cc8fb0bc806.md",
|
||||
"fc84dc1dbfdd3d17f6f23a53fd038b5af463a7ed9143947dab9d708738a4380d": "docs_md/articles/basal-ganglia-calcification_f8dc8f27-f256-480d-9393-7ec3495a3d27.md",
|
||||
"ebd5f4965299235e9bcbc2a27ab861287625c94cbc98f1252cf1baf5dc8aa73f": "docs_md/articles/tracheal-dilatation_25c1fd77-52ff-4a56-b5c4-6ee1335ba369.md",
|
||||
"e2481024360ea361b614c58a1be925b0577fc23f9065a60911dfaae5f56dd877": "docs_md/articles/fusiform-arterial-enlargement_31d50b93-b057-4da3-86b5-4cc8fb0bc806.md",
|
||||
"1c51f424633e172889296e4cb1007ca961aaa5cfaf3420c6afbdac5dbb92fcb2": "docs_md/articles/finger-in-glove-sign_81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a.md",
|
||||
"1a2e0f63869449f4b1c0e259faa9bfa605feeece026f04deac7ad4ac884e1af1": "docs_md/articles/basal-ganglia-calcification_f8dc8f27-f256-480d-9393-7ec3495a3d27.md",
|
||||
"59fc989036cc1002e1d9a845fb1be1211b633fd03218abca52a18da207d2bb1d": "docs_md/articles/basal-ganglia-calcification_f8dc8f27-f256-480d-9393-7ec3495a3d27.md",
|
||||
"9a381c6dfb5307d9f4b59795664d7e42da29f23fb6f459eb660c502467dad6f8": "docs_md/articles/ahle_0ec0bca6-abee-4931-a6ed-43541b626261.md",
|
||||
"df1007d92225181b62e797be096644e39a533d39738e0b6fd01c84cf0338d9ce": "docs_md/articles/cidp_12e4033c-edc8-46ff-8081-3acc433cda78.md",
|
||||
"8f07b3788d67420c4f613dbbf0514d46dca951f5e23b971c69d5789f792af47c": "docs_md/articles/tracheal-dilatation_25c1fd77-52ff-4a56-b5c4-6ee1335ba369.md",
|
||||
"3c067c8a7c135ae01f98624162782f54f41b300ad52b770ee8955838ee75d2b5": "docs_md/articles/fusiform-arterial-enlargement_31d50b93-b057-4da3-86b5-4cc8fb0bc806.md",
|
||||
"d31d92e11baffcac780eba08ca3f1502e04044acbfb40be74be2301aff96be8d": "docs_md/articles/abdominal-lymph-nodes_3ca98d42-20ef-48fe-9265-ebfe570ba54b.md",
|
||||
"014160558d98095bd763a88c2249fd8b4ce346c4edbc6cbd36ce527953a254a8": "docs_md/articles/neuromyelitis-optica-spectrum-disorders_54d4a8bc-9267-4df6-98c1-f22aae051d01.md",
|
||||
"d343fccdf7061a7f36457f5cd731f5a3acad4d7e72add0fe2fb3fd8b01d16e54": "docs_md/articles/autoimmune-encephalitis_6eb3d5d6-7f6a-4367-a792-b5d4b19675da.md",
|
||||
"660b5e82781cca0cda2c76a2bd69b201f467b79a5f33cc714b525e403e4032ce": "docs_md/articles/multiple-sclerosis_7892b2a2-f52a-4d7f-9858-a326f2b7ab04.md",
|
||||
"21eeaa868ff11f52df39a304e3fd798d339c1dc91448517ef8316f86d73f9472": "docs_md/articles/finger-in-glove-sign_81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a.md",
|
||||
"625ec5fae91e0b4638ac30a5495837721ee6ded2aaadbccf85a8e82dab40d0c5": "docs_md/articles/adem_a3fafeb7-5861-4364-beb8-c0e30220564e.md",
|
||||
"8bcad3bb79edd2b8c92c23acff552a7266f3573e3b89696beb6499e9a81beb8f": "docs_md/articles/clippers_ba394f3b-bbff-4128-90b5-3e1c07564c5f.md",
|
||||
"563b895604c680678b512b8ae21074dec53daf80240a38a6940f9c8be59436f4": "docs_md/articles/guillain-barr-spectrum-disorders_c1f52a65-920e-4e28-8a75-07dfa208f290.md",
|
||||
"1738666e31bf37d2c51fad4970cdcbc43be8e5e6dce2d2d8bfdc8bf73a972939": "docs_md/articles/abdominal-wall_e708af38-508f-4404-b7c5-6b8c7d75804f.md",
|
||||
"a211d50b6dcf0b199b8706d728e1b50161ecfeee116bcdcb797468f5abdfe120": "docs_md/articles/basal-ganglia-calcification_f8dc8f27-f256-480d-9393-7ec3495a3d27.md"
|
||||
}
|
||||
@@ -0,0 +1,354 @@
|
||||
{
|
||||
"docs_md/articles/ahle_0ec0bca6-abee-4931-a6ed-43541b626261.md": [
|
||||
"images/app.statdx.com_image_93f46c03-6a13-429c-9a24-57e552795482_70fac743_20251018T070801Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_93f46c03-6a13-429c-9a24-57e552795482_size_168_quality_85_3867679d_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_93f46c03-6a13-429c-9a24-57e552795482_size_174_quality_85_9e4b189a_20251018T095217Z.jpg",
|
||||
"images/app.statdx.com_image_bc85bdf7-9d59-41a2-aa1c-4936434aeb8a_bb2e3243_20251018T070813Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_bc85bdf7-9d59-41a2-aa1c-4936434aeb8a_size_168_quality_85_ef2bd8af_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_57828b57-0c4e-4be9-80d0-971f2d79ffb4_b3737dfb_20251018T070817Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_57828b57-0c4e-4be9-80d0-971f2d79ffb4_size_168_quality_85_e0d7750b_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_9228cf7b-7628-4416-aff0-05b17a828cbc_2992bc89_20251018T070821Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9228cf7b-7628-4416-aff0-05b17a828cbc_size_168_quality_85_ee5c235b_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_328245bb-e479-4018-a04e-d266db0c951b_77fc58cc_20251018T070823Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_328245bb-e479-4018-a04e-d266db0c951b_size_168_quality_85_f1c882c4_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_cb9da6f4-8eb1-4e0f-8f9b-b3bc86522b86_9f11d750_20251018T070825Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_cb9da6f4-8eb1-4e0f-8f9b-b3bc86522b86_size_168_quality_85_5644deca_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_7dcafdbc-3901-40ca-96dd-74eccc11d791_size_168_quality_85_fcdd0bea_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_a68ad5c0-2643-4b64-9fb3-faea8207fe58_size_168_quality_85_11cb2b05_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_782f752f-48ad-404d-8836-0f634954e747_size_168_quality_85_9d3d21e2_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4c0a24f1-bc15-49c3-bf38-536daaefccb4_size_168_quality_85_1ae5e76e_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_bfa72b67-3004-4561-a0e0-e8111f33394e_size_168_quality_85_6e30ce1d_20251018T070800Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_ee366227-5d90-4e0d-bde0-f550da761ab8_size_168_quality_85_daba2c9c_20251018T070800Z.jpg"
|
||||
],
|
||||
"docs_md/articles/tracheal-dilatation_25c1fd77-52ff-4a56-b5c4-6ee1335ba369.md": [
|
||||
"images/app.statdx.com_image_thumbnail_5670debe-e644-4585-9a40-f7d4a53018aa_size_168_quality_85_22258a97_20251018T064726Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5670debe-e644-4585-9a40-f7d4a53018aa_size_174_quality_85_3228f37e_20251018T064243Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_7cb3b2f3-f444-446c-be9a-1f7d772f3a88_size_168_quality_85_c5b6c9d1_20251018T064726Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_ff259781-7958-48ea-bcd0-e18ea3e59c15_size_168_quality_85_b8a5fd6d_20251018T064726Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_57389c8c-db65-45e2-844b-3c7879b978a5_size_168_quality_85_be7d0cd2_20251018T064726Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_7b0b113d-6eb7-4267-9b7d-0448ee25497a_size_168_quality_85_91d706f1_20251018T064726Z.jpg"
|
||||
],
|
||||
"docs_md/articles/dolichoectasia_31d50b93-b057-4da3-86b5-4cc8fb0bc806.md": [
|
||||
"images/app.statdx.com_image_38e1497f-31e3-49db-8b46-4ab561bf1eac_fb437f8b_20251018T080401Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_38e1497f-31e3-49db-8b46-4ab561bf1eac_size_168_quality_85_e3c2ebff_20251018T080328Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_38e1497f-31e3-49db-8b46-4ab561bf1eac_size_174_quality_85_9fba439d_20251018T080313Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f63a9221-71c6-4320-af66-1ed581202eb9_size_168_quality_85_8a3ae196_20251018T080328Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_68b41ae0-9f3a-4484-8b02-69d6772626db_size_168_quality_85_8d79e53e_20251018T080328Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9c20720f-93e4-49ad-b302-93e2d3e03a65_size_168_quality_85_2e4b9fef_20251018T080329Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b62dcdb8-45c4-477b-a466-98935b57a9f5_size_168_quality_85_562a643f_20251018T080329Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8fb2594c-2abc-43d9-84bc-b8b67664090e_size_168_quality_85_e273dd7e_20251018T080329Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5a50f257-ef7f-4680-94e0-670c586154aa_size_168_quality_85_75bc027c_20251018T080401Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b0b88e99-082c-43e8-88d1-21dbf84262c4_size_168_quality_85_7b35a214_20251018T080401Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_c349506a-b897-4a04-9191-85e5090f0d6e_size_168_quality_85_37c748bd_20251018T080328Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_184ad0e5-e723-4b46-babc-4d119e6e3cab_size_168_quality_85_0cd5001e_20251018T080329Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9ca263bc-486c-4775-b315-df4cbc180a32_size_168_quality_85_2d099724_20251018T080355Z.jpg"
|
||||
],
|
||||
"docs_md/articles/abdominal-lymph-nodes_3ca98d42-20ef-48fe-9265-ebfe570ba54b.md": [
|
||||
"images/app.statdx.com_image_thumbnail_ab4df725-d6b7-4ec4-9927-2386b5c408a2_size_168_quality_85_de205e10_20251018T075930Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_ab4df725-d6b7-4ec4-9927-2386b5c408a2_size_174_quality_85_25ee9e7e_20251018T075929Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_7981cada-a91b-40db-b2a0-0364adb4dfe0_size_168_quality_85_bf37e853_20251018T075930Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_2e379e39-26bb-44c8-abac-9b45bb6805ea_size_168_quality_85_b0dcb3b0_20251018T075930Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_c9bb51e7-406b-4a8c-9470-645fab8cad17_size_168_quality_85_88281432_20251018T075930Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_d2118b53-1548-4f30-a85e-7f2ee6bbb477_size_168_quality_85_cfe336c5_20251018T075930Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_a34c0e87-39b4-416c-97f6-8eec67b25696_size_168_quality_85_a42b7381_20251018T075930Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5ddadb80-7b2a-43ea-a6a2-f2ec8c0d8467_size_168_quality_85_f73834ae_20251018T075930Z.jpg"
|
||||
],
|
||||
"docs_md/articles/finger-in-glove-sign_81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a.md": [
|
||||
"images/app.statdx.com_image_thumbnail_827b9b74-083a-4a9c-abb6-c4b077a6a9d3_size_168_quality_85_cc4c584a_20251018T064244Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_827b9b74-083a-4a9c-abb6-c4b077a6a9d3_size_174_quality_85_4fddaf16_20251018T064243Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e81790e2-a2f7-4a5b-a298-c63503b704f4_size_168_quality_85_86a39ad1_20251018T064244Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9da07da7-411f-4382-9f5d-2f7fa7d05601_size_168_quality_85_365199d9_20251018T064244Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_1071d522-815d-4575-96d2-36a52dee778b_size_168_quality_85_724d29b6_20251018T064244Z.jpg"
|
||||
],
|
||||
"docs_md/articles/adem_a3fafeb7-5861-4364-beb8-c0e30220564e.md": [
|
||||
"images/app.statdx.com_image_deba3310-8e09-466c-97d2-1e6bccb28edf_dafbadc1_20251018T064947Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_deba3310-8e09-466c-97d2-1e6bccb28edf_size_168_quality_85_3dfef960_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_deba3310-8e09-466c-97d2-1e6bccb28edf_size_174_quality_85_aa30115e_20251018T095217Z.jpg",
|
||||
"images/app.statdx.com_image_e18458d3-5f6e-43fd-ab6d-72c7a86dca92_0f3893d6_20251018T064949Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e18458d3-5f6e-43fd-ab6d-72c7a86dca92_size_168_quality_85_70272c40_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_53135c0f-4c9e-4fb9-ab09-df46c5b40f70_c986514a_20251018T064950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_53135c0f-4c9e-4fb9-ab09-df46c5b40f70_size_168_quality_85_3f185a62_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_b79995c4-6bff-49f1-af71-cb56fe4b4aa1_119a9c33_20251018T064951Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b79995c4-6bff-49f1-af71-cb56fe4b4aa1_size_168_quality_85_03275787_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_f74d958e-f845-47e7-884e-331bf3dcb299_89b1781b_20251018T064952Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f74d958e-f845-47e7-884e-331bf3dcb299_size_168_quality_85_10b7c767_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_3e8a9c1e-560e-4c5c-93bc-dda9b3773622_eda9eb67_20251018T064954Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_3e8a9c1e-560e-4c5c-93bc-dda9b3773622_size_168_quality_85_caf40da9_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_fa96c2d2-8153-44c2-bd76-be0296382093_e2505a5f_20251018T064955Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_fa96c2d2-8153-44c2-bd76-be0296382093_size_168_quality_85_93dd4c72_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_b9452b6b-6772-4d91-8ca4-47ceaafa25f4_ddfedaec_20251018T064957Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b9452b6b-6772-4d91-8ca4-47ceaafa25f4_size_168_quality_85_3dcd4458_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_113e918b-8d8f-46b8-8664-e0f617904251_b9bf7b86_20251018T064958Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_113e918b-8d8f-46b8-8664-e0f617904251_size_168_quality_85_1b06d2b7_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_6364dfb4-c43c-4ad6-afe6-c2abed27d385_15c7b525_20251018T065000Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_6364dfb4-c43c-4ad6-afe6-c2abed27d385_size_168_quality_85_a0acf936_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_bac2d338-fffe-48e4-be97-bb8258970076_425b9699_20251018T065002Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_bac2d338-fffe-48e4-be97-bb8258970076_size_168_quality_85_4b79e54c_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_674fcfe9-2db8-4d36-a55c-9ca0a0672252_4fcbd413_20251018T065003Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_674fcfe9-2db8-4d36-a55c-9ca0a0672252_size_168_quality_85_05b2865d_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_09b3df53-221b-4806-9896-be6e908b87e5_07de590e_20251018T065005Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_09b3df53-221b-4806-9896-be6e908b87e5_size_168_quality_85_c4b5370a_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_4544554f-59e5-452b-a6b3-42d96236d4b0_9de028d1_20251018T065007Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4544554f-59e5-452b-a6b3-42d96236d4b0_size_168_quality_85_d15beb2e_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_25db98bd-b92d-407c-b5f8-796cf53ee71f_b0040522_20251018T065008Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_25db98bd-b92d-407c-b5f8-796cf53ee71f_size_168_quality_85_861400ad_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_a985da5d-914a-4071-8be7-5090530a9b69_9ef143d1_20251018T065009Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_a985da5d-914a-4071-8be7-5090530a9b69_size_168_quality_85_72123be9_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_9115564d-21e2-45af-8636-0e4a32bd55e3_504d56ec_20251018T065011Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9115564d-21e2-45af-8636-0e4a32bd55e3_size_168_quality_85_184601eb_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_f2308cec-0c77-4d95-ae67-c7db7930d83e_b6945539_20251018T065012Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f2308cec-0c77-4d95-ae67-c7db7930d83e_size_168_quality_85_a2613b2e_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_92293bff-8c2c-40f0-83da-bafe77cc24c6_50085203_20251018T065013Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_92293bff-8c2c-40f0-83da-bafe77cc24c6_size_168_quality_85_8c339a53_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_f2086d11-e747-4b89-99d4-34c16ebd985c_cd1a99bd_20251018T065014Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f2086d11-e747-4b89-99d4-34c16ebd985c_size_168_quality_85_726f0ff0_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_cae7da61-ff92-4736-8487-7596beca115c_60dd87b3_20251018T065015Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_cae7da61-ff92-4736-8487-7596beca115c_size_168_quality_85_e460a925_20251018T064936Z.jpg",
|
||||
"images/app.statdx.com_image_21d4f966-efa4-4a49-84b0-70be248001f8_461342d2_20251018T065016Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_21d4f966-efa4-4a49-84b0-70be248001f8_size_168_quality_85_5f6fc3a6_20251018T064936Z.jpg"
|
||||
],
|
||||
"docs_md/articles/abdominal-wall_e708af38-508f-4404-b7c5-6b8c7d75804f.md": [
|
||||
"images/app.statdx.com_image_thumbnail_8f3087b2-14d5-4cd7-bbef-dd8b0c13f9df_size_168_quality_85_836875bc_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8f3087b2-14d5-4cd7-bbef-dd8b0c13f9df_size_174_quality_85_35712979_20251018T075929Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_92ffe79f-0c4f-4771-94d4-ca2129b36999_size_168_quality_85_d62040f0_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_7f0fec53-3d9b-4173-8067-546bc74a1007_size_168_quality_85_e6813be2_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_87dca2a6-b990-4574-9649-fe5d4061158e_size_168_quality_85_2de6f140_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b6f46244-3311-42ec-95aa-c027e7a76424_size_168_quality_85_1f3e0006_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_d3baeb35-7eb1-48e7-b368-767a9dce5aa4_size_168_quality_85_0eba3df6_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_3dbc0b27-cb12-41ce-a641-64e1ae133a2c_size_168_quality_85_9e52d714_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_57c60457-9578-4501-941a-49a611663f22_size_168_quality_85_582d8c35_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_fa86fdcb-cade-4eb8-98c4-9d0c05ec09f8_size_168_quality_85_93a89f03_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_d230fe09-788f-46f9-bf01-0827c70a1ca5_size_168_quality_85_fec0f1a6_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_6ac680b8-912b-4dc4-b6ad-f8292fd5fffd_size_168_quality_85_ec8d2b62_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f4883481-94ca-4c25-a7c1-eef31d18b59b_size_168_quality_85_fd7ca6c0_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_d01c7d05-0099-4155-b452-b42455f0e4e1_size_168_quality_85_a98e82c4_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_70ecd629-b26a-4fe0-baec-67f1cbe51a73_size_168_quality_85_80cba6be_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b04d3943-7be6-4585-859e-c2f1e103701c_size_168_quality_85_d13e52ac_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_d2e8a41f-6650-4a90-86d9-1e5f90ec062c_size_168_quality_85_d7164cde_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8ad2ec32-92a6-470e-825f-9a877e3a49e0_size_168_quality_85_511ab779_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_bc1a0aed-5369-4232-be5e-607d7889ee7f_size_168_quality_85_854ff258_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_358f525e-462c-4608-9f8e-e3ffbb0d5b7e_size_168_quality_85_d590af7a_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_af2b45a9-3842-4351-be9b-3a2306dab79d_size_168_quality_85_e5288c3b_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_63063731-ca72-4f92-8aad-c9c914a47988_size_168_quality_85_820c611b_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8d93b0e5-98b3-4e54-9a94-1d6d5f342e7d_size_168_quality_85_943677a2_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_87a8556a-03f6-44f6-b0d1-dd79f8cd9502_size_168_quality_85_91fb55ac_20251018T075950Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_3edb7aa6-7b08-44a4-92bc-a973c5de7afd_size_168_quality_85_354df975_20251018T080048Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_870a381d-352a-4238-aef6-9e818cb8482a_size_168_quality_85_92d3add5_20251018T080048Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_14a5b447-cc25-4068-85cd-77375af35f43_size_168_quality_85_56d42a03_20251018T080048Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_2f79e3b3-8b7a-4727-bcc4-7608262778b8_size_168_quality_85_49af75a4_20251018T080048Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_23538129-85ee-4f06-a95b-547cc4492677_size_168_quality_85_6ed0da45_20251018T080048Z.jpg"
|
||||
],
|
||||
"docs_md/articles/cidp_12e4033c-edc8-46ff-8081-3acc433cda78.md": [
|
||||
"images/app.statdx.com_image_thumbnail_e0d1598d-4a92-4d78-9124-87f27a196230_size_168_quality_85_41f53f54_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e0d1598d-4a92-4d78-9124-87f27a196230_size_174_quality_85_02106d72_20251018T095217Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_c27b3469-6c6e-4d3c-8cc8-a93671c5bf09_size_168_quality_85_8455ce81_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f40f3c68-4a6c-4e61-a1d0-818ea614c071_size_168_quality_85_b4a51382_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8ef8ec72-8984-4f90-8380-953114da6604_size_168_quality_85_e847b484_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_385d96c2-5ef1-466a-bbf7-bcfbf8fb9433_size_168_quality_85_3828ef00_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e85adcc5-c5d2-4c04-b676-83773765bd8e_size_168_quality_85_0a98e931_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4161f150-8dc2-4c83-94b9-4ee9d01c70f7_size_168_quality_85_efb486ac_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4683fb7b-747f-4882-8f72-0a9b82b28723_size_168_quality_85_b2a08acd_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_7443f593-4ded-4c77-b1e2-b2d61ecea64a_size_168_quality_85_52da947b_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_d53c481c-3aa4-4771-8aa3-b7081202b269_size_168_quality_85_93e086b6_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f2bfe031-78d4-4f16-baa0-c95a54f6e565_size_168_quality_85_0fab86e2_20251018T095234Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_7776240a-5af6-404a-bc66-83b9ee89150e_size_168_quality_85_e3313250_20251018T095234Z.jpg"
|
||||
],
|
||||
"docs_md/articles/neuromyelitis-optica-spectrum-disorders_54d4a8bc-9267-4df6-98c1-f22aae051d01.md": [
|
||||
"images/app.statdx.com_image_e8ba18d2-7677-4bf1-8a89-ea3f7610a1dd_96bc49eb_20251018T095348Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e8ba18d2-7677-4bf1-8a89-ea3f7610a1dd_size_168_quality_85_e6e9aa1a_20251018T095348Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e8ba18d2-7677-4bf1-8a89-ea3f7610a1dd_size_174_quality_85_871952c9_20251018T095217Z.jpg",
|
||||
"images/app.statdx.com_image_d26008df-62a0-4116-a5a3-ebf9f767936e_c629a840_20251018T095351Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_d26008df-62a0-4116-a5a3-ebf9f767936e_size_168_quality_85_7d1f7816_20251018T095348Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_18a3a92e-8b6e-4557-9a3e-308224813fb7_annotated_true_size_900_quality_90_ec13355e_20251018T095345Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_18a3a92e-8b6e-4557-9a3e-308224813fb7_size_168_quality_85_b02969d9_20251018T095348Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_68022be5-3461-4a7b-b463-bce85be372d7_annotated_true_size_900_quality_90_2f01d9e1_20251018T095345Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_68022be5-3461-4a7b-b463-bce85be372d7_size_168_quality_85_f3b0df93_20251018T095348Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f35b89c5-cc67-4525-a144-dce62ca75eb4_annotated_true_size_900_quality_90_cf43df8e_20251018T095345Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f35b89c5-cc67-4525-a144-dce62ca75eb4_size_168_quality_85_9dfd191d_20251018T095348Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_23f4c61a-3885-4def-aa58-ab1739b25892_annotated_true_size_900_quality_90_437f542a_20251018T095345Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_23f4c61a-3885-4def-aa58-ab1739b25892_size_168_quality_85_e2eb51a4_20251018T095348Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5cad442f-db96-4ae9-9274-e8133ea9ed78_annotated_true_size_900_quality_90_df39bf4a_20251018T095345Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5cad442f-db96-4ae9-9274-e8133ea9ed78_size_168_quality_85_08023041_20251018T095342Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_414b6d7b-239f-4fb1-bd21-074aa2d10de7_annotated_true_size_900_quality_90_37be6470_20251018T095345Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_414b6d7b-239f-4fb1-bd21-074aa2d10de7_size_168_quality_85_196c576a_20251018T095342Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e41a4f6e-cc0e-4e88-9043-7449c91ff599_annotated_true_size_900_quality_90_62b91eca_20251018T095345Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e41a4f6e-cc0e-4e88-9043-7449c91ff599_size_168_quality_85_0cf202eb_20251018T095343Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5abd7f5f-c219-4988-be56-6ab012cbd08c_annotated_true_size_900_quality_90_4488b678_20251018T095345Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5abd7f5f-c219-4988-be56-6ab012cbd08c_size_168_quality_85_abf644a3_20251018T095342Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_2c2321de-7889-40ce-8df8-04e4d3d797b4_size_168_quality_85_a4060e5c_20251018T095343Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f366a54b-a153-482a-9a92-4cc470920912_size_168_quality_85_4afd1519_20251018T095342Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0c76b02a-afd8-4735-91b3-86054aaebc0b_size_168_quality_85_48167667_20251018T095343Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e636432e-5135-43e6-a253-ca5aa5f3cb60_size_168_quality_85_6e526ceb_20251018T095342Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8d9ecb2b-7375-4a5d-b755-00d2cf0f6a6e_size_168_quality_85_5b5fdacd_20251018T095343Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_82abad06-b739-4851-b986-c84ef3ee2600_size_168_quality_85_f32b39c9_20251018T095343Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_06bed7ab-14a6-4703-b182-192335646122_size_168_quality_85_19338595_20251018T095342Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_db3d5458-48ba-4f3d-ba25-faaac039a137_size_168_quality_85_5f5ffb06_20251018T095343Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9ef79e0d-9f98-4092-a887-e607fe1a5b8a_size_168_quality_85_49b31cf4_20251018T095343Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_edd8c34f-8077-4ed1-82a4-b1ecbfd4416e_size_168_quality_85_a2a9bd81_20251018T095342Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8e2f3575-7388-4b4f-8548-7e248b2eebc5_size_168_quality_85_838a7979_20251018T095343Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_01660eb5-a786-4e07-86e9-89379547c8b8_size_168_quality_85_d91cf3d1_20251018T095343Z.jpg"
|
||||
],
|
||||
"docs_md/articles/autoimmune-encephalitis_6eb3d5d6-7f6a-4367-a792-b5d4b19675da.md": [
|
||||
"images/app.statdx.com_image_thumbnail_55b572ea-97f1-4aef-96e8-2d4953c437bb_size_168_quality_85_8c5e5586_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_55b572ea-97f1-4aef-96e8-2d4953c437bb_size_174_quality_85_f6fc1e32_20251018T095217Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f19048d1-415f-4f2a-8236-6c1c9c263ade_size_168_quality_85_afbb7b9e_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_bb9be3cc-b23c-4941-a7a4-16f0a1736308_size_168_quality_85_73cf1488_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b830356c-f148-4519-ba8d-65c67dbb5380_size_168_quality_85_1c0c9901_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_931ed2de-80d8-4747-a34c-d2a0a05f526e_size_168_quality_85_9bd3c62a_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_75dce6be-287e-4d7e-be14-8d0e424db77f_size_168_quality_85_5458e01b_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b8522ce7-c8be-4ed7-a7f9-4788abe7a535_size_168_quality_85_810aceae_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_fd5e962c-ebfb-4724-930d-dbda5d025098_size_168_quality_85_91e4482d_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_dda402f8-e60a-451f-a558-d44f1038c882_size_168_quality_85_41c962cf_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_adfb6224-fa92-44a6-8fb9-71bb22dd6eb3_size_168_quality_85_611d6d6f_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f2540964-3ae6-4b6b-a7dc-f128f8e94c29_size_168_quality_85_6e806d79_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_a4b705df-d7f3-498c-8ed1-a3f989922ee3_size_168_quality_85_7905ee41_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_72659a12-1bfa-4a0a-87f1-973e53c6b558_size_168_quality_85_aa2d61f2_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_63d4e718-6ee6-437c-a23b-bd2a56f8c106_size_168_quality_85_4a3881a2_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_88093894-f2b4-4a12-aa75-1ae5ec313f44_size_168_quality_85_6a739671_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_2871f764-a9a3-42a8-8368-0e308b38f69b_size_168_quality_85_7e80eab5_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_70b9a9d9-e630-45d3-854d-91ace5229992_size_168_quality_85_28b0318f_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_cc4230df-5bec-43d5-bc3b-9df86787806b_size_168_quality_85_98755dd1_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_34910713-5aa7-45ab-a7fe-44681c2acd17_size_168_quality_85_9229bcc4_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_eff199ae-0e2e-4db5-8473-f78aa2acb8e7_size_168_quality_85_dba11f26_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8ba47b07-a617-46ff-8081-bf3ee120aacf_size_168_quality_85_37a386d3_20251018T095220Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_1b9bf79c-994c-4fa6-81d7-5a5964383bfe_size_168_quality_85_be3dda6b_20251018T095220Z.jpg"
|
||||
],
|
||||
"docs_md/articles/multiple-sclerosis_7892b2a2-f52a-4d7f-9858-a326f2b7ab04.md": [
|
||||
"images/app.statdx.com_image_thumbnail_298cc9db-f7e6-4904-a92c-b4014d263b26_annotated_true_size_900_quality_90_4ffccac6_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_298cc9db-f7e6-4904-a92c-b4014d263b26_size_168_quality_85_89ae47ce_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_298cc9db-f7e6-4904-a92c-b4014d263b26_size_174_quality_85_096a3d66_20251018T095217Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_acb3f1b0-b500-47a5-9ed5-72dee0dd74dc_annotated_true_size_900_quality_90_b1fc515e_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_acb3f1b0-b500-47a5-9ed5-72dee0dd74dc_size_168_quality_85_59b609a2_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8e1b38d3-c2c0-4128-80a1-f2e3640c3b91_annotated_true_size_900_quality_90_ee44017f_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8e1b38d3-c2c0-4128-80a1-f2e3640c3b91_size_168_quality_85_9844f252_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b8524003-2e1d-4d59-94d3-bf5d7634b01d_annotated_true_size_900_quality_90_3e113c82_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b8524003-2e1d-4d59-94d3-bf5d7634b01d_size_168_quality_85_160c28d1_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5ab2519c-5653-43fe-b237-732e2fbc8b12_annotated_true_size_900_quality_90_35b15160_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5ab2519c-5653-43fe-b237-732e2fbc8b12_size_168_quality_85_c124921d_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_75e21646-c880-469e-850b-2caa2329b59b_annotated_true_size_900_quality_90_93df3be8_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_75e21646-c880-469e-850b-2caa2329b59b_size_168_quality_85_97d150ff_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f8983790-81fa-4667-ada8-b38b6cd1f153_annotated_true_size_900_quality_90_59a7af95_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f8983790-81fa-4667-ada8-b38b6cd1f153_size_168_quality_85_c4b7db24_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_52cb7d6b-f66d-4aa3-8c70-3058352b5bab_annotated_true_size_900_quality_90_b6ff6104_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_52cb7d6b-f66d-4aa3-8c70-3058352b5bab_size_168_quality_85_5e322455_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_c73d1451-8702-40c9-a7d6-52f7ced3fb44_annotated_true_size_900_quality_90_ad9b28fa_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_c73d1451-8702-40c9-a7d6-52f7ced3fb44_size_168_quality_85_70f447f9_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0cb35959-c58d-42c3-89d6-4e1e83002315_annotated_true_size_900_quality_90_9538bc08_20251018T095333Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0cb35959-c58d-42c3-89d6-4e1e83002315_size_168_quality_85_9b6eff9b_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4429c9c8-59de-4763-965e-b51fdf048a3c_annotated_true_size_900_quality_90_838371c0_20251018T095335Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4429c9c8-59de-4763-965e-b51fdf048a3c_size_168_quality_85_1a582782_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0da4da94-8e63-4d2c-931d-a09f0438166e_annotated_true_size_900_quality_90_8004a702_20251018T095335Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0da4da94-8e63-4d2c-931d-a09f0438166e_size_168_quality_85_13a1fd06_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_145b9fbf-434b-4db6-8c34-240875821d49_size_168_quality_85_59e955bb_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_26c1f577-7d97-43b9-812e-4f4db88d8fce_size_168_quality_85_18fb923b_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0471add5-e1df-4d93-b336-ccbd0de9aec7_size_168_quality_85_6dfd081e_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_d94ee5e0-f32e-4285-8795-d88b40cdd80a_size_168_quality_85_d2c1a91e_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_12fc34cf-5a21-42fd-9489-1ad3b6572f03_size_168_quality_85_52dc3401_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_654a4004-229b-416c-a753-42d402b6b3ab_size_168_quality_85_cdd40c1f_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_04cbe9a3-e39e-4fd3-865b-3f0d54163edf_size_168_quality_85_8932cd14_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_03b47bd7-3474-492a-bff6-01abe9eb5c8a_size_168_quality_85_8d6e2a10_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_35a96664-28f8-4752-9dbb-8d5a8fb99276_size_168_quality_85_dc4e58c2_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_c14ee6bd-8197-4368-81a7-8a12bdadf049_size_168_quality_85_8275dd1f_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9197159e-317a-41bb-9ee4-ed7ba31454fc_size_168_quality_85_cf86065a_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_ea96d27e-42c1-429b-98a3-024bea525827_size_168_quality_85_08aa276d_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_6a954445-52d5-4b02-9846-8e8f7a1d2d52_size_168_quality_85_3d20ae56_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4158830a-642a-434a-9dd1-61c9321b67ee_size_168_quality_85_372f6946_20251018T095337Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_408e2816-65c7-496c-b6d5-05a215d808ae_size_168_quality_85_de50003d_20251018T095337Z.jpg"
|
||||
],
|
||||
"docs_md/articles/clippers_ba394f3b-bbff-4128-90b5-3e1c07564c5f.md": [
|
||||
"images/app.statdx.com_image_thumbnail_3b810ab1-5bad-4ec7-936d-bc3cf0683b4d_size_168_quality_85_8ebb6805_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_3b810ab1-5bad-4ec7-936d-bc3cf0683b4d_size_174_quality_85_f2fb8c82_20251018T095217Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0412a98f-922e-4e0e-8106-5bf10bac5e68_size_168_quality_85_3093054b_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_bbe0d150-9cfd-4e4c-b8ca-2d1adceadb6b_size_168_quality_85_d66f7fff_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_014b1c32-e926-4656-987e-d8311c674576_size_168_quality_85_e2ebbeb7_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b7924d60-22a9-44a8-8eab-a122a8fabee9_size_168_quality_85_afe982f1_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_54794f9e-0cff-4b09-8514-3f0c0f658cbd_size_168_quality_85_ca6dda0c_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_179e89fa-d5c6-4f10-b298-b1179723c303_size_168_quality_85_f7ef21fc_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_6b5d2b9c-b124-4a6a-beba-fe65179bd0b6_size_168_quality_85_07b4c70d_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f849c125-5528-4f44-943a-db3c921f3a9b_size_168_quality_85_7fa9d5c0_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b1bf1bf1-9d90-4fe9-905b-3b85debd861f_size_168_quality_85_2931bc9a_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_56b83112-4e12-4510-beff-f833b9599c27_size_168_quality_85_dab3c1ff_20251018T095255Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_784cb251-3014-4189-b444-0f63b0f2a125_size_168_quality_85_1dac933c_20251018T095255Z.jpg"
|
||||
],
|
||||
"docs_md/articles/guillain-barr-spectrum-disorders_c1f52a65-920e-4e28-8a75-07dfa208f290.md": [
|
||||
"images/app.statdx.com_image_thumbnail_437a7388-6761-4ae6-bbe8-a94c64172505_size_168_quality_85_3b1ee2d9_20251018T095312Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_437a7388-6761-4ae6-bbe8-a94c64172505_size_174_quality_85_feea0730_20251018T095217Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5d50656f-8e56-40a4-9ad8-54778d94348f_size_168_quality_85_f640ff58_20251018T095312Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_121ccea5-3b17-4960-8fad-5e03c2574112_size_168_quality_85_55630496_20251018T095312Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_c7553e93-a863-4cb6-b052-a0e2437db982_size_168_quality_85_2af9fcb7_20251018T095312Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_62a77d2a-4a78-448b-891c-9f5482c408c9_size_168_quality_85_09feb623_20251018T095312Z.jpg"
|
||||
],
|
||||
"docs_md/articles/aging-brain-normal_f8dc8f27-f256-480d-9393-7ec3495a3d27.md": [
|
||||
"images/app.statdx.com_image_thumbnail_04a1f1d8-6210-4030-84ff-4f60f3f7f7bf_annotated_true_size_900_quality_90_08c876a3_20251018T115116Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_04a1f1d8-6210-4030-84ff-4f60f3f7f7bf_size_174_quality_85_63332bdc_20251018T115114Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_da569666-3c25-4be0-9f3d-339aa20a7c0c_annotated_true_size_900_quality_90_8a6ae188_20251018T115116Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b0b9b464-052e-445c-8496-65170c3de33e_annotated_true_size_900_quality_90_9497cb97_20251018T115116Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0cde205f-c504-4cff-a434-767e3b3a2ae8_annotated_true_size_900_quality_90_405aded7_20251018T115116Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f0e3cf04-b0e3-470c-bdbd-c107d15e3f9c_annotated_true_size_900_quality_90_cb776480_20251018T115116Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_ed6c9417-b34b-4907-8366-356990db3fb9_annotated_true_size_900_quality_90_b431c6b3_20251018T115116Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5ad4a574-3864-42f9-a599-327141dcd5f3_annotated_true_size_900_quality_90_b454c035_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_748de998-f123-46c4-a117-75d0346c3b7f_annotated_true_size_900_quality_90_6b0a6fe5_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4654db88-ccf0-4df6-999a-89cf5f0557ad_annotated_true_size_900_quality_90_9c702078_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_fffaa200-67bf-40c5-b757-0e8bb113efdb_annotated_true_size_900_quality_90_9da28efa_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_edaa1d8f-a0b7-4e05-bbc3-fb7aae9dfbe6_annotated_true_size_900_quality_90_c1ede758_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_28129b7b-5d13-4482-8650-8082bb482a0d_annotated_true_size_900_quality_90_3bf16796_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_ef776137-1e7e-4dc1-90ab-db50ada53983_annotated_true_size_900_quality_90_623c7634_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_fbbf14d8-1009-4986-a415-73b2526275e3_annotated_true_size_900_quality_90_a9a2f739_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_605ae9fe-3f65-4822-aa16-e1fb702ab39e_annotated_true_size_900_quality_90_e0888217_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_3cedfbd5-bca8-4bca-8e74-935aae58d99a_annotated_true_size_900_quality_90_8e36edc4_20251018T115116Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_eaa65018-6137-432c-a1ed-5a3ae9618ace_annotated_true_size_900_quality_90_e01ee62f_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0e2186ff-7c59-45f2-be8f-5a138892d853_annotated_true_size_900_quality_90_fce73888_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f246d5b8-b2df-4ff2-9a7a-6f2ffcc17839_annotated_true_size_900_quality_90_acd66b6c_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_097dc6e9-0bca-460b-963d-833ed2faf174_annotated_true_size_900_quality_90_0dca14ef_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_3bb44463-e628-45b7-8785-39dded84afec_annotated_true_size_900_quality_90_1fd8b260_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_412e2974-fe0e-4f6e-b74a-2d04cd27fd48_annotated_true_size_900_quality_90_461bb8bc_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_a6e65580-04b7-47a3-bbce-387a07099a5f_annotated_true_size_900_quality_90_7d6b77af_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e6d08d7c-abc6-487c-a163-99be5c9e83fb_annotated_true_size_900_quality_90_cb6277a9_20251018T115116Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_64bd7130-f9d5-4a77-82eb-76078fe00e59_annotated_true_size_900_quality_90_0087c294_20251018T100106Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_a5f73800-5f26-4f67-9632-32b720eef177_annotated_true_size_900_quality_90_0508662a_20251018T100106Z.jpg"
|
||||
],
|
||||
"docs_md/articles/fusiform-arterial-enlargement_31d50b93-b057-4da3-86b5-4cc8fb0bc806.md": [
|
||||
"images/app.statdx.com_image_38e1497f-31e3-49db-8b46-4ab561bf1eac_fb437f8b_20251018T080401Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_38e1497f-31e3-49db-8b46-4ab561bf1eac_size_168_quality_85_e3c2ebff_20251018T080328Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_38e1497f-31e3-49db-8b46-4ab561bf1eac_size_174_quality_85_9fba439d_20251018T080313Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f63a9221-71c6-4320-af66-1ed581202eb9_size_168_quality_85_8a3ae196_20251018T080328Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_68b41ae0-9f3a-4484-8b02-69d6772626db_size_168_quality_85_8d79e53e_20251018T080328Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9c20720f-93e4-49ad-b302-93e2d3e03a65_size_168_quality_85_2e4b9fef_20251018T080329Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b62dcdb8-45c4-477b-a466-98935b57a9f5_size_168_quality_85_562a643f_20251018T080329Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_8fb2594c-2abc-43d9-84bc-b8b67664090e_size_168_quality_85_e273dd7e_20251018T080329Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5a50f257-ef7f-4680-94e0-670c586154aa_size_168_quality_85_75bc027c_20251018T080401Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b0b88e99-082c-43e8-88d1-21dbf84262c4_size_168_quality_85_7b35a214_20251018T080401Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_c349506a-b897-4a04-9191-85e5090f0d6e_size_168_quality_85_37c748bd_20251018T080328Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_184ad0e5-e723-4b46-babc-4d119e6e3cab_size_168_quality_85_0cd5001e_20251018T080329Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_9ca263bc-486c-4775-b315-df4cbc180a32_size_168_quality_85_2d099724_20251018T080355Z.jpg"
|
||||
],
|
||||
"docs_md/articles/basal-ganglia-calcification_f8dc8f27-f256-480d-9393-7ec3495a3d27.md": [
|
||||
"images/app.statdx.com_image_thumbnail_04a1f1d8-6210-4030-84ff-4f60f3f7f7bf_annotated_true_size_900_quality_90_ab12a15f_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_04a1f1d8-6210-4030-84ff-4f60f3f7f7bf_size_174_quality_85_63332bdc_20251018T115114Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_da569666-3c25-4be0-9f3d-339aa20a7c0c_annotated_true_size_900_quality_90_69540ccd_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_b0b9b464-052e-445c-8496-65170c3de33e_annotated_true_size_900_quality_90_826e4674_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0cde205f-c504-4cff-a434-767e3b3a2ae8_annotated_true_size_900_quality_90_a68440f2_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f0e3cf04-b0e3-470c-bdbd-c107d15e3f9c_annotated_true_size_900_quality_90_1a8578b3_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_ed6c9417-b34b-4907-8366-356990db3fb9_annotated_true_size_900_quality_90_2ca56ccc_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_5ad4a574-3864-42f9-a599-327141dcd5f3_annotated_true_size_900_quality_90_d20f6a14_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_748de998-f123-46c4-a117-75d0346c3b7f_annotated_true_size_900_quality_90_5ed615f6_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_4654db88-ccf0-4df6-999a-89cf5f0557ad_annotated_true_size_900_quality_90_bde4bd47_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_fffaa200-67bf-40c5-b757-0e8bb113efdb_annotated_true_size_900_quality_90_a9cfc2df_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_edaa1d8f-a0b7-4e05-bbc3-fb7aae9dfbe6_annotated_true_size_900_quality_90_e68fbfb7_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_28129b7b-5d13-4482-8650-8082bb482a0d_annotated_true_size_900_quality_90_555ab385_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_ef776137-1e7e-4dc1-90ab-db50ada53983_annotated_true_size_900_quality_90_c3107045_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_fbbf14d8-1009-4986-a415-73b2526275e3_annotated_true_size_900_quality_90_f69ee382_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_605ae9fe-3f65-4822-aa16-e1fb702ab39e_annotated_true_size_900_quality_90_07c47430_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_3cedfbd5-bca8-4bca-8e74-935aae58d99a_annotated_true_size_900_quality_90_904c4796_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_eaa65018-6137-432c-a1ed-5a3ae9618ace_annotated_true_size_900_quality_90_0da4ca40_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_0e2186ff-7c59-45f2-be8f-5a138892d853_annotated_true_size_900_quality_90_59aabb0a_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_f246d5b8-b2df-4ff2-9a7a-6f2ffcc17839_annotated_true_size_900_quality_90_98f69ee6_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_097dc6e9-0bca-460b-963d-833ed2faf174_annotated_true_size_900_quality_90_a9a25b30_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_3bb44463-e628-45b7-8785-39dded84afec_annotated_true_size_900_quality_90_cf178072_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_412e2974-fe0e-4f6e-b74a-2d04cd27fd48_annotated_true_size_900_quality_90_0fc3fcfa_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_a6e65580-04b7-47a3-bbce-387a07099a5f_annotated_true_size_900_quality_90_897d613b_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_e6d08d7c-abc6-487c-a163-99be5c9e83fb_annotated_true_size_900_quality_90_09ea4ae4_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_64bd7130-f9d5-4a77-82eb-76078fe00e59_annotated_true_size_900_quality_90_38924eeb_20251018T121530Z.jpg",
|
||||
"images/app.statdx.com_image_thumbnail_a5f73800-5f26-4f67-9632-32b720eef177_annotated_true_size_900_quality_90_b9b07ad5_20251018T121530Z.jpg"
|
||||
]
|
||||
}
|
||||
@@ -0,0 +1,174 @@
|
||||
---
|
||||
title: "Abdominal Lymph Nodes"
|
||||
docid: "3ca98d42-20ef-48fe-9265-ebfe570ba54b"
|
||||
authors:
|
||||
- key: "07469ec4-05aa-4d65-a788-08b4d64048af"
|
||||
value: "Jade Wong-You-Cheong, MBChB, MRCP, FRCR, FSRU, FSAR"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Ultrasound"
|
||||
slug: "ultrasound"
|
||||
treeNodeId: "e7cdfeb1-bb55-4cca-9854-46cadee515d2"
|
||||
-
|
||||
name: "Anatomy"
|
||||
slug: "anatomy"
|
||||
treeNodeId: "d4765014-54f9-4477-8c9c-4b2ae0b82f24"
|
||||
-
|
||||
name: "Abdomen"
|
||||
slug: "abdomen"
|
||||
treeNodeId: "1e981810-ddca-4af9-82b9-38d5fdecad76"
|
||||
-
|
||||
name: "Abdominal Lymph Nodes"
|
||||
slug: "abdominal-lymph-nodes"
|
||||
treeNodeId: null
|
||||
category: "Ultrasound"
|
||||
documentVersionId: "43db6bf2-6355-41b6-9d98-6af776f561f7"
|
||||
imageCount: 7
|
||||
isBookmarked: false
|
||||
isComparable: false
|
||||
isInCompareCart: false
|
||||
lastUpdated: "05/03/21"
|
||||
pageDescription: "Abdominal Lymph Nodes"
|
||||
pageKeywords: "Ultrasound, Anatomy, Abdomen, Abdominal Lymph Nodes"
|
||||
pageTitle: "Abdominal Lymph Nodes | STATdx"
|
||||
enhancedTitle: "Abdominal Lymph Nodes"
|
||||
type: "ANATOMY"
|
||||
breadcrumbs:
|
||||
- "Ultrasound"
|
||||
- "Anatomy"
|
||||
- "Abdomen"
|
||||
- "Abdominal Lymph Nodes"
|
||||
---
|
||||
# GROSS ANATOMY
|
||||
|
||||
- ## Overview
|
||||
|
||||
|
||||
- Major lymphatic vessels and nodal chains lie along major blood vessels [aorta, inferior vena cava (IVC), iliac]
|
||||
- Lymph nodes carry same name as vessel they accompany
|
||||
- Lymph from alimentary tract, liver, spleen, and pancreas passes along celiac, superior mesenteric chains to nodes
|
||||
- Efferent vessels from alimentary nodes form intestinal lymphatic trunks
|
||||
- Cisterna chyli (chyle cistern)
|
||||
- Formed by confluence of intestinal lymphatic trunks and right and left lumbar lymphatic trunks, which receive lymph from nonalimentary viscera, abdominal wall, and lower extremities
|
||||
- May be discrete sac or plexiform convergence
|
||||
- Thoracic duct: Inferior extent is chyle cistern at L1-2 level
|
||||
- Formed by convergence of main lymphatic ducts of abdomen
|
||||
- Ascends through aortic hiatus in diaphragm to enter posterior mediastinum
|
||||
- Ends by entering junction of left subclavian and internal jugular veins
|
||||
- Lymphatic system drains surplus fluid from extracellular spaces and returns it to bloodstream
|
||||
- Important function in defense against infection, inflammation, and tumor via lymphoid tissue present in lymph nodes, gut wall, spleen, and thymus
|
||||
- Absorbs and transports dietary lipids from intestine to thoracic duct and bloodstream
|
||||
- Lymph nodes
|
||||
- Composed of cortex and medulla
|
||||
- Invested in fibrous capsule, which extends into nodal parenchyma to form trabeculae
|
||||
- Internal honeycomb structure filled with lymphocytes that collect and destroy pathogens
|
||||
- Hilum: In concave side, with artery and vein, surrounded by fat
|
||||
- ## Abdominopelvic Nodes
|
||||
|
||||
|
||||
- Preaortic nodes
|
||||
- Celiac nodes: Drainage from gastric nodes, hepatic nodes, and pancreaticosplenic nodes
|
||||
- Superior and inferior mesenteric nodes: Drainage from mesenteric nodes
|
||||
- Lateral aortic nodes (paraaortic)
|
||||
- Drainage from kidneys, adrenal glands, ureter, posterior abdominal wall, testes and ovary, uterus and fallopian tubes
|
||||
- Retroaortic nodes
|
||||
- Drainage from posterior abdominal wall
|
||||
- External iliac nodes
|
||||
- Primary drainage from inguinal nodes
|
||||
- Flow into common iliac nodes
|
||||
- Internal iliac nodes
|
||||
- Drainage from inferior pelvic viscera, deep perineum, and gluteal region
|
||||
- Flow into common iliac nodes
|
||||
- Common iliac nodes
|
||||
- Drainage from external iliac, internal iliac, and sacral nodes
|
||||
- Flow into lumbar (lateral aortic) chain of nodes
|
||||
- Superficial inguinal nodes
|
||||
- In superficial fascia parallel to inguinal ligament, along cephalad portion of greater saphenous vein
|
||||
- Receive lymphatic drainage from superficial lower extremity, superficial abdominal wall, and perineum
|
||||
- Flow into deep inguinal and external iliac nodes
|
||||
- Deep inguinal nodes
|
||||
- Along medial side of femoral vein, deep to fascia lata and inguinal ligament
|
||||
- Receive lymphatic drainage from superficial inguinal and popliteal nodes
|
||||
- Flow into external iliac nodes
|
||||
|
||||
# IMAGING ANATOMY
|
||||
|
||||
- ## Overview
|
||||
|
||||
|
||||
- CT is test of choice for cancer staging
|
||||
- May be supplemented by PET/CT or MR in select cancers
|
||||
- Ultrasound may be useful in children or thin adults
|
||||
- Normal nodes are elliptical with echogenic fatty hilum and uniform hypoechoic cortex
|
||||
- Normal lymph nodes rarely detected on abdominal ultrasound
|
||||
- Short-axis diameter > 10 mm typically considered enlarged, but normal diameter of lymph node varies depending on location
|
||||
- Retrocrural < 6 mm
|
||||
- Hepatogastric ligament < 8 mm, porta hepatis < 7 mm
|
||||
- Mesenteric < 5 mm
|
||||
- Inguinal < 15 mm
|
||||
|
||||
# ANATOMY IMAGING ISSUES
|
||||
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- Transducer: 2-5 MHz or 5-9 MHz for thinner patients
|
||||
- Patient examined in supine position with 6-8 hours of fasting to decrease bowel gas
|
||||
- Graded compression technique to clear overlying bowel loops
|
||||
|
||||
# CLINICAL IMPLICATIONS
|
||||
|
||||
- ## Clinical Importance
|
||||
|
||||
|
||||
- Nodal enlargement is nonspecific; may be neoplastic, inflammatory, or reactive
|
||||
- Normal-sized lymph nodes may harbor metastatic malignancy
|
||||
- Node morphology is more specific for pathology
|
||||
- Abnormal nodes have replacement or loss of fatty hilum
|
||||
- Look for central necrosis, cystic change, calcification or irregular margin, and location of nodes (if in drainage field of tumor)
|
||||
- Lymphoma
|
||||
- Multiple enlarged hypoechoic or anechoic nodes
|
||||
- Metastatic lymphadenopathy
|
||||
- More echogenic and heterogeneous nodes compared to lymphomatous nodes
|
||||
- Infectious/reactive lymphadenopathy
|
||||
- Nonspecific sonographic features
|
||||
- May contain necrotic centers in mycobacterial infection
|
||||
|
||||
344781fd-34ab-4335-bb66-19706f7d2d68
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Abdominal Lymph Nodes
|
||||
|
||||
|
||||
*Graphic shows that the major lymphatics and lymph nodes of the abdomen are located along, and share the same name as, the major blood vessels, such as the external iliac nodes, celiac, and superior mesenteric nodes. The paraaortic and paracaval nodes are also referred to as the lumbar nodes and receive afferents from the lower abdominal viscera, abdominal wall, and lower extremities; they are frequently involved in inflammatory and neoplastic processes. The lumbar trunks join with an intestinal trunk (at about the L1 level) to form the cisterna chyli, which may be a discrete sac or a plexiform convergence. The cisterna chyli and other major lymphatic trunks join to form the thoracic duct, which passes through the aortic hiatus to enter the mediastinum. After picking up additional lymphatic trunks within the thorax, the thoracic duct empties into the left subclavian or innominate vein.*
|
||||
|
||||
|
||||
*Graphic shows that the major lymphatics and lymph nodes of the abdomen are located along, and share the same name as, the major blood vessels, such as the external iliac nodes, celiac, and superior mesenteric nodes. The paraaortic and paracaval nodes are also referred to as the lumbar nodes and receive afferents from the lower abdominal viscera, abdominal wall, and lower extremities; they are frequently involved in inflammatory and neoplastic processes. The lumbar trunks join with an intestinal trunk (at about the L1 level) to form the cisterna chyli, which may be a discrete sac or a plexiform convergence. The cisterna chyli and other major lymphatic trunks join to form the thoracic duct, which passes through the aortic hiatus to enter the mediastinum. After picking up additional lymphatic trunks within the thorax, the thoracic duct empties into the left subclavian or innominate vein.*
|
||||
|
||||
|
||||
### Nonenlarged Nodes and Pathologic Nodes
|
||||
|
||||
|
||||
*Transverse ultrasound at the level of the pancreas and splenic vein shows a small interaortocaval node.*
|
||||
|
||||
|
||||
*Transverse ultrasound of the epigastric region shows an enlarged, hypoechoic, peripancreatic, lymph node anterior to the portal vein in a patient with hepatitis C. Normal-sized lymph nodes are rarely seen in adult abdominal ultrasound.*
|
||||
|
||||
|
||||
*Transverse ultrasound of the upper midline abdomen in a patient with lymphoma shows multiple abnormal enlarged, hypoechoic lymph nodes around the superior mesenteric artery.*
|
||||
|
||||
|
||||
### CT and Lymphangiogram
|
||||
|
||||
|
||||
*Axial CT shows a small benign interaortocaval lymph node.*
|
||||
|
||||
|
||||
*Coronal CT shows a row of small elliptical left paraaortic lymph nodes; the most inferior node has a clear fatty hilum. These were benign.*
|
||||
|
||||
|
||||
*Normal lymphatic channels and lymph nodes are best seen on a lymphangiogram performed with Lipiodol contrast. In this case, performed for chylous leak, normal pelvic and retroperitoneal nodes and lymphatics are opacified.*
|
||||
|
||||
@@ -0,0 +1,242 @@
|
||||
---
|
||||
title: "Abdominal Wall"
|
||||
docid: "e708af38-508f-4404-b7c5-6b8c7d75804f"
|
||||
authors:
|
||||
- key: "390c5f66-1ba7-429e-a1d6-23fd9c95b869"
|
||||
value: "Tara A. Morgan, MD"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Ultrasound"
|
||||
slug: "ultrasound"
|
||||
treeNodeId: "e7cdfeb1-bb55-4cca-9854-46cadee515d2"
|
||||
-
|
||||
name: "Anatomy"
|
||||
slug: "anatomy"
|
||||
treeNodeId: "d4765014-54f9-4477-8c9c-4b2ae0b82f24"
|
||||
-
|
||||
name: "Abdomen"
|
||||
slug: "abdomen"
|
||||
treeNodeId: "1e981810-ddca-4af9-82b9-38d5fdecad76"
|
||||
-
|
||||
name: "Abdominal Wall"
|
||||
slug: "abdominal-wall"
|
||||
treeNodeId: null
|
||||
category: "Ultrasound"
|
||||
documentVersionId: "385d1c6c-f4ac-463a-80b7-dfe4876e5da2"
|
||||
imageCount: 28
|
||||
isBookmarked: false
|
||||
isComparable: false
|
||||
isInCompareCart: false
|
||||
lastUpdated: "06/30/21"
|
||||
pageDescription: "Abdominal Wall"
|
||||
pageKeywords: "Ultrasound, Anatomy, Abdomen, Abdominal Wall"
|
||||
pageTitle: "Abdominal Wall | STATdx"
|
||||
enhancedTitle: "Abdominal Wall"
|
||||
type: "ANATOMY"
|
||||
breadcrumbs:
|
||||
- "Ultrasound"
|
||||
- "Anatomy"
|
||||
- "Abdomen"
|
||||
- "Abdominal Wall"
|
||||
---
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Abdomen is region between diaphragm and pelvis
|
||||
|
||||
# GROSS ANATOMY
|
||||
|
||||
- ## Anatomic Boundaries
|
||||
|
||||
|
||||
- Anterior abdominal wall bounded superiorly by xiphoid process and costal cartilages of 7th-10th ribs
|
||||
- Anterior wall bounded inferiorly by iliac crest, iliac spine, inguinal ligament, and pubis
|
||||
- Inguinal ligament is inferior edge of external oblique muscle aponeurosis
|
||||
- ## Muscles of Anterior Abdominal Wall
|
||||
|
||||
|
||||
- Consists of 3 flat muscles (external oblique, internal oblique, and transversus abdominis), and 1 strap-like muscle (rectus abdominis)
|
||||
- Combination of muscles and aponeuroses (sheet-like tendons) acts as corset to confine and protect abdominal viscera
|
||||
- Linea alba is fibrous raphe stretching from xiphoid to pubis
|
||||
- Forms central anterior attachment for abdominal wall muscles
|
||||
- Formed by interlacing fibers of aponeuroses of oblique and transversus abdominis muscles
|
||||
- Rectus sheath is also formed by these aponeuroses, as they surround rectus muscle
|
||||
- Linea semilunaris is vertical fibrous band at lateral edge of rectus sheath bilaterally
|
||||
- Aponeuroses of internal and transversus abdominis join in linea semilunaris before forming rectus sheath
|
||||
- External oblique muscle
|
||||
- Largest and most superficial of 3 flat abdominal muscles
|
||||
- Origin: External surfaces of ribs 5-12
|
||||
- Insertion: Linea alba, iliac crest, pubis via broad aponeurosis
|
||||
- Internal oblique muscle
|
||||
- Middle of 3 flat abdominal muscles
|
||||
- Runs at right angles to external oblique
|
||||
- Origin: Posterior layer of thoracolumbar fascia, iliac crest, and inguinal ligament
|
||||
- Insertion: Ribs 10-12 posteriorly, linea alba via broad aponeurosis, pubis
|
||||
- Transversus abdominis (transversalis) muscle
|
||||
- Innermost of 3 flat abdominal muscles
|
||||
- Origin: Lowest 6 costal cartilages, thoracolumbar fascia, iliac crest, inguinal ligament
|
||||
- Insertion: Linea alba via broad aponeurosis, pubis
|
||||
- Rectus abdominis muscle
|
||||
- Origin: Pubic symphysis and pubic crest
|
||||
- Insertion: Xiphoid process and costal cartilages 5-7
|
||||
- Rectus sheath: Strong fibrous compartment that envelops each rectus muscle
|
||||
- Contains superior and inferior epigastric vessels
|
||||
- Actions of anterior abdominal wall muscles
|
||||
- Support and protect abdominal viscera
|
||||
- Flex and twist trunk, maintain posture
|
||||
- Increase intraabdominal pressure for defecation, micturition, and childbirth
|
||||
- Stabilize pelvis during walking, sitting up
|
||||
- Transversalis fascia
|
||||
- Lies deep to abdominal wall muscles and lines entire abdominal wall
|
||||
- Separated from parietal peritoneum by layer of extraperitoneal fat
|
||||
- ## Muscles of Posterior Abdominal Wall
|
||||
|
||||
|
||||
- Consist of psoas (major and minor), iliacus, and quadratus lumborum
|
||||
- Psoas: Long thick, fusiform muscle lying lateral to vertebral column
|
||||
- Origin: Transverse processes and bodies of vertebrae T12-L5
|
||||
- Insertion: Lesser trochanter of femur (passing behind inguinal ligament)
|
||||
- Action: Flexes thigh at hip joint; bends vertebral column laterally
|
||||
- Iliacus: Large triangular sheet of muscle lying along lateral side of psoas
|
||||
- Origin: Superior part of iliac fossa
|
||||
- Insertion: Lesser trochanter of femur (after joining with psoas tendon)
|
||||
- Action: "Iliopsoas muscle" flexes thigh
|
||||
- Quadratus lumborum: Thick sheet of muscle lying adjacent to transverse processes of lumbar vertebrae
|
||||
- Invested by lumbodorsal fascia
|
||||
- Origin: Iliac crest and transverse processes of lumbar vertebrae
|
||||
- Insertion: 12th rib
|
||||
- Actions: Stabilizes position of thorax and pelvis during respiration, walking, bends trunk laterally
|
||||
- ## Paraspinal Muscles
|
||||
|
||||
|
||||
- a.k.a. erector spinae muscles
|
||||
- Invested by lumbodorsal fascia
|
||||
- Composed of 3 columns: Iliocostalis: Lateral; longissimus: Intermediate; spinalis: Medial
|
||||
- Origins: Sacrum, ilium, and spines of lumbar and 11th-12th thoracic vertebrae
|
||||
- Insertions: Ribs and vertebrae with additional muscle slips joining columns at successively higher levels
|
||||
- Action: Extends vertebral column
|
||||
|
||||
# ANATOMY IMAGING ISSUES
|
||||
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- Higher frequency (5-18 MHz) linear transducer for anterior abdominal wall and paraspinal muscles
|
||||
- 3-5 MHz for posterior abdominal wall muscles
|
||||
- Supine position for examination of anterior and lateral abdominal wall
|
||||
- Image during Valsalva maneuver and in standing position to increase abdominal pressure and elicit hernias
|
||||
- Prone position for ultrasound of paraspinal muscles
|
||||
- Compare with contralateral side to check for symmetry
|
||||
|
||||
46575243-9eec-43e0-9955-dd51cd5f49b4
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Anterior Abdominal Wall
|
||||
|
||||
|
||||
*Graphic shows the aponeuroses of the internal and external oblique and transverse abdominal muscles are 2 layered and interweave with each other, covering the rectus muscle and constituting the rectus sheath and linea alba. About midway between the umbilicus and symphysis, at the arcuate line, the posterior rectus sheath ends (arcuate line), and the transversalis fascia is the only structure between the rectus muscle and parietal peritoneum.*
|
||||
|
||||
|
||||
*Graphic shows the aponeuroses of the internal and external oblique and transverse abdominal muscles are 2 layered and interweave with each other, covering the rectus muscle and constituting the rectus sheath and linea alba. About midway between the umbilicus and symphysis, at the arcuate line, the posterior rectus sheath ends (arcuate line), and the transversalis fascia is the only structure between the rectus muscle and parietal peritoneum.*
|
||||
|
||||
|
||||
*Graphic shows the lumbar vertebrae are covered and attached by the anterior longitudinal ligament, and the diaphragmatic crura are closely attached to it, as are the origins of the psoas muscles, which also arise from the transverse processes. The iliacus muscle arises from the iliac fossa of the pelvis and inserts into the tendon of the psoas major, constituting the iliopsoas muscle, which inserts onto the lesser trochanter. Quadratus lumborum arises from the iliac crest and inserts onto the 12th rib and transverse processes of the lumbar vertebrae. Diaphragmatic and transversus abdominis fibers interlace. Psoas and quadratus lumborum pass behind the diaphragm under medial and lateral arcuate ligaments.*
|
||||
|
||||
|
||||
*Transverse grayscale ultrasound of the abdominal wall at the midline shows the bilateral rectus abdominis muscles approximated by the linea alba. A portion of the left lobe of the liver and bowel is seen within the peritoneum.*
|
||||
|
||||
|
||||
*Also in the transverse plane, color Doppler is applied to show the right inferior epigastric artery and vein deep to the rectus abdominis muscle. These are important to identify in order to avoid when performing procedures and are landmarks that are used to determine hernia type when present.*
|
||||
|
||||
|
||||
*Longitudinal image with color Doppler flow in the same location shows the right inferior epigastric artery and its perforating branches into the rectus abdominis muscle. These are of relevance when this muscle is harvested for a possible flap used for reconstruction.*
|
||||
|
||||
|
||||
### Anterolateral Abdominal Wall
|
||||
|
||||
|
||||
*Longitudinal extended FOV grayscale image shows the relationship between the rectus abdominis and the oblique muscles.*
|
||||
|
||||
|
||||
*High-resolution transverse grayscale ultrasound at the right anterolateral abdominal wall shows the relationship of the lateral abdominal wall muscles in better detail. Note the oblique and transversus abdominis muscles taper medially as they become aponeuroses.*
|
||||
|
||||
|
||||
*Correlative, axial CECT illustrates the muscles of the abdominal wall. The rectus abdominis muscle in the anterior abdominal wall, and the oblique and transversus abdominis muscles in the anterolateral abdominal wall and their aponeuroses are shown.*
|
||||
|
||||
|
||||
### Posterior Abdominal Wall
|
||||
|
||||
|
||||
*Longitudinal grayscale ultrasound at the level of the lower pole of the right kidney shows the psoas and oblique muscles.*
|
||||
|
||||
|
||||
*Transverse grayscale ultrasound of right midabdomen using the kidney as an acoustic window is shown. The kidney is anterior and lateral to the psoas and anterior to the quadratus lumborum. The psoas runs along the paravertebral region in its entire abdominal course. The quadratus lumborum originates from the iliolumbar ligament and iliac crest to insert into the last rib and lumbar transverse processes. It is easily identified as the muscle on which the kidney rests.*
|
||||
|
||||
|
||||
*Transverse grayscale ultrasound of the right upper abdomen more inferiorly shows the relationship of the posterior abdominal wall muscles are maintained.*
|
||||
|
||||
|
||||
*Axial correlative CECT below the kidneys shows the quadratus lumborum muscle is more laterally located, and the psoas muscle is directly anterior to the erector spinae muscle.*
|
||||
|
||||
|
||||
*Axial correlative CECT shows the psoas muscle has begun its dorsolateral course and is now anterior to the iliacus muscle. The iliacus muscle is easily identified as a flat muscle filling the iliac fossa, arising from the upper 2/3 of the iliac fossa, inner lip of the iliac crest, anterior sacroiliac and the iliolumbar ligaments, and base of the sacrum.*
|
||||
|
||||
|
||||
*Axial correlative CECT shows the psoas and iliacus muscles have converged and are now indistinguishable from one another. The resultant iliopsoas muscle passes beneath the inguinal ligament and becomes tendinous as it inserts into the lesser trochanter of the femur.*
|
||||
|
||||
|
||||
### Muscles of Back In Situ
|
||||
|
||||
|
||||
*Transverse extended FOV grayscale ultrasound of the back (with patient prone) shows the erector spinae muscles flanking the spinous process. They are invested by lumbodorsal fascia, which also invests the anteriorly located quadratus lumborum muscle. The kidneys are partially demonstrated.*
|
||||
|
||||
|
||||
*Transverse oblique grayscale ultrasound of the left erector spinae muscle (with patient prone) is shown. The 3 columns (iliocostalis, longissimus, and spinalis muscles, from lateral to medial) comprising the erector spinae are not clearly separated from one another on ultrasound. They are identified collectively as a thick, fleshy muscle lateral to the spinous process.*
|
||||
|
||||
|
||||
*Axial correlative CECT of the paraspinal muscles at the level of the kidneys shows that the erector spinae muscles originate from a broad and thick tendon, which originates from the sacrum and iliac crest, lumbar, and 11th and 12th thoracic spinous processes.*
|
||||
|
||||
|
||||
### Posterior Abdominal Wall, CT Correlation
|
||||
|
||||
|
||||
*Coronal correlative CECT shows the paralumbar location of the psoas muscles and their medial location relative to the kidneys. The psoas muscles originate from the lumbar and 12th thoracic vertebral bodies and their transverse processes and run past the pelvic brim, where they course inferolaterally to be joined by the iliacus muscle.*
|
||||
|
||||
|
||||
*Axial correlative CECT better illustrates the anatomic relationships of the kidney with the posterior abdominal wall muscles. The kidney is lateral to the psoas muscle and rests upon the quadratus lumborum muscle. The erector spinae muscles are immediately posterior to the quadratus lumborum, and the 2 muscles are invested by the lumbodorsal fascia.*
|
||||
|
||||
|
||||
*Axial correlative CECT at the level of the inferior pole of the right kidney is shown. The psoas muscle and quadratus lumborum muscles, seen in their midsections, are now thicker.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Longitudinal color Doppler ultrasound shows a perforating branch <img src='/img/arrows/BS.png'/> of the deep inferior epigastric artery <img src='/img/arrows/WS.png'/> extending into the rectus muscle <img src='/img/arrows/WC.png'/>. These perforators are important for breast reconstruction with abdominal wall flaps.*
|
||||
|
||||
|
||||
*Graphic shows the paraspinal muscles and muscles of the back. The latissimus dorsi muscles are not included. The erector spinae have thick tendinous origins from the sacral and iliac crests and the lumbar and 11th-12th thoracic spinous processes. Superiorly, the muscle becomes fleshy, and in the upper lumbar region subdivides to become the iliocostalis, longissimus, and spinalis muscles (from lateral to medial), tapering as they insert into the vertebrae and ribs. The erector muscles flank the spinous processes and span the length of the posterior thorax and abdomen. They are responsible for extension of the vertebral column.*
|
||||
|
||||
|
||||
*Transverse grayscale ultrasound in the lower abdominal region shows the right psoas muscle, composed of the psoas minor which rests upon the psoas major. The 2 muscles cannot be separated clearly on ultrasound. Because of their depth, the paraspinal muscles cannot be demonstrated in detail.*
|
||||
|
||||
|
||||
*Transverse grayscale ultrasound of the right lower abdomen in the same case shows that the distal psoas muscle has diminished in size. It rests on the medial portion of the iliacus muscle; the latter is a flat muscle that fills the iliac fossa. Both continue inferiorly together.*
|
||||
|
||||
|
||||
*Distally, the fibers from the iliacus muscle converge and insert into the lateral side of the psoas muscle to form the iliopsoas muscle. Common iliac vessels can be seen medially.*
|
||||
|
||||
|
||||
*Axial T2 HASTE MR in a younger male patient shows more bulky abdominal wall musculature with little intermuscular fat.*
|
||||
|
||||
|
||||
*Axial T2 HASTE MR in an older patient with muscle atrophy shows fat in between the individual muscles of the anterior and posterior abdominal wall.*
|
||||
|
||||
|
||||
*Axial T1 MR at a lower level shows the iliopsoas as 1 muscle bundle.*
|
||||
|
||||
@@ -0,0 +1,499 @@
|
||||
---
|
||||
title: "ADEM"
|
||||
docid: "a3fafeb7-5861-4364-beb8-c0e30220564e"
|
||||
authors:
|
||||
- key: "99e1aff7-f42c-43a0-95ae-d89c8551aa01"
|
||||
value: "Kevin R. Moore, MD"
|
||||
- key: "a25c450b-3d34-4f64-bba3-cc0834813df6"
|
||||
value: "Miral D. Jhaveri, MD, MBA"
|
||||
- key: "b2e6dabb-ee1c-42a4-a332-9f0814c1c607"
|
||||
value: "Surjith Vattoth, MD, FRCR"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Brain"
|
||||
slug: "brain"
|
||||
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
||||
-
|
||||
name: "Diagnosis"
|
||||
slug: "diagnosis"
|
||||
treeNodeId: "51c00394-446e-4a38-94af-d3b1d14d34e8"
|
||||
-
|
||||
name: "Pathology-Based Diagnoses"
|
||||
slug: "pathology-based-diagnoses"
|
||||
treeNodeId: "d9d3a8ed-f21b-4831-8c77-591a3500ef77"
|
||||
-
|
||||
name: "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
slug: "infectious-inflammatory-and-demyel-"
|
||||
treeNodeId: "7210f860-fe5f-4a2d-81cc-4fe06c769607"
|
||||
-
|
||||
name: "Inflammatory and Demyelinating Disease"
|
||||
slug: "inflammatory-and-demyelinating-dis-"
|
||||
treeNodeId: "62ab4dc3-dbf6-45a9-8532-f0e962aa62dc"
|
||||
-
|
||||
name: "ADEM"
|
||||
slug: "adem"
|
||||
treeNodeId: null
|
||||
category: "Brain"
|
||||
documentVersionId: "c2a39730-fd89-4f20-9447-d7fb297710c6"
|
||||
imageCount: 22
|
||||
isBookmarked: false
|
||||
isComparable: true
|
||||
isInCompareCart: false
|
||||
lastUpdated: "08/07/20"
|
||||
pageDescription: "ADEM"
|
||||
pageKeywords: "Brain, Diagnosis, Pathology-Based Diagnoses, Infectious, Inflammatory, and Demyelinating Disease, Inflammatory and Demyelinating Disease, ADEM"
|
||||
pageTitle: "ADEM | STATdx"
|
||||
enhancedTitle: "ADEM"
|
||||
type: "DX"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
- "Inflammatory and Demyelinating Disease"
|
||||
- "ADEM"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Autoimmune-mediated white matter (WM) demyelination of brain &/or spinal cord, usually with remyelination
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Best diagnostic clue: Multifocal WM and deep gray lesions days to weeks following infection/vaccination
|
||||
- May involve both brain and spinal cord; WM > gray matter, but usually both affected
|
||||
- Both supratentorial and infratentorial lesions
|
||||
- Multifocal punctate to large flocculent FLAIR hyperintensities
|
||||
- Deep/juxtacortical WM > periventricular WM
|
||||
- Do not usually involve callososeptal interface
|
||||
- Most lesions show increased signal on DWI (T2 shine-through)
|
||||
- Punctate, ring, incomplete ring, peripheral enhancement
|
||||
- Absence of enhancement does not exclude diagnosis
|
||||
- MRS: ↓ NAA within lesions; may see ↑ Cho, ↑ lactate
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Multiple sclerosis
|
||||
- Autoimmune-mediated vasculitis
|
||||
- Acute hypertensive encephalopathy, PRES
|
||||
- Fabry disease
|
||||
- Behçet disease
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- > 30 different infectious agents and immunizations reported
|
||||
- Anti-MOG (myelin oligodendrocyte glycoprotein) IgG antibodies found more commonly in younger patients
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Mean age 5-8 years, but can occur at any age
|
||||
- Male predominance (M:F = 1:0.6-0.8), unlike MS
|
||||
- Usually monophasic, self-limited
|
||||
- Complete recovery within 1 month: 50-60%
|
||||
- Mortality: 10-30%
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- Imaging findings often lag behind symptom onset, resolution
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Acute disseminated encephalomyelitis (ADEM)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Autoimmune-mediated white matter (WM) demyelination of brain &/or spinal cord, usually with remyelination
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Multifocal WM/basal ganglia lesions days to weeks following infection/vaccination
|
||||
- 93% within 3 weeks of infection, 5% within 1 month of vaccination
|
||||
- ### Location
|
||||
|
||||
|
||||
- May involve both brain and spinal cord; WM > gray matter, but usually both affected
|
||||
- Deep/juxtacortical WM > periventricular WM
|
||||
- Both supratentorial and infratentorial lesions
|
||||
- ### Size
|
||||
|
||||
|
||||
- Tumefactive lesions may be large, but with less mass effect than expected from tumor size
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Punctate to flocculent
|
||||
- Tumefactive, mass-like lesions possible
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Initial CT normal in 40%
|
||||
- ### CECT
|
||||
|
||||
|
||||
- Multifocal punctate or ring-enhancing lesions
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Hyperintensities may be better visualized in brainstem and posterior fossa on T2
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- Multifocal punctate to large, flocculent FLAIR hyperintensities
|
||||
- Bilateral but asymmetric
|
||||
- Involve peripheral WM-gray matter junction subcortical WM
|
||||
- Thalami and basal ganglia frequently involved, typically symmetric
|
||||
- Can involve brainstem and posterior fossa
|
||||
- Do not usually involve callososeptal interface
|
||||
- ### DWI
|
||||
|
||||
|
||||
- Variably hyperintense lesions on DWI (trace) images
|
||||
- Apparent diffusion coefficient (ADC) may be increased or decreased
|
||||
- Most lesions show increased signal (T2 shine-through)
|
||||
- Diffusion restriction uncommon, suggests worse prognosis
|
||||
- Diffusivity normal within normal-appearing WM (NAWM), unlike MS
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- Punctate, ring, incomplete ring, peripheral enhancement
|
||||
- Cranial nerve(s) may enhance
|
||||
- Absence does not exclude diagnosis
|
||||
- ### MRS
|
||||
|
||||
|
||||
- NAA low within lesions; lactate may be elevated
|
||||
- Choline often elevated in acute lesions
|
||||
- NAA normalizes with resolution of symptoms/MR abnormalities
|
||||
- Magnetization transfer ratio (MTR)
|
||||
- ADEM MTR normal within NAWM, unlike MS
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- Contrast-enhanced MR
|
||||
- Initial imaging often normal but more sensitive than CT
|
||||
- May appear identical to MS; repeat MR necessary to distinguish with certainty
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- Limited rapid interval follow-up may be provided by FLAIR alone
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- Tc-99m-HMPAO SPECT shows more extensive hypoperfusion than T2 lesions
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Multiple Sclerosis](/document/pediatric-multiple-sclerosis-brain/f2592b04-f800-4235-9eea-a43f2bf4adfe)
|
||||
- Predilection for periventricular WM (callososeptal interface), involves subcortical U fibers, commonly in posterior fossa
|
||||
- Lesions often more symmetric than ADEM
|
||||
- Relapsing-remitting course common
|
||||
- [Autoimmune-Mediated Vasculitis](/document/miscellaneous-vasculitis/5a4d4cbd-67e3-4722-8a44-8d411cbb98f0)
|
||||
- Multifocal gray matter-WM lesions
|
||||
- Bilateral, usually cortical/subcortical, basal ganglia/thalami
|
||||
- Ring-enhancing lesions may mimic infection
|
||||
- [Acute Hypertensive Encephalopathy, PRES](/document/acute-hypertensive-encephalopathy--/efc6f9c2-dad9-4eb8-bad2-421bfaf1ec57)
|
||||
- Typically posterior circulation in cortex/subcortical WM
|
||||
- May affect deep gray nuclei
|
||||
- [Aging Brain With Hyperintense WM Lesions](/document/normal-aging-brain/2a315550-b2ea-4afe-a2ef-f93a2209f276)
|
||||
- Atherosclerotic brain changes in 50% patients > 50 years old
|
||||
- Found in normotensive patients; more common in hypertensives patients
|
||||
- Present in 10-30% of cognitively normal elderly patients
|
||||
- MR: Scattered, asymmetric WM lesions, without enhancement
|
||||
- Often periatrial; posterior fossa uncommon
|
||||
- Spares callososeptal interface, subcortical U fibers
|
||||
- [Fabry Disease](/document/fabry-disease/83fd222a-9b37-4087-afab-34ba74525887)
|
||||
- Synonym: Angiokeratoma corporis diffusum universalis
|
||||
- X-linked recessive; incidence 1/40,000
|
||||
- Deficiency α-galactosidase A; overaccumulation of glycosphingolipids within lysosomes
|
||||
- MR: Scattered, asymmetric WM lesions without enhancement
|
||||
- May involve brainstem and posterior fossa
|
||||
- Spares callososeptal interface and subcortical U fibers
|
||||
- Cranial MR sensitive to identify neurologic involvement in asymptomatic patients
|
||||
- Present with renal failure/heart disease
|
||||
- [Behçet Disease](/document/behet-disease/4e447bb6-0f14-40e1-929a-4c1465feec0a)
|
||||
- MR: Scattered, asymmetric, subcortical WM lesions without cortical involvement
|
||||
- Nodular enhancement in acute phase
|
||||
- Predilection for midbrain
|
||||
- ADC ↑, similar to ADEM
|
||||
- Classic triad: Oral and genital ulcerations with uveitis
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Autoimmune-mediated severe acute demyelination
|
||||
- Following nonspecific upper respiratory tract infection, often viral
|
||||
- > 30 different infectious agents and immunizations reported
|
||||
- After specific viral illness: Epstein-Barr, influenza A, mumps, coronavirus
|
||||
- Especially after exanthematous diseases of childhood (chickenpox, measles)
|
||||
- After vaccination: Diphtheria, influenza, rabies, smallpox, tetanus, typhoid
|
||||
- Spontaneous (no known cause)
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- ADEM associated with DRB1*01 and DRB1*017(03) in Russian population
|
||||
- ### Associated abnormalities
|
||||
|
||||
|
||||
- Acute hemorrhagic leukoencephalopathy variant associated with ulcerative colitis and asthma
|
||||
- Anti-MOG (myelin oligodendrocyte glycoprotein) IgG antibodies found more commonly in younger patients
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- None, unless hemorrhage (rare) or tumefactive edema
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Acute myelin breakdown
|
||||
- Perivenous inflammation; lymphocytic infiltrates
|
||||
- Relative axonal preservation; atypical astrogliosis
|
||||
- Virus generally not found, unlike viral encephalitides
|
||||
- Similar to experimental allergic encephalomyelitis, supporting autoimmune-related etiology
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Usually preceded by prodromal phase: Fever, malaise, myalgia
|
||||
- Multifocal neurologic symptoms, 2 days to 4 weeks after viral illness/immunization
|
||||
- Initial symptoms: Headache, fever, drowsiness
|
||||
- Cranial nerve palsies, seizures, hemiparesis
|
||||
- Decreased consciousness (from lethargy to coma)
|
||||
- Behavioral changes
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- Seizures in 10-35%
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- Cerebrospinal fluid (CSF) normal in 60%
|
||||
- If abnormal (lymphocyte pleocytosis, elevated protein)
|
||||
- Usually lacks CSF oligoclonal bands
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Children > adults
|
||||
- Mean age 5-8 years, but can occur at any age
|
||||
- ### Sex
|
||||
|
||||
|
||||
- Male predominance (M:F = 1.0:0.6-0.8), unlike MS
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- Rare, yet most common para-/postinfectious disorder
|
||||
- Most common in winter and spring
|
||||
- Exact epidemiology unknown, but increasingly reported
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Usually monophasic, self-limited
|
||||
- Variable prognosis
|
||||
- Complete recovery within 1 month (50-60%)
|
||||
- Neurologic sequelae (most commonly seizures) (20-30%)
|
||||
- Mortality (10-30%)
|
||||
- Relapses are rare
|
||||
- "Relapsing disseminated encephalomyelitis"
|
||||
- May not be separate entity from relapsing-remitting MS
|
||||
- Typically delay between symptom onset and imaging findings
|
||||
- Varicella and rubella ADEM have preferential patterns
|
||||
- Varicella ADEM characterized by cerebellar ataxia and mild pyramidal dysfunction
|
||||
- Rubella ADEM characterized by acute explosive onset, seizures, coma, and moderate pyramidal signs
|
||||
- Rare manifestations of ADEM
|
||||
- Acute hemorrhagic leukoencephalopathy (2%)
|
||||
- Young patients with abrupt symptom onset
|
||||
- Fulminant, often ending in death
|
||||
- Bilateral striatal necrosis (usually in infants, may be reversible)
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Immunosuppressive/immunomodulatory therapy
|
||||
- MR may show prompt improvement after therapy
|
||||
- Plasma exchange therapy
|
||||
- 40% of patients failing steroid treatment may show marked improvement
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Imaging findings often lag behind symptom onset, resolution
|
||||
|
||||
3aec74c8-de53-4430-a00a-d8165ad210c7
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
*Axial FLAIR MR shows peripheral, confluent areas of hyperintensity predominantly involving the subcortical white matter (WM) in this child with ADEM. The bilateral but asymmetric pattern is typical of ADEM.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows peripheral, confluent areas of hyperintensity predominantly involving the subcortical white matter (WM) in this child with ADEM. The bilateral but asymmetric pattern is typical of ADEM.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows peripheral, confluent areas of hyperintensity predominantly involving the subcortical white matter (WM) in this child with ADEM. The bilateral but asymmetric pattern is typical of ADEM.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR in the same patient shows marked, irregular enhancement of nearly all lesions. As ADEM is a monophasic illness, enhancement of the majority of lesions is typical; all lesions have a similar time course. Enhancement of multiple sclerosis (MS) lesions is more variable.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR in the same patient shows marked, irregular enhancement of nearly all lesions. As ADEM is a monophasic illness, enhancement of the majority of lesions is typical; all lesions have a similar time course. Enhancement of multiple sclerosis (MS) lesions is more variable.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR shows an incomplete ring of peripheral enhancement, typical of a demyelinating process. Other contrast enhancement patterns include ovoid or punctate homogeneous enhancement.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR shows an incomplete ring of peripheral enhancement, typical of a demyelinating process. Other contrast enhancement patterns include ovoid or punctate homogeneous enhancement.*
|
||||
|
||||
|
||||
*Axial DWI MR shows increased signal in areas of FLAIR hyperintensity. The foci were hypointense on ADC images, indicating diffusion restriction. Both WM and gray matter involvement is present. Diffusion restriction is an uncommon imaging finding and is associated with a worse prognosis.*
|
||||
|
||||
|
||||
*Axial DWI MR shows increased signal in areas of FLAIR hyperintensity. The foci were hypointense on ADC images, indicating diffusion restriction. Both WM and gray matter involvement is present. Diffusion restriction is an uncommon imaging finding and is associated with a worse prognosis.*
|
||||
|
||||
|
||||
*Axial T2 MR shows hyperintense lesions in the brachium pontis bilaterally, typical for demyelination. The right-sided lesion shows a targetoid <img src='/img/arrows/WS.png'/> appearance. Enhancement of several lesions was present on postcontrast T1 images (not shown).*
|
||||
|
||||
|
||||
*Axial T2 MR shows hyperintense lesions in the brachium pontis bilaterally, typical for demyelination. The right-sided lesion shows a targetoid <img src='/img/arrows/WS.png'/> appearance. Enhancement of several lesions was present on postcontrast T1 images (not shown).*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows large, confluent regions of hyperintense signal <img src='/img/arrows/CC.png'/> in the periventricular and subcortical WM in a 14 year old who presented with neck stiffness, fatigue, and seizures.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows large, confluent regions of hyperintense signal <img src='/img/arrows/CC.png'/> in the periventricular and subcortical WM in a 14 year old who presented with neck stiffness, fatigue, and seizures.*
|
||||
|
||||
|
||||
*Axial SWI MR in the same patient shows petechial hemorrhages <img src='/img/arrows/CS.png'/> in regions of FLAIR signal abnormality.*
|
||||
|
||||
|
||||
*Axial SWI MR in the same patient shows petechial hemorrhages <img src='/img/arrows/CS.png'/> in regions of FLAIR signal abnormality.*
|
||||
|
||||
|
||||
*Sagittal T1 C+ MR in the same patient shows extensive irregular ring enhancement <img src='/img/arrows/CC.png'/> in multiple subcortical WM lesions. Acute hemorrhagic leukoencephalopathy (AHL) is a rare manifestation of ADEM occurring in 2% of cases. AHL is associated with a very poor prognosis. Aggressive therapeutic management is a prerequisite to avoid usual disease course with fatal outcome.*
|
||||
|
||||
|
||||
*Sagittal T1 C+ MR in the same patient shows extensive irregular ring enhancement <img src='/img/arrows/CC.png'/> in multiple subcortical WM lesions. Acute hemorrhagic leukoencephalopathy (AHL) is a rare manifestation of ADEM occurring in 2% of cases. AHL is associated with a very poor prognosis. Aggressive therapeutic management is a prerequisite to avoid usual disease course with fatal outcome.*
|
||||
|
||||
|
||||
*Coronal T2 MR shows large, confluent regions of hyperintense signal in the WM <img src='/img/arrows/WO.png'/> and deep gray nuclei <img src='/img/arrows/WS.png'/> of a child with ADEM. Although ADEM predominantly involves WM, gray matter is often affected.*
|
||||
|
||||
|
||||
*Coronal T2 MR shows large, confluent regions of hyperintense signal in the WM <img src='/img/arrows/WO.png'/> and deep gray nuclei <img src='/img/arrows/WS.png'/> of a child with ADEM. Although ADEM predominantly involves WM, gray matter is often affected.*
|
||||
|
||||
|
||||
*MRS at long TE in a patient with acute lesions in ADEM demonstrates ↑ choline <img src='/img/arrows/CC.png'/>, ↓ NAA <img src='/img/arrows/CS.png'/>, and the presence of a lactate doublet <img src='/img/arrows/WS.png'/>. Increase in choline with corresponding reductions in NAA normalize as the clinical and conventional neuroimaging abnormalities resolve.*
|
||||
|
||||
|
||||
*MRS at long TE in a patient with acute lesions in ADEM demonstrates ↑ choline <img src='/img/arrows/CC.png'/>, ↓ NAA <img src='/img/arrows/CS.png'/>, and the presence of a lactate doublet <img src='/img/arrows/WS.png'/>. Increase in choline with corresponding reductions in NAA normalize as the clinical and conventional neuroimaging abnormalities resolve.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Axial FLAIR MR shows multiple bilateral, asymmetric, flocculent, hyperintense lesions of acute disseminated encephalomyelitis.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows multiple bilateral, asymmetric, flocculent, hyperintense lesions of acute disseminated encephalomyelitis.*
|
||||
|
||||
|
||||
*Coronal T1 C+ MR demonstrates partial peripheral enhancement around multiple asymmetric, flocculent lesions of acute disseminated encephalomyelitis. Note the supra- and infratentorial lesions.*
|
||||
|
||||
|
||||
*Coronal T1 C+ MR demonstrates partial peripheral enhancement around multiple asymmetric, flocculent lesions of acute disseminated encephalomyelitis. Note the supra- and infratentorial lesions.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows asymmetric, flocculent, nearly confluent, hyperintense lesions of acute disseminated encephalomyelitis within posterior fossa structures.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows asymmetric, flocculent, nearly confluent, hyperintense lesions of acute disseminated encephalomyelitis within posterior fossa structures.*
|
||||
|
||||
|
||||
*Axial FLAIR MR reveals multiple asymmetric, primarily punctate, hyperintense lesions of acute disseminated encephalomyelitis.*
|
||||
|
||||
|
||||
*Axial FLAIR MR reveals multiple asymmetric, primarily punctate, hyperintense lesions of acute disseminated encephalomyelitis.*
|
||||
|
||||
|
||||
*Axial FLAIR MR demonstrates a large, tumefactive, hyperintense lesion. Less mass effect is present than expected for lesion size. Smaller lesions were also present at other locations.*
|
||||
|
||||
|
||||
*Axial FLAIR MR demonstrates a large, tumefactive, hyperintense lesion. Less mass effect is present than expected for lesion size. Smaller lesions were also present at other locations.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR demonstrates a large, tumefactive, hypointense lesion with minimal partial peripheral enhancement. Less mass effect is present than expected for lesion size. More lesions were seen elsewhere.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR demonstrates a large, tumefactive, hypointense lesion with minimal partial peripheral enhancement. Less mass effect is present than expected for lesion size. More lesions were seen elsewhere.*
|
||||
|
||||
|
||||
*Axial FLAIR MR demonstrates a rare manifestation of ADEM: Bilateral striatal necrosis, evidenced by asymmetric confluent hyperintensity involving the gray and white matter of bilateral corpus striatum.*
|
||||
|
||||
|
||||
*Axial FLAIR MR demonstrates a rare manifestation of ADEM: Bilateral striatal necrosis, evidenced by asymmetric confluent hyperintensity involving the gray and white matter of bilateral corpus striatum.*
|
||||
|
||||
|
||||
*Axial DWI MR confirms the rare manifestation of ADEM, displaying bilateral striatal necrosis, as evidenced by asymmetric confluent restricted diffusion involving gray and white matter of bilateral corpus striatum.*
|
||||
|
||||
|
||||
*Axial DWI MR confirms the rare manifestation of ADEM, displaying bilateral striatal necrosis, as evidenced by asymmetric confluent restricted diffusion involving gray and white matter of bilateral corpus striatum.*
|
||||
|
||||
|
||||
*Axial T2 MR shows multiple bilateral, but asymmetric, T2-hyperintense foci <img src='/img/arrows/WS.png'/>. None of the lesions demonstrate significant mass effect in this adult patient with ADEM. Imaging mimics multiple sclerosis, vasculitis, and microvascular ischemia.*
|
||||
|
||||
|
||||
*Axial T2 MR shows multiple bilateral, but asymmetric, T2-hyperintense foci <img src='/img/arrows/WS.png'/>. None of the lesions demonstrate significant mass effect in this adult patient with ADEM. Imaging mimics multiple sclerosis, vasculitis, and microvascular ischemia.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows a large, tumefactive, hyperintense ADEM lesion <img src='/img/arrows/WS.png'/> with mass effect less than expected for the size of the lesion. Another clue to its nonneoplastic nature is the right-sided lesion <img src='/img/arrows/WC.png'/>.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows a large, tumefactive, hyperintense ADEM lesion <img src='/img/arrows/WS.png'/> with mass effect less than expected for the size of the lesion. Another clue to its nonneoplastic nature is the right-sided lesion <img src='/img/arrows/WC.png'/>.*
|
||||
|
||||
|
||||
*MRS at a long TE in the same patient shows the tumefactive lesion has a depressed choline <img src='/img/arrows/WC.png'/> and NAA <img src='/img/arrows/WO.png'/> metabolites in the presence of a large lactate doublet <img src='/img/arrows/WS.png'/>. This MRS helps distinguish this lesion from a neoplasm. MRS of ADEM may show elevated choline acutely.*
|
||||
|
||||
|
||||
*MRS at a long TE in the same patient shows the tumefactive lesion has a depressed choline <img src='/img/arrows/WC.png'/> and NAA <img src='/img/arrows/WO.png'/> metabolites in the presence of a large lactate doublet <img src='/img/arrows/WS.png'/>. This MRS helps distinguish this lesion from a neoplasm. MRS of ADEM may show elevated choline acutely.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows typical findings of ADEM with peripheral, subcortical hyperintense foci <img src='/img/arrows/WC.png'/>. Bilateral insular involvement is seen <img src='/img/arrows/WS.png'/>. Periventricular and callososeptal lesions, which are typical of multiple sclerosis, are not commonly seen in ADEM.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows typical findings of ADEM with peripheral, subcortical hyperintense foci <img src='/img/arrows/WC.png'/>. Bilateral insular involvement is seen <img src='/img/arrows/WS.png'/>. Periventricular and callososeptal lesions, which are typical of multiple sclerosis, are not commonly seen in ADEM.*
|
||||
|
||||
@@ -1,334 +0,0 @@
|
||||
---
|
||||
title: "Adrenal Adenoma"
|
||||
docid: "e2916d86-5f9f-4dd3-9576-1a7b89d8dda0"
|
||||
breadcrumbs:
|
||||
- "Genitourinary"
|
||||
- "Diagnosis"
|
||||
- "Adrenal"
|
||||
- "Benign Neoplasms"
|
||||
- "Adrenal Adenoma"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Well-circumscribed, uniform, low-attenuation, small adrenal mass
|
||||
- Low attenuation due to abundant intracytoplasmic lipid
|
||||
- Imaging features of typical lipid-rich adenomas
|
||||
- NECT: < 10 HU (71% sensitivity, 98% specificity)
|
||||
- MR: Significant decrease in signal on out-of-phase T1WI due to intravoxel lipid and water
|
||||
- May show focal areas of heterogeneous attenuation or absence of signal loss due to degeneration, hemorrhage, and fibrin deposition
|
||||
- Clinical context key to differentiate from collision tumor: Unlikely in absence of extraadrenal malignancy
|
||||
- Lipid-poor adenomas (10-40% cases): Utilize relative or absolute CT contrast washout kinetics for diagnosis
|
||||
- Accounts for vast majority of adrenal "incidentalomas"
|
||||
- Imaging intensive algorithm suggested for incidental adrenal lesions, though overwhelming majority are benign and hormonally inactive
|
||||
- Primary hyperaldosteronism (Conn syndrome): 80% due to unilateral, typically small (< 2 cm) adenoma
|
||||
- Cushing syndrome: 80-85% due to adrenal hyperplasia
|
||||
- Typically shows FDG uptake < that of liver on PET/CT
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Adrenal metastases and lymphoma
|
||||
- Adrenal (macronodular) hyperplasia
|
||||
- Pheochromocytoma
|
||||
- Adrenal carcinoma
|
||||
- Adrenal myelolipoma
|
||||
- Gastric diverticulum
|
||||
- Adrenal cyst
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- Asymptomatic mass: Usually nonfunctioning adenoma, even in patients with known cancer
|
||||
- NECT and MR are equally accurate for diagnosis of lipid-rich adenoma
|
||||
- Utilize dedicated CECT adrenal protocol with 15-minute delayed imaging for diagnosis of potential lipid-poor adenomas
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Benign adrenal cortical tumor
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Imaging strategies target typical adenoma histology: Abundant intracytoplasmic lipid
|
||||
- Low attenuation (< 10 HU) on NECT
|
||||
- Significant loss of signal on out-of-phase T1WI MR (intravoxel fat and water)
|
||||
- ### Size
|
||||
|
||||
|
||||
- Cushing syndrome adenoma: 2-5 cm
|
||||
- Conn syndrome adenoma: Classically < 2 cm (20% < 1 cm)
|
||||
- Vast majority of incidental, hormonally inactive adrenal adenomas are small (< 2 cm)
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Usually round to oval suprarenal mass
|
||||
- Key concepts
|
||||
- Most common adrenal cortex tumor (10% bilateral)
|
||||
- Accounts for > 90% of all "incidentalomas"
|
||||
- May occur in up to 9% of general population, diagnosed on 5% of CT exams with various indications
|
||||
- Lipid-rich adrenal adenoma: 60-90% of adenomas
|
||||
- Lipid-poor adrenal adenoma: 10-40% of adenomas
|
||||
- Increased incidence in patients with diabetes and hypertension
|
||||
- NECT (or chemical shift MR): Study of choice to diagnose incidental adrenal masses
|
||||
- Classified into 2 types based on function
|
||||
- Nonhyperfunctioning: Normal hormone levels
|
||||
- Hyperfunctioning: Primary hyperaldosteronism, Cushing syndrome, hyperandrogenism
|
||||
- **Cushing syndrome**
|
||||
- 15-25% of cases are due to autonomous adrenal adenoma
|
||||
- 80-85% of cases are due to**adrenal hyperplasia**
|
||||
- Adenomas usually > 2 cm
|
||||
- **Primary hyperaldosteronism (Conn syndrome)**
|
||||
- 80% of cases are due to****adrenal adenoma
|
||||
- 20% of cases are due to adrenal hyperplasia
|
||||
- Adenomas are often small (< 2 cm)
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Smooth, well defined, round or oval in shape
|
||||
- Homogeneous soft tissue mass of 0-20 HU
|
||||
- **Lipid-rich adrenal adenoma** (60-90% of cases)
|
||||
- Uniform low attenuation
|
||||
- Metaanalysis of < 10 HU threshold: 71% sensitivity, 98% specificity
|
||||
- Sensitivity may increase to almost 90% with histogram analysis (identify negative pixels), though variable results and scanner dependent
|
||||
- **Lipid-poor adrenal adenoma** (10-40% of cases)
|
||||
- Attenuation varies from 10-30 HU
|
||||
- Difficult to differentiate from metastases on NECT
|
||||
- Cushing syndrome due to adrenal adenoma
|
||||
- Remainder of ipsilateral gland and contralateral adrenal gland may be atrophic due to ↓ ACTH levels
|
||||
- ↑ cortisol: Feedback inhibition on pituitary ACTH
|
||||
- ACTH-independent macronodular hyperplasia: Multiple, bilateral, functioning adrenal adenomas
|
||||
- Conn syndrome due to adrenal adenoma
|
||||
- Remainder of ipsilateral gland and contralateral adrenal gland appear normal
|
||||
- Large adenomas
|
||||
- More heterogeneous than small adenomas
|
||||
- ± hemorrhage, cystic degeneration, calcification
|
||||
- Growth should raise suspicion for malignancy
|
||||
- ### CECT
|
||||
|
||||
|
||||
- Enhancing adrenal mass that deenhances rapidly
|
||||
- Dedicated adrenal CT exam incorporates initial dynamic enhanced phase (~ 70-second delay) and 15-minute delay
|
||||
- Relative percentage washout = dynamic enhanced (HU) - delayed (HU) / dynamic enhanced HU
|
||||
- Relative percentage washout > 40%: 96% sensitivity, 100% specificity
|
||||
- Absolute percentage washout (if NECT available) = dynamic enhanced (HU) - delayed (HU) / dynamic enhanced (HU) - unenhanced (HU)
|
||||
- Absolute percentage washout > 60%: 86-88% sensitivity, 92-96% specificity
|
||||
- 10-minute delay utilized by some centers, but shorter delay may decrease sensitivity
|
||||
- Adrenal washout calculators readily available online
|
||||
- Utilize technique for indeterminate, potentially lipid-poor adenomas
|
||||
- Clinical context critical: Rapid washout can be seen with pheochromocytomas, renal cell, hepatocellular carcinoma, and hypervascular metastases
|
||||
- Dual-energy CT and iodine subtraction techniques can generate virtual noncontrast (VNC) images
|
||||
- May identify lipid-rich adenomas and obviate need for additional imaging
|
||||
- Iodine:VNC ratio ≥ 6.7 has sensitivity and specificity of 95% for adenoma (higher ratios in adenoma compared to metastasis)
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- T1WI and T2WI
|
||||
- Low to intermediate signal
|
||||
- Chemical shift (in- and out-of-phase) imaging
|
||||
- Mainstay of MR diagnosis
|
||||
- Sensitivity and specificity equivalent to NECT
|
||||
- Signal loss on out-of-phase T1WI due to intravoxel water and fat protons
|
||||
- Inverse relationship between percentage of lipid-rich cells and relative ↓ signal on out-of-phase imaging
|
||||
- May not identify lipid-poor adenomas
|
||||
- Visual inspection of signal in phase (SIP) and out of phase (SOP), though quantitative analysis may be helpful
|
||||
- Adrenal to spleen chemical shift imaging (CSI) ratio: Lesion:spleen SOP/adrenal/spleen SIP
|
||||
- < .71 = adenoma
|
||||
- Adrenal signal intensity index: 100 x (SIP - SOP) / SIP
|
||||
- > 16.5% = adenoma
|
||||
- Beware technical pitfalls
|
||||
- Sampling of 1st echo pair at 3T is challenging
|
||||
- India ink artifact mimics signal loss, particularly in small adrenal lesions
|
||||
- Other primary or secondary adrenal lesions may contain lipid
|
||||
- Adenomas and metastases may coexist in same gland (collision tumor)
|
||||
- T1 C+ MR
|
||||
- Rapid, uniform enhancement and deenhancement
|
||||
- Ancillary MR techniques
|
||||
- Diffusion MR: Not specific (ADC overlap between adenomas and metastases)
|
||||
- MR spectroscopy: Choline:creatinine and choline:lipid ratio discriminatory threshold ratios may aid in adrenal lesion characterization, though larger studies needed
|
||||
- ## Ultrasonographic Findings
|
||||
|
||||
|
||||
- ### Grayscale ultrasound
|
||||
|
||||
|
||||
- Nonspecific, solid suprarenal mass
|
||||
- Right suprarenal mass seen more clearly left due to acoustic window provided by liver
|
||||
- ## Angiographic Findings
|
||||
|
||||
|
||||
- Conventional
|
||||
- Adrenal arteriography
|
||||
- Catheterization of renal or inferior adrenal arteries shows vascular supply of adrenal tumors
|
||||
- Adenomas are usually hypo- to moderately vascular
|
||||
- No arterial encasement or venous laking or puddling, which are malignant vascular features
|
||||
- Adrenal venography
|
||||
- Most commonly to obtain adrenal vein samples
|
||||
- Advocated for patients with primary hyperaldosteronism triaged to adrenalectomy
|
||||
- Technically difficult study but may confirm laterality of small, aldosterone-secreting adenoma
|
||||
- Technical approach and criteria for positive study varies; ACTH stimulation may increase accuracy
|
||||
- Adrenal adenoma is seen as filling defect within adrenal gland displacing adjacent vessels
|
||||
- Circumferential vein frequently seen around adrenal adenoma
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- PET/CT
|
||||
- Utilized as part of malignancy staging
|
||||
- Markedly increased F-18 FDG uptake characteristic of metastases
|
||||
- Adenomas may also accumulate F-18 FDG, typically less intense than liver
|
||||
- Potential false-negatives: Metastases from primary carcinomas that are non-FDG avid (e.g., neuroendocrine tumors)
|
||||
- SUV thresholds published but adenomas typically less intense than liver
|
||||
- Adrenocortical scintigraphy by using NP-59
|
||||
- NP-59 is cholesterol analog that binds to low-density lipoprotein receptors of adrenal cortex
|
||||
- NP-59 used and dexamethasone: Accentuate uptake in non-ACTH-dependent adrenal tissues (adenoma)
|
||||
- Normal NP-59: When both adrenal glands are seen 5 days after injection or thereafter
|
||||
- Adrenal adenoma: Unilateral early adrenal visualization before day 5 after NP-59 injection
|
||||
- Adrenal hyperplasia: Bilateral early adrenal visualization before day 5 after NP-59 injection
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- NECT is initial study of choice to confirm diagnosis of lipid-rich adrenal adenoma
|
||||
- ROI should encompass lesion: Attenuation < 10 HU is diagnostic
|
||||
- In- and out-of-phase MR equivalent to NECT for lipid-rich lesions
|
||||
- Signal dropout on out-of-phase T1WI MR: Qualitative assessment typically suffices
|
||||
- CECT, including 15-minute delayed phase, used for potential lipid-poor adenomas: Calculate either relative or absolute washout
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Adrenal Metastases and Lymphoma](/document/adrenal-lymphoma/44639c90-bd04-4e2a-a470-2c28a0e2ff78)
|
||||
- Adrenal metastases
|
||||
- Unilateral or bilateral masses ± central necrosis, hemorrhage
|
||||
- Usually known to have malignancy elsewhere
|
||||
- NECT: Metastases mimic lipid-poor adenoma
|
||||
- CECT: Hypo- or hypervascular and prolonged washout pattern
|
||||
- Adrenal lymphoma
|
||||
- Usually spread to adrenal gland from retroperitoneal tumor
|
||||
- Unilateral or bilateral masses
|
||||
- Unilateral primary lymphoma (non-Hodgkin) can mimic adenoma
|
||||
- Hypovascular; moderate enhancement with contrast
|
||||
- [Adrenal Myelolipoma](/document/adrenal-myelolipoma/5813a554-06a4-4696-af71-7ce50693039d)
|
||||
- Small or large, asymptomatic adrenal mass
|
||||
- Intramural macroscopic fatty elements on imaging
|
||||
- [Adrenal Hyperplasia](/document/adrenal-hyperplasia/90d09395-41d4-49b4-bb1d-4cb00b8bc272)
|
||||
- Adrenal glands are often symmetrically enlarged
|
||||
- Width of adrenal gland limbs > 10 mm (diagnostic)
|
||||
- No discrete mass or nodule seen as rule
|
||||
- Dominant macronodule of macronodular hyperplasia mimics small adrenal adenomas
|
||||
- Cortisol-secreting adenoma: Remainder of ipsilateral and contralateral glands, atrophic (↓ ACTH)
|
||||
- Macronodular hyperplasia: Both glands are enlarged (due to elevated ACTH levels)
|
||||
- No obvious enhancement and washout pattern seen
|
||||
- [Pheochromocytoma](/document/pheochromocytoma/7d3c4062-643c-4030-8783-f85184ad8132)
|
||||
- Tumor > 3 cm in most cases; classically T2 hyperintense
|
||||
- Highly vascular tumor prone to hemorrhage, necrosis
|
||||
- Bilateral adrenal tumors in multiple endocrine neoplasia (MEN) syndromes
|
||||
- [Unilateral Adrenal Hemorrhage](/document/adrenal-hemorrhage/5812e5c4-ca8a-4af5-884b-f75795bcde0f)
|
||||
- Chronic hematoma: Well-defined, round, low-density, mass-like lesion simulating adenoma
|
||||
- [Adrenal Carcinoma](/document/adrenal-cortical-carcinoma/bdc7a08b-a64f-4bd2-9dfc-24331728e85e)
|
||||
- Rare, unilateral, invasive and enhancing mass
|
||||
- > 6 cm when initially diagnosed
|
||||
- [Gastric Diverticulum](/document/gastric-diverticulum/eeb101f0-8bdf-4771-b44a-fe6e73b3a463)
|
||||
- Abnormal, rounded soft tissue lesion in left suprarenal area; mimics adrenal mass
|
||||
- Diverticular contents do not enhance, whereas adenomas do
|
||||
- Distend stomach with gas and fluid; scan in prone position to distend diverticulum
|
||||
- [Ganglioneuroma](/document/pheochromocytoma/7d3c4062-643c-4030-8783-f85184ad8132)
|
||||
- Younger patients; mean age: 27 years
|
||||
- Larger mass; average tumor size: 8 cm
|
||||
- ## Adrenal Cyst
|
||||
|
||||
|
||||
- Attenuation similar to lipid-rich adenoma
|
||||
- Lack of enhancement, rim calcification may suggest diagnosis
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Unknown
|
||||
- ### Associated abnormalities
|
||||
|
||||
|
||||
- MEN syndromes
|
||||
- Most adrenals with adenoma have normal function
|
||||
- Occasionally adenoma causes adrenal hyperfunction
|
||||
- Normal adrenocortical secretory hormones
|
||||
- Cortisol, aldosterone, androgens
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Well-delineated, tan-yellow, ovoid mass
|
||||
- 3 microscopic patterns
|
||||
- Pure (fasciculata- or reticularis-type cells), mixed, or hybrid
|
||||
- May have focal areas of degeneration, hemorrhage, and fibrin deposition
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- 70% of adenomas: High % of intracytoplasmic lipid
|
||||
- 30% of adenomas: Low % of intracytoplasmic lipid
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Asymptomatic incidental CT finding
|
||||
- Conn syndrome: Hypertension and weakness
|
||||
- Cushing syndrome: Moon facies, truncal obesity, purple striae, and buffalo hump
|
||||
- Virilization in women
|
||||
- Lab data: ↑ aldosterone, cortisol, &/or androgens
|
||||
- Diagnosis: Clinical, biochemical, imaging, histology
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Prevalence of adenoma increases with age
|
||||
- Peak at 60-69 years, decreasing thereafter
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- Most common adrenal tumor of all incidentalomas
|
||||
- ↑ incidence in patients with diabetes or hypertension
|
||||
- Occurs in up to 9% of population (postmortem data)
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Prognosis: Excellent when incidental and nonhyperfunctioning
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- No treatment when asymptomatic incidental finding
|
||||
- Laparoscopic removal of gland if hyperfunctioning
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Asymptomatic mass: Usually nonhyperfunctioning adenoma, even in patient with known cancer
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Well-defined, low-density (< 10 HU) suprarenal mass
|
||||
- Enhances with washout pattern > 50% within 15 minutes
|
||||
- Out-of-phase T1WI MR: Signal dropout, lipid-rich mass
|
||||
|
||||
adc00b93-b4c7-4e75-91bd-72023f4cd548
|
||||
@@ -1,256 +0,0 @@
|
||||
---
|
||||
title: "Adrenal Cyst"
|
||||
docid: "c5d717a3-3d6e-4e86-9efe-1ad0ec14740f"
|
||||
breadcrumbs:
|
||||
- "Genitourinary"
|
||||
- "Diagnosis"
|
||||
- "Adrenal"
|
||||
- "Benign Neoplasms"
|
||||
- "Adrenal Cyst"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- "Adrenal cyst" is descriptive term, not pathological diagnosis
|
||||
- True adrenal cysts
|
||||
- Majority are endothelial cysts (lymphangiomas)
|
||||
- Epithelial cysts exceedingly rare
|
||||
- Simple, or minimally complex, adrenal cyst, thin rim calcification, no enhancement
|
||||
- Pseudocysts
|
||||
- Prior hemorrhage inferred
|
||||
- Nonenhancing but complex contents and wall calcification
|
||||
- Relevant history (extraadrenal malignancy, rapid growth), biochemical evaluation (cortisol, metanephrines): Consider underlying adrenal neoplasm
|
||||
- Enhancing soft tissue components may suggest adrenal mass hemorrhage and pseudocyst formation
|
||||
- Parasitic (echinococcal) cyst
|
||||
- Rare outside endemic areas
|
||||
- Typically in setting of generalized echinococcus
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Adrenal adenoma
|
||||
- CECT: Enhancing mass without visible wall or peripheral calcifications
|
||||
- Gastric diverticulum
|
||||
- Air-, fluid-, or contrast-filled mass with no enhancement of contents
|
||||
- Adrenal myelolipoma
|
||||
- Macroscopic fat
|
||||
- Necrotic adrenal tumor
|
||||
- Complex wall with heterogeneous contents
|
||||
- Retroperitoneal bronchogenic cyst
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- No treatment required usually
|
||||
- Imaging surveillance performed, although intensity and length of follow-up not defined
|
||||
- Biochemical evaluation (cortisol, metanephrines) routinely performed to exclude underlying adrenal neoplasm
|
||||
- Surgical resection for complex cyst with enhancing components, or symptomatic cyst
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- Complicated cyst has high attenuation, thick enhancing wall, &/or septations
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- "Adrenal cyst" is descriptive term, not pathological diagnosis
|
||||
- Can mean true cyst, pseudocyst, or cystic mass
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Well-defined, nonenhancing, water-density adrenal mass ± calcifications
|
||||
- ### Location
|
||||
|
||||
|
||||
- Suprarenal
|
||||
- Unilateral > bilateral (8-10% of cases)
|
||||
- ### Size
|
||||
|
||||
|
||||
- < 5 cm (50%), up to 20 cm
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Unilocular or multilocular mass
|
||||
- Well-defined, round to oval, homogeneous mass usually with water (0 HU) or near-water density
|
||||
- Higher- or mixed-attenuation mass (hemorrhage, intracystic debris, crystals)
|
||||
- Wall usually very thin
|
||||
- ↑ wall thickness, up to 3 mm for complex cysts
|
||||
- Calcifications
|
||||
- Rim-like or nodular (51-69%)
|
||||
- Centrally in intracystic septation (19%)
|
||||
- Punctate within intracystic hemorrhage (5%)
|
||||
- ### CECT
|
||||
|
||||
|
||||
- No central enhancement ± wall enhancement
|
||||
- Coronal reformats helpful to determine organ of origin if large cyst
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Homogeneous, hypointense mass
|
||||
- Hyperintense mass (hemorrhage)
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Hyperintense mass
|
||||
- ## Ultrasonographic Findings
|
||||
|
||||
|
||||
- Simple or septated suprarenal cyst
|
||||
- Shadowing from calcification
|
||||
- Real-time examination helpful to differentiate adrenal cyst from adjacent (renal, pancreatic) cyst
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- CECT or MR; US for confirmation
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Adrenal Adenoma](/document/adrenal-adenoma/e2916d86-5f9f-4dd3-9576-1a7b89d8dda0)
|
||||
- NECT: Lipid-rich adenoma (< 10 HU) mimics adrenal cyst
|
||||
- Peripheral or septal calcification favors adrenal cyst
|
||||
- CECT: **Enhancing mass** without visible wall or peripheral calcifications
|
||||
- Assess washout kinetics to diagnose lipid-poor adenoma
|
||||
- MR: Signal suppression at out-of-phase, chemical-shift imaging
|
||||
- US: Solid adrenal lesion
|
||||
- [Gastric Diverticulum](/document/gastric-diverticulum/eeb101f0-8bdf-4771-b44a-fe6e73b3a463)
|
||||
- May simulate left adrenal cyst
|
||||
- Air-, fluid-, or contrast-filled suprarenal mass
|
||||
- No enhancement
|
||||
- Normal adjacent adrenal gland
|
||||
- [Adrenal Myelolipoma](/document/adrenal-myelolipoma/5813a554-06a4-4696-af71-7ce50693039d)
|
||||
- Fat (not fluid) attenuation mass
|
||||
- ## Necrotic Adrenal Tumor
|
||||
|
||||
|
||||
- Primary (pheochromocytoma or carcinoma) or metastatic
|
||||
- Clinical history, biochemical evaluation, lesion complexity suggest correct diagnosis
|
||||
- Enhancing soft tissue components
|
||||
- ## Retroperitoneal Bronchogenic Cyst
|
||||
|
||||
|
||||
- Rare, benign, suprarenal fluid or soft tissue attenuation lesion
|
||||
- Adjacent to but separate from adrenal gland
|
||||
- ## Renal Cyst
|
||||
|
||||
|
||||
- Coronal MR/CT or US useful to determine organ of origin of large, retroperitoneal cystic lesions
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Congenital (endothelial, epithelial) cysts
|
||||
- Acquired (post hemorrhagic, inflammatory) pseudocysts
|
||||
- Cystic, hemorrhagic degeneration of underlying adrenal neoplasm
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- Accepted classification scheme
|
||||
- Pseudocyst
|
||||
- Most common type of cystic adrenal lesion in surgical series
|
||||
- No epithelial or endothelial lining: Fibrous cyst wall
|
||||
- Potentially as complication of prior trauma or hemorrhage though history of such often not elicited
|
||||
- May be associated with underlying adrenal neoplasm (pheochromocytoma, adrenal carcinoma, myelolipoma)
|
||||
- Attenuation and complexity at imaging varies depending upon hemorrhagic component
|
||||
- Wall and septal calcification common
|
||||
- Endothelial cyst
|
||||
- Subtypes: Lymphangiomatous and hemangiomatous
|
||||
- True cyst: Endothelial lining
|
||||
- Originate from preexisting vascular malformation or obstructed, ectatic lymphatic channels
|
||||
- Thin rim calcification typical
|
||||
- Epithelial cyst
|
||||
- Extremely rare: No acinar structures within normal adrenal gland
|
||||
- Mesothelial origin suggested (mesothelial cells potentially incorporated within adrenal gland during embryogenesis)
|
||||
- Parasitic (hydatid) cyst
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Typically asymptomatic
|
||||
- Larger cysts may be symptomatic
|
||||
- Abdominal pain
|
||||
- Hemorrhage
|
||||
- Clinical history (malignancy, hypertension) elicited
|
||||
- May indicate cystic degeneration of underlying adrenal neoplasm (e.g., metastasis, pheochromocytoma)
|
||||
- Diagnosis
|
||||
- Usually incidental finding at imaging
|
||||
- Endocrine-biochemical evaluation performed to exclude underlying functional adrenal tumor
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Any, though patients 20-50 years of age most common
|
||||
- ### Sex
|
||||
|
||||
|
||||
- M:F = 1:3
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- Uncommon entity: Autopsy incidence 0.064-0.18%
|
||||
- Accounts for 1% of incidental adrenal lesions in large imaging series
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Complications
|
||||
- Hypertension, infection, rupture, hemorrhage
|
||||
- Excellent prognosis for vast majority of incidental, benign adrenal cysts
|
||||
- Prognosis for pseudocysts secondary to adrenal neoplasm depends upon tumor histology
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- No treatment required usually
|
||||
- Imaging follow-up typically performed
|
||||
- Intensity and length of surveillance not defined
|
||||
- Cysts may enlarge over time
|
||||
- Endocrine evaluation (cortisol, metanephrine, etc.) performed
|
||||
- Surgical resection if symptomatic, underlying adrenal neoplasm
|
||||
- Laparoscopic resection preferred
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Complicated cyst may suggest underlying adrenal neoplasm
|
||||
- Clinical history, biochemical evaluation, and prior imaging helpful
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Simple adrenal cyst: Scant septation, no enhancement, thin rim calcification
|
||||
- Likely benign endothelial cyst or pseudocyst
|
||||
- Coronal imaging helpful to determine organ of origin (and exclude exophytic renal or pancreatic cyst)
|
||||
- Complicated cyst: High attenuation, thick enhancing wall, &/or septations
|
||||
- Complexity may suggest underlying adrenal neoplasm and secondary pseudocyst
|
||||
|
||||
35fa0290-3451-422f-8726-c69b68aadbb5
|
||||
@@ -1,234 +0,0 @@
|
||||
---
|
||||
title: "Adrenal Myelolipoma"
|
||||
docid: "5813a554-06a4-4696-af71-7ce50693039d"
|
||||
breadcrumbs:
|
||||
- "Genitourinary"
|
||||
- "Diagnosis"
|
||||
- "Adrenal"
|
||||
- "Benign Neoplasms"
|
||||
- "Adrenal Myelolipoma"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Uncommon benign tumor composed of mature fat tissue and hematopoietic elements (myeloid and erythroid cells)
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Benign, nonfunctioning adrenal tumor
|
||||
- Accounts for 7-15% of incidental adrenal masses, usually in older population
|
||||
- Typically unilateral and very rarely bilateral
|
||||
- Large tumors can mimic retroperitoneal lipomas, liposarcomas
|
||||
- Asymptomatic, though larger tumors may hemorrhage
|
||||
- CT
|
||||
- Lesion containing fat attenuation (-30 to -90 HU)
|
||||
- Usually well-defined mass with recognizable pseudocapsule (remaining adrenal)
|
||||
- Punctate calcifications seen in 24% of cases
|
||||
- Coronal reconstruction helpful to differentiate from exophytic renal angiomyolipoma
|
||||
- MR
|
||||
- Tumor with major fat component
|
||||
- T1WI in phase: Typically hyperintense
|
||||
- FS sequences: Loss of signal
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Adrenal adenoma
|
||||
- Intracellular lipid vs. macroscopic fat
|
||||
- Adrenal metastases and lymphoma
|
||||
- Retroperitoneal liposarcoma
|
||||
- Involving perirenal space, may simulate adrenal (or renal) fatty tumor
|
||||
- Pheochromocytoma
|
||||
- Highly vascular, prone to hemorrhage and necrosis
|
||||
- Adrenal carcinoma
|
||||
- Renal angiomyelolipoma
|
||||
- Coronal CT reconstruction or MR useful to determine organ of origin
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Uncommon benign tumor composed of mature adipose tissue and hematopoietic elements
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Suprarenal mass containing fat
|
||||
- ### Location
|
||||
|
||||
|
||||
- Suprarenal
|
||||
- Rare extraadrenal myelolipomas (presacral, retroperitoneal)
|
||||
- ### Size
|
||||
|
||||
|
||||
- Usually 2-10 cm, rarely 10-20 cm
|
||||
- Key concepts
|
||||
- Benign neoplasm of adrenal gland
|
||||
- Autopsy prevalence rate of 0.2-0.4%
|
||||
- Accounts for 7-15% of adrenal "incidentalomas"
|
||||
- Usually unilateral incidental finding in older patient
|
||||
- Larger tumors can bleed spontaneously
|
||||
- Most are nonfunctioning (do not secrete hormones)
|
||||
- Large myelolipomas can mimic retroperitoneal lipoma or liposarcoma
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- CT appearance depends on histologic composition
|
||||
- Most tumors are heterogeneous adrenal masses composed of varying percentages of fat
|
||||
- Low-attenuation suprarenal lesion containing fat density (-30 to -90 HU)
|
||||
- Average NECT attenuation value of tumor: -74 HU in one series
|
||||
- Interspersed soft tissue attenuation components: Myeloid elements, hemorrhage
|
||||
- Presence of macroscopic fat within tumor is diagnostic
|
||||
- Punctate calcifications seen in 24% of cases
|
||||
- Usually well-defined mass with recognizable pseudocapsule (remnant adrenal)
|
||||
- Coronal reconstructions may help determine organ of origin: Adrenal myelolipoma vs. exophytic renal angiomyelolipoma
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- MR appearance depends on histologic composition
|
||||
- Tumor with major fat component
|
||||
- T1WI in phase: Typically hyperintense
|
||||
- T1WI out phase: Persistent hyperintensity of macroscopic fat
|
||||
- T1WI FS: Confirmatory suppression of signal
|
||||
- Bone marrow elements (myeloid and erythroid cells)
|
||||
- Low signal on T1WI, moderate signal on T2WI
|
||||
- Hemorrhage: Varying T1, T2 signal depending on age of blood
|
||||
- ## Ultrasonographic Findings
|
||||
|
||||
|
||||
- ### Grayscale ultrasound
|
||||
|
||||
|
||||
- Well-defined, echogenic mass (↑ fat tissue)
|
||||
- Often overlooked: Lack of mass effect and isoechogenicity relative to retroperitoneal fat
|
||||
- Heterogeneous mass (↑ myeloid cells)
|
||||
- ## Angiographic Findings
|
||||
|
||||
|
||||
- Conventional
|
||||
- Differentiate myelolipoma from retroperitoneal liposarcoma by determining origin of blood supply and vascularity of tumors
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- Typically not metabolically active, though uptake reported at FDG PET
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- Helical NECT or MR with FS sequence
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Adrenal Adenoma](/document/adrenal-adenoma/e2916d86-5f9f-4dd3-9576-1a7b89d8dda0)
|
||||
- Lipid-rich adenoma: ↓ attenuation (< 10 HU) at NECT
|
||||
- Can contain small amounts of macroscopic fat due to lipomatous metaplasia
|
||||
- CECT: Washout 15 minutes post injection: > 50%
|
||||
- Relative washout: > 40%
|
||||
- Absolute washout: > 60%
|
||||
- [Metastases and Lymphoma, Adrenal](/document/adrenal-lymphoma/44639c90-bd04-4e2a-a470-2c28a0e2ff78)
|
||||
- Bilateral lesions: Clinical history paramount
|
||||
- Metastases: Soft tissue attenuation (signal)
|
||||
- Lymphoma: May maintain adreniform shape, adjacent retroperitoneal adenopathy
|
||||
- [Liposarcoma, Retroperitoneal](/document/retroperitoneal-sarcoma/c1466b30-b730-41c4-a065-2c2de018a5f7)
|
||||
- Retroperitoneal primary sarcoma involving perirenal space may simulate adrenal (or renal) fatty tumor
|
||||
- [Pheochromocytoma](/document/pheochromocytoma/7d3c4062-643c-4030-8783-f85184ad8132)
|
||||
- Highly vascular, prone to hemorrhage and necrosis
|
||||
- Hyperintense on T2WI, bilateral in multiple endocrine neoplasia syndromes (MEN) syndromes
|
||||
- Clinical history (labile hypertension) and urinary catecholamines
|
||||
- [Adrenal Carcinoma](/document/adrenal-cortical-carcinoma/bdc7a08b-a64f-4bd2-9dfc-24331728e85e)
|
||||
- Rare, unilateral, invasive, enhancing mass
|
||||
- Venous invasion, distant metastases
|
||||
- May contain fat: Engulfed retroperitoneal fat vs. lipomatous metaplasia
|
||||
- ## Renal Angiomyelolipoma
|
||||
|
||||
|
||||
- Exophytic upper pole angiomyolipoma may mimic
|
||||
- Coronal reconstruction/MR helpful to determine organ of origin
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Unknown
|
||||
- Best hypothesis: Reticuloendothelial cell metaplasia of capillaries in adrenal (stress/infection/necrosis)
|
||||
- Secondary hypothesis: Myelolipoma represents site of extramedullary hematopoiesis
|
||||
- ### Associated abnormalities
|
||||
|
||||
|
||||
- Adrenal collision tumors (coexistent myelolipoma and adenoma typical)
|
||||
- Large, bilateral myelolipomas reported with longstanding, poorly treated congenital adrenal hyperplasia
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Cut section: Fat, soft tissue components
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Mature fat cells and megakaryocytes; no malignant cells
|
||||
- Calcification
|
||||
- Hemorrhage within larger lesions
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Asymptomatic
|
||||
- Usually incidental finding on CT, MR
|
||||
- Typically biochemically nonfunctioning
|
||||
- Symptomatic
|
||||
- Acute abdomen: Flank pain due to rupture and hemorrhage
|
||||
- Case reports of hormonally active tumors: Cushing, Conn syndromes, virilization
|
||||
- Diagnosis: Pathognomonic MR/CT features
|
||||
- Biopsy reserved for larger, atypical lesions, though prone to sampling error
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Usually older patients (50-70 years old)
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- Autopsy incidence: 0.2-0.4%
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Complication: Rupture with hemorrhage (rare)
|
||||
- Prognosis: Excellent
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- When diagnosis is certain, surgery not needed for lesions < 5-7 cm
|
||||
- Surgery reserved for larger, symptomatic, or atypical lesions
|
||||
- Surgical series have confirmed utility of laparoscopic resection
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Differentiate from other tumors (lipid-rich adenoma)
|
||||
- Key is presence of imaging-apparent adipose tissue; avoid further work-up for incidental mass
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Well-defined, heterogeneous, fat-attenuation tumor on CT
|
||||
- T1 hyperintense, signal loss with fat suppression
|
||||
|
||||
81ce3ad3-c446-4b08-8b87-df9511f95360
|
||||
@@ -1,113 +0,0 @@
|
||||
---
|
||||
title: "Adrenal"
|
||||
docid: "082ca43c-db5c-4770-aeed-0c6ea317e8fc"
|
||||
breadcrumbs:
|
||||
- "Genitourinary"
|
||||
- "Anatomy"
|
||||
- "Adrenal"
|
||||
---
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Adrenal corticotrophic hormone (ACTH)
|
||||
|
||||
# GROSS ANATOMY
|
||||
|
||||
- ## Overview
|
||||
|
||||
|
||||
- Adrenal (**suprarenal**) glands are part of endocrine and neurological systems
|
||||
- Essentially different organs within same structure, composed of thick outer cortex and thin inner medulla
|
||||
- Lie within**perirenal space**bilaterally, bounded by**renal** (**perirenal**)**fascia**, above/medial to kidneys
|
||||
- Composed of "body" and 2 limbs (medial and lateral)
|
||||
- ## Anatomic Relationships
|
||||
|
||||
|
||||
- Right adrenal is usually more apical in location
|
||||
- Lies anterolateral to right crus of diaphragm, medial to liver, and posterior to inferior vena cava (IVC)
|
||||
- Often pyramidal in shape with inverted V shape on transverse section
|
||||
- Left adrenal is usually more caudal and lies medial to upper pole of left kidney, lateral to left crus of diaphragm, and posterior to splenic vein and pancreas
|
||||
- Often crescentic in shape with λ or triangular shape on transverse section
|
||||
- ## Divisions
|
||||
|
||||
|
||||
- **Adrenal cortex**
|
||||
- Embryologically derived from mesoderm
|
||||
- Divided into 3 distinct zones (zona glomerulosa, zona fasciculata, and zona reticularis)
|
||||
- Secretes **mineralocorticoids**(aldosterone) from zona glomerulosa, **glucocorticoids**(cortisol) from zona fasciculata, and **androgens**from zona reticularis
|
||||
- **Adrenal medulla**
|
||||
- Embryologically derived from neural crest
|
||||
- Part of sympathetic nervous system
|
||||
- **Chromaffin cells** secrete **catecholamines** (mostly epinephrine) into bloodstream
|
||||
- **Vessels**,**nerves**, and **lymphatics**
|
||||
- Arteries
|
||||
- **Superior adrenal arteries**: Typically 6-8; from inferior phrenic arteries
|
||||
- **Middle adrenal artery**: 1; from abdominal aorta
|
||||
- **Inferior adrenal artery**: 1; from renal arteries
|
||||
- Veins
|
||||
- **Right adrenal vein** drains into IVC
|
||||
- **Left adrenal vein** drains into left renal vein (usually after joining left inferior phrenic vein)
|
||||
- Nerves
|
||||
- Extensive sympathetic connection to adrenal medulla
|
||||
- Presynaptic sympathetic fibers from paravertebral ganglia end directly on secretory cells of medulla
|
||||
- Lymphatics
|
||||
- Drain to **lumbar** (**aortic** and **caval**) **nodes**
|
||||
|
||||
# ANATOMY IMAGING ISSUES
|
||||
|
||||
- ## Multimodality Imaging Appearance
|
||||
|
||||
|
||||
- No consensus on "normal" size or thickness of adrenals but average thickness of ~ 3 mm for medial/lateral limbs
|
||||
- While not based on any strong evidence, > 10-mm thickness can be used as threshold for hyperplasia
|
||||
- MR: Generally isointense to liver on T1 MR and isointense to slightly hyperintense to liver on T2 MR
|
||||
- Ultrasound: Easiest to visualize in newborns (as result of physiologic enlargement) and become progressively more difficult to visualize with age
|
||||
- Right adrenal gland easier to visualize than left (due to lack of liver as acoustic window and overlying bowel gas)
|
||||
- Adrenal glands in adults usually hypoechoic (juxtaposed against hyperechoic periadrenal fat), although medulla can rarely be discretely seen and appears hyperechoic
|
||||
- ## Key Concepts
|
||||
|
||||
|
||||
- **Adrenal** (**cortical**) **adenomas**
|
||||
- Very common (at least 2% of general population) but usually cause no symptoms
|
||||
- Mostly "nonfunctioning" but identical to "functional" adenomas that cause Cushing/Conn syndrome
|
||||
- Most adenomas contain abundant lipid (precursor to steroid hormones), allowing definitive diagnosis using CT/MR sequences that highlight lipid
|
||||
- Lipid is intracellular/intercellular (not macroscopic deposits of fat)
|
||||
- Best CT technique: Nonenhanced CT with nodule measuring < 10 HU; or multiphase-enhanced CT with nodule demonstrating "washout" kinetics
|
||||
- Best MR technique: Chemical-shift MR with signal dropout within nodule on opposed-phase images
|
||||
- Standard imaging features for diagnosis of adenoma should be used for nodules measuring < 4 cm, while lesions > 4 cm should raise concern for malignancy
|
||||
- **Pheochromocytoma** (tumor of adrenal medulla)
|
||||
- Signs: Headache, palpitations, excessive perspiration
|
||||
- 90% arise in adrenal, 90% unilateral, 90% benign
|
||||
- Similar tumor arising in other chromaffin cells of sympathetic ganglia is called **paraganglioma**
|
||||
- More common with multiple endocrine neoplasia, neurofibromatosis, and von Hippel-Lindau
|
||||
- Often markedly hypervascular in arterial phase
|
||||
- **Adrenal myelolipoma**
|
||||
- Uncommon benign tumor (usually incidental finding) composed of mature adipose and hematopoietic tissue
|
||||
- Characterized by presence of **macroscopic fat**
|
||||
- May have internal soft tissue component or calcification
|
||||
- **Adrenocortical carcinoma**
|
||||
- Highly aggressive malignancy with poor prognosis
|
||||
- Large, heterogeneous mass (often with necrosis, hemorrhage, or calcification) with frequent local invasion, vascular invasion, and distant metastases
|
||||
- **Cushing syndrome** (excess cortisol)
|
||||
- Signs: Truncal obesity, hirsutism, hypertension
|
||||
- Causes: Pituitary tumors (→ adrenal corticotrophic hormone), exogenous (medications) > adrenal adenoma > carcinoma
|
||||
- **Conn syndrome** (excess aldosterone)
|
||||
- Signs: Hypertension, hypokalemic alkalosis
|
||||
- Causes: Adrenal adenomas > hyperplasia > carcinoma
|
||||
- **Addison syndrome**(adrenal insufficiency)
|
||||
- Signs: Hypotension, weight loss, altered pigmentation
|
||||
- Causes: Autoimmune disease > adrenal metastases > adrenal hemorrhage > adrenal infection
|
||||
|
||||
# CLINICAL IMPLICATIONS
|
||||
|
||||
- ## Clinical Importance
|
||||
|
||||
|
||||
- Rich adrenal blood supply due to endocrine function
|
||||
- Results in adrenal glands being common site for hematologic **metastases** (lung, breast, melanoma, etc.)
|
||||
- Adrenal glands respond to stress (trauma, sepsis, surgery, etc.) by secreting ↑ cortisol and epinephrine
|
||||
- Overwhelming stress may result in **adrenal hemorrhage**or acute adrenal insufficiency (addisonian crisis)
|
||||
|
||||
d7703d36-250d-428e-bf99-6439a7cdc980
|
||||
@@ -0,0 +1,215 @@
|
||||
---
|
||||
title: "Aging Brain, Normal"
|
||||
docid: "f8dc8f27-f256-480d-9393-7ec3495a3d27"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Supratentorial Brain Parenchyma"
|
||||
- "Anatomically Based Differentials"
|
||||
- "Basal Ganglia Calcification"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Basal ganglia (BG) Ca⁺⁺ is end result of multiple toxic, metabolic, inflammatory, & infectious insults
|
||||
- Location of Ca⁺⁺ helpful to determine underlying cause [globus pallidus (GP) vs. putamen vs. caudate]
|
||||
- Patient age may impact differential diagnosis
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Aging B****rain, Normal**
|
||||
- Commonly affects GP more than putamen
|
||||
- Seen in aging brain as normal variant
|
||||
- Typically in patients older than 30 years
|
||||
- If occurs with other Ca⁺⁺, consider pathologic condition
|
||||
- **Neurocysticercosis**
|
||||
- May occur anywhere in brain
|
||||
- Convexity subarachnoid spaces most common
|
||||
- Imaging varies with pathologic stage
|
||||
- Ca⁺⁺ in nodular calcified (healed) stage
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Fahr Disease**
|
||||
- Bilateral symmetric BG Ca⁺⁺, often with Ca⁺⁺ in other locations
|
||||
- GP is most common site of Ca⁺⁺ (lateral > medial)
|
||||
- Other locations: Putamen, caudate, thalami, dentate nuclei of cerebellum, cerebral white matter (WM), internal capsule
|
||||
- Associated abnormalities: Parkinsonism in autosomal dominant Fahr disease (FD)
|
||||
- **Hypoxic-Ischemic Injury**
|
||||
- **Term**: Profound acute injury results in decreased BG & thalamic density ± hemorrhage acutely
|
||||
- Lateral thalami & posterior putamen typical
|
||||
- May show Ca⁺⁺ in chronic phase
|
||||
- **Adults**: Putamen > GP typically
|
||||
- May have history of anoxic event
|
||||
- MR > CT for acute changes
|
||||
- May show Ca⁺⁺ in chronic phase
|
||||
- **Mitochondrial Disorders**
|
||||
- Mitochondrial myopathy, encephalopathy, lactic acidosis, & stroke-like episodes (MELAS): BG Ca⁺⁺ in child or young adult with cortical lesions (parietooccipital > temporoparietal)
|
||||
- Myoclonic epilepsy with ragged red fibers (MERRF): BG Ca⁺⁺ with watershed ischemia
|
||||
- **Congenital Infections**
|
||||
- **HIV, congenital**
|
||||
- Symmetric BG Ca⁺⁺ & cerebral atrophy
|
||||
- GP & putamen > caudate
|
||||
- Subcortical WM Ca⁺⁺ common
|
||||
- Ca⁺⁺ occurs in fairly symmetric fashion, result of calcific vasculopathy of medium & small arteries
|
||||
- **CMV, congenital**
|
||||
- Periventricular Ca⁺⁺, microcephaly, & cortical dysplasia
|
||||
- Periventricular > > BG Ca⁺⁺
|
||||
- **Endocrinologic Disorders**
|
||||
- Imaging of hyperparathyroidism, hypoparathyroidism, pseudohypoparathyroidism, pseudopseudohypoparathyroidism, hypothyroidism in nearly indistinguishable
|
||||
- Bilateral BG: GP & putamen, dentate nuclei, thalami, subcortical areas
|
||||
- Ca⁺⁺ in primary hypoparathyroidism is more diffuse than in other etiologies of Ca⁺⁺
|
||||
- **Toxoplasmosis, Acquired**
|
||||
- Typically multifocal, but BG common site (up to 75%)
|
||||
- Enhancing lesion most common acutely
|
||||
- Post therapy, Ca⁺⁺ is common
|
||||
- **Leigh Syndrome**
|
||||
- Bilateral, symmetric ↑ T2/FLAIR putamina & periaqueductal gray matter
|
||||
- Putamen > caudate > GP, Ca⁺⁺ when chronic
|
||||
- **Tuberculosis**
|
||||
- Typically causes tuberculous meningitis &/or localized CNS infection, tuberculoma
|
||||
- ~ 20% of tuberculomas calcify
|
||||
- **Radiation****&****Chemotherapy**
|
||||
- Mineralizing microangiopathy causes BG & subcortical WM Ca⁺⁺, atrophy
|
||||
- Mineralizing microangiopathy common with chemotherapy & XRT
|
||||
- Typically occurs 2 or more years after XRT
|
||||
- **Cavernous Malformation (Mimic)**
|
||||
- Hyperdense mass (Ca⁺⁺ & blood products) may occur in any location
|
||||
- **Vascular Calcification (Mimic)**
|
||||
- May relate to physiologic vascular calcification, atherosclerosis, aneurysm, or vascular mass
|
||||
- **Tuberous Sclerosis Complex (Mimic)**
|
||||
- Subependymal nodules are typically calcified; occur along caudothalamic groove, periventricular
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Developmental Venous Anomaly**
|
||||
- Congenital cerebral vascular malformation with mature venous elements
|
||||
- "Medusa head" with many small veins joining into collector vein
|
||||
- Seen on contrast CT/MR, CTA/CTV, MRV, DSA, SWI
|
||||
- Unilateral BG/thalami Ca⁺⁺ rare
|
||||
- May be related to venous congestion/ischemia
|
||||
- **Pantothenate Kinase-Associated Neurodegeneration**
|
||||
- Rare neurodegenerative disorder with brain iron accumulation
|
||||
- T2 MR characteristic: High signal within bilateral GP with surrounding low signal, eye of the tiger appearance
|
||||
- CT may show mineralization in GP
|
||||
- Formerly known as Hallervorden-Spatz
|
||||
- **Carbon Monoxide Poisoning**
|
||||
- Typically hypodense, symmetric GP on CT, T2 hyperintense
|
||||
- GP Ca⁺⁺ occurs as end result
|
||||
- **Parasites, Miscellaneous**
|
||||
- **Amebic encephalitis**: Supratentorial, frontal lobes, & BG
|
||||
- Typically enhancing lesions acutely, may calcify in chronic phase
|
||||
- **Malaria**: Predilection for BG, cortex
|
||||
- Hemorrhage, infarcts, & cerebral edema
|
||||
- May show Ca⁺⁺ in chronic phase
|
||||
- **Paragonimiasis**: Acutely often hemorrhage or infarct, followed by Ca⁺⁺ granulomas
|
||||
- ## Alternative Differential Approaches
|
||||
|
||||
|
||||
- BG Ca⁺⁺ in **child**
|
||||
- Mitochondrial encephalopathies: MELAS, MERRF, Leigh syndrome
|
||||
- Congenital infections: HIV, CMV
|
||||
- HIE, term
|
||||
- Associated with Down syndrome
|
||||
- Aicardi-Goutières syndrome (pseudo-TORCH)
|
||||
- Cockayne syndrome
|
||||
- Long-term complications of radiation therapy for childhood brain tumors & intrathecal chemotherapy
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
*Axial NECT shows typical basal ganglia (BG) Ca⁺⁺ in this 75-year-old man who presented after minor trauma. Note the location within the globus pallidus (GP) <img src='/img/arrows/CS.png'/>, typical for normal aging brain. Physiologic Ca⁺⁺ is typically seen in adults over 30 years.*
|
||||
|
||||
|
||||
*Axial NECT shows typical basal ganglia (BG) Ca⁺⁺ in this 75-year-old man who presented after minor trauma. Note the location within the globus pallidus (GP) <img src='/img/arrows/CS.png'/>, typical for normal aging brain. Physiologic Ca⁺⁺ is typically seen in adults over 30 years.*
|
||||
|
||||
|
||||
*Axial CT shows multiple calcified nodules in the deep gray nuclei <img src='/img/arrows/CS.png'/> & along the cortex related to the nodular, calcified (healed) stage of neurocysticercosis. This intracranial parasitic infection is caused by the pork tapeworm Taenia solium.*
|
||||
|
||||
|
||||
*Axial NECT shows the typical CT appearance of Fahr disease (FD) with extensive calcifications present in the BG, cerebral white matter (WM), & at the subcortical gray matter-WM junctions.*
|
||||
|
||||
|
||||
*Axial NECT shows calcification of thalami & BG <img src='/img/arrows/WC.png'/> from status marmoratus. There is atrophy & a collapsed calvarium following remote mixed hypoxic-ischemic injury (HII) in this infant. Profound acute HII typically affects the BG.*
|
||||
|
||||
|
||||
*Axial NECT in a teenager shows bilateral GP <img src='/img/arrows/WS.png'/> Ca⁺⁺, a rare finding in patients < 30 years.*
|
||||
|
||||
|
||||
*FLAIR MR (same patient) shows left frontal & parietal hyperintensity related to recent middle cerebral artery <img src='/img/arrows/CS.png'/> & anterior cerebral artery <img src='/img/arrows/CO.png'/> infarcts. Muscle biopsy showed myoclonic epilepsy with ragged-red fibers. This rare mitochondrial disorder often presents with myoclonus & seizures. Imaging mimics other mitochondrial disorders, incl. mitochondrial myopathy, encephalopathy, lactic acidosis, & stroke-like episodes (MELAS).*
|
||||
|
||||
|
||||
*Axial NECT shows Ca⁺⁺ of the GP bilaterally <img src='/img/arrows/WS.png'/> in this child with MELAS. Note the low density in the medial occipital lobes related to <img src='/img/arrows/CO.png'/> infarcts. BG Ca⁺⁺ is abnormal in children & young adults.*
|
||||
|
||||
|
||||
*Axial NECT in a patient with congenital HIV shows bilateral symmetrical BG Ca⁺⁺ predominantly in the GP <img src='/img/arrows/CS.png'/>. This Ca⁺⁺ is seen typically months after birth. With HIV, involvement of the lentiform nuclei Ca⁺⁺ is greater than the caudate heads.*
|
||||
|
||||
|
||||
*Axial NECT shows periventricular & BG Ca⁺⁺ as well as open Sylvian fissures & ventriculomegaly. Periventricular Ca⁺⁺, ventriculomegaly, & microcephaly strongly suggest congenital CMV infection.*
|
||||
|
||||
|
||||
*Axial NECT in a patient with with hypothyroidism shows diffuse hyperdense Ca⁺⁺ within the BG, thalami, & subcortical WM. Ca⁺⁺ related to systemic disease is typically symmetric.*
|
||||
|
||||
|
||||
*Axial NECT in a patient with pseudohypoparathyroidism shows dense Ca⁺⁺ within the BG & subcortical WM in a pseudohypoparathyroidism patient. There is significant imaging overlap between systemic diseases with abnormal calcium deposition.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR shows an enhancing right BG mass <img src='/img/arrows/CS.png'/> in an AIDS patient. Post therapy, enhancing lesions typically calcify. The BG is the most common location for toxoplasmosis followed by the thalamus, then the cerebral hemispheres.*
|
||||
|
||||
|
||||
*Axial T2WI MR shows symmetric T2 hyperintensity in the BG <img src='/img/arrows/BS.png'/> bilaterally in this child with neurodegeneration. Ca⁺⁺ of the BG is seen in chronic cases.*
|
||||
|
||||
|
||||
*Axial NECT shows mineralizing microangiopathy related to radiation therapy & chemotherapy for a remote childhood neoplasm. Note the symmetric Ca⁺⁺ in the BG & subcortical WM. This typically occurs ~ 2 years after therapy with XRT & chemotherapy.*
|
||||
|
||||
|
||||
*Axial T2 MR shows calcified subependymal nodules in the foramen of Monro region <img src='/img/arrows/CS.png'/> in this child with seizures, mimicking BG Ca⁺⁺. These nodules occur in 98% of patients with tuberous sclerosis.*
|
||||
|
||||
|
||||
*Axial NECT shows dense Ca⁺⁺ in right BG <img src='/img/arrows/CS.png'/> & thalamus. CE images (not shown) revealed an underlying developmental venous anomaly. These are congenital cerebral vascular malformations with mature venous elements, which may rarely have Ca⁺⁺ possibly related to underlying venous congestion & ischemia.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Axial NECT shows a variant CT appearance of FD with extensive Ca⁺⁺ present in the BG, cerebral WM, & at the subcortical gray matter-WM junctions.*
|
||||
|
||||
|
||||
*Axial NECT shows globus pallidus mineralization bilaterally <img src='/img/arrows/CS.png'/> in a patient with pantothenate kinase-associated neurodegeneration. CT is typically normal. T2 MR shows classic the eye of the tiger appearance with globus pallidus hypointensity related to iron accumulation with medial T2 hyperintensity.*
|
||||
|
||||
|
||||
*Axial NECT shows marked atrophy & minimal BG Ca⁺⁺ in this child with congenital CMV. The Ca⁺⁺ seen in CMV is typically asymmetric & associated with migrational abnormalities & microcephaly.*
|
||||
|
||||
|
||||
*Axial NECT shows mineralizing microangiopathy related to radiation therapy & chemotherapy for a posterior fossa medulloblastoma. Note the symmetric Ca⁺⁺ in the BG & subcortical WM.*
|
||||
|
||||
|
||||
*Axial NECT shows periventricular & BG Ca⁺⁺. Periventricular calcifications, ventriculomegaly, & microcephaly strongly suggest congenital CMV infection.*
|
||||
|
||||
|
||||
*Axial CECT shows an enhancing BG mass <img src='/img/arrows/WS.png'/> in an AIDS patient. Post therapy, enhancing lesions typically calcify. BG is the most common location followed by thalamus, then hemispheres.*
|
||||
|
||||
|
||||
*Axial NECT shows intracranial atherosclerotic disease with extensive Ca⁺⁺ in internal carotid & middle cerebral arteries <img src='/img/arrows/WS.png'/>, which mimics BG Ca⁺⁺. Posterior fossa aneurysm is partially visible.*
|
||||
|
||||
|
||||
*Axial NECT shows calcified subependymal nodules in the foramen of Monro & periventricular regions, which mimic BG Ca⁺⁺. These typically accompany cortical tubers <img src='/img/arrows/WC.png'/>, better seen on MR.*
|
||||
|
||||
|
||||
*Axial CECT shows a case of paragonimiasis with a hyperdense left BG nodule <img src='/img/arrows/WS.png'/>. This parasite often presents with conglomerated granulomas, which may hemorrhage. Multiple Ca⁺⁺ are common.*
|
||||
|
||||
|
||||
*Axial CECT shows a calcified left putamen nodule <img src='/img/arrows/CS.png'/> that represents the nodular, calcified (healed) stage of neurocysticercosis. Note the right external capsule cyst with a central "dot" representing a scolex.*
|
||||
|
||||
|
||||
*Axial NECT shows diffuse calcifications within the BG & subcortical WM in a pseudohypoparathyroidism patient. There is significant imaging overlap between systemic diseases with abnormal calcium deposition.*
|
||||
|
||||
|
||||
*Axial NECT shows symmetric BG calcification with scattered foci of subcortical calcification. Note the typical HIV involvement of the lentiform nuclei is greater than the caudate heads.*
|
||||
|
||||
@@ -0,0 +1,317 @@
|
||||
---
|
||||
title: "AHLE"
|
||||
docid: "0ec0bca6-abee-4931-a6ed-43541b626261"
|
||||
authors:
|
||||
- key: "5cff4116-3654-4b3a-bb75-5ebe0b8c9850"
|
||||
value: "Anne G. Osborn, MD, FACR"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Brain"
|
||||
slug: "brain"
|
||||
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
||||
-
|
||||
name: "Diagnosis"
|
||||
slug: "diagnosis"
|
||||
treeNodeId: "51c00394-446e-4a38-94af-d3b1d14d34e8"
|
||||
-
|
||||
name: "Pathology-Based Diagnoses"
|
||||
slug: "pathology-based-diagnoses"
|
||||
treeNodeId: "d9d3a8ed-f21b-4831-8c77-591a3500ef77"
|
||||
-
|
||||
name: "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
slug: "infectious-inflammatory-and-demyel-"
|
||||
treeNodeId: "7210f860-fe5f-4a2d-81cc-4fe06c769607"
|
||||
-
|
||||
name: "Inflammatory and Demyelinating Disease"
|
||||
slug: "inflammatory-and-demyelinating-dis-"
|
||||
treeNodeId: "62ab4dc3-dbf6-45a9-8532-f0e962aa62dc"
|
||||
-
|
||||
name: "AHLE"
|
||||
slug: "ahle"
|
||||
treeNodeId: null
|
||||
category: "Brain"
|
||||
documentVersionId: "05d076c7-6110-4f03-952a-c22726d85e4d"
|
||||
imageCount: 12
|
||||
isBookmarked: false
|
||||
isComparable: true
|
||||
isInCompareCart: false
|
||||
lastUpdated: "08/05/20"
|
||||
pageDescription: "AHLE"
|
||||
pageKeywords: "Brain, Diagnosis, Pathology-Based Diagnoses, Infectious, Inflammatory, and Demyelinating Disease, Inflammatory and Demyelinating Disease, AHLE"
|
||||
pageTitle: "AHLE | STATdx"
|
||||
enhancedTitle: "AHLE"
|
||||
type: "DX"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
- "Inflammatory and Demyelinating Disease"
|
||||
- "AHLE"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Hyperacute, fulminant hemorrhagic perivascular demyelinating disorder
|
||||
- Usually viral or immunization related
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Best imaging: MR with T2* GRE, SWI
|
||||
- CT: May be normal if only microbleeds present
|
||||
- MR
|
||||
- Multifocal scattered or confluent WM hyperintensities on T2/FLAIR
|
||||
- T2* shows multifocal blooming microbleeds in WM (often striking sparing of cortex)
|
||||
- Most striking in corpus callosum
|
||||
- Less common: Large, lobar, confluent hemorrhages
|
||||
- SWI significantly more sensitive than GRE
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Acute disseminated encephalomyelitis (ADEM)
|
||||
- Multiple sclerosis
|
||||
- Acute necrotizing encephalopathy
|
||||
- Other brain "microbleeds"
|
||||
- Critical illness associated (e.g., ARDS ± on ECMO)
|
||||
- Trauma (DAI), fat emboli, HUS/TTP
|
||||
- Sepsis, vasculitis, hemorrhagic viral fevers
|
||||
- High-altitude cerebral edema
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Demographics
|
||||
- AHLE represents ~ 2% of ADEM cases
|
||||
- All ages but children, young adults most common
|
||||
- Presentation and course
|
||||
- Fever, then rapid neurologic deterioration
|
||||
- 60-80% mortality without treatment
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- T2* (GRE or SWI) MR in all febrile CNS illnesses with rapid clinical deterioration
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Acute hemorrhagic leukoencephalitis (AHLE)
|
||||
- Acute disseminated encephalomyelopathy (ADEM)
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Acute hemorrhagic encephalomyelitis (AHEM)
|
||||
- Weston-Hurst disease
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Hyperacute, fulminant, hemorrhagic perivascular demyelinating disorder
|
||||
- Usually post viral or immunization related
|
||||
- May be exceptionally severe, fulminant form of ADEM
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- T2* shows multifocal petechial white matter (WM) microhemorrhages with striking sparing of cortex
|
||||
- Less common: Large, lobar, confluent hemorrhages
|
||||
- ### Location
|
||||
|
||||
|
||||
- WM
|
||||
- Corpus callosum, subcortical WM (U fibers)
|
||||
- Less common: Basal ganglia, midbrain, pons, cerebellum
|
||||
- ### Size
|
||||
|
||||
|
||||
- Punctate microbleeds > large, lobar hemorrhages
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- May be normal if only microbleeds present
|
||||
- ± WM edema with hypodensity
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Often normal
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Multifocal scattered or confluent WM hyperintensities
|
||||
- Most striking in corpus callosum
|
||||
- May have reversible corpus callosum splenium lesion
|
||||
- ### T2* GRE
|
||||
|
||||
|
||||
- Multifocal blooming microbleeds
|
||||
- SWI significantly more sensitive than GRE
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- MR with T2* GRE, SWI
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Acute Disseminated Encephalomyelitis](/document/adem/a3fafeb7-5861-4364-beb8-c0e30220564e)
|
||||
- AHLE may be most severe form of ADEM
|
||||
- ADEM usually less fulminant
|
||||
- ADEM lacks lobar or perivascular hemorrhages of AHLE
|
||||
- [Multiple Sclerosis](/document/multiple-sclerosis/7892b2a2-f52a-4d7f-9858-a326f2b7ab04)
|
||||
- Acute fulminant multiple sclerosis
|
||||
- Lacks hemorrhage, high fever, marked leukocytosis
|
||||
- ## Acute Necrotizing Encephalopathy
|
||||
|
||||
|
||||
- Rare complication of acute viral infection, such as influenza A
|
||||
- Children < 4 years most common
|
||||
- Bilateral, symmetric lesions in thalami typical
|
||||
- WM predominance rare
|
||||
- ## Other Etiologies of Brain Microbleeds
|
||||
|
||||
|
||||
- Diffuse, traumatic vascular injury
|
||||
- Critical illness-associated (e.g., ARDS ± on ECMO)
|
||||
- Sepsis, vasculitis
|
||||
- Fat emboli
|
||||
- HUS/TTP
|
||||
- Hemorrhagic infections
|
||||
- Viral (H1N1, coronavirus), malaria, rickettsia
|
||||
- High-altitude cerebral edema
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Predominantly involves WM of brain ± spinal cord
|
||||
- May affect basal ganglia but usually spares cortical gray matter
|
||||
- Focal confluent &/or multifocal petechial WM hemorrhages
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Fibrinoid necrosis of vessel walls
|
||||
- Perivascular demyelination, hemorrhages
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Fever, then rapid neurologic deterioration
|
||||
- Somnolence, impaired consciousness
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- Long-tract signs
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- AHLE represents ~ 2% of ADEM cases
|
||||
- All ages but children, young adults most common
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Rapid clinical deterioration; death within days typical course
|
||||
- Mortality: 60-80%
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Aggressive IV steroids, immunoglobulin, plasmapheresis
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- T2* (GRE or SWI) MR in all febrile CNS illnesses with rapid clinical deterioration
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Corpus callosum, subcortical WM microbleeds with striking sparing of overlying cortex typical for AHLE
|
||||
|
||||
8f325204-5ce7-4da8-b816-cb545fa5b054
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
*Close-up view of autopsied brain in a patient with acute hemorrhagic leukoencephalitis (AHLE) shows innumerable tiny microbleeds in the subcortical and deep white matter (WM) <img src='/img/arrows/BO.png'/> and corpus callosum <img src='/img/arrows/BS.png'/>. Note the overlying cortex is almost completely spared <img src='/img/arrows/BC.png'/>. (Courtesy E. Rushing, MD.)*
|
||||
|
||||
|
||||
*Close-up view of autopsied brain in a patient with acute hemorrhagic leukoencephalitis (AHLE) shows innumerable tiny microbleeds in the subcortical and deep white matter (WM) <img src='/img/arrows/BO.png'/> and corpus callosum <img src='/img/arrows/BS.png'/>. Note the overlying cortex is almost completely spared <img src='/img/arrows/BC.png'/>. (Courtesy E. Rushing, MD.)*
|
||||
|
||||
|
||||
*Close-up view of autopsied brain in a patient with acute hemorrhagic leukoencephalitis (AHLE) shows innumerable tiny microbleeds in the subcortical and deep white matter (WM) <img src='/img/arrows/BO.png'/> and corpus callosum <img src='/img/arrows/BS.png'/>. Note the overlying cortex is almost completely spared <img src='/img/arrows/BC.png'/>. (Courtesy E. Rushing, MD.)*
|
||||
|
||||
|
||||
*Axial FLAIR MR in a 28-year-old man with rapidly declining mental status after a flu-like illness shows patchy hyperintensities in the corpus callosum <img src='/img/arrows/WC.png'/> and deep/subcortical WM <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Axial FLAIR MR in a 28-year-old man with rapidly declining mental status after a flu-like illness shows patchy hyperintensities in the corpus callosum <img src='/img/arrows/WC.png'/> and deep/subcortical WM <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Axial T2* GRE MR in the same patient shows multiple tiny hypointensities in the corpus callosum <img src='/img/arrows/BC.png'/> and deep/subcortical WM <img src='/img/arrows/BS.png'/>. The cortex is largely spared.*
|
||||
|
||||
|
||||
*Axial T2* GRE MR in the same patient shows multiple tiny hypointensities in the corpus callosum <img src='/img/arrows/BC.png'/> and deep/subcortical WM <img src='/img/arrows/BS.png'/>. The cortex is largely spared.*
|
||||
|
||||
|
||||
*Axial T2* SWI MR MIP shows the innumerable microbleeds in the corpus callosum <img src='/img/arrows/CC.png'/> with diffuse involvement of the hemispheric WM <img src='/img/arrows/CS.png'/> in this patient with AHLE.*
|
||||
|
||||
|
||||
*Axial T2* SWI MR MIP shows the innumerable microbleeds in the corpus callosum <img src='/img/arrows/CC.png'/> with diffuse involvement of the hemispheric WM <img src='/img/arrows/CS.png'/> in this patient with AHLE.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Axial FLAIR MR in a 25-year-old man with fever and rapidly decreasing mental status shows no definite abnormalities.*
|
||||
|
||||
|
||||
*Axial FLAIR MR in a 25-year-old man with fever and rapidly decreasing mental status shows no definite abnormalities.*
|
||||
|
||||
|
||||
*Axial T2* GRE MR in the same patient shows a few punctate "blooming" foci in the corpus callosum genu <img src='/img/arrows/WO.png'/> and splenium <img src='/img/arrows/WS.png'/>. The remainder of the WM appears normal.*
|
||||
|
||||
|
||||
*Axial T2* GRE MR in the same patient shows a few punctate "blooming" foci in the corpus callosum genu <img src='/img/arrows/WO.png'/> and splenium <img src='/img/arrows/WS.png'/>. The remainder of the WM appears normal.*
|
||||
|
||||
|
||||
*Axial SWI MR n the same patient shows innumerable tiny "blooming" microbleeds in the corpus callosum <img src='/img/arrows/BO.png'/> and subcortical and deep WM <img src='/img/arrows/BS.png'/>. The cortex is largely spared.*
|
||||
|
||||
|
||||
*More cephalad axial T2* SWI MR shows innumerable tiny "blooming" foci in the WM, especially in the corpus callosum <img src='/img/arrows/BC.png'/>. These imaging findings are characteristic of AHLE.*
|
||||
|
||||
|
||||
*Autopsy shows 2 areas of gross hemorrhagic necrosis <img src='/img/arrows/BS.png'/>. These findings and clinical history of prior flu-like illness with rapidly progressive fatal clinical course are characteristic of AHLE. (Courtesy R. Hewlett, MD).*
|
||||
|
||||
|
||||
*Axial T2* GRE MR in a patient with rapid decline after a flu-like illness shows a large left frontal hemorrhage <img src='/img/arrows/WO.png'/> with numerous "blooming" foci in multiple WM lesions <img src='/img/arrows/BS.png'/>. Diagnosis was AHLE. (Courtesy R. Ramakantan, MD).*
|
||||
|
||||
|
||||
*Axial NECT in a patient with AHLE shows patchy hemorrhages in the corpus callosum splenium <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Axial T2* SWI MR MIP in the same patient shows the microbleeds are heavily concentrated in the corpus callosum <img src='/img/arrows/BC.png'/> and hemispheric WM <img src='/img/arrows/BS.png'/>. Note involvement of the internal capsules and relative sparing of the basal ganglia and cortex.*
|
||||
|
||||
-70
@@ -1,70 +0,0 @@
|
||||
---
|
||||
title: "Allergic Bronchopulmonary Aspergillosis"
|
||||
docid: "81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a"
|
||||
breadcrumbs:
|
||||
- "Chest"
|
||||
- "Differential Diagnosis"
|
||||
- "Airways"
|
||||
- "General Imaging Patterns"
|
||||
- "Finger-in-Glove Sign"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Finger-in-glove sign: Mucoid impaction with resultant dilated or impacted bronchi
|
||||
- Bronchial obstruction: Atresia, foreign body, neoplasm
|
||||
- Nonobstructive entities: Allergic bronchopulmonary aspergillosis, cystic fibrosis
|
||||
- Radiography/CT: Branching tubular opacities that typically radiate from hilum toward lung periphery
|
||||
- Differential diagnosis of bronchial branching tubular opacities
|
||||
- Arteriovenous malformation
|
||||
- Exhibits contrast enhancement
|
||||
- Demonstrates afferent and efferent vessels: Feeding artery(ies) and draining vein(s)
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Allergic Bronchopulmonary Aspergillosis**
|
||||
- Immunologic disorder caused by hypersensitivity to*Aspergillus fumigatus*
|
||||
- Predisposing conditions: Asthma, cystic fibrosis
|
||||
- Laboratory findings: Positive aspergillus skin test, elevated IgE levels against *Aspergillus fumigatus*
|
||||
- Total IgE levels > 1,000 IU/mL
|
||||
- IgG antibodies against*A. fumigatus* in serum
|
||||
- Total eosinophil count > 500 cells/mL
|
||||
- Imaging: Branching tubular opacities, high attenuation on CT due to intrinsic calcium oxalate
|
||||
- **Congenital Bronchial Atresia**
|
||||
- Focal atresia of segmental bronchus
|
||||
- Typically affects left upper lobe apicoposterior segment
|
||||
- Recurrent infection in 20% of patients
|
||||
- CT: Tubular or branching opacity surrounded by hyperlucent lung due to air-trapping and oligemia
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Bronchiectasis**
|
||||
- Cystic fibrosis
|
||||
- Autosomal recessive disorder that affects regulation of chloride transport
|
||||
- Recurrent infection, progressive bronchial wall injury
|
||||
- Diffuse bronchiectasis (upper lobe predominant); central and peripheral airways affected
|
||||
- Primary ciliary dyskinesia
|
||||
- Structural abnormality that affects ciliary motion
|
||||
- Bronchiectasis, sinusitis, infertility
|
||||
- Basilar predominant airway involvement
|
||||
- **Benign Airway Neoplasm**
|
||||
- Hamartoma
|
||||
- Endobronchial (1.4% of cases)
|
||||
- Fat &/or calcification in endobronchial lesion supports diagnosis
|
||||
- Lipoma
|
||||
- Endobronchial lipoma (0.1-0.5% of lung tumors)
|
||||
- Nonenhancing homogeneous fat attenuation lesion
|
||||
- **Malignant Airway Neoplasm**
|
||||
- Carcinoid tumor
|
||||
- Low-grade neuroendocrine neoplasm
|
||||
- Intrinsic calcification; may be eccentric
|
||||
- Marked contrast enhancement
|
||||
- Lung cancer
|
||||
- Centrally obstructing mass
|
||||
- Mucoid impaction uncommon
|
||||
- **Foreign Body**
|
||||
- Patients < 15 years of age (70%)
|
||||
- Most frequent location: Right lower lobe bronchus and bronchus intermedius
|
||||
- Adults: Chronic clinical course, recurrent pneumonia
|
||||
@@ -1,358 +0,0 @@
|
||||
---
|
||||
title: "Alzheimer Disease"
|
||||
docid: "2aad3ac4-44fd-43e5-8e50-a86987483af3"
|
||||
breadcrumbs:
|
||||
- "Nuclear Medicine"
|
||||
- "Central Nervous System"
|
||||
- "Neurodegeneration"
|
||||
- "Alzheimer Disease"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Alzheimer disease (AD)
|
||||
- Progressive neurodegenerative brain disease related to build up of (Aβ) neuritic plaques and subsequent tau neurofibrillary tangles (NFTs)
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Amyloid PET
|
||||
- Cortical amyloid deposition on PET is early biomarker in AD and appears prior to clinical symptoms
|
||||
- Absence of amyloid plaque rules out AD in patients with dementia
|
||||
- ↓ gray-white matter differentiation in at least 2 regions or single area of focally ↑ gray matter uptake are signs of positive florbetapir study
|
||||
- F-18 FDG PET
|
||||
- Glucose hypometabolism in parietotemporal, posterior cingulate, and precuneus regions; usually symmetric
|
||||
- Glucose hypometabolism continues to worsen with disease progression
|
||||
- Atypical AD variants can show hypometabolism in occipital lobes, frontal lobes, or with marked bilateral asymmetry
|
||||
- SPECT
|
||||
- 2nd-line study if PET is not available/reimbursed
|
||||
- Tau PET
|
||||
- Cortical deposition of tau NFTs in posterolateral temporal lobes, parietal lobes, occipital lobes, and cingulate gyrus can stage disease severity
|
||||
- Negative to early disease stage by tau PET can predict better response to amyloid targeting therapies (ATTs) with 50% of patients showing improved memory function at 3 years of treatment
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Alzheimer disease (AD)
|
||||
- Progressive neurodegenerative brain disease generally characterized by impairments in episodic memory and other cognitive domains
|
||||
- Likely related to β-amyloid (Aβ) neuritic plaques and tau neurofibrillary tangles (NFTs) leading to synaptic dysfunction, neuronal/glial cell death
|
||||
- ATN(C) classification defines patient status according to amyloid (A), tau (T), neurodegeneration (N), and clinical (C) status
|
||||
- Amyloid determined by PET &/or certain cerebrospinal fluid (CSF) biomarkers with plasma biomarkers on horizon
|
||||
- Tau determined by PET &/or CSF markers with plasma biomarkers on horizon
|
||||
- Neurodegeneration typical for AD via MR, FDG PET, or CSF biomarkers
|
||||
- Clinical status by formal neurocognitive evaluation/screening with MMSE or MoCA
|
||||
- Role of imaging
|
||||
- Early detection of AD neuropathologic changes (ADNCs) prior to symptom onset
|
||||
- Diagnosis of AD with clinical presentation and other biomarkers
|
||||
- Differential diagnosis between AD and other causes of dementia
|
||||
- Preclinical AD or asymptomatic ADNC
|
||||
- Stage of disease process where pathologic Aβ plaque or tau NFT deposition has occurred but prior to onset of significant clinically detectable symptoms
|
||||
- Amyloid PET positive; positive CSF Aβ42 or p-tau181/217
|
||||
- Mild cognitive impairment (MCI)
|
||||
- Clinical symptoms of memory &/or other cognitive problems greater than normal for age and education
|
||||
- ↑ risk of conversion to AD but not all progress to full dementia
|
||||
- Annual conversion rate from MCI to dementia ~ 5-10%
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- ADNC (A+T+/-N+/-C-)
|
||||
- Amyloid PET positive (or CSF biomarker positive)
|
||||
- May or may not show changes on tau PET or FDG PET/MR
|
||||
- ↑ risk of developing AD symptoms
|
||||
- MCI and early AD (A+T+/-N+/-C+) clinically meeting criteria for MCI
|
||||
- Amyloid PET positive
|
||||
- F-18 FDG PET, tau PET, and MR abnormalities become more evident and can help stage disease severity, risk for symptomatic conversion of ADNC, and help assess likelihood that symptoms are related to AD
|
||||
- Mild clinical symptoms
|
||||
- Late AD (A+T+/-N+/-C+) clinically meeting criteria for dementia
|
||||
- Amyloid and F-18 FDG PET grossly positive
|
||||
- FDG PET hypometabolism and cortical tau PET accumulation can become more extensive or involve atypical areas
|
||||
- More extensive atrophy present (CT/MR)
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- Amyloid PET imaging
|
||||
- F-18 florbetapir, flutemetamol, and florbetaben tracers are FDA approved
|
||||
- ↑ brain amyloid in gray matter on PET, normal off-target white matter binding to myelin proteins
|
||||
- Earliest imaging biomarker in AD
|
||||
- Absence of amyloid plaque rules out AD in patients with dementia
|
||||
- Interpretation of amyloid PET images
|
||||
- View in black-on-white background at high contrast levels (flutemetamol can be read in color)
|
||||
- View axial images 1st
|
||||
- Coronal and sagittal views for confirmation
|
||||
- Cerebellum gray-white differentiation is baseline for discerning normal gray matter from physiologic tracer retained in white matter
|
||||
- Positive scan (moderate or frequent Aβ deposition in cerebral cortex)
|
||||
- Blurring of gray/white matter junction due to radiotracer uptake in gray matter
|
||||
- ↑ gray matter uptake in temporal, parietal, and frontal cortices
|
||||
- Uptake in posterior cingulate gyrus and precuneus (may be early deposition sign)
|
||||
- F-18 florbetapir: ↓ gray-white matter differentiation in at least 2 regions or single area of focally ↑ gray matter uptake ≥ adjacent white matter = positive
|
||||
- Extent of amyloid deposition does not correlate with severity of AD
|
||||
- Negative scan (no evidence of significant Aβ deposition)
|
||||
- Symptoms unlikely due to AD
|
||||
- Does not exclude non-AD dementia
|
||||
- Artifacts and pitfalls
|
||||
- Severely diminished gray matter volume in AD patients may make abnormal exam appear normal due to contoured cortex
|
||||
- View fused PET/CT or PET/MR images as supplement to evaluate uptake relative to white and gray matter
|
||||
- Highest transaxial images above orbits often have diminished gray-white matter differentiation, even in normal patients
|
||||
- F-18 FDG PET
|
||||
- General F-18 FDG uptake patterns
|
||||
- MCI: Medial temporal lobe hypometabolism
|
||||
- Early AD
|
||||
- Relative reduction in activity in parietal, temporal lobes and posterior cingulate gyri and precuneus, usually symmetric
|
||||
- Advanced AD
|
||||
- Progression of findings present in early AD
|
||||
- Usually symmetric
|
||||
- Frontal lobe hypometabolism can develop later in disease course
|
||||
- Moderate to severe atrophy
|
||||
- Atypical AD patterns
|
||||
- Posterior cortical atrophy: Similar hypometabolism to typical AD + asymmetric occipital hypometabolism
|
||||
- Logopenic variant primary progressive aphasia (lvPPA): Similar to typical AD though with strong left-sided predominance (language dominant hemisphere)
|
||||
- Behavioral or dysexecutive AD: 50% similar to typical AD + extensive frontal hypometabolism; 50% indistinguishable from frontotemporal dementia (FTD) without parietal involvement
|
||||
- F-18 FDG PET most accurate when read in conjunction with quantitative software that compares F-18 FDG uptake to age-matched normal database
|
||||
- Surface projections also ↑ sensitivity for AD detection
|
||||
- SPECT perfusion with Tc-99m HMPAO or Tc-99m ethyl cystine dimer (ECD) has similar appearance as PET but ↓ resolution and sensitivity
|
||||
- Tau PET
|
||||
- Flortaucipir: Only FDA-approved tau PET tracer
|
||||
- Compare uptake to reference region [1.65 x mean standardized uptake value ratio (SUV) cerebellum], which acts as internal negative control during interpretation
|
||||
- Negative if cortical binding is limited to mesial and anteromedial temporal lobes or isolated frontal lobes, off-target binding to choroid plexus
|
||||
- Mild/early AD may be indistinguishable from normal study
|
||||
- Moderate AD if cortical binding extends to posterolateral temporal lobes and temporooccipital regions
|
||||
- Advanced AD if cortical binding extends beyond to parietal, occipital, and cingulate regions
|
||||
- Negative to early disease stage by tau PET can predict better response to amyloid targeting therapies (ATTs) with 50% of patients showing improved memory function at 3 years of treatment
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- T1WI, T2WI
|
||||
- Atrophy of medial temporal lobe structures (entorhinal cortex, hippocampus); visible as early as MCI and posterior structures (precuneus and parietal convexities)
|
||||
- Rates of whole-brain and hippocampal atrophy may be used to monitor progression of neurodegeneration and help stage AD severity
|
||||
- Can use volumetrix to quantitatively assess volume loss
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- Amyloid PET best for ruling out AD
|
||||
- Appropriate Use Criteria (AUC) for amyloid PET (SNMMI and AA joint task force)
|
||||
- Objectively confirmed persistent or progressive unexplained cognitive impairment
|
||||
- May satisfy core clinical criteria for AD but unclear presentation, such as atypical or mixed
|
||||
- Progressive dementia and atypically early age of onset (< 65 years)
|
||||
- Candidacy for ATTs
|
||||
- If considering amyloid PET, knowledge of Aβ pathology should ↑ diagnostic certainty &/or patient management
|
||||
- Amyloid and F-18 FDG PET can help to differentiate between AD and other causes of dementia (FTD, Lewy body dementia)
|
||||
- PET may be used in early diagnosis of ADNC
|
||||
- Correlate imaging results with clinical picture and other biomarkers of AD
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- Amyloid PET
|
||||
- Patient preparation
|
||||
- Patient needs to lie still for 20-30 min; thus, immobilization techniques may be necessary
|
||||
- Radiopharmaceutical, dose, and time of scan post injection
|
||||
- F-18 florbetapir (Amyvid), 10 mCi, 30-50 min
|
||||
- F-18 flutemetamol (Vizamyl), 5 mCi, 90 min
|
||||
- F-18 florbetaben (Neuraceq), 8 mCi, 45-130 min
|
||||
- Dosimetry: Gallbladder wall receives highest dose, followed by intestines
|
||||
- Image acquisition
|
||||
- Depends largely on available PET scanner
|
||||
- CT typically used for attenuation correction; older PET scanners may use separate source (e.g., Ge-68/68-Ga) for transmission scan
|
||||
- Imaging begins 30-130 min after injection
|
||||
- 20-min acquisition
|
||||
- Matrix: Transaxial 128 x 128 or 256 x 256
|
||||
- Pixel size: 2-3 mm
|
||||
- Slice thickness: 2-4 mm
|
||||
- Filtered back projection or iterative reconstruction
|
||||
- F-18 FDG PET
|
||||
- Patient preparation
|
||||
- Patient should fast, stop IV fluids containing dextrose, and stop parenteral feeding for 4-6 hours
|
||||
- Blood sugar should be < 150-200 mg/dL
|
||||
- Patient should be placed in quiet, dimly lit room prior to and after injection for 30 min
|
||||
- Radiopharmaceutical: F-18 FDG
|
||||
- Dose: 5-20 mCi (185-740 MBq)
|
||||
- Dosimetry: Urinary bladder receives largest dose
|
||||
- Image acquisition: 30-60 min after injection
|
||||
- Perfusion SPECT
|
||||
- 2nd-line study if PET is not available
|
||||
- Patient preparation
|
||||
- Place patient in quiet, dimly lit room prior to and after injection for 30 min
|
||||
- Radiopharmaceutical
|
||||
- Tc-99m exametazime (HMPAO)
|
||||
- Tc-99m bicisate (ECD)
|
||||
- Dose: 15-30 mCi (555 MBq to 1.1 GBq)
|
||||
- Dosimetry
|
||||
- Tc-99m HMPAO: Kidneys receive highest dose
|
||||
- Tc-99m ECD: Bladder wall receives highest dose
|
||||
- Image acquisition
|
||||
- Optimal imaging time for Tc-99m HMPAO: 90 min post injection
|
||||
- Optimal imaging time for Tc-99m ECD: 45 min post injection
|
||||
- Tau PET
|
||||
- Dose: 10 mCi flortaucipir
|
||||
- Image acquisition: ~ 80 min after injection, 20-min acquisition
|
||||
- Dosimetry: Intestines and liver are critical organs
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Vascular Dementia (Multiinfarct Dementia)
|
||||
|
||||
|
||||
- Impaired blood supply to brain regions
|
||||
- 2nd most common cause of dementia
|
||||
- Global atrophy with diffuse white matter lesions/infarcts that generally correlate with cognitive symptoms
|
||||
- ## Alzheimer Disease Mixed Dementia
|
||||
|
||||
|
||||
- AD and other dementia
|
||||
- ## Dementia With Lewy Bodies
|
||||
|
||||
|
||||
- Commonly presents with hallucinations, sleep disturbances, and parkinsonian motor features
|
||||
- F-18 FDG PET hypometabolism in occipital cortex distinguishes from typical amnestic AD
|
||||
- Consider DaT SPECT or FDOPA PET to help exclude posterior cortical atrophy if clinically uncertain
|
||||
- Can consider cardiac MIBG scan (reduced cardiac sympathetic activity in dementia with Lewy bodies, see on MIBG)
|
||||
- Skin biopsy for α-synuclein
|
||||
- ## Frontotemporal Dementia
|
||||
|
||||
|
||||
- Commonly presents with personality and behavioral changes, which can also be seen with behavioral/dysexecutive AD variants
|
||||
- Atrophy of frontal and anterior temporal lobes
|
||||
- Language variant FTDs (semantic and nonfluent agrammatic PPA) can mimic lvPPA
|
||||
- F-18 FDG PET hypometabolism primarily in frontal and anterior temporal lobes
|
||||
- Negative amyloid PET; helps exclude AD in favor of FTD
|
||||
- ## Creutzfeldt-Jakob Disease
|
||||
|
||||
|
||||
- Rapidly fatal, prion-related disease with impairments in cognition and behavioral changes
|
||||
- MR DWI: Hyperintensity in striatum, cingulum, neocortex
|
||||
- ## Causes of Reversible Dementia
|
||||
|
||||
|
||||
- [Normal-pressure hydrocephalus](/document/normal-pressure-hydrocephalus/834ccc3e-2116-4295-8408-0ac9a06bd2ff)
|
||||
- Hypothyroidism
|
||||
- Infections: Neurosyphilis, HIV
|
||||
- Trauma (e.g., chronic subdural hematoma)
|
||||
- Tumor, other mass lesions
|
||||
- Depression
|
||||
- Vitamin B12 deficiency
|
||||
- ## Other Neurodegenerative Disease
|
||||
|
||||
|
||||
- Parkinson disease
|
||||
- Huntington disease
|
||||
- ## Cerebral Amyloid Angiopathy
|
||||
|
||||
|
||||
- Abnormal accumulation of amyloid in leptomeningeal and cortical vessels, leading to intracranial hemorrhage
|
||||
- Can present with cognitive decline concerning for AD
|
||||
- Amyloid positive scan
|
||||
- MR is most helpful for finding lobar predominant microhemorrhages and superficial siderosis
|
||||
- Can have inflammatory variants and even amyloidomas (mimicking intracranial mass)
|
||||
- ## Primary Age-Related Tauopathy (A-T+N+/-C+)
|
||||
|
||||
|
||||
- Tau-related NFTs limited to temporal lobes without amyloid deposition on PET
|
||||
- Patients are typically much older than AD, and cognitive decline rate is typically slower
|
||||
- ## Limbic-Predominant Age-Related TDP-43 Encephalopathy
|
||||
|
||||
|
||||
- Amyloid negative (unless associated with AD copathology)
|
||||
- Typically in older patients (> 80 years)
|
||||
- Extensive temporal lobe FDG hypometabolism with less involvement of parietal structures
|
||||
- MR may show marked hippocampal sclerosis
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Most likely combination of genetic, lifestyle, and environmental factors
|
||||
- Pathologic deposition of Aβ neuritic plaques and subsequent tau NFTs in pathogenesis
|
||||
- Accumulation of extracellular amyloid plaques contribute to disrupted synaptic communication and neuronal death
|
||||
- Accumulation of intracellular tau NFTs contribute to disruption of nutrient and molecular transfer and neuronal death
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- Early-onset, familial AD
|
||||
- Single-gene mutation
|
||||
- βA precursor protein (*APP*) gene on chromosome 21
|
||||
- Presenilin 1 (*PSEN1*) gene on chromosome 14
|
||||
- Presenilin 2 (*PSEN2*) gene on chromosome 1
|
||||
- Results in formation of abnormal proteins involved in APP
|
||||
- May contribute to production of harmful forms of βA and βA-related pathology
|
||||
- Late-onset, sporadic AD
|
||||
- Significant risk is related to apolipoprotein E (*APOE*) gene on chromosome 19
|
||||
- ApoE plays role in cholesterol transport and βA maintenance
|
||||
- ApoE exists as 3 alleles (e2, e3, e4) with each individual carrying 2 copies
|
||||
- ApoE-e4 allele is present in 20-30% of USA population and confers ↑ risk for AD development
|
||||
- 40-65% of individuals with AD carry at least 1 copy of e4 allele
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Significant impairment in memory and cognition with typical AD
|
||||
- Mood and personality changes with behavioral/dysexecutive AD variant
|
||||
- Language impairment, including sentence repetition, preserved single-word meaning with lvPPA
|
||||
- Visuospatial and visuoperceptual impairment with posterior cortical atrophy
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- Preclinical AD
|
||||
- Amyloid PET turns positive during this period
|
||||
- No noticeable symptoms of AD with early AD brain changes (up to 20 years before symptoms)
|
||||
- MCI
|
||||
- Change in cognition within ≥ 1 cognitive domains with functional independence intact
|
||||
- Possible AD
|
||||
- Significant cognitive/behavioral symptoms
|
||||
- Must represent change from prior status
|
||||
- Must interfere with functional ability
|
||||
- In presence of sudden onset &/or another disorder that could cause similar symptoms, e.g., cerebrovascular disease
|
||||
- Probable AD
|
||||
- Insidious change of cognitive/behavioral symptoms that interferes with functional ability
|
||||
- Not in presence of another disorder that could cause similar symptoms
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- ~ 5.2 million in USA affected by AD
|
||||
- Most common cause of dementia (60-80% of cases)
|
||||
- Prevalence
|
||||
- ~ 11% of adults ≥ 65 years
|
||||
- ~ 32% of adults ≥ 85 years
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Novel amyloid-targeting antibody therapies slow decline and may improve mental status if started early
|
||||
- Requires initial baseline MR to exclude cerebral amyloid and preexisting risk for hemorrhage
|
||||
- Requires surveillance for development of amyloid-related imaging abnormalities (ARIA)
|
||||
- Cholinesterase inhibitors may delay worsening of cognitive symptoms for 6-12 months
|
||||
- NMDA inhibitors may temporarily delay worsening of symptoms
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Key Imaging Findings
|
||||
|
||||
|
||||
- AD neuropathic change
|
||||
- Amyloid PET positive or positive key CSF biomarkers
|
||||
- AD
|
||||
- FDG hypometabolism develops in parietal lobes, precuneus, posterior cingulate gyrus, posterior temporal lobes, and frontal lobes in advanced cases
|
||||
- Tau PET shows NFTs in posterolateral temporal neocortex, temporooccipital regions, and, eventually, parietal and cingulate regions
|
||||
|
||||
47897414-6c3f-419d-8061-50a189ef4e1f
|
||||
@@ -1,325 +0,0 @@
|
||||
---
|
||||
title: "Alzheimer Disease"
|
||||
docid: "f71f5cf5-b1af-4c6d-b145-b4c10eec7b58"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Acquired Toxic/Metabolic/Degenerative Disorders"
|
||||
- "Dementias and Degenerative Disorders"
|
||||
- "Alzheimer Disease"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Alzheimer disease (AD)
|
||||
- Slowly progressive neurodegenerative disease
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Current role of imaging in AD
|
||||
- Exclude other causes of dementia
|
||||
- Identify region-specific patterns of brain volume loss
|
||||
- Identify imaging markers of coexistent disease, such as amyloid angiopathy
|
||||
- Identify early AD for possible innovative therapy
|
||||
- Best imaging = volumetric MR, F-18 FDG PET
|
||||
- Thinned gyri, widened sulci, and enlarged ventricles
|
||||
- Medial temporal lobe particularly hippocampus and entorhinal cortex disproportionately affected
|
||||
- F-18 FDG PET
|
||||
- Early-stage AD: ↓ metabolism in parietotemporal association cortices, posterior cingulate, and precuneus regions
|
||||
- Moderate to severe AD: Additional frontal lobe involvement
|
||||
- Amyloid PET imaging: High sensitivity in detecting amyloid plaques and vascular amyloid in vivo
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Normal aging
|
||||
- Vascular dementia
|
||||
- Normal-pressure hydrocephalus
|
||||
- Frontotemporal lobar degeneration
|
||||
- Dementia with Lewy bodies
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Most common cause of dementia > age 65
|
||||
- Age is biggest risk factor
|
||||
- 1-2% prevalence at age 65
|
||||
- Incidence doubles every 5 years after age of 60
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- Look for reversible causes of dementia
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Alzheimer disease (AD)
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Senile/presenile dementia of Alzheimer type
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- AD dementia is progressive neurodegenerative condition characterized by progressive cognitive decline, memory impairment, and adverse impact on activities of daily living
|
||||
- National Institute on Aging and Alzheimer's Association (NIA-AA) 2011 workgroup recommendations
|
||||
- Phases of AD pathophysiological processes
|
||||
- Preclinical AD
|
||||
- Mild cognitive impairment (MCI) in AD
|
||||
- AD dementia
|
||||
- AD is pathologic process reflected in specific postmortem histopathologic criteria, which is frequently but not necessarily associated with characteristic dementia syndrome
|
||||
- Probable AD dementia: Clinical syndrome meeting core clinical criteria specified in NIA-AA workgroup report
|
||||
- Possible AD dementia: Clinical syndrome meeting core clinical criteria for AD dementia in terms of nature of cognitive deficits for AD dementia, but either 1) has sudden onset of impairment or demonstrates insufficient historical detail or objective documentation of progression, or 2) has mixed etiological presentation due to evidence of vascular or Lewy body pathology
|
||||
- MCI: Clinical syndrome meeting published core clinical criteria for MCI; generally agreed core features include 1) concern for change in cognition, 2) impairment in one or more cognitive domains, and 3) preservation of independence in functional activities, but 4) not demented
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- MR: Temporal/parietal cortical atrophy
|
||||
- Disproportionate hippocampal volume loss
|
||||
- FDG PET: Regional ↓ glucose metabolism
|
||||
- Temporoparietal lobes, posterior cingulum
|
||||
- **Current role of imaging in AD**
|
||||
- Exclude other structural abnormalities
|
||||
- Evaluate degree and location of atrophic changes
|
||||
- Evaluate for metabolic abnormalities
|
||||
- When structural abnormalities absent/uncharacteristic (i.e., early in disease course)
|
||||
- Identify preclinical and MCI in AD for possible innovative therapy
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Screening to exclude potentially reversible or treatable causes of dementia
|
||||
- Medial temporal lobe atrophy in early disease and generalized atrophy in late stages
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- Current role of MR
|
||||
- Exclude other causes of dementia
|
||||
- Identify region-specific patterns of brain volume loss
|
||||
- Identify imaging markers of coexistent disease, such as amyloid angiopathy
|
||||
- T1 to assess medial temporal atrophy score and atrophy patterns
|
||||
- High resolution (MPRAGE/SPGR) for volumetric analysis
|
||||
- Thinned gyri, widened sulci, and enlarged ventricles
|
||||
- Medial temporal lobe disproportionately affected
|
||||
- May help distinguish patients with MCI from normal elderly
|
||||
- Average hippocampal volume reduction 20-25% in AD and 10-15% in MCI
|
||||
- T2* GRE/SWI for microhemorrhages, amyloid angiopathy
|
||||
- MRS
|
||||
- ↓ NAA and ↑ mI in AD, even in early stage
|
||||
- NAA:mI ratio relatively sensitive and highly specific in differentiating AD from normal elderly
|
||||
- NAA:Cr ratio in posterior cingulate gyri and left occipital cortex predicts conversion of MCI to probable AD
|
||||
- DTI: ↓ FA in multiple regions, especially superior longitudinal fasciculus and splenium
|
||||
- Perfusion MR: ↓ rCBV in temporal, parietal regions
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- F-18 FDG PET
|
||||
- Early-stage AD
|
||||
- ↓ metabolism in parietotemporal association cortices, posterior cingulate, and precuneus regions
|
||||
- Most reliable early changes in posterior cingulate
|
||||
- Moderate to severe AD
|
||||
- Additional frontal lobe involvement
|
||||
- MCI in AD
|
||||
- Same pattern of ↓ metabolism as AD
|
||||
- Higher accuracy than MR for diagnosing early AD
|
||||
- Amyloid (Aβ) PET imaging
|
||||
- Specifically bind to Aβ plaques and retention of tracer is specific for Aβ neuritic plaque pathology
|
||||
- F-18 florbetapir, F-18 florbetaben, and F-18 flutemetamol FDA approved for clinical use
|
||||
- Positive scan shows loss of gray/white matter distinction due to tracer uptake in neocortex
|
||||
- Negative scan retains gray/white matter distinction
|
||||
- Criteria for appropriate use (AUC) of amyloid PET
|
||||
- Persistent/progressive unexplained MCI
|
||||
- Possible AD with unclear presentation
|
||||
- Atypical early-onset progressive dementia
|
||||
- In patients with MCI fulfilling clinical AUC, Aβ-PET is associated with
|
||||
- Significant improvement in diagnostic confidence
|
||||
- High impact on therapeutic management
|
||||
- Tau PET imaging
|
||||
- Currently under development
|
||||
- Signal matches anatomic distribution of neurofibrillary tangles
|
||||
- Earliest detection in entorhinal cortex and hippocampus, later inferior and lateral temporal, followed by parietal and occipital, and finally frontal cortices
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- Volumetric MR (MPRAGE/SPGR sequences)
|
||||
- F-18 FDG PET
|
||||
- Aβ PET for patients who meet AUC
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- MPRAGE or SPGR for volumetric measurement
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Causes of Reversible Dementia
|
||||
|
||||
|
||||
- [Thiamine deficiency, vitamin B12 deficiency, hypothyroidism](/document/alcoholic-encephalopathy/88021852-b73d-4cdf-a719-dd4ae3231e45)
|
||||
- Depression ("pseudodementia")
|
||||
- [Normal-pressure hydrocephalus](/document/normal-pressure-hydrocephalus/ba3f857d-58de-4f21-8463-1631b4cb9972)
|
||||
- [Mass lesions (chronic subdural hematoma, tumor, etc.)](/document/chronic-subdural-hematoma/cc7b52b4-c6a0-4b4e-ae8c-f05bfc5c5cb2)
|
||||
- [Vascular Dementia](/document/vascular-dementia/f59dab57-c511-4369-8fcc-592421a4b8d1)
|
||||
- 2nd most common dementia (15-30%)
|
||||
- Parenchymal hyperintensities, focal atrophy (infarcts)
|
||||
- [Frontotemporal Lobar Degeneration](/document/frontotemporal-lobar-degeneration/49510d0e-acf7-45cb-9eb1-53f8193b0b6d)
|
||||
- Frontal &/or anterior temporal atrophy
|
||||
- [Dementia With Lewy Bodies](/document/dementia-with-lewy-bodies/e8e46d1d-46d2-4e5a-880f-f025a84c5871)
|
||||
- Hypometabolism of entire brain
|
||||
- [Corticobasal Degeneration](/document/corticobasal-degeneration/23f97d4e-8724-4229-b9f8-08f63906ebd8)
|
||||
- Prominent extrapyramidal, cortical symptoms
|
||||
- Asymmetric severe frontoparietal atrophy
|
||||
- [Creutzfeldt-Jakob Disease](/document/creutzfeldt-jakob-disease-cjd/e1b27954-6591-4bb0-a659-b13790492620)
|
||||
- Dementia with myoclonus, EEG abnormalities
|
||||
- Hyperintensity in anterior basal ganglia, cortex
|
||||
- [Cerebral Amyloid Angiopathy](/document/cerebral-amyloid-disease/48e9458e-102f-40bd-8eec-bc0bc97101c6)
|
||||
- Often coexists with AD
|
||||
- Microhemorrhages on T2* GRE/SWI
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Extracellular β-amyloid plaques
|
||||
- Located in cerebral cortex
|
||||
- Intracellular accumulation of neurofibrillary tangles (NTs)
|
||||
- Initially around hippocampus, later spread to other cortical areas
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- Most cases late-onset sporadic AD
|
||||
- Deterministic genetic mutation not found
|
||||
- Apolipoprotein E (*ApoE*) ε4 allele is major genetic risk factor
|
||||
- Rare early-onset AD
|
||||
- Mutations in 1 of 3 genes
|
||||
- Amyloid precursor protein gene on chromosome 21
|
||||
- Presenilin-1 (*PSEN1*) gene on chromosome 14
|
||||
- Presenilin-2 (*PSEN2*) gene on chromosome 1
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- Consortium to Establish a Registry for Alzheimer Disease (CERAD)
|
||||
- Semiquantitative approach counting plaques/tangles
|
||||
- Frequent, moderate, or infrequent
|
||||
- Braak and Braak (B&B)
|
||||
- 6 levels of staging
|
||||
- Transentorhinal stage (1-2): NTs develop in parahippocampal gyrus (clinically asymptomatic)
|
||||
- Limbic stage (3-4): NTs dramatically increase in parahippocampal gyrus, begin to develop in hippocampus (mild cognitive impairment)
|
||||
- Neocortical stage (5-6): NTs develop in temporal and parietal cortex, eventually spread to entire neocortex (severe dementia)
|
||||
- NIA-Reagan
|
||||
- Likelihood high
|
||||
- CERAD frequent, B&B 5/6
|
||||
- Likelihood intermediate
|
||||
- CERAD moderate, B&B 3/4
|
||||
- Likelihood low
|
||||
- CERAD infrequent, B&B 1/2
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Shrunken gyri, widened sulci
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- 2 abnormal protein aggregates characterize AD pathologically
|
||||
- Neurofibrillary tangles
|
||||
- Intracellular aggregates in neurons due to hyperphosphorylation of tau protein
|
||||
- Begins in entorhinal cortex, progresses to hippocampus, paralimbic system, and adjacent medial-basal temporal lobe
|
||||
- Aβ deposition
|
||||
- Hallmark of Aβ peptide deposit in AD is neuritic plaque
|
||||
- Dense Aβ core with inflammatory cells and dystrophic neurites in its periphery
|
||||
- Neurodegeneration: Synapse and neuron loss
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Slowly progressive neurodegenerative disease
|
||||
- Initially affects episodic memory
|
||||
- Then, at least 1 other area of cognition
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- Clinical subtypes
|
||||
- MCI: Early, mild memory impairment; no deficits in cognitive domains other than memory, not impairing daily function
|
||||
- Possible AD: Dementia features in presence of 2nd disease that could cause memory deficit but is not likely cause
|
||||
- Probable AD: Memory deficits on neuropsychological testing, progressive worsening of memory and ≥ 2 cognitive functions
|
||||
- Definite AD: Pathologic diagnosis
|
||||
- 5 major biomarkers for AD
|
||||
- Amyloid accumulation: CSF Aβ 42, Aβ-PET imaging
|
||||
- Neurogeneration or neuronal injury: CSF tau (total and phosphorylated), structural MR, and FDG PET
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Biggest risk factor
|
||||
- 1-2% prevalence at age 65
|
||||
- Incidence doubles every 5 years after age of 60
|
||||
- ### Sex
|
||||
|
||||
|
||||
- Women more commonly affected
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- AD most common neurodegenerative dementia
|
||||
- 5-7 million new AD dementia cases every year
|
||||
- Currently ~ 5.3 million in USA
|
||||
- 13% of individuals > 65 years and > 50% of individuals > 85 years
|
||||
- Other risk factors
|
||||
- Family history (20%)
|
||||
- Head trauma, metabolic syndrome
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Chronic, progressive
|
||||
- Patients live average 8-10 years after diagnosis
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- No established treatments
|
||||
- May transiently improve cognitive function
|
||||
- Cholinesterase inhibitors, NMDA receptor antagonists
|
||||
- Many current disease-modifying drugs to reduce Aβ
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Look for
|
||||
- Reversible causes of dementia
|
||||
- Ventricular enlargement, sulcal widening proportionate
|
||||
- ↑ temporal horns of lateral ventricle
|
||||
- Hippocampal, entorhinal cortex volume loss
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- MR volumetric analysis helps distinguish MCI in AD from normal elderly subjects, measure change hippocampus/parahippocampal gyri over time
|
||||
- F-18 FDG PET
|
||||
- Helps distinguish AD from frontotemporal dementia
|
||||
- May identify early AD when MR normal
|
||||
|
||||
5dea6eed-cbf2-4d32-8c2b-43f74913fca6
|
||||
-341
@@ -1,341 +0,0 @@
|
||||
---
|
||||
title: "Amyotrophic Lateral Sclerosis (ALS)"
|
||||
docid: "23de52b7-d9bd-441c-a18c-95c8afccb470"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Acquired Toxic/Metabolic/Degenerative Disorders"
|
||||
- "Dementias and Degenerative Disorders"
|
||||
- "Amyotrophic Lateral Sclerosis (ALS)"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Amyotrophic lateral sclerosis (ALS)
|
||||
- Selective degeneration of somatic motor neurons of brainstem/spinal cord & large pyramidal neurons of motor cortex
|
||||
- Eventual loss of corticospinal tract (CST) fibers
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Small percentage demonstrate CST hyperintensity
|
||||
- As CST is normally slightly hyperintense, especially at 3.0 T, this finding lacks sensitivity & specificity
|
||||
- T2-hyperintense CST may be specific for ALS when seen on corresponding PD images
|
||||
- Consider FLAIR & PD in suspected ALS
|
||||
- DWI hyperintensity (↓ diffusivity) in CST
|
||||
- Hypointense gray matter in precentral gyrus (motor cortex)
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Primary lateral sclerosis
|
||||
- Wallerian degeneration
|
||||
- Hypertrophic olivary degeneration
|
||||
- Metabolic diseases involving bilateral CSTs
|
||||
- Demyelinating & inflammatory diseases
|
||||
- Neoplasms: Brainstem glioma, malignant lymphoma
|
||||
- CST can appear hyperintense on 3T MR normally
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- Majority of ALS cases are sALS
|
||||
- 5-10% are familial (fALS)
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- UMN signs: Babinski sign, spasticity, hyperreflexia
|
||||
- LMN signs: Asymmetric muscle weakness, atrophy, fasciculations, hyporeflexia
|
||||
- Bulbar signs: Slurred speech, dysphagia
|
||||
- Classic ALS: Both UMN & LMN affected
|
||||
- Peaks in 6th-8th decades of life
|
||||
- Complete disability & death within 1 decade
|
||||
- Some patients with familial, juvenile-onset ALS survive for longer periods (2-3 decades)
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Amyotrophic lateral sclerosis (ALS)
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Lou Gehrig disease, motor neuron disease (MND)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Selective degeneration of somatic motor neurons of brainstem/spinal cord {lower motor neurons (LMN) & large pyramidal neurons of motor cortex [upper motor neurons (UMN)]}
|
||||
- Eventual loss of corticospinal tract (CST) fibers
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Bilateral hyperintensities along CST extending from corona radiata to brainstem on T2WI/PD/FLAIR
|
||||
- ### Location
|
||||
|
||||
|
||||
- Hallmark is CST & LMN degeneration
|
||||
- LMN in anterior horn of spinal cord & brainstem
|
||||
- Corticospinal UMN in precentral gyrus (motor cortex)
|
||||
- White matter (WM) & gray matter (GM)
|
||||
- Frequently, prefrontal motor neurons involved in planning or orchestrating work of UMN & LMN
|
||||
- ### Size
|
||||
|
||||
|
||||
- Atrophy of motor system, particularly pyramidal tract, in advanced stages of ALS
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Oval or thin, curvilinear hyperintensities conforming to CST
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Serial CT exams may show progressive atrophy
|
||||
- Frontal, anterior temporal lobes → precentral gyrus → postcentral gyrus, anterior cingulate gyrus, corpus callosum, tegmentum
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Different T1 appearances of CST
|
||||
- Isointensity (most common) may reflect ↑ content of free radicals
|
||||
- Hypointense or mild hyperintense signal
|
||||
- CST differs between ALS patients & normal subjects only at internal capsule
|
||||
- T1 hyperintensity in anterolateral cervical cord is associated with younger patients & rapid disease progression
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Hyperintense CST
|
||||
- Hyperintensity can occur anywhere from subcortical WM of precentral gyrus to posterior limb internal capsules, cerebral peduncles, & pons
|
||||
- As CST is normally slightly hyperintense especially at 3.0 T, this finding lacks sensitivity & specificity
|
||||
- T2 hyperintense CST may be specific for ALS when seen on corresponding PD images
|
||||
- Hypointense GM in precentral gyrus (motor cortex)
|
||||
- Nonspecific; may be due to iron & heavy metals accumulating in cortex of aged patients
|
||||
- ### PD/intermediate
|
||||
|
||||
|
||||
- Hyperintense CST
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- More sensitive & less specific than T2 FSE for detecting hypointensity in precentral gyrus
|
||||
- Hyperintense CST
|
||||
- More frequently seen on FLAIR than on T2/T1/PD
|
||||
- ### T2* GRE
|
||||
|
||||
|
||||
- Hypointensity in precentral gyri
|
||||
- ### DWI
|
||||
|
||||
|
||||
- Hyperintensity in CST
|
||||
- May be seen in absence of T2 hyperintensity
|
||||
- Diffusion tensor imaging (DTI)
|
||||
- ROI-based approaches & tractography demonstrates significant changes in diffusion parameters along CST
|
||||
- Most common finding: ↓ fractional anisotropy (FA) in CST due to UMN degeneration
|
||||
- ↓ FA in CST; most significant in posterior limb internal capsule & correlates with disease severity
|
||||
- ↑ mean diffusivity (MD) along CST which correlates with disease duration
|
||||
- ↑ MD in corpus callosum, frontal & temporal WM
|
||||
- ↓ FA & ↑ MD in cervical cord correlate with disease severity & duration respectively
|
||||
- ¹H-MRS useful for assessing UMN involvement
|
||||
- ↓ NAA, ↓ NAA/Cr, ↓ NAA/Cho, & ↓ NAA/(Cr + Cho) in motor cortex
|
||||
- NAA present primarily in neurons; these metabolic changes reflect loss or dysfunction of motor neurons
|
||||
- ↓ NAA/Cr:NAA/Cho ratio along CST; most pronounced in precentral gyrus & corona radiata
|
||||
- ↓ NAA in pons & upper medulla in patients with prominent UMN or bulbar signs
|
||||
- ↑ Cho in posterior limb internal capsule
|
||||
- ↑ myo-inositol (mI) in motor cortex
|
||||
- ↓ NAA:mI ratio has better sensitivity & specificity in detecting ALS than any other metabolites
|
||||
- Magnetization-transfer ratio (MTR) measurements
|
||||
- ↓ MTR in CST
|
||||
- CST hyperintensity on T1 MT contrast-enhanced images: 80% sensitivity, 100% specificity
|
||||
- May detect CST degeneration of ALS at early stage
|
||||
- Voxel-based morphometry (VBM)
|
||||
- Regional GM loss in motor cortex, frontal, temporal, parietal, & limbic regions
|
||||
- Frontal severe atrophy in ALS & frontotemporal dementia
|
||||
- WM loss in corpus callosum, cerebellum, frontotemporal, & occipital regions
|
||||
- ↓ Brain parenchymal fraction (BPF) & very mild global brain atrophy
|
||||
- Functional MR
|
||||
- Pattern of cortical reorganization
|
||||
- ↑ activation of contralateral sensorimotor cortex, supplementary motor area, basal ganglia, & cerebellum during motor tasks
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- PET, Tc-99m HMPAO SPECT
|
||||
- ↓ regional cerebral metabolism/perfusion throughout brain with marked changes in sensorimotor cortex & putamen
|
||||
- ↑ ALS severity correlated with ↓ GM perfusion
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- Best imaging tool: MR with T2, PD, FLAIR, DTI
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Primary Lateral Sclerosis
|
||||
|
||||
|
||||
- Neurodegeneration restricted to UMN
|
||||
- T2WI shows changes in motor pathways
|
||||
- *ALS2* mutations reported
|
||||
- Autosomal recessive disease with juvenile onset
|
||||
- Infantile-onset hereditary spastic paraplegia
|
||||
- Spastic paralysis with ascending progression, only UMN involvement
|
||||
- Mutations described in alsin & spastin genes
|
||||
- [Wallerian Degeneration](/document/wallerian-degeneration/e4bb682d-6534-4176-9d39-34c1a42f3771)
|
||||
- Dynamic signal intensities change along CST in patients with various cortical/subcortical lesions
|
||||
- [Hypertrophic Olivary Degeneration](/document/hypertrophic-olivary-degeneration/78257543-6d52-4879-84b1-445f3611d996)
|
||||
- Secondary degeneration of inferior olivary nucleus (ION), usually caused by primary lesions in dento-rubro-olivary pathway
|
||||
- ## Conditions With T2-Hyperintense Lesions Along CST
|
||||
|
||||
|
||||
- Metabolic diseases may involve CST bilaterally
|
||||
- [X-linked adrenoleukodystrophy, Wilson disease](/document/wilson-disease/3d4d4876-4ce4-4af0-9e75-1a419bdd813c)
|
||||
- Hypoglycemic coma: Reversible CST changes
|
||||
- [Demyelinating & inflammatory diseases](/document/adem/a3fafeb7-5861-4364-beb8-c0e30220564e)
|
||||
- [Multiple sclerosis, ADEM, Behçet disease, AIDS, cervical myelopathy](/document/behet-disease/4e447bb6-0f14-40e1-929a-4c1465feec0a)
|
||||
- Neoplasms: Brainstem glioma, malignant lymphoma
|
||||
- [Intoxication: Heroin inhalation](/document/drug-abuse/e4502a67-4b96-4d98-a167-6e90f6b65faf)
|
||||
- ## Normal Individuals
|
||||
|
||||
|
||||
- CST can appear hyperintense on 3T MR (normal fully myelinated brain at any age) & mimic ALS
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Sporadic ALS (sALS) etiology is largely unknown
|
||||
- Proposed potential mechanisms include
|
||||
- Abnormal RNA processing, SOD1-mediated toxicity, excitotoxicity, cytoskeletal derangements, mitochondrial dysfunction
|
||||
- Viral infections, apoptosis, growth factor abnormalities, & inflammatory responses
|
||||
- Pathological hallmarks include loss of MNs with intraneuronal ubiquitin-immunoreactive inclusions in UMN & TDP-43 immunoreactive inclusions in degenerating LMN
|
||||
- ↑ expression of cyclooxygenase-2 in spinal cord, frontal cortex, & hippocampus
|
||||
- Apoptosis, free radical-mediated oxidative stress, excessive glutamate-mediated excitotoxicity
|
||||
- Dopamine deficiency probably has important role
|
||||
- Biochemical studies have shown ↓ glutamate levels in CNS tissue & ↑ levels in CSF
|
||||
- Mutations in single gene can lead to selective degeneration of motor neurons
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- 90-95% of cases are sALS
|
||||
- 5-10% of cases are familial (fALS)
|
||||
- Most common ALS-related gene mutation occurs in *C9ORF72*, *SOD1*, *TARDBP*, & *FUS*
|
||||
- In European population: Most common is *C9ORF72*repeats
|
||||
- In Asian population: Most common is *SOD1* mutation
|
||||
- Rare autosomal recessive juvenile-onset ALS
|
||||
- *ALS2* gene on chromosome 2q encodes alsin
|
||||
- ### Associated abnormalities
|
||||
|
||||
|
||||
- ALS-plus syndrome: MND with other symptoms or signs outside of voluntary motor system
|
||||
- 2–3% of cases, ALS is accompanied by frontotemporal dementia
|
||||
- ~ 50% of cases show cognitive impairment
|
||||
- Can be associated with frontotemporal dementia (FTD), autonomic insufficiency, parkinsonism, supranuclear gaze paresis, &/or sensory loss
|
||||
- ALS-like MND can occur as paraneoplastic syndrome
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Focal atrophy of motor cortex & along course of CST
|
||||
- Atrophy of anterior & lateral portions of spinal cord
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Loss of cortical motor neurons (pyramidal & Betz cells) & astrocytosis
|
||||
- Retrograde axonal loss & gliosis in CST
|
||||
- "Senescent changes" with lipofuscin pigment atrophy
|
||||
- Various cytoplasmic inclusions with chromatolysis
|
||||
- Proximal & distal axonopathy with axonal spheroids
|
||||
- Surviving motor neurons are smaller & abnormal
|
||||
- Frequently undetected CST pathology in progressive muscular atrophy variant of ALS
|
||||
- Bunina bodies (eosinophilic aggregates are positive for cystatin C) are unique for ALS
|
||||
- Other intracellular inclusions: Neurofilament inclusions, ubiquitinated inclusions, TDP-43 inclusions, & immunoreactive inclusions to*FUS*
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- UMN signs: Babinski sign, spasticity, hyperreflexia
|
||||
- LMN signs: Asymmetric muscle weakness, atrophy, fasciculations, hyporeflexia
|
||||
- Split-hand syndrome: Frequent pattern of weakness & atrophy in ALS involving thenar muscles more than hypothenar muscles
|
||||
- Bulbar signs: Slurred speech, dysphagia
|
||||
- Difficulty walking, unexplained weight loss
|
||||
- Hypoxia, cardiac arrhythmia
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- El Escorial criteria diagnosis of ALS: Evidence of UMN findings, LMN findings, & progression
|
||||
- 4 regions or levels: Bulbar, cervical, thoracic, lumbosacral
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- Classic ALS: Both UMN & LMN affected
|
||||
- UMN-dominant ALS can be difficult to distinguish from primary lateral sclerosis
|
||||
- Predominantly bulbar form usually leads to more rapid deterioration & death
|
||||
- fALS associated with *SOD1* abnormality has mean age at 42 years limb onset, slow evolution
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Peaks in 6th to 8th decades; can occur in young adults
|
||||
- ### Sex
|
||||
|
||||
|
||||
- M:F = 1.5:1.0
|
||||
- ### Ethnicity
|
||||
|
||||
|
||||
- Slightly higher in Non-Hispanics white population
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- Incidence: 1-3 cases/100,000 people
|
||||
- Prevalence: 2.7-7.4 cases/100,000 people
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Progressive (distal to proximal)
|
||||
- Median survival from diagnosis to death: 3-4 years
|
||||
- 10% of patients survive > 10 years
|
||||
- Some patients with familial, juvenile-onset ALS survive for longer periods (2-3 decades)
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Riluzole (glutamate release inhibitor & insulin-like growth factor) may prolong survival
|
||||
- ↑ NAA/Cr in precentral gyrus & supplementary motor area after riluzole therapy
|
||||
- This suggests population of sublethally injured, metabolically compromised neurons that are amenable to therapeutic rescue
|
||||
- No improvement in perirolandic neuronal integrity (no change in NAA:Cr ratio) was detected after gabapentin treatment, which agrees with equivocal clinical effectiveness
|
||||
- Baclofen, dantrolene, or diazepam for spasticity
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- FLAIR & PD MR in all patients with suspected ALS
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- High T2 signal intensity in posterior limb of IC is suggestive for ALS when also visible on PD MR
|
||||
- T1- & PD-weighted images differentiate real degeneration from normal areas
|
||||
- DTI can assess CST lesions before pyramidal symptoms
|
||||
|
||||
c693ffa3-6052-4eb1-8840-2ce1ab8bebf8
|
||||
@@ -1,85 +0,0 @@
|
||||
---
|
||||
title: "Attention Control Network"
|
||||
docid: "a1bedda5-6478-40b2-98e7-6c5f5363b06f"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Anatomy"
|
||||
- "Brain Network Anatomy"
|
||||
- "Attention Control Network"
|
||||
---
|
||||
# IMAGING ANATOMY
|
||||
|
||||
- ## Overview
|
||||
|
||||
|
||||
- Attention control network is a constellation of distributed brain networks processing attention to external stimuli and symbols
|
||||
- Many aliases: Task-positive network, frontoparietal network, executive control network, and central executive network, each referring to subsets of the attention control network
|
||||
- Terminology is not standard in the literature, and different authors use many of these terms interchangeably or to refer to different subsets of a broader attentional network
|
||||
- ## Dorsal Attention Network
|
||||
|
||||
|
||||
- Function: Voluntary control of attentional focus and goal-directed behavior
|
||||
- Regions: Intraparietal sulcus, frontal eye fields, middle temporal, dorsolateral prefrontal cortex
|
||||
- Intraparietal sulcus
|
||||
- Weighting of sensory inputs: Direct control of relative "value" or "attention" to sensory stimuli
|
||||
- Topographically organized by stimulus modality and spatial location
|
||||
- Frontal eye fields and supplementary eye fields
|
||||
- Control of direction of gaze to attentionally relevant stimuli
|
||||
- Middle temporal (MT)
|
||||
- Motion perception, dynamic features of attention
|
||||
- Dorsolateral prefrontal cortex (DLPFC)
|
||||
- Shared with ventral attention network, representations of objects and symbols, working memory
|
||||
- ## Ventral Attention Network
|
||||
|
||||
|
||||
- Function: Control of reorienting to relevant stimuli, working memory
|
||||
- Aliases: Frontoparietal control network, executive control network
|
||||
- Regions: Supramarginal and angular gyri, inferior frontal gyrus, dorsolateral prefrontal cortex, ventral anterior cingulate cortex
|
||||
- Inferior parietal lobule (supramarginal and angular gyri)
|
||||
- Inferior frontal gyrus
|
||||
- DLPFC
|
||||
- Ventral anterior cingulate cortex
|
||||
- ## Salience Network
|
||||
|
||||
|
||||
- Function: Detection of novel or salient stimuli
|
||||
- Aliases: Novelty detection network, cingulo-opercular network
|
||||
- Regions: Frontoinsula, dorsal anterior cingulate cortex
|
||||
- Frontoinsula
|
||||
- "Sensory" arm of salience network
|
||||
- Mid superior insula: Detection of stimulus salience
|
||||
- Mid inferior insula: Detection of emotive salience
|
||||
- Anterior insula: Control of attention
|
||||
- Dorsal anterior cingulate cortex
|
||||
- "Motor" arm of salience network
|
||||
- More anterior (pregenual) cingulate more associated with emotive salience, merges with ventral attention network
|
||||
|
||||
# ANATOMY IMAGING ISSUES
|
||||
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- Specific subnetworks may be activated by specific tasks (e.g., oddball task for salience network, n-back task for dorsal attention network)
|
||||
- ## Imaging Pitfalls
|
||||
|
||||
|
||||
- Many fMRI tasks have differential stimulus attention between active and control conditions
|
||||
- Activation in attentional regions may not be task specific, but a general consequence of differential attention between conditions
|
||||
- ## Network Relationships
|
||||
|
||||
|
||||
- Attention control network is anticorrelated to default mode network: When one is active, the other tends to be less active
|
||||
- Allows focus of attention to shift between external and internal stimuli
|
||||
- Gradients of anticorrelation across the attention control network are seen with specific subregions of each network hub showing greatest anticorrelation
|
||||
- Attentional regions typically located in association cortex in regions spatially "equidistant" from primary sensory areas
|
||||
- Flow of information from primary sensory to unimodal sensory association cortex to polymodal association cortex
|
||||
|
||||
# CLINICAL IMPLICATIONS
|
||||
|
||||
- ## Clinical Importance
|
||||
|
||||
|
||||
- Right-dominant network for attention in most individuals
|
||||
- Lesions of right ventral attention network may produce hemispatial neglect
|
||||
|
||||
8145fc24-f946-49ef-9ae0-c4315a58d768
|
||||
@@ -0,0 +1,434 @@
|
||||
---
|
||||
title: "Autoimmune Encephalitis"
|
||||
docid: "6eb3d5d6-7f6a-4367-a792-b5d4b19675da"
|
||||
authors:
|
||||
- key: "8d5254e9-8dda-478b-8f08-bdee97a32c79"
|
||||
value: "Karen L. Salzman, MD, FACR"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Brain"
|
||||
slug: "brain"
|
||||
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
||||
-
|
||||
name: "Diagnosis"
|
||||
slug: "diagnosis"
|
||||
treeNodeId: "51c00394-446e-4a38-94af-d3b1d14d34e8"
|
||||
-
|
||||
name: "Pathology-Based Diagnoses"
|
||||
slug: "pathology-based-diagnoses"
|
||||
treeNodeId: "d9d3a8ed-f21b-4831-8c77-591a3500ef77"
|
||||
-
|
||||
name: "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
slug: "infectious-inflammatory-and-demyel-"
|
||||
treeNodeId: "7210f860-fe5f-4a2d-81cc-4fe06c769607"
|
||||
-
|
||||
name: "Inflammatory and Demyelinating Disease"
|
||||
slug: "inflammatory-and-demyelinating-dis-"
|
||||
treeNodeId: "62ab4dc3-dbf6-45a9-8532-f0e962aa62dc"
|
||||
-
|
||||
name: "Autoimmune Encephalitis"
|
||||
slug: "autoimmune-encephalitis"
|
||||
treeNodeId: null
|
||||
category: "Brain"
|
||||
documentVersionId: "cc8c3891-88b7-44bb-9e2a-3a321d092f4c"
|
||||
imageCount: 22
|
||||
isBookmarked: false
|
||||
isComparable: true
|
||||
isInCompareCart: false
|
||||
lastUpdated: "08/05/20"
|
||||
pageDescription: "Autoimmune Encephalitis"
|
||||
pageKeywords: "Brain, Diagnosis, Pathology-Based Diagnoses, Infectious, Inflammatory, and Demyelinating Disease, Inflammatory and Demyelinating Disease, Autoimmune Encephalitis"
|
||||
pageTitle: "Autoimmune Encephalitis | STATdx"
|
||||
enhancedTitle: "Autoimmune Encephalitis"
|
||||
type: "DX"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
- "Inflammatory and Demyelinating Disease"
|
||||
- "Autoimmune Encephalitis"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Autoimmune encephalitis (AE): Immune-mediated disease with antibody-mediated inflammation of brain
|
||||
- May be immune mediated or paraneoplastic
|
||||
- Paraneoplastic: Remote neurologic effects of cancer, associated with extra-CNS tumors
|
||||
- Most common tumor: Small cell lung carcinoma
|
||||
- Limbic encephalitis (LE) is most common clinical paraneoplastic syndrome
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- AE: T2/FLAIR hyperintensities in cortex/subcortical white matter, basal ganglia (BG), thalami, brainstem
|
||||
- AE: May have no associated imaging findings
|
||||
- LE: Hyperintensity in mesial temporal lobes/limbic system
|
||||
- Mimics herpes encephalitis but subacute/chronic
|
||||
- Paraneoplastic cerebellar degeneration (PCD): Cerebellar atrophy
|
||||
- Brainstem encephalitis: T2 hyperintensity in midbrain, pons, cerebellar peduncles, BG
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- AE: Viral encephalitis, ADEM, vasculitis
|
||||
- LE: Herpes encephalitis, diffuse astrocytoma, status epilepticus, gliomatosis cerebri imaging pattern
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- AE: 2 distinct groups (group I and group II) have overlapping clinical and imaging features
|
||||
- Group I (intracellular) or group II (cell surface) antigens
|
||||
- < 1% of patients with systemic cancers develop paraneoplastic syndrome
|
||||
- LE: Memory loss, cognitive dysfunction, dementia, psychological features, seizures
|
||||
- PCD: Ataxia, incoordination, dysarthria, nystagmus
|
||||
- Brainstem encephalitis: Brainstem dysfunction
|
||||
- Treatment of primary tumor may improve symptoms
|
||||
- AE treated with immunosuppressive therapy
|
||||
- AE may occur as complication of cancer treatment (immune checkpoint inhibitors)
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Paraneoplastic syndromes (PS), paraneoplastic disease
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Autoimmune encephalitis (AE): Immune-mediated disease with antibody-mediated inflammation of brain
|
||||
- Includes autoimmune and paraneoplastic encephalitis
|
||||
- Paraneoplastic: Remote neurologic effects of cancer, associated with extra-CNS tumors
|
||||
- Most common tumor: Small cell lung carcinoma
|
||||
- Limbic encephalitis (LE) is most common clinical paraneoplastic syndrome
|
||||
- Only PS with clearly defined imaging features
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- AE: Hyperintensity in mesial temporal lobes, limbic system
|
||||
- Often mimics herpes encephalitis but has different clinical course (subacute vs. chronic)
|
||||
- Initial study normal in 20-40%
|
||||
- Most PS do not have associated imaging findings
|
||||
- ### Location
|
||||
|
||||
|
||||
- AE: Limbic structures, deep gray nuclei, brainstem, cortex and subcortical white matter (WM)
|
||||
- LE: Hippocampus, amygdala, cingulate gyrus, pyriform cortex, subfrontal cortex, insula
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- NECT: Initial CT scan normal in > 95%
|
||||
- Rare: Low density within mesial temporal lobes
|
||||
- CECT: Usually no visible enhancement
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- AE: Hypointensity in cortex, WM, deep gray, or brainstem
|
||||
- LE: Hypointensity in mesial temporal lobes (hippocampus, amygdala), insula, cingulate gyrus, subfrontal cortex, inferior frontal WM
|
||||
- May see minimal mass effect
|
||||
- May see atrophy in chronic cases
|
||||
- No hemorrhage
|
||||
- ### DWI
|
||||
|
||||
|
||||
- Diffusion restriction rare
|
||||
- T2WI: Hyperintensity in mesial temporal lobes &/or cortex, WM, deep gray, or brainstem
|
||||
- May see minimal mass effect
|
||||
- FLAIR: Hyperintensity
|
||||
- T2* GRE: No hemorrhage
|
||||
- If blood products seen, consider herpes encephalitis
|
||||
- T1WI C+: Patchy enhancement may be seen
|
||||
- Brainstem encephalitis: T2 hyperintensity in midbrain, pons, cerebellar peduncles, basal ganglia
|
||||
- Paraneoplastic cerebellar degeneration (PCD): Cerebellar atrophy
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- FDG PET: Increased glucose metabolism in medial temporal lobes in LE patients
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- MR is most sensitive
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- Contrast-enhanced MR with coronal T2 or FLAIR
|
||||
- Consider repeat MR if initial scan normal with high clinical suspicion
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Herpes Encephalitis](/document/herpes-encephalitis/6bbe5645-2178-411e-871e-8878d244f482)
|
||||
- T2 hyperintensity in temporal lobes, limbic system
|
||||
- Mass effect common; restricted DWI common
|
||||
- Rapid onset, febrile illness
|
||||
- HSV titers (CSF, serum) may be negative early
|
||||
- Late acute/subacute may hemorrhage
|
||||
- May be indistinguishable from LE
|
||||
- ## Diffuse Astrocytoma (WHO Grade 2)
|
||||
|
||||
|
||||
- Unilateral T2-hyperintense mass
|
||||
- May involve medial temporal lobe
|
||||
- No enhancement typical
|
||||
- [Status Epilepticus](/document/status-epilepticus/a058b733-4b80-46a1-8097-d68685ecf921)
|
||||
- Seizures related to abnormal T2/FLAIR of mesial temporal lobes
|
||||
- Cortical enhancement with DWI is typical
|
||||
- Clinical history of seizures
|
||||
- Follow-up imaging may be necessary
|
||||
- ## Gliomatosis Cerebri Imaging Pattern
|
||||
|
||||
|
||||
- Diffuse process; no predilection for limbic system
|
||||
- T2 hyperintensity in multiple contiguous lobes
|
||||
- Enlarges affected area
|
||||
- ## Vasculitis
|
||||
|
||||
|
||||
- Multiple T2/FLAIR hyperintensities
|
||||
- Blood products common
|
||||
- Small infarcts common
|
||||
- ## Acute Disseminated Encephalomyelitis
|
||||
|
||||
|
||||
- T2/FLAIR hyperintensities in WM and deep gray nuclei
|
||||
- Enhancement typical
|
||||
- Often 1-2 weeks following infection/vaccination
|
||||
- ## Parenchymal Metastases
|
||||
|
||||
|
||||
- Typically multifocal, enhancing lesions
|
||||
- Primary tumor often known
|
||||
- No predilection for limbic system
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- AE may be characterized as either **group I**or **group II** according to location of their neuronal antigens
|
||||
- **Group I**antibodies targeting **intracellular antigens**
|
||||
- **Group II**antibodies targeting **antigens on cell surface**:1, 2, 6, 7, 9, 27
|
||||
- Distinction clinically relevant: Implications for treatment response, association with underlying malignancy, and prognosis
|
||||
- **Group I**antibodies are more closely associated with underlying malignancy
|
||||
- Immune mediated by **autoantibodies** or cytotoxic T cell-related mechanisms
|
||||
- 60% of patients have circulating serum **autoantibodies**
|
||||
- **Anti-Hu** (75% small cell lung cancer): LE pattern
|
||||
- **Anti-Ma/Ta** (testicular germ cell tumors > > lung cancer > breast cancer): LE, brainstem encephalitis
|
||||
- **Anti-Yo** (breast and ovarian): PCD pattern
|
||||
- **Anti-Tr** (Hodgkin disease): PCD pattern
|
||||
- **Anti-Ri**(lung, breast, ovarian): Opsoclonus myoclonus, brainstem encephalitis
|
||||
- **Anti-CV2**(small-cell lung cancer, malignant thymoma): T2/FLAIR-hyperintense lesions in striatum
|
||||
- **Anti-glutamic acid decarboxylase (GAD65)**(not typically associated with malignancy): LE pattern
|
||||
- Stiff man syndrome, cerebellar ataxia, seizures
|
||||
- Reversible extralimbic paraneoplastic encephalopathy
|
||||
- Associated with breast cancer and lung cancer
|
||||
- Reversible when primary tumors controlled
|
||||
- **Group II**cell surface antigens
|
||||
- **Voltage-gated potassium channels (VGKC)** and N-methyl-D-aspartate receptor (**NMDAR**)
|
||||
- Appear to be antibody mediated and respond better to immunotherapy (90%)
|
||||
- Associated with other tumors (thymoma, teratoma, Hodgkin lymphoma)
|
||||
- Patients may present with LE; more frequently manifest severe psychiatric symptoms, seizures, dyskinesias, autonomic instability, or hypoventilation
|
||||
- Antibody to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (**AMPAr**)
|
||||
- Associated with LE pattern, T2 hyperintensities in hippocampus
|
||||
- May occur with other antibodies
|
||||
- Often associated with lung, breast, or thymic tumors
|
||||
- γ aminobutyric acid encephalitis (**GABAr**)
|
||||
- LE pattern ± other MR findings, seizures
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- 2 distinct groups (group I and group II) have overlapping clinical and imaging features
|
||||
- PSs divided into disorders of CNS, peripheral NS (PNS), CNS/PNS, neuromuscular junction
|
||||
- CNS: PCD, opsoclonus myoclonus, retinopathy
|
||||
- PNS: Sensory-motor neuropathy, autonomic neuropathy
|
||||
- Both CNS/PNS: Encephalomyelitis (LE, brainstem encephalitis, myelitis, motor neuron disease)
|
||||
- Neuromuscular junction: Lambert-Eaton myasthenic syndrome
|
||||
- LE is most common AE (paraneoplastic, group I)
|
||||
- Nonparaneoplastic LE reported
|
||||
- PCD is 2nd most common PS
|
||||
- Multiple PSs may occur in same patient
|
||||
- NMDAR and VGKC encephalitis are most common group II subtypes of AE
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- AE: Ill-defined softening, discoloration of gray matter
|
||||
- LE: Hippocampus, cingulate gyrus, pyriform cortex, frontal orbital surface of temporal lobe, insula, amygdala; typically bilateral
|
||||
- PCD: Cerebellar atrophy, gyral thinning
|
||||
- Brainstem encephalitis: Brainstem softening
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- AE: Neuronal loss, reactive gliosis, perivascular infiltration of lymphocytes, microglial nodules
|
||||
- No neoplasm and no viral inclusions
|
||||
- PCD: Purkinje cell loss, microglial proliferation, Bergmann glia hyperplasia, decrease in granule cells
|
||||
- Brainstem encephalitis: Perivascular inflammatory infiltrates, glial nodules, neuronophagia
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- AE: Memory loss, cognitive dysfunction, dementia, psychological features (anxiety, depression, hallucinations), seizures; subacute presentation
|
||||
- PCD: Ataxia, incoordination, dysarthria, nystagmus
|
||||
- In patients > 50 years, cerebellar degeneration is paraneoplastic in 50% of cases, often precedes remote malignancy
|
||||
- Brainstem encephalitis: Brainstem dysfunction including cranial nerve palsies, visual changes
|
||||
- PSs represent spectrum of neurologic manifestations
|
||||
- In patients with known primary tumor, must exclude other complications
|
||||
- Metastases, infection, metabolic disorder, chemotherapy effects
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- Up to 60% of LE patients have no known primary tumor at presentation, many have no tumor found at work-up
|
||||
- Identification of antineuronal antibodies in serum or cerebrospinal fluid (CSF) facilitates diagnosis of PS and primary cancer
|
||||
- AE may occur as complication of cancer treatment (immune checkpoint inhibitors)
|
||||
- Primary neoplasms
|
||||
- LE
|
||||
- Most common: Small cell lung carcinoma
|
||||
- Other: Gastrointestinal, genitourinary (ovary > renal > uterus), lymphoma, breast, testicular, thymus, neuroblastoma (pediatric)
|
||||
- 90% have positive CSF (pleocytosis, increased protein, oligoclonal bands)
|
||||
- EEG reveals involvement of temporal lobes
|
||||
- PCD
|
||||
- Genitourinary (ovary), breast, lung, lymphoma
|
||||
- Opsoclonus myoclonus
|
||||
- Neuroblastoma, lung cancer
|
||||
- Lambert-Eaton myasthenic syndrome
|
||||
- Small cell lung cancer
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Sex
|
||||
|
||||
|
||||
- No sex predominance
|
||||
- Age: Occurs at all ages, most commonly adults
|
||||
- Epidemiology: < 1% of patients with systemic cancers develop paraneoplastic syndrome
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- AE has variable prognosis
|
||||
- Prognosis of PS may relate to primary neoplasm
|
||||
- Relates to type of paraneoplastic syndrome
|
||||
- Slow, long-term cognitive decline (LE)
|
||||
- Progressive ataxia, weakness (PCD, spinal cord degeneration)
|
||||
- Some reports suggest patients with PSs have more indolent primary tumor growth than those without
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- AE often treated with immunotherapy (IV steroids, plasma exchange, IVIg) ± rituximab or cyclophosphamide
|
||||
- Treatment of primary malignancy may improve neurologic symptoms of PS
|
||||
- Primary neoplasm resected, ± chemoradiation
|
||||
- Treatment of PS is variable
|
||||
- Treatment of primary tumor is best therapy
|
||||
- ± steroids, immunoglobulins, plasmapheresis
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- LE is only PS with defined imaging features
|
||||
- PS are often clinically evident before diagnosis of primary tumor
|
||||
- Repeat MR if initial scan normal and high clinical suspicion, as initial MR often normal in LE
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Herpes encephalitis mimics LE on imaging but has acute presentation
|
||||
- Patients often initially treated with antiviral therapy until HSV titers final
|
||||
- Hemorrhage suggests herpes rather than LE
|
||||
|
||||
89d11c00-03ef-4d5a-aea9-2d9c2669fa58
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
*Axial FLAIR MR shows abnormal hyperintensity in the bilateral medial temporal lobes <img src='/img/arrows/CS.png'/>, characteristic of limbic encephalitis (LE), the most common paraneoplastic syndrome. Bilateral involvement is typical of limbic encephalitis.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows abnormal hyperintensity in the bilateral medial temporal lobes <img src='/img/arrows/CS.png'/>, characteristic of limbic encephalitis (LE), the most common paraneoplastic syndrome. Bilateral involvement is typical of limbic encephalitis.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR in the same patient shows no significant enhancement in the medial temporal lobes. Enhancement is often present in limbic encephalitis. The patient's symptoms often improve after treatment of the primary tumor.*
|
||||
|
||||
|
||||
*Axial FLAIR MR in a 61 year old with multiple myeloma who presented with seizures shows abnormal hyperintensity <img src='/img/arrows/CS.png'/> in the cortex and subcortical white matter of the temporal lobes.*
|
||||
|
||||
|
||||
*Axial T1 C+ FS MR in the same patient shows no enhancement. Differential considerations include autoimmune encephalitis (AE), acute demyelinating encephalomyelitis (ADEM), viral encephalitis, and vasculitis in this case. AE related to GABAr was diagnosed by CSF and serum markers.*
|
||||
|
||||
|
||||
*Axial FLAIR MR in a 71 year old with altered mental status shows abnormal hyperintensity in the left temporal lobe <img src='/img/arrows/CS.png'/>. Differential considerations include infectious, inflammatory, and neoplastic etiologies. GAD65 AE was diagnosed at brain biopsy.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows hyperintensity in the medial temporal lobes <img src='/img/arrows/CS.png'/> in this patient with subacute dementia and voltage-gated potassium channel (VGKC) autoimmunity. VGKC may occur with or without a primary neoplasm and may have an LE pattern.*
|
||||
|
||||
|
||||
*Axial T2 MR shows midbrain hyperintensity <img src='/img/arrows/CS.png'/> related to brainstem encephalitis, which is characterized by hyperintensity in the midbrain, pons, cerebellar peduncle, and basal ganglia.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR in the same patient shows patchy enhancement of the midbrain lesions <img src='/img/arrows/CS.png'/> and the medial temporal lobe <img src='/img/arrows/CO.png'/>. This patient was diagnosed with LE with new brainstem symptoms. Multiple paraneoplastic syndromes may occur in the same patient.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows abnormal hyperintensity in the medial temporal lobes bilaterally, related to LE. As imaging mimics herpes encephalitis, most patients are initially treated with antiviral therapy until HSV titers are found to be negative. < 1% of cancer patients develop a paraneoplastic syndrome.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR in the same patient shows patchy enhancement <img src='/img/arrows/CO.png'/> of the medial temporal lobes. LE is the only paraneoplastic syndrome with defined imaging features.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Axial T2 MR shows abnormal hyperintensity in the right medial temporal lobe <img src='/img/arrows/CO.png'/>, typical of limbic encephalitis. Note the abnormal hyperintensity in the midbrain <img src='/img/arrows/CS.png'/>, indicative of brainstem encephalitis. Brainstem encephalitis is a very uncommon paraneoplastic syndrome. Multiple paraneoplastic syndromes can occur in the same patient.*
|
||||
|
||||
|
||||
*Axial FLAIR MR in a patient with subacute dementia and lung cancer shows hyperintensity within the medial temporal lobes, classic for limbic encephalitis. Imaging mimics herpes encephalitis.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR shows subtle patchy enhancement of the medial temporal lobes bilaterally <img src='/img/arrows/CS.png'/>, which is a typical enhancement pattern for limbic encephalitis. Bilateral involvement is common.*
|
||||
|
||||
|
||||
*Coronal T2 MR in a patient with limbic encephalitis shows abnormal hyperintensity in the medial temporal lobes and right insula <img src='/img/arrows/CS.png'/> in this patient with severe memory loss and dementia. Symptoms improved after the removal of the primary tumor.*
|
||||
|
||||
|
||||
*Coronal T1 C+ MR shows abnormal gyriform enhancement in the medial temporal lobes and left insula <img src='/img/arrows/CS.png'/>. The more typical patchy enhancement pattern of limbic encephalitis is seen in the hippocampi bilaterally.*
|
||||
|
||||
|
||||
*Axial T1 MR shows hyperintensity representing blood products in the medial temporal lobes in this patient with treated lung cancer and limbic encephalitis. Blood products are rare in limbic encephalitis, in which imaging mimics herpes encephalitis.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows abnormal hyperintensity in the right medial temporal lobe and midbrain in this patient with a history of limbic encephalitis and new brainstem symptoms positive for anti-Hu autoantibody.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR shows enhancement in the medial temporal lobes and left anterior temporal lobe related to limbic encephalitis. As imaging mimics herpes encephalitis, most patients are initially treated with antiviral therapy until HSV titers are found to be negative.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows abnormal hyperintensity in the medial temporal lobes bilaterally, characteristic of limbic encephalitis, the most common paraneoplastic syndrome. Bilateral involvement is typical of limbic encephalitis.*
|
||||
|
||||
|
||||
*Axial FLAIR MR in an older adult with small cell lung cancer and subacute dementia shows striking hyperintensity in the right insula <img src='/img/arrows/WO.png'/>.*
|
||||
|
||||
|
||||
*Coronal T2 MR in the same patient shows abnormal hyperintensity in both medial temporal lobes <img src='/img/arrows/WS.png'/> and right insular cortex <img src='/img/arrows/WO.png'/>. Imaging of limbic encephalitis mimics that of herpes encephalitis; however, patients with limbic encephalitis have a subacute presentation. Hemorrhage suggests herpes rather than limbic encephalitis.*
|
||||
|
||||
|
||||
*Axial FLAIR MR shows abnormal hyperintensity in the medial temporal lobes bilaterally, characteristic of limbic encephalitis, the most common paraneoplastic syndrome. Bilateral involvement is typical of limbic encephalitis.*
|
||||
|
||||
@@ -0,0 +1,281 @@
|
||||
---
|
||||
title: "Basal Ganglia Calcification"
|
||||
docid: "f8dc8f27-f256-480d-9393-7ec3495a3d27"
|
||||
authors:
|
||||
- key: "8d5254e9-8dda-478b-8f08-bdee97a32c79"
|
||||
value: "Karen L. Salzman, MD, FACR"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Brain"
|
||||
slug: "brain"
|
||||
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
||||
-
|
||||
name: "Differential Diagnosis"
|
||||
slug: "differential-diagnosis"
|
||||
treeNodeId: "a7fdd139-664e-4bb8-8d18-400e4733ff60"
|
||||
-
|
||||
name: "Supratentorial Brain Parenchyma"
|
||||
slug: "supratentorial-brain-parenchyma"
|
||||
treeNodeId: "6683b329-de24-4726-a77a-bf760698fa6a"
|
||||
-
|
||||
name: "Anatomically Based Differentials"
|
||||
slug: "anatomically-based-differentials"
|
||||
treeNodeId: "205377bb-d221-4519-aec2-85bad8ed08de"
|
||||
-
|
||||
name: "Basal Ganglia Calcification"
|
||||
slug: "basal-ganglia-calcification"
|
||||
treeNodeId: null
|
||||
category: "Brain"
|
||||
cmeTopicId: "b45f0261-eda5-4a33-a468-2c2632ec25af"
|
||||
documentVersionId: "c3a08182-fe6e-42b1-a8a1-bf4b64c51892"
|
||||
imageCount: 28
|
||||
isBookmarked: false
|
||||
isComparable: false
|
||||
isInCompareCart: false
|
||||
lastUpdated: "02/01/23"
|
||||
pageDescription: "Basal Ganglia Calcification"
|
||||
pageKeywords: "Brain, Differential Diagnosis, Supratentorial Brain Parenchyma, Anatomically Based Differentials, Basal Ganglia Calcification"
|
||||
pageTitle: "Basal Ganglia Calcification | STATdx"
|
||||
enhancedTitle: "Basal Ganglia Calcification"
|
||||
type: "DDX"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Supratentorial Brain Parenchyma"
|
||||
- "Anatomically Based Differentials"
|
||||
- "Basal Ganglia Calcification"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Basal ganglia (BG) Ca⁺⁺ is end result of multiple toxic, metabolic, inflammatory, & infectious insults
|
||||
- Location of Ca⁺⁺ helpful to determine underlying cause [globus pallidus (GP) vs. putamen vs. caudate]
|
||||
- Patient age may impact differential diagnosis
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Aging B****rain, Normal**
|
||||
- Commonly affects GP more than putamen
|
||||
- Seen in aging brain as normal variant
|
||||
- Typically in patients older than 30 years
|
||||
- If occurs with other Ca⁺⁺, consider pathologic condition
|
||||
- **Neurocysticercosis**
|
||||
- May occur anywhere in brain
|
||||
- Convexity subarachnoid spaces most common
|
||||
- Imaging varies with pathologic stage
|
||||
- Ca⁺⁺ in nodular calcified (healed) stage
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Fahr Disease**
|
||||
- Bilateral symmetric BG Ca⁺⁺, often with Ca⁺⁺ in other locations
|
||||
- GP is most common site of Ca⁺⁺ (lateral > medial)
|
||||
- Other locations: Putamen, caudate, thalami, dentate nuclei of cerebellum, cerebral white matter (WM), internal capsule
|
||||
- Associated abnormalities: Parkinsonism in autosomal dominant Fahr disease (FD)
|
||||
- **Hypoxic-Ischemic Injury**
|
||||
- **Term**: Profound acute injury results in decreased BG & thalamic density ± hemorrhage acutely
|
||||
- Lateral thalami & posterior putamen typical
|
||||
- May show Ca⁺⁺ in chronic phase
|
||||
- **Adults**: Putamen > GP typically
|
||||
- May have history of anoxic event
|
||||
- MR > CT for acute changes
|
||||
- May show Ca⁺⁺ in chronic phase
|
||||
- **Mitochondrial Disorders**
|
||||
- Mitochondrial myopathy, encephalopathy, lactic acidosis, & stroke-like episodes (MELAS): BG Ca⁺⁺ in child or young adult with cortical lesions (parietooccipital > temporoparietal)
|
||||
- Myoclonic epilepsy with ragged red fibers (MERRF): BG Ca⁺⁺ with watershed ischemia
|
||||
- **Congenital Infections**
|
||||
- **HIV, congenital**
|
||||
- Symmetric BG Ca⁺⁺ & cerebral atrophy
|
||||
- GP & putamen > caudate
|
||||
- Subcortical WM Ca⁺⁺ common
|
||||
- Ca⁺⁺ occurs in fairly symmetric fashion, result of calcific vasculopathy of medium & small arteries
|
||||
- **CMV, congenital**
|
||||
- Periventricular Ca⁺⁺, microcephaly, & cortical dysplasia
|
||||
- Periventricular > > BG Ca⁺⁺
|
||||
- **Endocrinologic Disorders**
|
||||
- Imaging of hyperparathyroidism, hypoparathyroidism, pseudohypoparathyroidism, pseudopseudohypoparathyroidism, hypothyroidism in nearly indistinguishable
|
||||
- Bilateral BG: GP & putamen, dentate nuclei, thalami, subcortical areas
|
||||
- Ca⁺⁺ in primary hypoparathyroidism is more diffuse than in other etiologies of Ca⁺⁺
|
||||
- **Toxoplasmosis, Acquired**
|
||||
- Typically multifocal, but BG common site (up to 75%)
|
||||
- Enhancing lesion most common acutely
|
||||
- Post therapy, Ca⁺⁺ is common
|
||||
- **Leigh Syndrome**
|
||||
- Bilateral, symmetric ↑ T2/FLAIR putamina & periaqueductal gray matter
|
||||
- Putamen > caudate > GP, Ca⁺⁺ when chronic
|
||||
- **Tuberculosis**
|
||||
- Typically causes tuberculous meningitis &/or localized CNS infection, tuberculoma
|
||||
- ~ 20% of tuberculomas calcify
|
||||
- **Radiation****&****Chemotherapy**
|
||||
- Mineralizing microangiopathy causes BG & subcortical WM Ca⁺⁺, atrophy
|
||||
- Mineralizing microangiopathy common with chemotherapy & XRT
|
||||
- Typically occurs 2 or more years after XRT
|
||||
- **Cavernous Malformation (Mimic)**
|
||||
- Hyperdense mass (Ca⁺⁺ & blood products) may occur in any location
|
||||
- **Vascular Calcification (Mimic)**
|
||||
- May relate to physiologic vascular calcification, atherosclerosis, aneurysm, or vascular mass
|
||||
- **Tuberous Sclerosis Complex (Mimic)**
|
||||
- Subependymal nodules are typically calcified; occur along caudothalamic groove, periventricular
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Developmental Venous Anomaly**
|
||||
- Congenital cerebral vascular malformation with mature venous elements
|
||||
- "Medusa head" with many small veins joining into collector vein
|
||||
- Seen on contrast CT/MR, CTA/CTV, MRV, DSA, SWI
|
||||
- Unilateral BG/thalami Ca⁺⁺ rare
|
||||
- May be related to venous congestion/ischemia
|
||||
- **Pantothenate Kinase-Associated Neurodegeneration**
|
||||
- Rare neurodegenerative disorder with brain iron accumulation
|
||||
- T2 MR characteristic: High signal within bilateral GP with surrounding low signal, eye of the tiger appearance
|
||||
- CT may show mineralization in GP
|
||||
- Formerly known as Hallervorden-Spatz
|
||||
- **Carbon Monoxide Poisoning**
|
||||
- Typically hypodense, symmetric GP on CT, T2 hyperintense
|
||||
- GP Ca⁺⁺ occurs as end result
|
||||
- **Parasites, Miscellaneous**
|
||||
- **Amebic encephalitis**: Supratentorial, frontal lobes, & BG
|
||||
- Typically enhancing lesions acutely, may calcify in chronic phase
|
||||
- **Malaria**: Predilection for BG, cortex
|
||||
- Hemorrhage, infarcts, & cerebral edema
|
||||
- May show Ca⁺⁺ in chronic phase
|
||||
- **Paragonimiasis**: Acutely often hemorrhage or infarct, followed by Ca⁺⁺ granulomas
|
||||
- ## Alternative Differential Approaches
|
||||
|
||||
|
||||
- BG Ca⁺⁺ in **child**
|
||||
- Mitochondrial encephalopathies: MELAS, MERRF, Leigh syndrome
|
||||
- Congenital infections: HIV, CMV
|
||||
- HIE, term
|
||||
- Associated with Down syndrome
|
||||
- Aicardi-Goutières syndrome (pseudo-TORCH)
|
||||
- Cockayne syndrome
|
||||
- Long-term complications of radiation therapy for childhood brain tumors & intrathecal chemotherapy
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
**Aging Brain, Normal**
|
||||
*Axial NECT shows typical basal ganglia (BG) Ca⁺⁺ in this 75-year-old man who presented after minor trauma. Note the location within the globus pallidus (GP) <img src='/img/arrows/CS.png'/>, typical for normal aging brain. Physiologic Ca⁺⁺ is typically seen in adults over 30 years.*
|
||||
|
||||
|
||||
**Aging Brain, Normal**
|
||||
*Axial NECT shows typical basal ganglia (BG) Ca⁺⁺ in this 75-year-old man who presented after minor trauma. Note the location within the globus pallidus (GP) <img src='/img/arrows/CS.png'/>, typical for normal aging brain. Physiologic Ca⁺⁺ is typically seen in adults over 30 years.*
|
||||
|
||||
|
||||
**Neurocysticercosis**
|
||||
*Axial CT shows multiple calcified nodules in the deep gray nuclei <img src='/img/arrows/CS.png'/> & along the cortex related to the nodular, calcified (healed) stage of neurocysticercosis. This intracranial parasitic infection is caused by the pork tapeworm Taenia solium.*
|
||||
|
||||
|
||||
**Fahr Disease**
|
||||
*Axial NECT shows the typical CT appearance of Fahr disease (FD) with extensive calcifications present in the BG, cerebral white matter (WM), & at the subcortical gray matter-WM junctions.*
|
||||
|
||||
|
||||
**Hypoxic-Ischemic Injury**
|
||||
*Axial NECT shows calcification of thalami & BG <img src='/img/arrows/WC.png'/> from status marmoratus. There is atrophy & a collapsed calvarium following remote mixed hypoxic-ischemic injury (HII) in this infant. Profound acute HII typically affects the BG.*
|
||||
|
||||
|
||||
**Mitochondrial Disorders**
|
||||
*Axial NECT in a teenager shows bilateral GP <img src='/img/arrows/WS.png'/> Ca⁺⁺, a rare finding in patients < 30 years.*
|
||||
|
||||
|
||||
**Mitochondrial Disorders**
|
||||
*FLAIR MR (same patient) shows left frontal & parietal hyperintensity related to recent middle cerebral artery <img src='/img/arrows/CS.png'/> & anterior cerebral artery <img src='/img/arrows/CO.png'/> infarcts. Muscle biopsy showed myoclonic epilepsy with ragged-red fibers. This rare mitochondrial disorder often presents with myoclonus & seizures. Imaging mimics other mitochondrial disorders, incl. mitochondrial myopathy, encephalopathy, lactic acidosis, & stroke-like episodes (MELAS).*
|
||||
|
||||
|
||||
**Mitochondrial Disorders**
|
||||
*Axial NECT shows Ca⁺⁺ of the GP bilaterally <img src='/img/arrows/WS.png'/> in this child with MELAS. Note the low density in the medial occipital lobes related to <img src='/img/arrows/CO.png'/> infarcts. BG Ca⁺⁺ is abnormal in children & young adults.*
|
||||
|
||||
|
||||
**HIV, Congenital**
|
||||
*Axial NECT in a patient with congenital HIV shows bilateral symmetrical BG Ca⁺⁺ predominantly in the GP <img src='/img/arrows/CS.png'/>. This Ca⁺⁺ is seen typically months after birth. With HIV, involvement of the lentiform nuclei Ca⁺⁺ is greater than the caudate heads.*
|
||||
|
||||
|
||||
**CMV, Congenital**
|
||||
*Axial NECT shows periventricular & BG Ca⁺⁺ as well as open Sylvian fissures & ventriculomegaly. Periventricular Ca⁺⁺, ventriculomegaly, & microcephaly strongly suggest congenital CMV infection.*
|
||||
|
||||
|
||||
**Endocrinologic Disorders**
|
||||
*Axial NECT in a patient with with hypothyroidism shows diffuse hyperdense Ca⁺⁺ within the BG, thalami, & subcortical WM. Ca⁺⁺ related to systemic disease is typically symmetric.*
|
||||
|
||||
|
||||
**Endocrinologic Disorders**
|
||||
*Axial NECT in a patient with pseudohypoparathyroidism shows dense Ca⁺⁺ within the BG & subcortical WM in a pseudohypoparathyroidism patient. There is significant imaging overlap between systemic diseases with abnormal calcium deposition.*
|
||||
|
||||
|
||||
**Toxoplasmosis, Acquired**
|
||||
*Axial T1 C+ MR shows an enhancing right BG mass <img src='/img/arrows/CS.png'/> in an AIDS patient. Post therapy, enhancing lesions typically calcify. The BG is the most common location for toxoplasmosis followed by the thalamus, then the cerebral hemispheres.*
|
||||
|
||||
|
||||
**Leigh Syndrome**
|
||||
*Axial T2WI MR shows symmetric T2 hyperintensity in the BG <img src='/img/arrows/BS.png'/> bilaterally in this child with neurodegeneration. Ca⁺⁺ of the BG is seen in chronic cases.*
|
||||
|
||||
|
||||
**Radiation & Chemotherapy**
|
||||
*Axial NECT shows mineralizing microangiopathy related to radiation therapy & chemotherapy for a remote childhood neoplasm. Note the symmetric Ca⁺⁺ in the BG & subcortical WM. This typically occurs ~ 2 years after therapy with XRT & chemotherapy.*
|
||||
|
||||
|
||||
**Tuberous Sclerosis Complex (Mimic)**
|
||||
*Axial T2 MR shows calcified subependymal nodules in the foramen of Monro region <img src='/img/arrows/CS.png'/> in this child with seizures, mimicking BG Ca⁺⁺. These nodules occur in 98% of patients with tuberous sclerosis.*
|
||||
|
||||
|
||||
**Developmental Venous Anomaly**
|
||||
*Axial NECT shows dense Ca⁺⁺ in right BG <img src='/img/arrows/CS.png'/> & thalamus. CE images (not shown) revealed an underlying developmental venous anomaly. These are congenital cerebral vascular malformations with mature venous elements, which may rarely have Ca⁺⁺ possibly related to underlying venous congestion & ischemia.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
**Fahr Disease**
|
||||
*Axial NECT shows a variant CT appearance of FD with extensive Ca⁺⁺ present in the BG, cerebral WM, & at the subcortical gray matter-WM junctions.*
|
||||
|
||||
|
||||
**Pantothenate Kinase-Associated Neurodegeneration**
|
||||
*Axial NECT shows globus pallidus mineralization bilaterally <img src='/img/arrows/CS.png'/> in a patient with pantothenate kinase-associated neurodegeneration. CT is typically normal. T2 MR shows classic the eye of the tiger appearance with globus pallidus hypointensity related to iron accumulation with medial T2 hyperintensity.*
|
||||
|
||||
|
||||
**CMV, Congenital**
|
||||
*Axial NECT shows marked atrophy & minimal BG Ca⁺⁺ in this child with congenital CMV. The Ca⁺⁺ seen in CMV is typically asymmetric & associated with migrational abnormalities & microcephaly.*
|
||||
|
||||
|
||||
**Radiation & Chemotherapy**
|
||||
*Axial NECT shows mineralizing microangiopathy related to radiation therapy & chemotherapy for a posterior fossa medulloblastoma. Note the symmetric Ca⁺⁺ in the BG & subcortical WM.*
|
||||
|
||||
|
||||
**CMV, Congenital**
|
||||
*Axial NECT shows periventricular & BG Ca⁺⁺. Periventricular calcifications, ventriculomegaly, & microcephaly strongly suggest congenital CMV infection.*
|
||||
|
||||
|
||||
**Toxoplasmosis, Acquired**
|
||||
*Axial CECT shows an enhancing BG mass <img src='/img/arrows/WS.png'/> in an AIDS patient. Post therapy, enhancing lesions typically calcify. BG is the most common location followed by thalamus, then hemispheres.*
|
||||
|
||||
|
||||
**Vascular Calcification (Mimic)**
|
||||
*Axial NECT shows intracranial atherosclerotic disease with extensive Ca⁺⁺ in internal carotid & middle cerebral arteries <img src='/img/arrows/WS.png'/>, which mimics BG Ca⁺⁺. Posterior fossa aneurysm is partially visible.*
|
||||
|
||||
|
||||
**Tuberous Sclerosis Complex (Mimic)**
|
||||
*Axial NECT shows calcified subependymal nodules in the foramen of Monro & periventricular regions, which mimic BG Ca⁺⁺. These typically accompany cortical tubers <img src='/img/arrows/WC.png'/>, better seen on MR.*
|
||||
|
||||
|
||||
**Parasites, Miscellaneous**
|
||||
*Axial CECT shows a case of paragonimiasis with a hyperdense left BG nodule <img src='/img/arrows/WS.png'/>. This parasite often presents with conglomerated granulomas, which may hemorrhage. Multiple Ca⁺⁺ are common.*
|
||||
|
||||
|
||||
**Neurocysticercosis**
|
||||
*Axial CECT shows a calcified left putamen nodule <img src='/img/arrows/CS.png'/> that represents the nodular, calcified (healed) stage of neurocysticercosis. Note the right external capsule cyst with a central "dot" representing a scolex.*
|
||||
|
||||
|
||||
**Pseudohypoparathyroidism**
|
||||
*Axial NECT shows diffuse calcifications within the BG & subcortical WM in a pseudohypoparathyroidism patient. There is significant imaging overlap between systemic diseases with abnormal calcium deposition.*
|
||||
|
||||
|
||||
**HIV, Congenital**
|
||||
*Axial NECT shows symmetric BG calcification with scattered foci of subcortical calcification. Note the typical HIV involvement of the lentiform nuclei is greater than the caudate heads.*
|
||||
|
||||
@@ -1,158 +0,0 @@
|
||||
---
|
||||
title: "Brain Tumor in Child > 1 Year"
|
||||
docid: "7d64f5fb-c62c-4861-8ff4-654a12074605"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Brain Parenchyma, General"
|
||||
- "Clinically Based Differentials"
|
||||
- "Brain Tumor in Child > 1 Year"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- General rule: Decreased diffusion = higher grade
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Posterior Fossa** (most common location)
|
||||
- **Pilocytic astrocytoma**
|
||||
- Low-density NECT
|
||||
- Solid, enhancing nodule and cyst: Classic appearance
|
||||
- Solid nodule has increased diffusion = good prognosis
|
||||
- Off midline compared to classic 4th ventricular tumors but may pedunculate into ventricle
|
||||
- Characterized by *KIAA1549*::*BRAF* fusion
|
||||
- **Medulloblastoma**
|
||||
- Hyperdense posterior fossa mass on NECT
|
||||
- Decreased diffusion
|
||||
- Molecular subgroups predicts outcome
|
||||
- WNT-activated: Up to 90% overall survival, 4th ventricle and cerebellopontine angle (CPA) location, rarest subgroup
|
||||
- SHH-activated: Poor to good prognosis, cerebellar hemispheric location, + *TP53* mutation = poor prognosis
|
||||
- Group 3: Worst prognosis with frequent metastases, midline 4th ventricle
|
||||
- Group 4: Intermediate prognosis with occasional metastases, midline 4th ventricle, minimal to no enhancement, most common subgroup
|
||||
- **Ependymoma**
|
||||
- Less common than pilocytic astrocytoma and medulloblastoma
|
||||
- 60% posterior fossa
|
||||
- "Plastic" tumor in 4th ventricle, extrudes through foramina
|
||||
- Can have mixed calcification and cysts
|
||||
- Molecular subgroups predict outcome
|
||||
- Posterior fossa type A: Younger children, lateral location, characterized by H3 K27 alteration, poor outcome
|
||||
- Posterior fossa type B: Adolescents, midline location, good outcome, uncommon
|
||||
- **Diffuse midline glioma, H3 K27-altered**
|
||||
- **Diffuse intrinsic pontine glioma**
|
||||
- T2-hyperintense expansion of pons, little to no enhancement
|
||||
- Can also involve cerebellum and spinal cord
|
||||
- Poor prognosis
|
||||
- **Supratentorial**(more common in infants and adolescents)
|
||||
- **Craniopharyngioma**
|
||||
- Nearly 1/2 of pediatric suprasellar masses, typically adamantinomatous
|
||||
- 90% calcification/cystic/enhance
|
||||
- Squamous cell from Rathke cleft
|
||||
- **Pilocytic astrocytoma**
|
||||
- Commonly involves optic pathway or around 3rd ventricle, tectal plate
|
||||
- Optic "gliomas" are commonly associated with *NF1*
|
||||
- Heterogeneous appearance and enhancement
|
||||
- Pilomyxoid astrocytoma variant is more locally aggressive and more likely to present with leptomeningeal metastases
|
||||
- Similar genetic and molecular characteristics; was removed as separate grading designation in WHO 2016
|
||||
- Supratentorial likely to have *BRAF*V600E mutation
|
||||
- **Diffuse low-grade glioma, pediatric**
|
||||
- Hemispheres, thalami (can be bithalamic), tectum
|
||||
- 50% of brainstem "gliomas" are low-grade diffusely infiltrating astrocytomas
|
||||
- Can be poorly marginated or focal
|
||||
- Hypointense on T1WI, hyperintense on T2WI, little to no enhancement
|
||||
- WHO 2021 has 4 tumor types in this family
|
||||
- **Diffuse astrocytoma, MYB- or MYBL1-altered**
|
||||
- **Diffuse low-grade glioma, MAPK pathway-altered**
|
||||
- **Polymorphous low-grade neuroepithelial tumor of the young** (PLNTY): Commonly cortical with heterogeneous T2 signal from calcification
|
||||
- **Angiocentric glioma**
|
||||
- **Subependymal giant cell astrocytoma**
|
||||
- Seen in tuberous sclerosis
|
||||
- Location at foramina of Monro is typical
|
||||
- Look for cortical/subcortical tubers and subependymal nodules
|
||||
- Heterogenous calcification, marked enhancement
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Intraaxial: Peripheral and Cortical**
|
||||
- **Dysembryoplastic neuroepithelial tumor**
|
||||
- Bubbly-appearing, cortically based mass
|
||||
- Bright ring sign on FLAIR MR
|
||||
- Almost all in patients < 20 years old, chronic epilepsy
|
||||
- **Pleomorphic xanthoastrocytoma**
|
||||
- Cortically based tumor (temporal lobe most common)
|
||||
- Enhancing mass + cyst, dural reaction (tail) common
|
||||
- Majority demonstrate *BRAF*V600E mutation
|
||||
- **Ganglioglioma**
|
||||
- Temporal lobe predilection with seizure presentation
|
||||
- Solid or solid with cyst, ± enhancement
|
||||
- **Oligodendroglioma**
|
||||
- Cortically based, frontal lobe predominance
|
||||
- Calcification common
|
||||
- Predominantly T2 hyperintense ± enhancement
|
||||
- Characterized by 1p/19q codeletion; if 1p/19q intact, represents astrocytoma with poorer outcome
|
||||
- **Intraaxial: Deep and Hemispheric**
|
||||
- **Diffuse high-grade glioma, pediatric**
|
||||
- Diffusely infiltrating, heterogeneous, ± enhancement
|
||||
- WHO 2021 has 4 tumor types in this family (all have poor outcome)
|
||||
- **Diffuse midline glioma, H3 K27-altered**: Central location, involves thalami and brainstem
|
||||
- **Diffuse hemispheric glioma, H3 G34-mutant**
|
||||
- **Diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype**
|
||||
- **Infant-type hemispheric glioma**
|
||||
- **CNS embryonal tumor**
|
||||
- Primitive neuroepithelial tumor terminology removed from 2016 WHO CNS tumors
|
||||
- Infant with large, bulky, complex hemispheric mass
|
||||
- Calcification, hemorrhage, necrosis common
|
||||
- Peritumoral edema sparse/absent, less than expected for size
|
||||
- **Supratentorial ependymoma**
|
||||
- Diffuse infiltrating, heterogeneously enhancing tumor
|
||||
- Origin is periventricular from ependymal rests
|
||||
- Molecular subgroups predict outcome
|
||||
- *ZFTA* fusion-positive, younger children, poor outcome
|
||||
- *YAP1* fusion-positive, older children, good outcome, rare
|
||||
- **Extraaxial**
|
||||
- **Choroid plexus tumor**
|
||||
- Intraventricular: Lateral > 4th > 3rd ventricles
|
||||
- Densely enhancing, frond-like
|
||||
- Although **choroid plexus carcinoma** may show parenchymal invasion, it is not reliably distinguished from **papilloma** on imaging
|
||||
- **Neurofibromatosis type 2**
|
||||
- Vestibular **schwannomas**
|
||||
- If multiple schwannomas, think neurofibromatosis type 2
|
||||
- Look for "hidden" dural-based**meningiomas**
|
||||
- **Midline Pineal and Suprasellar Location**
|
||||
- **Germ cell tumor**
|
||||
- Organized by cell lineage and maturity
|
||||
- Germinomatous germ cell tumor
|
||||
- **Germinoma**: Common in older children and adolescents, excellent prognosis
|
||||
- Homogeneous with enhancement and decreased diffusion in pure germinomas
|
||||
- Nongerminomatous germ cell tumors
|
||||
- **Teratoma**: Fetal life to adolescence; mature teratomas may have fat and calcification; smaller teratomas that are easily resected have good prognosis; **immature teratomas** have poor prognosis
|
||||
- **Embryonal carcinoma****,** **yolk sac tumor****, and** **choriocarcinoma**: Rare; older children and adolescents, poor prognosis
|
||||
- Heterogeneous with enhancement
|
||||
- **Mixed germ cell tumor**: Includes germinomatous and nongerminomatous components
|
||||
- Worse prognosis than pure germinomas due to nongerminomatous components
|
||||
- Suprasellar + pineal lobular, enhancing masses together best clue
|
||||
- Engulfs pineal calcification on CT
|
||||
- **Pineoblastoma**
|
||||
- Decreased diffusion
|
||||
- Look for CSF spread (ventricles, ependyma)
|
||||
- Difficult to distinguish from germinoma
|
||||
- "Exploding" pineal calcification on CT
|
||||
- Pineoblastoma more common than lower grade varieties, such as **pineocytoma** and **pineal parenchymal tumor of intermediate differentiation**
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Atypical Teratoid-Rhabdoid Tumor**
|
||||
- Heterogeneous intracranial mass in infants and children
|
||||
- 50% infratentorial; early CSF spread
|
||||
- Typically decreased diffusion, greater amount of cysts than medulloblastoma
|
||||
- **Astroblastoma,****MN1****-Altered**
|
||||
- Typically peripheral, well circumscribed
|
||||
- Solid and cystic heterogeneous enhancement
|
||||
- **Central Neurocytoma**
|
||||
- "Bubbly," lobulated mass in body of lateral ventricle
|
||||
- Often along septum pellucidum
|
||||
- **Dysplastic Cerebellar Gangliocytoma**
|
||||
- Not associated with PTEN hamartoma syndrome in children
|
||||
- T2-hyperintense, striated cerebellum with enlarged folia
|
||||
-122
@@ -1,122 +0,0 @@
|
||||
---
|
||||
title: "Brain Tumor in Newborn/Infant"
|
||||
docid: "12b32579-c99b-41c0-95fd-f2ad1fc4a4fd"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Brain Parenchyma, General"
|
||||
- "Clinically Based Differentials"
|
||||
- "Brain Tumor in Newborn/Infant"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Newborn/infant brain tumors
|
||||
- Typically large, bulky, inhomogeneous
|
||||
- 60-70% supratentorial
|
||||
- Infratentorial more common in older children
|
||||
- Immature, high-grade tumors more common
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Teratoma**
|
||||
- Most common fetal and congenital brain tumor
|
||||
- Midline, supratentorial
|
||||
- Small, lobular or holocranial
|
||||
- Contents
|
||||
- Ca⁺⁺, cysts
|
||||
- Fat in mature teratoma, less commonly in immature teratoma; enhancing soft tissue
|
||||
- Look for associated congenital brain anomalies
|
||||
- **Infant-Type Hemispheric Glioma**
|
||||
- Large, heterogeneous, hemispheric
|
||||
- High-grade cellular astrocytoma
|
||||
- Better outcome than other histone-associated pediatric high-grade gliomas
|
||||
- **Medulloblastoma**
|
||||
- SHH-activated and non-WNT/non-SHH (group 3) more common in infants
|
||||
- Posterior fossa mass with hydrocephalus
|
||||
- Restricts on DWI (best MR clue)
|
||||
- Enhancement usual (may be late/slow)
|
||||
- Sparse Ca⁺⁺: ~ 20%; hemorrhage rare
|
||||
- Hypercellularity reflected on imaging
|
||||
- Hyperdense (NECT), hypointense (T2)
|
||||
- SHH-activated
|
||||
- Cerebellar hemisphere, not centered in 4th ventricle
|
||||
- Intense enhancement
|
||||
- Additional *TP53* mutation carries poor prognosis
|
||||
- Group 3
|
||||
- Classic 4th ventricular location
|
||||
- Enhancement common, group 4 has less enhancement
|
||||
- Poor prognosis when presenting with dissemination
|
||||
- **Ependymoma,****Posterior Fossa Type A**
|
||||
- Posterior fossa A ependymomas characterized by ↓ H3 K27 expression
|
||||
- Younger children, poor outcome
|
||||
- Lateral in 4th ventricle, extends through foramina of Luschka
|
||||
- Heterogeneous enhancement
|
||||
- Ca⁺⁺ ± hemorrhage
|
||||
- **Supratentorial Ependymoma**
|
||||
- Periventricular/extraventricular > intraventricular
|
||||
- Derived from periventricular ependymal rests
|
||||
- Large, bulky; Ca⁺⁺: ~ 50%
|
||||
- Variable necrosis, hemorrhage
|
||||
- *ZFTA* fusion-positive: Seen in infants and older children, poor prognosis
|
||||
- *YAP1* fusion-positive: Usually seen in infants, good prognosis
|
||||
- **Choroid Plexus Papilloma**
|
||||
- Choroid plexus papilloma (CPP): Lobulated intraventricular mass
|
||||
- Lateral > 4th > 3rd
|
||||
- NECT: Isointense to dense
|
||||
- Isointense to slightly hyperintense on T2WI
|
||||
- Vividly enhancing
|
||||
- Hydrocephalus common
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Pilocytic Astrocytoma, Pilomyxoid Variant**
|
||||
- Younger age presentation than typical pilocytic astrocytoma (PA)
|
||||
- Often presents as large, enhancing, infiltrative mass involving optic pathway
|
||||
- Despite low-grade tumor, it can have leptomeningeal seeding
|
||||
- **Atypical Teratoid-Rhabdoid Tumor**
|
||||
- Medulloblastoma-like, +
|
||||
- Metastases at diagnosis more common
|
||||
- Cysts, hemorrhage more common
|
||||
- Variable contrast enhancement
|
||||
- Cerebellopontine angle cistern location more common
|
||||
- Seeding via CSF pathway common
|
||||
- **CNS Embryonal Tumor**
|
||||
- Previously primitive neuroectodermal tumor (PNET)
|
||||
- Large, complex mass
|
||||
- Restricts on DWI
|
||||
- Heterogeneous signal enhancement
|
||||
- Ca⁺⁺ more common than in posterior fossa PNETs
|
||||
- Hemorrhage, necrosis common
|
||||
- Hemispheric
|
||||
- Mean diameter: 5 cm
|
||||
- Especially newborn/infants
|
||||
- Minimal peritumoral edema
|
||||
- Suprasellar: Early neuroendocrine, visual disturbances
|
||||
- **Desmoplastic Infantile Ganglioglioma/Astrocytoma**
|
||||
- Desmoplastic infantile gangliogliomas(DIGs)/astrocytoma often have large cyst
|
||||
- Cortically based, enhancing tumor nodule
|
||||
- Enhancing adjacent pia and dura; low grade
|
||||
- Good outcome with complete surgical resection
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Choroid Plexus Carcinoma**
|
||||
- Similar to CPP, +
|
||||
- Brain invasion; Ca⁺⁺, cysts, bleed
|
||||
- Ependymal, subarachnoid space seeding (can be seen with both CPP, choroid plexus carcinoma)
|
||||
- **Embryonal Tumor With Multilayered Rosettes**
|
||||
- Rare malignant embryonal brain tumor
|
||||
- Young children (< 5 years)
|
||||
- Histologic differentiation varies
|
||||
- Neuronal, astrocytic, ependymal, melanotic, etc.
|
||||
- Imaging appearance reflects variable differentiation
|
||||
- Medulloepithelioma, ependymoblastoma, and embryonal tumor with abundant neuropil and true rosettes (ETANTR) all have similar molecular features and are grouped as embryonal tumor with multilayered rosettes (ETMR)
|
||||
- **Neurocutaneous Melanosis (Melanoma/Melanocytoma)**
|
||||
- Giant or multiple cutaneous melanocytic nevi, +
|
||||
- Melanosis: Bright T1 lesions in amygdala, cerebellum without fat saturation
|
||||
- T2 hypointense to isointense, no enhancement
|
||||
- Melanoma: Melanosis + diffuse leptomeningeal enhancement
|
||||
- Degeneration into malignant melanoma common
|
||||
@@ -0,0 +1,325 @@
|
||||
---
|
||||
title: "CIDP"
|
||||
docid: "12e4033c-edc8-46ff-8081-3acc433cda78"
|
||||
authors:
|
||||
- key: "b2e6dabb-ee1c-42a4-a332-9f0814c1c607"
|
||||
value: "Surjith Vattoth, MD, FRCR"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Brain"
|
||||
slug: "brain"
|
||||
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
||||
-
|
||||
name: "Diagnosis"
|
||||
slug: "diagnosis"
|
||||
treeNodeId: "51c00394-446e-4a38-94af-d3b1d14d34e8"
|
||||
-
|
||||
name: "Pathology-Based Diagnoses"
|
||||
slug: "pathology-based-diagnoses"
|
||||
treeNodeId: "d9d3a8ed-f21b-4831-8c77-591a3500ef77"
|
||||
-
|
||||
name: "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
slug: "infectious-inflammatory-and-demyel-"
|
||||
treeNodeId: "7210f860-fe5f-4a2d-81cc-4fe06c769607"
|
||||
-
|
||||
name: "Inflammatory and Demyelinating Disease"
|
||||
slug: "inflammatory-and-demyelinating-dis-"
|
||||
treeNodeId: "62ab4dc3-dbf6-45a9-8532-f0e962aa62dc"
|
||||
-
|
||||
name: "CIDP"
|
||||
slug: "cidp"
|
||||
treeNodeId: null
|
||||
category: "Brain"
|
||||
documentVersionId: "96729e13-6c4b-4fd3-be3e-4e1a940566fd"
|
||||
imageCount: 12
|
||||
isBookmarked: false
|
||||
isComparable: true
|
||||
isInCompareCart: false
|
||||
lastUpdated: "06/08/20"
|
||||
pageDescription: "CIDP"
|
||||
pageKeywords: "Brain, Diagnosis, Pathology-Based Diagnoses, Infectious, Inflammatory, and Demyelinating Disease, Inflammatory and Demyelinating Disease, CIDP"
|
||||
pageTitle: "CIDP | STATdx"
|
||||
enhancedTitle: "CIDP"
|
||||
type: "DX"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
- "Inflammatory and Demyelinating Disease"
|
||||
- "CIDP"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Clinically heterogeneous, grossly symmetric, sensory & motor neuropathy evolving as monophasic, relapsing, or progressive disorder
|
||||
- Develops over > 8 weeks
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Sagittal FLAIR may reveal hyperintense brain lesions similar to multiple sclerosis
|
||||
- Enlargement & abnormal T2 hyperintensity of nerve roots, plexi, or peripheral nerves
|
||||
- ↑ nerve root diameter, cross-sectional area (CSA), & volume
|
||||
- Spinal nerve roots & peripheral nerves (extraforaminal > intradural)
|
||||
- Lumbar > cervical, brachial plexus, thoracic/intercostal > cranial nerve
|
||||
- Fair degree of CSA correlation between high-resonance nerve ultrasound (HRUS) & MR neurography (MRN)
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Guillain-Barré (AIDP)
|
||||
- Inherited demyelinating neuropathy (Charcot-Marie-Tooth)
|
||||
- Neurofibromatosis type 1, schwannomatosis
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- Autoimmune disease of cellular & humoral immunity
|
||||
- Hallmarks of CIDP: Enlarged nerves with onion bulb formations, demyelination
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Usually **clinical**diagnosis based on progressive weakness/sensory loss & response to steroids
|
||||
- Typical: Symmetric proximal & distal weakness, sensory loss
|
||||
- Abnormal EMG/NCV: Key electrophysiologic features → nerve conduction block, slowed conduction velocities suggestive of demyelination
|
||||
- Diagnosis relies primarily on clinical, electrophysiologic examination supplemented by nerve biopsy
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Chronic inflammatory demyelinating polyneuropathy (CIDP)
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Chronic inflammatory demyelinating polyradiculoneuropathy
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Chronic acquired, immune-mediated demyelinating neuropathy characterized by relapsing or progressive muscle weakness ± sensory loss
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Enlargement & abnormal T2 hyperintensity of nerve roots, plexi, or peripheral nerves
|
||||
- Spinal nerve roots & peripheral nerves (extraforaminal > intradural)
|
||||
- Lumbar > cervical, brachial plexus, thoracic/intercostal > cranial nerves (CNs)
|
||||
- ### Size
|
||||
|
||||
|
||||
- Nerve size varies; small → very large
|
||||
- Mean diameter of spinal nerve roots in CIDP: Cervical 6-6.8 mm; lumbosacral 7.3-10.4 mm
|
||||
- 5-mm best cut-off value of C6, C7, C8 nerve root diameters to distinguish CIDP patients from controls
|
||||
- CIDP nerves larger volumes, which positively correlate with disease duration
|
||||
- Recent MR neurography (MRN) of L3-S1 nerve roots of lumbosacral plexus using 3D multiple echo recalled gradient-echo (3D MERGE) sequence showed
|
||||
- ↑ mean cross-sectional area (CSA): 28.04 ± 8.55 mm² in CIDP (14.91 ± 2.36 square mm² in normal); optimal cut-off value 19.20 mm²
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Focal or diffuse fusiform enlargement of cauda equina, nerve roots/plexi, & peripheral nerves
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Isodense nerve enlargement
|
||||
- ### CECT
|
||||
|
||||
|
||||
- Mild to moderate nerve enhancement
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Enlargement, abnormal hyperintensity of intradural & extradural spinal nerves/branches
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- Sagittal FLAIR may reveal hyperintense brain lesions similar to multiple sclerosis (MS)
|
||||
- ### DWI
|
||||
|
||||
|
||||
- Diffusion-weighted MRN
|
||||
- DTI: ↓ nerve fractional anisotropy (FA) (mean 0.42 ± 0.08) in CIDP compared to healthy controls (0.52 ± 0.04)
|
||||
- ↓ FA due to ↑ radial diffusivity (RD); axial diffusivity (AD) not significant
|
||||
- FA & RD correlate strongly with electrophysiological markers of demyelination
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- Mild to moderate nerve enhancement
|
||||
- ## Ultrasonographic Findings
|
||||
|
||||
|
||||
- ### Grayscale ultrasound
|
||||
|
||||
|
||||
- Hypoechoic, hypertrophic nerves
|
||||
- Fair degree of CSA correlation in high resonance nerve US (HRUS) & MRN of cervical plexus, & peripheral nerves in CIDP
|
||||
- CSA in HRUS correlate well with markers of nerve integrity, such as ↓ FA in DTI & with ↑ T2 signal
|
||||
- HRUS-CSA of interscalene brachial plexus correlated significantly with MRN-CSA & T2 signal of L5 & S1 lumbar plexus roots
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- MRN, T2WI, enhanced coronal & axial T1WI sequences with fat suppression best delineate nerve lesions
|
||||
- Brain MR to detect subclinical CNS demyelination
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Conditions Recently Proposed to be Included Under CIDP Syndrome
|
||||
|
||||
|
||||
- Antimyelin associated glycoprotein (MAG) neuropathy
|
||||
- Chronic neuropathies associated with IgG4 antibodies against paranodal/nodal proteins; chronic immune sensory polyradiculopathy (CISP); multifocal motor neuropathy
|
||||
- [Guillain-Barré (Acute Inflammatory Demyelinating Polyneuropathy)](/document/guillain-barr-spectrum-disorders/c1f52a65-920e-4e28-8a75-07dfa208f290)
|
||||
- Pial, nerve root enhancement similar to CIDP
|
||||
- Differs from CIDP in onset duration, clinical course
|
||||
- Acute onset of ascending paralysis with relative sensory preservation
|
||||
- [Hereditary Motor and Sensory Neuropathy](/document/hypertrophic-neuropathy/e246f4d1-0262-4ca7-b8e1-6f2a4bd67c06)
|
||||
- Also called Charcot-Marie-Tooth (CMT) disease
|
||||
- CMT1, CMT 3 (Dejerine-Sottas disease) CMT4, CMTX1
|
||||
- Genetic testing, clinical phenotype distinguish from CIDP
|
||||
- [Neurofibromatosis Type 1](/document/neurofibromatosis-type-1-spine/89236653-e750-4fa7-b2b1-0a3c4ed31a87)
|
||||
- Diffuse nerve root enlargement, enhancement
|
||||
- Genetic testing & distinctive clinical stigmata to distinguish
|
||||
- ## Lateral Meningocele
|
||||
|
||||
|
||||
- CSF density/signal intensity (not solid) ± foraminal enlargement, dural ectasia
|
||||
- Usually coexisting NF1 or connective tissue disorder (Marfan syndrome)
|
||||
- ## Schwannomatosis
|
||||
|
||||
|
||||
- Multiple schwannomas of peripheral nerves & CNs [nonvestibular schwannomas (nVS)]
|
||||
- However, unilateral VS described with germline mutations of Schwannomatosis in SMARCB1 & LZTR1
|
||||
- ## Other Clinical Differential Diagnosis
|
||||
|
||||
|
||||
- Diabetic neuropathy, amyloid neuropathy due to TTR mutations, vasculitic neuropathy, POEMS syndrome
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Exact pathogenesis of CIDP unclear; involves both cellular & humoral immune factors
|
||||
- Polyneuropathies co-occurring with MS: Underdiagnosed; extra disability burden; includes CIDP
|
||||
- 1/3 of MS-CIDP cases with serum testing show IgG4 autoantibodies to neurofascin-155
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Extensive fusiform nerve enlargement ± gross onion bulb formations
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Large nerve, onion bulb formations, demyelination
|
||||
- Macrophage, T-cell infiltration → perivascular inflammatory infiltrates, nerve demyelination & remyelination
|
||||
- Onion bulb formation: Excessive Schwann cell process proliferation → repetitive demyelination/remyelination
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Mixed sensorimotor neuropathy; typical form: Symmetric proximal & distal weakness, sensory loss
|
||||
- Rarer atypical form (Lewis-Sumner syndrome)
|
||||
- Predominantly uni- or multifocal as well as distal
|
||||
- CNs are occasionally affected, with particular tropism for CNVII, but ophthalmoplegia or bulbar weakness can be present
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- Chronic progressive: Progressively deteriorate until treatment is given
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Sex
|
||||
|
||||
|
||||
- M = F
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Average disease duration: 7.5 years
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- European Federation of Neurological Societies/Peripheral Nerve Society Guideline on management of chronic inflammatory demyelinating polyradiculoneuropathy; immunomodulation or immunosuppression therapy
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Consider CIDP in differential of nerve root/peripheral nerve enlargement
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- MR findings imperfectly correlate with clinical disease activity/severity, laboratory findings
|
||||
|
||||
0f953548-b230-4137-9147-51d6ed147c6c
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
*Sagittal T1 C+ MR of the cervical spine shows marked hypertrophy and enhancement of all exiting cervical nerve roots <img src='/img/arrows/CS.png'/>. 5 mm is considered an adequate cut-off value of cervical spinal nerve root diameter, discriminating CIDP from controls. Mean diameter of spinal nerve roots in CIDP: Cervical 6-6.8 mm; lumbosacral 7.3-10.4 mm.*
|
||||
|
||||
|
||||
*Sagittal T1 C+ MR of the cervical spine shows marked hypertrophy and enhancement of all exiting cervical nerve roots <img src='/img/arrows/CS.png'/>. 5 mm is considered an adequate cut-off value of cervical spinal nerve root diameter, discriminating CIDP from controls. Mean diameter of spinal nerve roots in CIDP: Cervical 6-6.8 mm; lumbosacral 7.3-10.4 mm.*
|
||||
|
||||
|
||||
*Sagittal T2WI MR reveals enlargement and T2 hyperintensity of exiting extradural lumbosacral nerves <img src='/img/arrows/CS.png'/>. High signal of CSF should be excluded while measuring nerve root size/area in T2 MR.*
|
||||
|
||||
|
||||
*Axial T1WI C+ MR depicts enlargement and abnormal enhancement of exiting extradural lumbosacral nerves <img src='/img/arrows/CS.png'/>. Blood-nerve barrier breakdown can cause contrast enhancement. Axon loss associated with demyelination is the most important factor of disability and resistance to treatment. Root hypertrophy also may cause stenosis symptoms.*
|
||||
|
||||
|
||||
*Sagittal FLAIR MR demonstrates periventricular ovoid hyperintensities <img src='/img/arrows/CO.png'/> in a typical case of marked fusiform CIDP nerve enlargement with brain demyelination.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Axial T1WI C+ MR shows thickening and enhancement of ventral and dorsal cauda equina nerve roots <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Sagittal T2WI MR demonstrates diffuse thickening of the intradural cauda equina nerve roots.*
|
||||
|
||||
|
||||
*Sagittal FLAIR MR of the brain in a CIDP patient shows a typical paraventricular demyelinating lesion <img src='/img/arrows/WS.png'/> similar to those seen in multiple sclerosis patients.*
|
||||
|
||||
|
||||
*Sagittal T2WI MR depicts enlarged lumbar nerve roots extending into extraforaminal ventral primary rami <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Axial T2WI MR shows diffuse thickening and hyperintensity of thoracic nerve roots and paraspinal intercostal nerves.*
|
||||
|
||||
|
||||
*Axial T2WI MR reveals bilateral symmetric enlargement, hyperintensity of cervical nerve roots and brachial plexus <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Sagittal T1WI C+ MR demonstrates diffuse pial thickening and enhancement extending into the cauda equina nerve roots. Clinical course distinguished from Guillain-Barré (AIDP).*
|
||||
|
||||
|
||||
*Axial T2WI MR shows marked enlargement of the lumbar/sacral nerve roots <img src='/img/arrows/BS.png'/> and lumbosacral trunk <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
@@ -0,0 +1,306 @@
|
||||
---
|
||||
title: "CLIPPERS"
|
||||
docid: "ba394f3b-bbff-4128-90b5-3e1c07564c5f"
|
||||
authors:
|
||||
- key: "5cff4116-3654-4b3a-bb75-5ebe0b8c9850"
|
||||
value: "Anne G. Osborn, MD, FACR"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Brain"
|
||||
slug: "brain"
|
||||
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
||||
-
|
||||
name: "Diagnosis"
|
||||
slug: "diagnosis"
|
||||
treeNodeId: "51c00394-446e-4a38-94af-d3b1d14d34e8"
|
||||
-
|
||||
name: "Pathology-Based Diagnoses"
|
||||
slug: "pathology-based-diagnoses"
|
||||
treeNodeId: "d9d3a8ed-f21b-4831-8c77-591a3500ef77"
|
||||
-
|
||||
name: "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
slug: "infectious-inflammatory-and-demyel-"
|
||||
treeNodeId: "7210f860-fe5f-4a2d-81cc-4fe06c769607"
|
||||
-
|
||||
name: "Inflammatory and Demyelinating Disease"
|
||||
slug: "inflammatory-and-demyelinating-dis-"
|
||||
treeNodeId: "62ab4dc3-dbf6-45a9-8532-f0e962aa62dc"
|
||||
-
|
||||
name: "CLIPPERS"
|
||||
slug: "clippers"
|
||||
treeNodeId: null
|
||||
category: "Brain"
|
||||
documentVersionId: "259b8c88-93cc-45d6-93d8-75d279e9ead2"
|
||||
imageCount: 12
|
||||
isBookmarked: false
|
||||
isComparable: true
|
||||
isInCompareCart: false
|
||||
lastUpdated: "08/05/20"
|
||||
pageDescription: "CLIPPERS"
|
||||
pageKeywords: "Brain, Diagnosis, Pathology-Based Diagnoses, Infectious, Inflammatory, and Demyelinating Disease, Inflammatory and Demyelinating Disease, CLIPPERS"
|
||||
pageTitle: "CLIPPERS | STATdx"
|
||||
enhancedTitle: "CLIPPERS"
|
||||
type: "DX"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
- "Inflammatory and Demyelinating Disease"
|
||||
- "CLIPPERS"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- **C**hronic **l**ymphocytic **i**nflammation with**p**ontine **p**erivascular **e**nhancement **r**esponsive to **s**teroids (CLIPPERS)
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Location predominantly pons/cerebellum **but****may extend
|
||||
- Laterally into cerebellar peduncles or hemispheres
|
||||
- Rostrally into midbrain
|
||||
- Caudally into medulla, spinal cord
|
||||
- ≈ 60% have CNS lesions **outside**pontocerebellar region
|
||||
- Basal ganglia, hemispheric white matter, cortex
|
||||
- MR
|
||||
- Punctate/curvilinear enhancing foci "peppering" pons
|
||||
- May exhibit subtle radiating pattern
|
||||
- No ring or patchy enhancement
|
||||
- Patchy/"speckled" punctate hyperintensities on T2/FLAIR
|
||||
- Does not significantly exceed areas of T1 C+ enhancement
|
||||
- Caution: May begin as isolated, enhancing mass in pons/cerebellar peduncle before exhibiting typical pattern of multifocal punctate pontine lesions
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Angiocentric (intravascular) lymphoma
|
||||
- Neurosarcoidosis
|
||||
- Demyelinating disease (multiple sclerosis, MOG spectrum)
|
||||
- Vasculitis (primary, secondary, Behçet)
|
||||
- Lymphomatoid granulomatosis
|
||||
- Histiocytosis (e.g., hemophagocytic lymphohistiocytosis)
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- Perivascular predominance lymphohistiocytic infiltrates + diffuse adjacent parenchymal inflammatory infiltrate
|
||||
- May be type of macrophage activation syndrome (secondary hemophagocytic lymphohistiocytosis)
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Mean age at onset 50 years (range: 13-86 years)
|
||||
- Subacute pontocerebeller dysfunction
|
||||
- Often relapsing-remitting course (without treatment)
|
||||
- Keep in mind: CLIPPERS is diagnosis of exclusion!
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- **C**hronic **l**ymphocytic **i**nflammation with**p**ontine **p**erivascular **e**nhancement responsive to **s**teroids (CLIPPERS)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Recently described inflammatory CNS disorder
|
||||
- Distinct form of nonneoplastic encephalitis with predominant T-cell pathology
|
||||
- Predominantly involves brainstem, adjacent rhombencephalic structures
|
||||
- Striking clinical, imaging response to glucocorticosteroids
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Enhancing punctate/curvilinear lesions "peppering" pons
|
||||
- ### Location
|
||||
|
||||
|
||||
- Predominantly pons/cerebellum **but**may extend
|
||||
- Caudally into medulla, spinal cord
|
||||
- Rostrally into midbrain
|
||||
- ≈ 60% have CNS lesions **outside** pontocerebellar region
|
||||
- Basal ganglia, hemispheric white matter, cortex
|
||||
- Meningeal inflammation
|
||||
- Caution: May begin as isolated, enhancing mass in pons/cerebellar peduncle before exhibiting typical pattern of multifocal punctate pontine lesions
|
||||
- ### Size
|
||||
|
||||
|
||||
- Usually (but not always) ≤ 3mm
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Typically small, punctate or curvilinear
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- Usually normal
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Usually normal
|
||||
- Pontocerebellar/cerebellar, cord, cerebral atrophy may be late changes
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- ± faint, patchy or "speckled" punctate hyperintensities on T2/FLAIR
|
||||
- Minimal or no mass effect, vasogenic edema
|
||||
- Homogeneous hyperintensity; does not significantly exceed T1 C+ enhancement
|
||||
- ### T2* GRE
|
||||
|
||||
|
||||
- Usually negative
|
||||
- ### DWI
|
||||
|
||||
|
||||
- Usually absent
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- Punctate &/or curvilinear enhancing foci ("peppering" pons)
|
||||
- No ring or patchy enhancement
|
||||
- ↓ to absence of enhancement following steroids
|
||||
- ## Angiographic Findings
|
||||
|
||||
|
||||
- DSA normal without evidence for vasculitis
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- MR ± contrast (include coronal T1C+), DWI, T2*
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Lymphoma, Angiocentric (Intravascular)
|
||||
|
||||
|
||||
- Stroke-like symptoms, dementia
|
||||
- Hemorrhage, foci of restricted diffusion common
|
||||
- [Neurosarcoidosis](/document/neurosarcoid/fef69139-0019-4be3-9bdc-e26bc3644251)
|
||||
- Dura, leptomeningeal lesions common
|
||||
- Pituitary-hypothalamus often affected
|
||||
- [Vasculitis](/document/miscellaneous-vasculitis/5a4d4cbd-67e3-4722-8a44-8d411cbb98f0)
|
||||
- Primary angiitis of CNS (PACNS), systemic vasculitides
|
||||
- Neuro-Behçet
|
||||
- [Demyelinating Disease](/document/multiple-sclerosis/7892b2a2-f52a-4d7f-9858-a326f2b7ab04)
|
||||
- Multiple sclerosis (MS), MOG antibody-associated disease
|
||||
- Seropositive autoimmune encephalitides
|
||||
- ## Lymphomatoid Granulomatosis
|
||||
|
||||
|
||||
- Brain often more diffusely involved
|
||||
- [CNS Histiocytosis](/document/langerhans-cell-histiocytosis-skul-/6515bdbb-ce3d-47ef-9930-2dbb1949f807)
|
||||
- Hemophagocytic lymphohistiocytosis (HLH) resembles CLIPPERS on brain biopsy
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- May be type of macrophage activation syndrome (secondary HLH)
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Perivascular predominance lymphohistiocytic infiltrates + diffuse adjacent parenchymal inflammatory infiltrate
|
||||
- Marked CD3-positive T lymphocytes, variable macrophage components
|
||||
- Variable tissue destruction, astrogliosis, myelin loss
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Subacute pontocerebeller dysfunction
|
||||
- ± other CNS symptoms (e.g., cognitive dysfunction, myelopathy)
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Mean age at onset 50 years (range: 13-86 years)
|
||||
- ### Sex
|
||||
|
||||
|
||||
- M:F = 3:1
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Generally subacute presentation
|
||||
- Often relapsing-remitting course (without treatment)
|
||||
- Relapse rare when daily glucocorticoids ≥ 30 mg
|
||||
- Diagnosis of exclusion
|
||||
- Requires careful exclusion of alternative diagnoses
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Corticosteroids (marked clinical, imaging response key to diagnosis)
|
||||
- Corticosteroid responsiveness also common but not universal in non-CLIPPERS diagnoses
|
||||
- Relapse off treatment common
|
||||
- Hydroxychloroquine has been reported to induce, maintain remission of symptoms
|
||||
|
||||
0e17b374-1564-4020-a6e2-552480332e98
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
*Sagittal FLAIR MR in a 56-year-old woman with weight loss and a 3-week history of diplopia and disequilibrium shows confluent and punctate hyperintensities in the pons <img src='/img/arrows/WO.png'/> and medulla <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Sagittal FLAIR MR in a 56-year-old woman with weight loss and a 3-week history of diplopia and disequilibrium shows confluent and punctate hyperintensities in the pons <img src='/img/arrows/WO.png'/> and medulla <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR in the same patient shows multiple punctate and curvilinear enhancing foci "peppering" the pons <img src='/img/arrows/WS.png'/>. Additional lesions are present in both cerebellar peduncles, vermis, and the left cerebellar hemisphere.*
|
||||
|
||||
|
||||
*More cephalad T1 C+ MR scan in the same patient shows the punctate <img src='/img/arrows/WS.png'/> and curvilinear <img src='/img/arrows/WC.png'/> lesions involving the upper pons.*
|
||||
|
||||
|
||||
*Coronal T1 C+ FS MR in the same patient shows the lesions "peppering" the pons. Note cephalad extension into the cerebral peduncles <img src='/img/arrows/WO.png'/> and inferior extension into the medulla <img src='/img/arrows/WC.png'/> and upper cervical cord <img src='/img/arrows/WS.png'/>. DSA (not shown) was negative. The lesions resolved with corticosteroids, so this is a presumed case of CLIPPERS.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Sagittal FLAIR in a 52-year-old man with diplopia, dysarthria, and facial numbness shows confluent hyperintensity in the pons <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR shows scattered, faint, punctate enhancing foci <img src='/img/arrows/WS.png'/> as well as larger confluent, nodular <img src='/img/arrows/WO.png'/>, and partial ring-enhancing <img src='/img/arrows/WC.png'/> lesions in the pons.*
|
||||
|
||||
|
||||
*Coronal T1 C+ MR in the same patient shows large, confluent, patchy enhancing lesions <img src='/img/arrows/WS.png'/> in the pons. Differential diagnosis included lymphoma, lymphomatoid granulomatosis, vasculitis, and CLIPPERS. The patient improved on steroids.*
|
||||
|
||||
|
||||
*Sagittal FLAIR in the same patient obtained a year later when symptoms relapsed off steroids shows multiple punctate hyperintensities "peppering" the pons <img src='/img/arrows/WS.png'/> and medulla <img src='/img/arrows/WC.png'/>. Note extension into upper spinal cord <img src='/img/arrows/WO.png'/>.*
|
||||
|
||||
|
||||
*Axial T1 C + FS MR in the same patient shows small, punctate foci of enhancement <img src='/img/arrows/WS.png'/> "peppering" the pons, cerebellar peduncles.*
|
||||
|
||||
|
||||
*More inferior T1 C+ FS MR in the same patient shows additional small enhancing foci in the medulla <img src='/img/arrows/WS.png'/>.*
|
||||
|
||||
|
||||
*More cephalad T1 C+ FS MR in the same patient shows additional lesions in the midbrain <img src='/img/arrows/WS.png'/> and medial temporal lobe <img src='/img/arrows/WC.png'/>.*
|
||||
|
||||
|
||||
*More cephalad T1 C+ FS MR in the same patient shows a solitary enhancing lesion <img src='/img/arrows/WS.png'/> in the subcortical white matter of the "hand knob." One of the cerebellar lesions was biopsied and disclosed CD4+ T-cell perivascular infiltrates, consistent with CLIPPERS. In rare cases, CLIPPERS initially manifests as a more mass-like confluent pontine lesion before the typical peppering pattern emerges.*
|
||||
|
||||
@@ -1,321 +0,0 @@
|
||||
---
|
||||
title: "Craniopharyngioma"
|
||||
docid: "00e66680-6731-4287-b5a1-3f0b3f09053b"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Anatomy-Based Diagnoses"
|
||||
- "Sella and Pituitary"
|
||||
- "Neoplasms"
|
||||
- "Craniopharyngioma"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Benign, partially cystic sellar region tumor derived from remnants of craniopharyngeal duct/Rathke pouch epithelium
|
||||
- 2 types
|
||||
- Adamantinomatous (cystic mass in childhood)
|
||||
- Papillary (solid mass in older adults)
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- General features
|
||||
- Multilobulated, often large (> 5 cm)
|
||||
- Occasionally giant, multicompartmental
|
||||
- CT: Cystic (90%), Ca⁺⁺ (90%), enhancing (90%)
|
||||
- MR: Signal varies with cyst contents
|
||||
- Cysts variably hyperintense on T1WI and T2WI
|
||||
- Solid portions enhance heterogeneously; cyst walls enhance strongly
|
||||
- Cyst contents show broad lipid peak (0.9-1.5 ppm) on MR spectroscopy
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- Most common pediatric intracranial tumor of nonglial origin
|
||||
- WHO grade 1
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Bimodal age distribution
|
||||
- Peak 5-15 years; adults 45-60 years (commonly papillary)
|
||||
- Pediatric patient with morning headache, visual defect, short stature
|
||||
- Endocrine disturbances include growth hormone (GH) deficiency, luteinizing hormone (LH)/follicle-stimulating hormone (FSH) deficiency
|
||||
- Others = hypothyroidism > adrenal failure > diabetes insipidus
|
||||
- Surgical resection is primary therapy
|
||||
- Surgery, radiation therapy, or cyst aspiration for recurrent tumors
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Craniopharyngioma (CP)
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Craniopharyngeal duct tumor, Rathke pouch tumor, adamantinoma
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Benign, partially cystic sellar region tumor derived from Rathke pouch epithelium
|
||||
- 2 histologies: Adamantinomatous and papillary
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- CT: Partially Ca⁺⁺ mixed solid/cystic suprasellar mass in child
|
||||
- MR: Complex signal intensity suprasellar mass
|
||||
- ### Location
|
||||
|
||||
|
||||
- Surgical division of CPs into 3 groups
|
||||
- Sellar
|
||||
- Prechiasmatic
|
||||
- Retrochiasmatic
|
||||
- Imaging locations of CPs (adamantinomatous type)
|
||||
- Suprasellar (75%)
|
||||
- Suprasellar + intrasellar component (21%)
|
||||
- Entirely intrasellar (4%)
|
||||
- Often extends into multiple cranial fossae: Anterior (30%), middle (23%), posterior, &/or retroclival (20%)
|
||||
- Rare ectopic locations
|
||||
- Optic chiasm, 3rd ventricle
|
||||
- Other: Nasopharynx, paranasal sinuses, pineal gland, sphenoid (clivus), cerebellopontine angle
|
||||
- ### Size
|
||||
|
||||
|
||||
- Variable; often large at presentation (> 5 cm)
|
||||
- Occasionally giant, multicompartmental
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Multilobulated, multicystic
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Adamantinomatous type (90% rule)
|
||||
- 90% mixed solid (isodense), cystic (hypodense)
|
||||
- 90% calcify
|
||||
- 90% enhance (solid = nodule; rim = capsule)
|
||||
- Papillary type: Often solid, isodense, rarely calcifies
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Signal varies with cyst contents
|
||||
- Short T1 due to high protein content
|
||||
- Classic (adamantinomatous type)
|
||||
- Hyperintense cyst + heterogeneous nodule
|
||||
- Less common (papillary type)
|
||||
- Isointense solid component
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Cysts are variably hyperintense
|
||||
- Solid component = heterogeneous (iso-/hyperintense, Ca⁺⁺ portions hypointense)
|
||||
- Hyperintense signal in brain parenchyma adjacent to tumor may indicate
|
||||
- Gliosis, tumor invasion, irritation from leaking cyst fluid
|
||||
- Edema from compression of optic chiasm/tracts
|
||||
- Hypointense T2* = Ca⁺⁺
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- Cyst contents typically hyperintense
|
||||
- ### DWI
|
||||
|
||||
|
||||
- Variable depending upon character of cyst fluid
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- Solid portions enhance heterogeneously; cyst walls enhance strongly
|
||||
- ### MRA
|
||||
|
||||
|
||||
- Vascular displacement &/or encasement
|
||||
- ### MRS
|
||||
|
||||
|
||||
- Cyst contents show broad lipid spectrum (0.9-1.5 ppm)
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- MR with thin sagittal, coronal sequences
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- Pre-/postcontrast T1WI, T2, FLAIR, GRE, DWI, MRS
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Rathke Cleft Cyst](/document/rathke-cleft-cyst/8f1561f7-92a7-485c-a0ae-2e2d5c8c1628)
|
||||
- Noncalcified, less heterogeneous
|
||||
- Look for intracystic nodule on T2
|
||||
- Does not enhance
|
||||
- Claw sign (enhancing pituitary draped around cyst)
|
||||
- Small Rathke cleft cyst (RCC) may be indistinguishable from rare intrasellar CP
|
||||
- RCCs express CK8 and CK20 (CPs generally do not)
|
||||
- ## Suprasellar Arachnoid Cyst
|
||||
|
||||
|
||||
- No Ca⁺⁺, enhancement
|
||||
- ## Hypothalamic/Chiasmatic Astrocytoma
|
||||
|
||||
|
||||
- Solid or with small cystic/necrotic components
|
||||
- Ca⁺⁺ is rare; robust enhancement is common
|
||||
- ## Pituitary Adenoma
|
||||
|
||||
|
||||
- Rare in prepubescent children
|
||||
- Isointense with brain
|
||||
- Enhances strongly
|
||||
- Can mimic CP when cystic and hemorrhagic
|
||||
- ## Epidermoid/Dermoid Tumors
|
||||
|
||||
|
||||
- Minimal or no enhancement
|
||||
- ## Thrombosed Aneurysm
|
||||
|
||||
|
||||
- Contains blood products; use SWI
|
||||
- Look for residual patent lumen, phase artifact
|
||||
- [Germinoma or Mixed Germ Cell Tumor With Cystic Component(s)](/document/germinoma/078b68a2-67de-457e-818a-63655cec95aa)
|
||||
- Cerebrospinal fluid spread is common, Ca⁺⁺ is rare
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- 2 proposed theories
|
||||
- CPs arise from remnants of craniopharyngeal duct and Rathke pouch epithelium
|
||||
- CPs arise from squamous epithelial cells in pars tuberalis of adenohypophysis
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- No known genetic susceptibility (rare reports of siblings, parent-child)
|
||||
- Small subset of CPs are monoclonal tumors that arise from oncogenes at specific loci
|
||||
- Adamantinomatous: *CTNNB1* mutations and aberrant nuclear expression of β-catenin in up to 95% of cases
|
||||
- Papillary:*BRAF* V600E mutations in 81-95% of cases
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- WHO grade 1
|
||||
- MIB-1 labeling index > 7% predicts recurrence
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Solid tumor with variable cysts
|
||||
- Adamantinomatous cysts often contain thick "crankcase oil" fluid
|
||||
- Epithelial fronds penetrate adjacent hypothalamus/chiasm
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Adamantinomatous (mostly pediatric)
|
||||
- Multistratified squamous epithelium with nuclear palisading
|
||||
- Nodules of "wet" keratin
|
||||
- Dystrophic Ca⁺⁺
|
||||
- Papillary (mostly adults)
|
||||
- Sheets of squamous epithelium form pseudopapillae
|
||||
- Villous fibrovascular stroma
|
||||
- Malignant transformation, distant metastases rare
|
||||
- May occur with varied histologies, resulting in poor prognosis
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Symptoms vary with location, size of tumor, age of patient
|
||||
- Visual disturbances (60-85%)
|
||||
- Bitemporal hemianopsia
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- Endocrine disturbances (52-87%)
|
||||
- Growth hormone (GH) deficiency (75%) > luteinizing hormone (LH)/follicle-stimulating hormone (FSH) deficiency > hypothyroidism > adrenal failure > diabetes insipidus
|
||||
- Headaches
|
||||
- Cognitive impairment (~ 50%)
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- Pediatric patient with morning headache, visual defect, short stature
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Bimodal distribution (peak 5-15 years, with smaller peak 45-60 years)
|
||||
- Papillary CP: 40-55 years
|
||||
- ### Sex
|
||||
|
||||
|
||||
- M = F
|
||||
- ### Ethnicity
|
||||
|
||||
|
||||
- More common in Japanese children
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- Most common pediatric intracranial tumor of nonglial origin
|
||||
- Comprise 1.2-4.6% of all intracranial tumors across all ages
|
||||
- 6-11% of all pediatric intracranial tumors
|
||||
- Incidence = 0.5-2.5 new cases per 1 million per year
|
||||
- ~ 54% of all pediatric sellar/chiasmatic region tumors are CPs
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Typically slow-growing benign neoplasm
|
||||
- Prognosis based upon size, extent of tumor at presentation
|
||||
- < 5 cm, recurrence rate: 20%
|
||||
- > 5 cm, recurrence rate: 83%
|
||||
- Overall 10-year survival: 64-96%
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Methods of primary treatment
|
||||
- Radical surgery = gross total resection
|
||||
- Complications = hypothalamic injury, endocrine symptoms, vasa vasorum injury, and pseudoaneurysm
|
||||
- Surgery may occur via craniotomy, transnasal, transorbital, or endoscopic routes
|
||||
- Less invasive surgery = subtotal resection + radiation therapy
|
||||
- Biopsy, cyst drainage, and radiation therapy
|
||||
- Treatment for residual or recurrent tumor
|
||||
- Surgery, radiation therapy, or cyst aspiration
|
||||
- Cyst instillation with intracavitary radioisotopes, bleomycin, or other sclerosing agents
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Preoperative ophthalmologic and endocrine evaluations
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Use NECT to detect Ca⁺⁺ if MR diagnosis is in question
|
||||
- Adamantinomatous CP = 90% rule (90% cystic, calcified, enhancing)
|
||||
- Papillary CP is typically solid and primarily adult neoplasm
|
||||
|
||||
c497473c-5835-4221-bfa1-0d2be04bee73
|
||||
-329
@@ -1,329 +0,0 @@
|
||||
---
|
||||
title: "Creutzfeldt-Jakob Disease (CJD)"
|
||||
docid: "e1b27954-6591-4bb0-a659-b13790492620"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Acquired Toxic/Metabolic/Degenerative Disorders"
|
||||
- "Dementias and Degenerative Disorders"
|
||||
- "Creutzfeldt-Jakob Disease (CJD)"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Creutzfeldt-Jakob disease (CJD): Rapidly progressing, fatal, potentially transmissible dementia caused by prion
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Best imaging clue: Progressive DWI/FLAIR hyperintensity of basal ganglia (BG), thalamus, and cerebral cortex
|
||||
- Predominantly gray matter (GM): Caudate and putamen > globus pallidus (GP)
|
||||
- Thalamus: Common in variant CJD (vCJD)
|
||||
- Cerebral cortex: Frontal, parietal, and temporal
|
||||
- Heidenhain variant: Occipital lobe
|
||||
- 2 signs seen in 90% of vCJD but can also occur in sporadic CJD (sCJD)
|
||||
- Pulvinar sign: Symmetric T2 hyperintensity of pulvinar of thalamus
|
||||
- Hockey stick sign: Symmetric pulvinar and dorsomedial thalamic nuclear hyperintensity
|
||||
- Best imaging tool: MR with DWI
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Hypoxic-ischemic injury
|
||||
- Osmotic demyelination syndrome
|
||||
- Other causes of dementia
|
||||
- Alzheimer, frontotemporal, and multiinfarct dementia; dementia in motor neuron disease
|
||||
- Leigh syndrome
|
||||
- Corticobasal degeneration
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Definite CJD diagnosed by neuropathology
|
||||
- Progressive dementia associated with myoclonic jerks and akinetic mutism; variable constellation of pyramidal, extrapyramidal, and cerebellar signs
|
||||
- CSF protein biomarkers: 14-3-3 protein, total tau (t-tau), S100 and neuron-specific enolase (NSE)
|
||||
- DWI MR has higher diagnostic accuracy, 97% more than any or all of these CSF biomarkers
|
||||
- Incidence 1 per 1,000,000 (USA and internationally)
|
||||
- sCJD (85%), familial (15%), infectious/iatrogenic (< 1%) (includes vCJD)
|
||||
- Death usually ensues within months of onset
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Creutzfeldt-Jakob disease (CJD)
|
||||
- Sporadic Creutzfeldt-Jakob disease (sCJD)
|
||||
- Variant Creutzfeldt-Jakob disease (vCJD)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Rapidly progressing, fatal, neurodegenerative disorder caused by prion (proteinaceous infectious particle devoid of DNA and RNA)
|
||||
- Transmissible spongiform encephalopathy
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Progressive T2 hyperintensity of basal ganglia (BG), thalamus, and cerebral cortex
|
||||
- ### Location
|
||||
|
||||
|
||||
- Predominantly gray matter (GM)
|
||||
- BG: Caudate and putamen > globus pallidus (GP)
|
||||
- Thalamus (common in vCJD)
|
||||
- Cerebral cortex (most commonly frontal, parietal, and temporal lobes)
|
||||
- Cortical involvement often asymmetric
|
||||
- Heidenhain variant: Occipital lobe
|
||||
- Brownell-Oppenheimer: Cerebellum
|
||||
- May involve only peripheral cortex
|
||||
- Cortical involvement often asymmetric
|
||||
- Primary sensorimotor cortex relatively spared
|
||||
- White matter (WM) usually not involved
|
||||
- Size: Slight decrease (atrophy)
|
||||
- Morphology: Hyperintense T2 signal conforms to outline of BG and gyriform pattern in cortex
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- NECT: Usually normal
|
||||
- May show rapidly progressive atrophy and ventricular dilatation on serial CT
|
||||
- Serial CT illustrates atrophy progression
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Normal
|
||||
- GP hyperintensity reported in sCJD
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Hyperintense signal in BG, thalami, cortex
|
||||
- Cerebral atrophy
|
||||
- With time, hyperintense foci may develop in WM
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- 2 signs seen in 90% of vCJD but can also occur in sCJD
|
||||
- **Pulvinar**sign: Bilateral symmetrical hyperintensity of **pulvinar** (posterior) nuclei of **thalamus**
|
||||
- **Hockey stick** sign: Symmetrical **pulvinar and dorsomedial thalamic** nuclear hyperintensity
|
||||
- Periaqueductal GM hyperintensity
|
||||
- Cortical hyperintensity (common in sCJD)
|
||||
- ### DWI
|
||||
|
||||
|
||||
- Progressive hyperintensity in striatum and cortex
|
||||
- Gyriform hyperintense areas in cerebral cortex (cortical ribbon sign*)*
|
||||
- Correspond to localization of periodic sharp wave complexes on EEG
|
||||
- DWI hyperintensity may disappear late in disease
|
||||
- T1WI C+: No abnormal enhancement
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- F-18 FDG PET: Regional glucose hypometabolism correlates with sites of neuropathologic lesions
|
||||
- SPECT with N-isopropyl-p-(I-123) iodoamphetamine (DaTSCAN)
|
||||
- ↓ uptake of tracer in BG reported
|
||||
- Sometimes in asymmetrical pattern
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- Best imaging tool: MR with DWI and FLAIR
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Hypoxic-Ischemic Injury](/document/adult-hypoxic-ischemic-injury/dfb41c7a-2914-4a29-b05b-3a45c241f4a1)
|
||||
- BG and parasagittal cortical areas involved
|
||||
- Hyperintense BG lesions on T1WI and T2WI
|
||||
- DWI + symmetric GM involvement
|
||||
- [Osmotic Demyelination Syndrome](/document/osmotic-demyelination-syndrome/e061cc1f-61b4-4c4c-8b91-f53bf170180e)
|
||||
- Extrapontine: T2-hyperintense putamen and caudate
|
||||
- DWI positive acutely
|
||||
- ## Leigh Syndrome
|
||||
|
||||
|
||||
- Primarily seen in pediatric patients
|
||||
- T2 hyperintensity in putamen and GP
|
||||
- [Other Causes of Dementia](/document/alzheimer-disease/f71f5cf5-b1af-4c6d-b145-b4c10eec7b58)
|
||||
- [Alzheimer disease](/document/alzheimer-disease/f71f5cf5-b1af-4c6d-b145-b4c10eec7b58)
|
||||
- [Dementia in motor neuron disease](/document/amyotrophic-lateral-sclerosis-als/23de52b7-d9bd-441c-a18c-95c8afccb470)
|
||||
- [Frontotemporal dementia](/document/frontotemporal-lobar-degeneration/49510d0e-acf7-45cb-9eb1-53f8193b0b6d)
|
||||
- [Multiinfarct dementia](/document/vascular-dementia/f59dab57-c511-4369-8fcc-592421a4b8d1)
|
||||
- [Corticobasal Degeneration](/document/corticobasal-degeneration/23f97d4e-8724-4229-b9f8-08f63906ebd8)
|
||||
- Neuronal loss in substantia nigra, frontoparietal cortex, and striatum (BG atrophy may be subtle)
|
||||
- MR: Symmetric/asymmetric atrophy of pre- and postcentral gyri; prominent parasagittal involvement
|
||||
- Subcortical gliosis: High intensity on T2WI
|
||||
- [Wilson Disease](/document/wilson-disease/3d4d4876-4ce4-4af0-9e75-1a419bdd813c)
|
||||
- WM and deep GM lesions (BG, dentate nucleus, brainstem); variably T2 hyperintense
|
||||
- T1-hypointense (rarely hyperintense) lesions
|
||||
- [Arteriolosclerosis](/document/arteriolosclerosis/ce5a75ed-3a88-42a4-a0e8-4f339375c062)
|
||||
- BG involvement: Typically asymmetric and multifocal (rather than diffuse as in CJD)
|
||||
- Focal hyperintensities in deep WM
|
||||
- DWI negative, unless acute
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Prion protein is misfolded isoform (PrPSc) of normal host-encoded protein (PrPc)
|
||||
- PrPSc = conformationally isomer of PrPc
|
||||
- PrPSc introduced into healthy cells → initiates self-perpetuating vicious cycle: PrPc → PrPSc → neurotoxicity
|
||||
- sCJD: Spontaneous PrPc → PrPSc or somatic mutation
|
||||
- Familial CJD (fCJD): Mutations in *PRNP*gene
|
||||
- Iatrogenic CJD: Infection from prion-containing material
|
||||
- Surgical instruments, dura mater grafts, stereotactic electrodes
|
||||
- Cadaveric corneal transplants, human pituitary hormones (growth hormone and gonadotropins)
|
||||
- vCJD: Bovine spongiform encephalopathy in cattle is transmitted to humans through infected beef
|
||||
- Primarily present in UK
|
||||
- a.k.a. new variant CJD (nvCJD)
|
||||
- Risk for health care workers
|
||||
- Physical contact with patients is no risk for transmission
|
||||
- Special precautions in handling brain tissue
|
||||
- All used materials and instruments decontaminated as per established protocols
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- Can be inherited, sporadic, or acquired (infectious)
|
||||
- 10-15% of human prion disease cases associated with dominant mutations in autosomal prion protein (PrPc) gene (*PRNP*) on chromosome 20
|
||||
- PrPc is normal host protein on surface of many cells, particularly neurons
|
||||
- ### Associated abnormalities
|
||||
|
||||
|
||||
- EEG: Periodic (high-voltage) sharp wave complexes (PSWCs) on background of low-voltage activity
|
||||
- 67-95% patients with sCJD show PSWCs at some point during course of illness
|
||||
- False-positive EEG findings in Alzheimer dementia and vascular dementia patients
|
||||
- PSWCs helpful in differentiating sCJD from other prion disease
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- Sporadic CJD
|
||||
- Definite
|
||||
- Characteristic neuropathology (biopsy or autopsy)
|
||||
- Protease-resistant PrPSc (PrPres) by Western blot
|
||||
- Probable
|
||||
- Neuropsychiatric disorder with positive RT-QuIC in CSF or other tissues
|
||||
- OR
|
||||
- Rapidly progressive dementia and at least 2 out of 4 clinical features listed in table 1
|
||||
- AND positive result on at least 1 of 3 lab tests listed in table 1
|
||||
- AND without routine investigations indicating alternative diagnosis
|
||||
- Possible
|
||||
- Progressive dementia and at least 2 out of 4 clinical features listed in table 1
|
||||
- AND absence of positive lab tests that would classify case as "probable"
|
||||
- AND duration of illness < 2 years
|
||||
- AND without routine investigations indicating alternative diagnosis
|
||||
- Iatrogenic CJD: Progressive cerebellar syndrome in recipient of human cadaveric-derived pituitary hormone; or sporadic CJD with recognized exposure risk, e.g., antecedent neurosurgery with dura mater implantation
|
||||
- Familial CJD: Definite or probable CJD **with** definite or probable CJD in 1st-degree relative; &/or neuropsychiatric disorder **with** disease-specific PrP gene mutation
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Mild cortical atrophy
|
||||
- Diffuse or confined to affected structures
|
||||
- Ventricular enlargement
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Spongiform encephalopathy: GM most affected
|
||||
- Marked neuronal loss with reactive astrocytosis
|
||||
- Replacement gliosis
|
||||
- Neuronal vacuolation with spongiform changes
|
||||
- Spongiform panencephalopathy (very rare)
|
||||
- Primary extensive involvement of WM
|
||||
- Loss of myelin and axons associated with generalized spongiform change in WM
|
||||
- ± diffuse cerebral atrophy, loss of neurons, and proliferation of astrocytes in cerebral cortex
|
||||
- 10% of patients with CJD have amyloid plaques in cerebellum or cerebral hemispheres
|
||||
- Apple-green birefringence using Congo red staining when viewed under polarized light
|
||||
- Variable accumulation of PrPSc in brain tissue
|
||||
- PrPSc = abnormal, insoluble, protease-resistant amyloid form of PrPc
|
||||
- Diffuse (common in sCJD) or discrete plaques
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Rapidly progressive dementia associated with myoclonic jerks and akinetic mutism
|
||||
- Variable constellation of pyramidal, extrapyramidal, and cerebellar signs
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- **sCJD**: Cerebellar dysfunction, rapidly progressive cognitive impairment, both
|
||||
- 6 molecular subtypes: MM1, MM2 (thalamic and cortical), MV1, MV2, VV1, and VV2
|
||||
- Vary with respect to age at onset, disease duration, early symptoms, and neuropathology
|
||||
- **vCJD**: Psychiatric and sensory symptoms
|
||||
- **Heidenhain variant** of CJD
|
||||
- Isolated visual signs/symptoms (initially)
|
||||
- Predominantly occipital lobe degeneration
|
||||
- Normal conventional T1 and T2WI of brain
|
||||
- DWI/FLAIR may detect early cortical abnormalities
|
||||
- **Brownell-Oppenheimer**: Cerebellar signs/symptoms
|
||||
- Extrapyramidal type of CJD
|
||||
- May show ↑ signal intensity in BG
|
||||
- Pyramidal involvement with disease progression
|
||||
- BG dysfunction
|
||||
- Spinal cord involvement → muscle atrophy and fasciculations
|
||||
- **CSF studies**
|
||||
- CSF protein biomarkers: 14-3-3 protein, total tau (t-tau), S100, neuron-specific enolase (NSE), and thymosin β4
|
||||
- 14-3-3 protein detection is adjunctive rather than diagnostic for prior disease
|
||||
- t-tau > 1,150 picogram/mL has superior accuracy and specificity than 14-3-3 protein for CJD
|
||||
- Significant false-positives and negatives with 14-3-3 and t-tau protein test results
|
||||
- DWI MR has higher diagnostic accuracy than any or all CSF biomarkers
|
||||
- Real-time quaking-induced conversion (RT-QUIC) testing of CSF to detected PrPsc
|
||||
- More sensitive using olfactory epithelium (nasal brushing) than CSF
|
||||
- Nasal brushing not performed in USA
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Younger in vCJD, older in sCJD (6th-7th decades)
|
||||
- ### Sex
|
||||
|
||||
|
||||
- No sex preponderance
|
||||
- ### Ethnicity
|
||||
|
||||
|
||||
- sCJD occurs throughout world, in all races
|
||||
- In USA, CJD ↓ in Blacks, American Indians, and Alaskan natives than White population
|
||||
- vCJD limited to Europe (nearly all cases in UK)
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- Incidence 1.0-1.5 per million in USA
|
||||
- sCJD (85-95%), familial (5-15%), infectious/iatrogenic (< 1%)
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Long incubation period but rapidly progressive once clinical symptoms begin
|
||||
- Rapidly progressing dementia with death usually ensuing within months of onset
|
||||
- Median survival from time of onset of symptoms to death is 4.5 months
|
||||
- 90% live < 1 year
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- No effective treatment
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Heidenhain variant of CJD in patients with visual disorders of unclear origin and dementia
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Lack of BG findings does not rule out CJD
|
||||
|
||||
94600a52-3136-46e8-a827-05e281f28d7e
|
||||
-188
@@ -1,188 +0,0 @@
|
||||
---
|
||||
title: "Crossed Cerebellar Diaschisis"
|
||||
docid: "c1e384b3-3c6e-4f67-bf79-5187bd6a1b86"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Acquired Toxic/Metabolic/Degenerative Disorders"
|
||||
- "Dementias and Degenerative Disorders"
|
||||
- "Crossed Cerebellar Diaschisis"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Diaschisis: Sudden loss of function in brain connected to (but at distance from) damaged area
|
||||
- CCD: ↓ blood flow/metabolism in cerebellar hemisphere contralateral to supratentorial infarct
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Acute: CT/MR perfusion shows ↓ CBF in cerebellar hemisphere opposite acute hemispheric infarct
|
||||
- ↑ TTP, ↓ CBF in cerebellum contralateral to infarct
|
||||
- Add DTI as subtle cases may show ↓ FA when conventional MR normal
|
||||
- F-18 FDG PET/CT shows diffusely reduced uptake in contralateral cerebellar hemisphere
|
||||
- Chronic: CT or MR shows atrophic cerebellar hemisphere opposite old cerebral hemispheric infarct/insult
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Superior cerebellar artery infarct
|
||||
- CCD involved > just SCA territory
|
||||
- Encephalomalacia
|
||||
- Trauma, infection, surgery
|
||||
- Cerebellitis
|
||||
- Cerebellum swollen, hyperintense (not shrunken, atrophic)
|
||||
- Bilateral > unilateral
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- CPC tract
|
||||
- Input to cerebellum via CPC tracts 40x all other afferent sources combined
|
||||
- Injury at any point along CPC can result in ↓ CBF, metabolism in contralateral cerebellar hemisphere
|
||||
- Most common cause: MCA infarct
|
||||
- Others: Status epilepticus, neoplasm, trauma, surgery,migraine, Rasmussen encephalitis, etc.
|
||||
- Occurrence & severity of CCD related to degree of low supratentorial perfusion & decrease in ADC value of infarct
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Crossed cerebellar diaschisis (CCD)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Diaschisis: Sudden loss of function in brain connected to (but at distance from) damaged area
|
||||
- CCD: Decreased blood flow/metabolism in cerebellar hemisphere contralateral to supratentorial infarct
|
||||
- Caused by interrupted afferent input through corticopontocerebellar tract (CPC)
|
||||
- CCD occurs in both acute & chronic phases
|
||||
- Acute CCD results from functional deafferentation
|
||||
- Subacute, chronic CCD reflects transneuronal degeneration
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Acute: CT/MR perfusion shows ↓ cerebral blood flow (CBF) in cerebellar hemisphere opposite acute cerebral hemispheric infarct
|
||||
- Chronic: CT or MR shows atrophic cerebellar hemisphere opposite old cerebral hemispheric infarct/insult
|
||||
- ### Location
|
||||
|
||||
|
||||
- Cerebellar hemisphere opposite cerebral hemispheric infarct
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- Acute: CT or MR perfusion
|
||||
- PET/CT also effective but expensive; variable availability
|
||||
- Chronic: MR with T2WI, FLAIR, DTI
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- Add DTI as subtle cases may show ↓ fractional anisotropy (FA) when conventional MR normal
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Acute: Normal
|
||||
- Chronic: Cerebellar atrophy contralateral to supratentorial infarct
|
||||
- ### CTA
|
||||
|
||||
|
||||
- Middle cerebral artery (MCA) occlusion
|
||||
- Cerebellar vessels appear normal
|
||||
- CT perfusion
|
||||
- ↑ TTP, ↓ CBF in cerebellum contralateral to infarct
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Unilateral cerebellar atrophy
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Folia shrunken, fissures enlarged
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- Except for atrophy, cerebellum usually normal
|
||||
- ### MRA
|
||||
|
||||
|
||||
- Posterior fossa vasculature normal
|
||||
- DTI
|
||||
- Shows ↓ FA in middle cerebellar peduncle
|
||||
- Visualizes altered CPC in chronic CCD that may not be seen on conventional MR
|
||||
- Arterial spin labeling (ASL) perfusion
|
||||
- ↓ CBF in cerebellum contralateral to cerebral hemispheric abnormality
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- ### PET/CT
|
||||
|
||||
|
||||
- F-18 FDG PET/CT shows diffusely reduced uptake in contralateral cerebellar hemisphere
|
||||
- L-(methyl-11C) methionine (MET) uptake not reduced
|
||||
- ### Tc-99m sulfur colloid
|
||||
|
||||
|
||||
- Tc-99m ECD, HMPAO SPECT can demonstrate distant areas of ↓ CBF, metabolism (diaschisis)
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Superior Cerebellar Artery Infarct
|
||||
|
||||
|
||||
- CCD involves most of cerebellum, not just superior cerebellar artery (SCA) territory
|
||||
- Contralateral MCA infarct absent
|
||||
- ## Encephalomalacia
|
||||
|
||||
|
||||
- No history of trauma, contralateral MCA infarct
|
||||
- [Cerebellitis](/document/cerebellitis/2a2d695e-63be-4839-9e1a-cd8813b005d6)
|
||||
- Cerebellum swollen, not shrunken
|
||||
- Bilateral > unilateral
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- CPC tract
|
||||
- Large afferent pathway derived from very extensive areas of cortex
|
||||
- Input to cerebellum via CPC tracts 40x all other afferent sources combined
|
||||
- 1st-order neurons arrive in ipsilateral pons
|
||||
- Synapse with 2nd-order neurons
|
||||
- Then cross to opposite cerebellar hemisphere via middle cerebellar peduncle
|
||||
- Injury at any point along CPC can result in ↓ CBF, metabolism in contralateral cerebellar hemisphere
|
||||
- Most common cause: MCA infarct
|
||||
- Others: Status epilepticus, neoplasm, trauma, surgery, migraine, Rasmussen encephalitis, etc.
|
||||
- Occurrence & severity of CCD related to degree of low supratentorial perfusion & decrease in ADC value of infarct
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- CCD represents temporal continuum
|
||||
- Early, reversible functional hypometabolism
|
||||
- Cerebellum recovers (typical)
|
||||
- Irreversible degeneration in up to 20%
|
||||
- Cerebellar atrophy
|
||||
- Can be seen decades after initial insult
|
||||
|
||||
d7407fea-fff9-488b-9712-71a4e559c250
|
||||
-155
@@ -1,155 +0,0 @@
|
||||
---
|
||||
title: "CSF-Like Parenchymal Lesion(s)"
|
||||
docid: "24559f7a-ed5a-4ab6-90ba-769f0b5c1197"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Brain Parenchyma, General"
|
||||
- "Generic Imaging Patterns"
|
||||
- "CSF-Like Parenchymal Lesion(s)"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Key imaging questions
|
||||
- Does lesion follow CSF on all modalities/sequences?
|
||||
- Is there any associated mass effect?
|
||||
- Does lesion enhance?
|
||||
- Included
|
||||
- CSF-like cystic mass(es), e.g., enlarged perivascular spaces (PVS), neuroglial cysts
|
||||
- Excluded
|
||||
- Cystic neoplasms, abscess, resolving hematoma (rarely exactly like CSF)
|
||||
- Developmental cysts that do not behave exactly like CSF (e.g., epidermoid, neurenteric cysts)
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Enlarged Perivascular Spaces**
|
||||
- PVS
|
||||
- Can be seen at all ages but ↑ with age
|
||||
- Filled with interstitial fluid but follow CSF on all sequences
|
||||
- Most have no abnormality in surrounding parenchyma on FLAIR
|
||||
- ~ 25% have thin, hyperintense rim
|
||||
- Bilateral > unilateral
|
||||
- Multiple > solitary
|
||||
- "Clusters" of variably sized, CSF-like cysts characteristic
|
||||
- Can occur anywhere but most common locations = basal ganglia (BG), hemispheric white matter (WM), midbrain, dentate nuclei
|
||||
- Variant (mostly in older adults) = "état criblé" ("cribriform state") with multiple tiny cysts in BG
|
||||
- Classification
|
||||
- Type I: BG
|
||||
- Type II: High convexity WM
|
||||
- Type III: Midbrain
|
||||
- Large PVS cause mass effect, assume bizarre configurations, and can mimic cystic neoplasm
|
||||
- **Encephalomalacia**
|
||||
- Etiology varies (trauma, infarction, etc.)
|
||||
- Can be solitary, multifocal, multicystic
|
||||
- CSF-like ± adjacent FLAIR hyperintensity
|
||||
- **Lacunar Infarction**
|
||||
- Solitary or multiple
|
||||
- Typically along single long, unpaired penetrating arteries &/or vascular watershed zones
|
||||
- BG, thalamus, WM common
|
||||
- Multifocal BG infarcts + surrounding gliosis = "état lacunaire" or "lacunar state"
|
||||
- **Neurocysticercosis**
|
||||
- Most neurocysticercosis (NCC) cysts are actually in sulci
|
||||
- Cysts in vesicular stage smooth, thin walled, with scolex generally visible as "dot" within cyst
|
||||
- Multiple lesions in mixed stages common
|
||||
- Some enhance, some do not
|
||||
- Ca⁺⁺ (multiple = starry-sky pattern)
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Porencephalic Cyst**
|
||||
- CSF-filled parenchymal cavity
|
||||
- Communicates with ventricle &/or pial surface
|
||||
- Lined by reactive gliosis/astrocytic proliferation
|
||||
- Does not enhance
|
||||
- Etiology varies (trauma, infarction, etc.)
|
||||
- **Multiple Sclerosis**
|
||||
- Chronic "burned-out" lesions
|
||||
- Appear as CSF foci with hyperintense rinds on FLAIR
|
||||
- Look for faint T1 hyperintensity surrounding lesions ("lesion within lesion")
|
||||
- Obtain sagittal FLAIR to look for other lesions along callososeptal interface
|
||||
- **Hippocampal Sulcus Remnants**
|
||||
- "String of beads" cysts medial to temporal horns of lateral ventricles
|
||||
- Developmental variant, incidental
|
||||
- Remnants of vestigial primary embryonic hippocampal sulcus
|
||||
- Imaging
|
||||
- Between hippocampus, dentate gyrus
|
||||
- Follow CSF on all sequences
|
||||
- No surrounding gliosis
|
||||
- **Connatal Cysts**
|
||||
- Single or multiple
|
||||
- Location
|
||||
- Intra- or periventricular (may actually be cysts of anterior choroid plexus)
|
||||
- Small cyst adjacent to tip of frontal horn may be normal anatomic variant
|
||||
- Lined with ependyma
|
||||
- Present at birth
|
||||
- Usually transient
|
||||
- Occasionally seen in older patients
|
||||
- No septations, no hemosiderin
|
||||
- Generally isolated without associated abnormalities
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Neuroglial Cyst**
|
||||
- Benign, glial-lined, nonenhancing CSF-like cyst
|
||||
- No surrounding signal abnormality
|
||||
- Does not communicate with ventricle
|
||||
- Subcortical WM, choroidal fissure common sites
|
||||
- Does not restrict on DWI
|
||||
- No enhancement
|
||||
- **Cryptococcosis**
|
||||
- Opportunistic fungal infection
|
||||
- Nonenhancing, gelatinous pseudocysts in PVS
|
||||
- BG, thalamus, brainstem, cerebellum, dentate nucleus, periventricular WM
|
||||
- Multifocal > > solitary lesions
|
||||
- Most patients have HIV/AIDS
|
||||
- **Parasites, Miscellaneous**
|
||||
- Other than NCC, parasitic brain cysts uncommon
|
||||
- Hydatid cyst
|
||||
- Unilocular cyst, isointense to CSF
|
||||
- T2-hypointense rim, no enhancement
|
||||
- **Mucopolysaccharidoses**
|
||||
- Group of lysosomal storage disorders
|
||||
- PVS dilated by accumulated glycosaminoglycans
|
||||
- Corpus callosum, peritrigonal WM
|
||||
- Multiple, bilateral
|
||||
- Dilated PVS in deep periventricular WM
|
||||
- FLAIR-hyperintense rim surrounding dilated PVS
|
||||
- **Germinolytic Cysts**
|
||||
- Periventricular/subependymal cysts
|
||||
- Cyst(s) along caudothalamic groove probably resulting from germinolysis
|
||||
- Glial (not ependymal)-lined cysts/pseudocysts
|
||||
- Distinguish from "connatal" cysts (intraventricular anterior choroid plexus cysts)
|
||||
- Many etiologies, including inherited metabolic disorders (e.g., Zellweger, infantile Refsum), congenital infections (CMV)
|
||||
- CSF-like; ± septations, hemosiderin; do not enhance
|
||||
- Look for associated abnormalities
|
||||
- Leukoencephalopathy
|
||||
- Delayed myelination
|
||||
- Polymicrogyria, pachygyria, heterotopias
|
||||
- **Miscellaneous Congenital Malformations**
|
||||
- Several have parenchymal CSF-like cysts as part of syndrome
|
||||
- van der Knaap leukoencephalopathies (megaloencephalic leukoencephalopathy with subcortical cysts, anterior temporal lobe cavitations)
|
||||
- Congenital muscular dystrophy (cerebellar cysts common, may represent dilated PVS)
|
||||
- Dorsal interhemispheric CSF cyst
|
||||
- Corpus callosal dysgenesis
|
||||
- Holoprosencephaly
|
||||
- ## Alternative Differential Approaches
|
||||
|
||||
|
||||
- **Based on location**
|
||||
- Deep gray nuclei
|
||||
- Enlarged PVS
|
||||
- Lacunar infarction
|
||||
- Cryptococcosis
|
||||
- Periventricular WM
|
||||
- Multiple sclerosis
|
||||
- Connatal cysts
|
||||
- Germinolytic cysts
|
||||
- Lobar
|
||||
- Encephalomalacia
|
||||
- NCC
|
||||
- Porencephalic cyst
|
||||
- Neuroglial cyst
|
||||
- Hydatid cyst
|
||||
@@ -1,137 +0,0 @@
|
||||
---
|
||||
title: "Cyst With Nodule"
|
||||
docid: "6cb71737-f574-4121-a8fb-02eeada9f9f7"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Brain Parenchyma, General"
|
||||
- "Generic Imaging Patterns"
|
||||
- "Cyst With Nodule"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Cystic lesions with solid nodular components can be divided into 2 categories
|
||||
- Lesions that typically demonstrate cyst with nodule morphology
|
||||
- Neurocysticercosis (NCC), pilocytic astrocytoma, ganglioglioma, hemangioblastoma, pleomorphic xanthoastrocytoma (PXA), desmoplastic infantile ganglioglioma (DIG), intraparenchymal schwannoma
|
||||
- Lesions that may demonstrate cyst with nodule morphology
|
||||
- Metastases, glioblastoma (GBM), abscess, toxoplasmosis, parasites, dysplastic neuroepithelial tumor (DNET), thrombosed arteriovenous malformation (AVM), supratentorial ependymoma
|
||||
- Although metastases, abscesses, & GBMs do not classically present as "cysts with nodules," they are included because of their overall prevalence
|
||||
- Statistically, atypical form of these common diseases may be more likely than some of other "classic" cysts with nodule lesions
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Neurocysticercosis**
|
||||
- Intracranial parasitic infection caused by pork tapeworm *Taenia solium*
|
||||
- Cyst with "dot" inside representing scolex
|
||||
- Imaging appearance varies with stage; increased enhancement & edema when organism dies (inflammatory host response)
|
||||
- Location: Convexity subarachnoid space > > cisterns > parenchyma > ventricles
|
||||
- Lesions may be at different stages in same patient
|
||||
- **Pilocytic Astrocytoma**
|
||||
- Cerebellar cystic mass with mural nodule in child; rarely supratentorial
|
||||
- T1 C+ MR: Nodule shows intense but heterogeneous enhancement
|
||||
- Cyst wall may show enhancement
|
||||
- T1 & T2 MR: Cyst content iso- to hyperintense to CSF
|
||||
- Most common brain tumor in children
|
||||
- **Ganglioglioma**
|
||||
- Cortically based, slow-growing, enhancing mass in older child or young adult
|
||||
- Circumscribed cyst with mural nodule most common
|
||||
- May be solid and appear well circumscribed
|
||||
- Often expands cortex; calcification common
|
||||
- Most common tumor to cause temporal lobe epilepsy
|
||||
- Cortical dysplasia is commonly associated
|
||||
- **Hemangioblastoma**
|
||||
- Vascular neoplasm of uncertain etiology
|
||||
- Parenchymal posterior fossa cyst with nodule mass in adult
|
||||
- T1 C+ MR: Nodule abuts pial surface & shows intense, homogeneous enhancement
|
||||
- Prominent flow voids may be seen
|
||||
- Multiple in von Hippel-Lindau syndrome (VHL) (25-40% of hemangioblastomas)
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Metastases, Parenchymal**
|
||||
- Discrete, gray-white interface mass(es) with adjacent vasogenic edema
|
||||
- Multiplicity, history of primary malignancy helpful if present
|
||||
- Solitary metastasis may mimic GBM
|
||||
- Often known history of primary neoplasm
|
||||
- **Glioblastoma, IDH-Wildtype**
|
||||
- Malignant white matter mass with central necrosis
|
||||
- Predilection to spread across midline along corpus callosum; "butterfly glioma"
|
||||
- T1 C+ MR: Thick, irregular, nodular, enhancing margins
|
||||
- T2/FLAIR MR: Surrounding hyperintensity & mass effect reflect edema + infiltrative tumor
|
||||
- **Pleomorphic Xanthoastrocytoma**
|
||||
- Cortically based cyst + nodule ± involvement of adjacent meninges
|
||||
- T1 C+ MR
|
||||
- Enhancing nodule
|
||||
- Thickening, enhancement of adjacent meninges
|
||||
- 70% have dural tail
|
||||
- Temporal lobe predominance; young adult
|
||||
- Maybe associated with cortical dysplasia
|
||||
- **Abscess**
|
||||
- T2 MR: Hypointense rim with surrounding edema classic
|
||||
- T1 C+ MR: Enhancing capsule thinnest at ventricular side
|
||||
- DWI MR: Cystic component bright (diffusion restriction)
|
||||
- SWI MR: Dual rim sign (hypointense outside, hyperintense inside )
|
||||
- **Opportunistic Infection, AIDS, Toxoplasmosis**
|
||||
- Caused by parasite *Toxoplasma gondii*
|
||||
- Toxoplasmosis: Ring-enhancing lesion containing eccentric nodule = eccentric target sign specific but not sensitive
|
||||
- Location: Basal ganglia > hemispheres
|
||||
- Clinical: Immunocompromised patient
|
||||
- **Parasites, Miscellaneous**
|
||||
- Multiple enhancing lesions typical
|
||||
- May mimic brain tumor
|
||||
- Travel history critical
|
||||
- **Dysplastic Neuroepithelial Tumor**
|
||||
- Bubbly, wedge-shaped, cortically based mass "points" toward lateral ventricle
|
||||
- T2 MR: Very hyperintense; nodular, septate; no surrounding edema
|
||||
- FLAIR MR: Hyperintense ring sign
|
||||
- Thin rim of well-defined peritumoral hyperintensity separating it from surrounding normal brain
|
||||
- T1 C+ MR: No to minimal enhancement; may be nodular
|
||||
- Temporal lobe predominance
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Desmoplastic Infantile Ganglioglioma**
|
||||
- Supratentorial cystic/nodular mass with dominance of cyst
|
||||
- Cortically based nodule with intense enhancement & dural tail
|
||||
- May be massive
|
||||
- Peak age: 3-6 months
|
||||
- **Schwannoma, Intraparenchymal**
|
||||
- Only 1-2% of schwannomas are parenchymal
|
||||
- Cyst with strongly enhancing nodule
|
||||
- **Arteriovenous Malformation**
|
||||
- When hemorrhagic with partial or complete thrombosis, may present as cyst with nodule
|
||||
- Blood breakdown products of various ages; fluid-fluid levels
|
||||
- **Ependymoma, Supratentorial**
|
||||
- 40% of supratentorial ependymomas are extraventricular
|
||||
- Large, complex, mixed solid/cystic mass
|
||||
- Calcification, intratumoral hemorrhage common
|
||||
- Moderate but inhomogeneous enhancement
|
||||
- **Meningioma (Cystic)**
|
||||
- Meningioma with intraparenchymal cyst may mimic cyst + nodule mass
|
||||
- **Rosette-Forming Glioneuronal Tumor**
|
||||
- Rare, slowly growing benign tumor of young adults
|
||||
- 4th ventricle most common site > cerebellum
|
||||
- Mixed solid-cystic appearance, variable Ca⁺⁺, hemorrhage
|
||||
- May show cyst with nodule configuration
|
||||
- **Papillary Glioneuronal Tumor**
|
||||
- Temporal lobe predilection
|
||||
- Parenchymal mass with solid, cystic, or cyst/mural nodule architecture
|
||||
- May show calcification
|
||||
- Imaging may be indistinguishable from ganglioglioma
|
||||
- ## Alternative Differential Approaches
|
||||
|
||||
|
||||
- By location
|
||||
- Posterior fossa: Pilocytic astrocytoma, hemangioblastoma, metastasis, Rosette-forming glioneuronal tumor
|
||||
- Temporal lobe: Ganglioglioma, PXA, DNET, papillary glioneuronal tumor
|
||||
- Gray-white junction: Metastases, abscess
|
||||
- Hemispheric: NCC, metastases, GBM, infections, DIG, AVM, supratentorial ependymoma
|
||||
- Patient age
|
||||
- Child & young adult: Pilocytic astrocytoma, ganglioglioma, PXA, DNET
|
||||
- Adult: Hemangioblastoma, GBM, metastases
|
||||
- Any age: NCC, abscess, other infections
|
||||
- Multiple lesions
|
||||
- Metastases (50-55%), NCC (50-70%), hemangioblastoma (VHL), abscesses (septic emboli), toxoplasmosis, parasites
|
||||
@@ -1,275 +0,0 @@
|
||||
---
|
||||
title: "Dementia With Lewy Bodies"
|
||||
docid: "e8e46d1d-46d2-4e5a-880f-f025a84c5871"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Acquired Toxic/Metabolic/Degenerative Disorders"
|
||||
- "Dementias and Degenerative Disorders"
|
||||
- "Dementia With Lewy Bodies"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Progressive neurodegenerative dementia
|
||||
- Parkinsonism, visual hallucinations prominent
|
||||
- Caused by abnormal accumulation of α-synuclein protein
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- MR may differentiate Alzheimer disease (AD) from dementia with Lewy bodies (DLB)
|
||||
- PET, SPECT most useful for DLB diagnosis
|
||||
- Voxel-based morphometry
|
||||
- Relatively preserved hippocampal/medial temporal lobe volume in DLB vs. AD
|
||||
- ↓ volume of hypothalamus, substantia innominata, & putamen in DLB vs. AD
|
||||
- FDG PET
|
||||
- ↓ in glucose metabolism in occipital cortex, especially primary visual cortex
|
||||
- F-18 fluorodopa-PET: ↓ striatal dopamine uptake in DLB vs. AD
|
||||
- SPECT: Occipital lobe hypoperfusion, especially visual cortex
|
||||
- 123 FP-CIT SPECT: ↓ uptake in striatum in DLB vs. AD
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Parkinson disease-associated dementia (PDD)
|
||||
- Similar clinical, pathological, imaging features with DLB
|
||||
- AD
|
||||
- Frontotemporal lobar degeneration (FTLD)
|
||||
- Vascular dementia
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- Pathologic aggregation of α-synuclein protein in neurites (LB)
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- Unlike AD, medial temporal lobe atrophy not prominent feature
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Dementia with Lewy bodies (DLB)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Neurodegenerative dementia characterized by cognitive fluctuations, visual hallucinations, & motor parkinsonism
|
||||
- Caused by pathologic aggregation of α-synuclein protein in neurites (LB)
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- MR may differentiate Alzheimer disease (AD) from DLB
|
||||
- PET, SPECT most useful for DLB diagnosis
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- PET or SPECT
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Mild generalized atrophy
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Nonspecific white matter (WM) hyperintensities
|
||||
- ### MRS
|
||||
|
||||
|
||||
- ↓ WM NAA/Cr in DLB vs. healthy controls (HC)
|
||||
- ↑ Cho/Cr ratios in DLB vs. HC
|
||||
- Normal levels of NAA/Cr & myoinositol in DLB vs. AD
|
||||
- Voxel-based morphometry
|
||||
- Relatively preserved hippocampal/medial temporal lobe volume in DLB vs. AD
|
||||
- ↓ volume of hypothalamus, substantia innominata, & putamen in DLB vs. AD
|
||||
- ↓ gray matter in temporal, parietal, & occipital regions vs. HC
|
||||
- DTI
|
||||
- ↑ mean diffusivity in amygdala
|
||||
- ↓ fractional anisotropy in pons & left thalamus vs. AD
|
||||
- ↓ fractional anisotropy in inferior longitudinal fasciculus & inferior occipitofrontal fasciculi vs. HC
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- ### PET
|
||||
|
||||
|
||||
- FDG PET: ↓ glucose metabolism in occipital cortex & visual association cortex with relative preservation of posterior cingulate
|
||||
- F-18 fluorodopa-PET: ↓ striatal dopamine uptake in DLB vs. AD
|
||||
- ### MIBG scintigraphy
|
||||
|
||||
|
||||
- ↓ myocardial uptake in DLB due to ↓ postganglionic sympathetic cardiac innervation
|
||||
- SPECT
|
||||
- Occipital lobe hypoperfusion, especially visual cortex
|
||||
- 123 FP-CIT SPECT: Visualize DAT (dopamine transporter) loss
|
||||
- ↓ uptake in striatum in DLB
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Parkinson Disease-Associated Dementia](/document/parkinson-disease/0bc3188a-935b-416d-b1a0-25b2d52c6399)
|
||||
- Dementia typically develops at least 12 months after onset of initial parkinsonian symptoms
|
||||
- Similar clinical, pathologic, imaging features to DLB
|
||||
- Less pronounced atrophy in temporal, occipital, & parietal lobes vs. DLB
|
||||
- [Alzheimer Disease](/document/alzheimer-disease/f71f5cf5-b1af-4c6d-b145-b4c10eec7b58)
|
||||
- Parietal/temporal cortical atrophy
|
||||
- Disproportionate hippocampal volume loss
|
||||
- Amyloid uptake of cerebral cortex in PiB-PET
|
||||
- More severe, faster rate of progression than DLB
|
||||
- [Frontotemporal Lobar Degeneration](/document/frontotemporal-lobar-degeneration/49510d0e-acf7-45cb-9eb1-53f8193b0b6d)
|
||||
- Asymmetric frontal, anterior temporal lobar atrophy
|
||||
- Behavioral variant: Both frontal lobes atrophic
|
||||
- Semantic variant: Asymmetric anterior temporal lobe atrophy
|
||||
- [Vascular Dementia](/document/vascular-dementia/f59dab57-c511-4369-8fcc-592421a4b8d1)
|
||||
- 2nd most common dementia (15-30%)
|
||||
- WM & deep gray lacunae
|
||||
- Infarcts of different ages
|
||||
- Hyperintense lesions on T2WI, hypodense areas on CT, & focal atrophy suggestive of chronic infarcts
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Accumulation of α-synuclein protein (LB)
|
||||
- LB, neuronal loss in substantia nigra → dopamine depletion
|
||||
- Loss of cholinergic neurons in nucleus basalis of Meynert
|
||||
- → cognitive impairment, visual hallucinations
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- Majority of DLB is sporadic; some are familial
|
||||
- α-synuclein gene mutation on chromosome 4 (*A53T*, *E46K* mutation)
|
||||
- Similar inheritance, similar genetic risk for PD
|
||||
- Other genes associated with DLB include *SNCA*, *APP*, *PSEN1*/*PSEN2*, *MAPT*, *GBA*, & *APOE*
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- 3 major forms: Brainstem dominant, limbic/transitional, diffuse neocortical
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Nonspecific & overlap with other neurodegenerative dementias
|
||||
- Cortical atrophy is less than AD
|
||||
- Atrophy affects frontal, temporal, & parietal lobes, relative sparing of occipital lobes
|
||||
- Amygdala & cingulate gyri can show severe atrophy
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- LB in substantia nigra, neocortex, limbic system
|
||||
- α-synuclein protein aggregates: Pale eosinophilic inclusions
|
||||
- α-synuclein
|
||||
- Physiologic function: Synaptic transmission, neuroprotective effect
|
||||
- Predominantly expressed in neurons
|
||||
- Lewy neurites in hippocampus, amygdala, brainstem nuclei
|
||||
- Neuronal loss in substantia nigra, locus ceruleus, nucleus basalis of Meynert, dorsal raphe nuclei
|
||||
- Relative preservation of cortical neurons
|
||||
- Superficial microvacuolation of cerebral cortex, especially temporal cortex in severe cases
|
||||
- 80% have associated AD-like pathology
|
||||
- Neuritic/diffuse plaques or neurofibrillary tangles
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Cognitive fluctuations, visual hallucinations, parkinsonism
|
||||
- Dysautonomia & sleep disorders
|
||||
- Clinical criteria for DLB diagnosis
|
||||
- Core clinical features
|
||||
- Fluctuating cognition with pronounced variations in attention & alertness
|
||||
- Recurrent visual hallucinations (typically well formed & detailed)
|
||||
- REM sleep behavior disorder (May precede cognitive decline)
|
||||
- 1 or more spontaneous cardinal features of parkinsonism (bradykinesia, rest tremor, rigidity)
|
||||
- Supportive clinical features
|
||||
- Severe sensitivity to antipsychotic agents
|
||||
- Postural instability, repeated falls
|
||||
- Syncope or other transient episodes of unresponsiveness
|
||||
- Severe autonomic dysfunction (constipation, orthostatic hypotension, urinary incontinence)
|
||||
- Hypersomnia, hyposmia, hallucinations in other modalities, systematized delusions
|
||||
- Apathy, anxiety, & depression
|
||||
- Indicative biomarkers
|
||||
- ↓ dopamine transporter uptake in basal ganglia by SPECT or PET
|
||||
- Abnormal (low-uptake) I-123-MIBG myocardial scintigraphy
|
||||
- Polysomnographic confirmation of REM sleep without atonia
|
||||
- Supportive biomarkers
|
||||
- Relative preservation of medial temporal lobe structures on CT/MR
|
||||
- Generalized low uptake on SPECT/PET perfusion/metabolism scan with ↓ occipital activity ± cingulate island sign on FDG PET imaging
|
||||
- Prominent posterior slow-wave activity on EEG with periodic fluctuations in pre-alpha/theta range
|
||||
- Probable DLB
|
||||
- ≥ 2 core clinical features of DLB with or without indicative biomarkers; **or**
|
||||
- Only 1 core clinical feature but with ≥ 1 indicative biomarkers
|
||||
- Probable DLB should not be diagnosed on basis of biomarkers alone
|
||||
- Possible DLB
|
||||
- Only 1 core clinical feature of DLB with no indicative biomarker evidence; **or**
|
||||
- ≥ 1 indicative biomarkers but no core clinical features
|
||||
- DLB is less likely
|
||||
- Presence of any other physical illness or brain disorder, including cerebrovascular disease, sufficient to account in part or in total for clinical picture
|
||||
- If parkinsonian features are only core clinical feature & appear for 1st time at stage of severe dementia
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- 55-85 years; age is only risk factor
|
||||
- Average at presentation is 75 years
|
||||
- ### Ethnicity
|
||||
|
||||
|
||||
- LB formation more common in African Americans than Caucasians, but clinical diagnosis of DLB is not significantly different
|
||||
- ### Sex
|
||||
|
||||
|
||||
- M:F = 4:1
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- 5% of general population & 30% of dementia cases
|
||||
- 2nd most common neurodegenerative dementia (after AD)
|
||||
- Incidence rate of 0.1% per year in general population & 3.2% for new dementia cases
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Average survival after diagnosis < 8 years
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- ### Options, risks, complications
|
||||
|
||||
|
||||
- No disease-modifying treatments for DLB
|
||||
- Symptomatic, targeted toward specific disease manifestations
|
||||
- Cholinesterase inhibitor for cognitive features
|
||||
- DLB responds better to cholinesterase inhibitor than AD
|
||||
- Treatment against hallucination should be conservative due to neuroleptic hypersensitivity of DLB
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- No characteristic features on standard MR
|
||||
- Clinical dementia + no/relatively mild medial temporal lobe atrophy
|
||||
- Unlike AD, medial temporal lobe atrophy is not prominent
|
||||
|
||||
2eb83d9f-537e-4b39-96ac-8099cafa2337
|
||||
@@ -0,0 +1,126 @@
|
||||
---
|
||||
title: "Dolichoectasia"
|
||||
docid: "31d50b93-b057-4da3-86b5-4cc8fb0bc806"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Arteries"
|
||||
- "Anatomically Based Differentials"
|
||||
- "Fusiform Arterial Enlargement"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Ectasia = elongated/tortuous artery
|
||||
- Fusiform aneurysm
|
||||
- Long-segment fusiform arterial dilatation
|
||||
- Can be acute (dissecting) or chronic (atherosclerosis, nonatherosclerotic vasculopathy)
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Dolichoectasia**
|
||||
- Dilated/elongated arteries ± slow flow
|
||||
- Vessel layers intact
|
||||
- Older patients, chronic hypertension
|
||||
- Vertebrobasilar > internal carotid artery (ICA)
|
||||
- Ectasia often extends into branches
|
||||
- **Atherosclerotic Fusiform Aneurysm**
|
||||
- Thick wall ± organized thrombus
|
||||
- Variable slow flow
|
||||
- **Dissecting Aneurysm/Pseudoaneurysm**
|
||||
- Focal arterial dilatation
|
||||
- Trauma = most common etiology
|
||||
- Next to hard/fixed structures (bone, dura)
|
||||
- **Nonaneurysmal Dissection**
|
||||
- Vertebral > basilar > ICA
|
||||
- Lacks changes of atherosclerosis in other vessels
|
||||
- Can be spontaneous or traumatic
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **CNS Vasculitis**
|
||||
- Involves multiple vessels
|
||||
- Alternating stenoses and fusiform dilatations
|
||||
- **Inherited Connective Tissue Disorders**
|
||||
- Abnormal connective tissue involves vessel walls
|
||||
- Aneurysm and dissections
|
||||
- Thoracic aorta most common location
|
||||
- **HIV Infection**
|
||||
- Vasculopathy may be present in children or adults
|
||||
- Multifocal fusiform enlargement involving supraclinoid ICA and basilar artery
|
||||
- No consistent infectious agent isolated
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Giant Serpentine Aneurysm**
|
||||
- Large, partially thrombosed mass
|
||||
- Distal branches arise from aneurysm dome
|
||||
- Lacks definable neck
|
||||
- ICA/middle cerebral artery > vertebrobasilar artery
|
||||
- **Atypical Saccular Aneurysm**
|
||||
- Arises from vessel bifurcations
|
||||
- Long "aspect ratio" → fusiform appearance
|
||||
- Often multilobulated, bizarre
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
*Axial CT shows fusiform dilatation and tortuosity of the basilar artery <img src='/img/arrows/CS.png'/> in an octogenarian related to dolichoectasia. Fusiform dolichoectasia is a common finding in the vertebrobasilar arteries in older patients.*
|
||||
|
||||
|
||||
*Axial CT shows fusiform dilatation and tortuosity of the basilar artery <img src='/img/arrows/CS.png'/> in an octogenarian related to dolichoectasia. Fusiform dolichoectasia is a common finding in the vertebrobasilar arteries in older patients.*
|
||||
|
||||
|
||||
*Axial CT shows fusiform dilatation and tortuosity of the basilar artery <img src='/img/arrows/CS.png'/> in an octogenarian related to dolichoectasia. Fusiform dolichoectasia is a common finding in the vertebrobasilar arteries in older patients.*
|
||||
|
||||
|
||||
*Coronal CTA shows fusiform dilatation <img src='/img/arrows/CS.png'/> of the right supraclinoid internal carotid artery (ICA). Irregularity from atherosclerotic disease can be seen of the M1 segment of the middle cerebral artery <img src='/img/arrows/CO.png'/>. No significant mural thrombus was noted in this fusiform aneurysm.*
|
||||
|
||||
|
||||
*Dissecting pseudoaneurysm in the V4 segment of the right vertebral artery seen on 3D TOF MRA <img src='/img/arrows/WS.png'/>, T2 <img src='/img/arrows/BS.png'/>, and T1 pre- <img src='/img/arrows/CS.png'/> and post <img src='/img/arrows/CO.png'/> DANTE VWI sequences shows peripheral enhancement, suggestive of instability.*
|
||||
|
||||
|
||||
*3D MIP MRA of the vertebrobasilar arteries in a teenage female with a history of type 4 Ehlers-Danlos shows fusiform dilatation of the vertebral artery <img src='/img/arrows/CS.png'/>. The affected gene is COL3A1, and this specific type of Ehlers-Danlos has a higher risk of aneurysm and vascular rupture.*
|
||||
|
||||
|
||||
*Axial MIP from CT arteriography shows fusiform dilatation of the left middle cerebral artery bifurcation <img src='/img/arrows/CS.png'/> in this child with a history of Marfan syndrome.*
|
||||
|
||||
|
||||
*Coronal MIP reformat from CT arteriography shows bilateral fusiform aneurysms of supraclinoid ICAs <img src='/img/arrows/CS.png'/>. This patient also had thoracic aortic aneurysm, which is consistent with familial thoracic aortic aneurysm and dissection and is associated with a mutation of ACTA2. This gene is responsible for a component of vascular smooth muscle.*
|
||||
|
||||
|
||||
*Axial T2WI MR shows strikingly enlarged middle cerebral arteries <img src='/img/arrows/CS.png'/> in this child with congenital HIV/AIDS (an uncommon but well-recognized cause of pediatric fusiform arteriopathy). The stroke-like presentations of HIV infection may relate to vasculopathies, including large-vessel aneurysmal vasculopathy.*
|
||||
|
||||
|
||||
*Axial NECT demonstrates a giant serpentine aneurysm in the basilar artery <img src='/img/arrows/WC.png'/> with associated mural thrombus <img src='/img/arrows/CC.png'/> seen on sagittal CTA.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Sagittal T1WI MR shows an elongated basilar artery with a slow-flow, thickened wall <img src='/img/arrows/WS.png'/>. The apex of the tortuous basilar artery indents the hypothalamus, 3rd ventricle <img src='/img/arrows/WO.png'/>.*
|
||||
|
||||
|
||||
*Axial T2WI MR shows an elongated, tortuous basilar artery with a thickened arterial wall <img src='/img/arrows/BS.png'/>, typical for atherosclerosis-associated fusiform ectasia.*
|
||||
|
||||
|
||||
*Lateral angiography shows a large fusiform middle cerebral artery aneurysm <img src='/img/arrows/BS.png'/> that extends into smaller, more distal branches <img src='/img/arrows/BO.png'/>. This is an unusual example because of the location (ICA, middle cerebral artery).*
|
||||
|
||||
|
||||
*Axial T1WI MR shows an enlarged right vertebral artery with high signal intensity <img src='/img/arrows/WS.png'/> as well as an absent flow void of the left vertebral artery <img src='/img/arrows/WC.png'/>.*
|
||||
|
||||
|
||||
*Anteroposterior oblique view of the left vertebral angiogram shows focal elongations and widening of the basilar artery <img src='/img/arrows/BS.png'/> in a 6-year-old child with Ehlers-Danlos type 4.*
|
||||
|
||||
|
||||
*Axial MRA submentovertex view shows an unusual nonatherosclerotic giant serpentine fusiform aneurysm. The patent channel <img src='/img/arrows/WS.png'/> lies within the clot in the partially thrombosed <img src='/img/arrows/WO.png'/> lumen.*
|
||||
|
||||
|
||||
*Lateral angiography in 30-year-old man with a subarachnoid hemorrhage shows an elongated, bizarre-appearing, multilobulated aneurysm <img src='/img/arrows/BS.png'/> with long aspect ratio, tit-like projections.*
|
||||
|
||||
@@ -1,311 +0,0 @@
|
||||
---
|
||||
title: "Empty Sella"
|
||||
docid: "39a0d2d1-1439-4558-8f5d-86a2a6d93e3a"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Anatomy-Based Diagnoses"
|
||||
- "Sella and Pituitary"
|
||||
- "Miscellaneous"
|
||||
- "Empty Sella"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Sella partially filled with arachnoid-lined CSF collection
|
||||
- Primary empty sella
|
||||
- Common normal variant (15% of brain MRs), incidental finding
|
||||
- Normal or increased CSF pressure
|
||||
- Near-normal volume of compressed pituitary tissue
|
||||
- Secondary empty sella
|
||||
- Prior pituitary surgery, radiation, or injury
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Intrasellar CSF, pituitary flattened against sellar floor
|
||||
- Bony sella may be normal or moderately enlarged (secondary to pulsatile CSF)
|
||||
- Bony margins intact, not eroded/demineralized
|
||||
- Infundibular stalk, pituitary gland enhance normally
|
||||
- Fluid exactly like CSF
|
||||
- Suppresses completely on FLAIR
|
||||
- Does not restrict on DWI
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Idiopathic intracranial hypertension
|
||||
- Secondary intracranial hypertension
|
||||
- Arachnoid cyst
|
||||
- Pituitary apoplexy
|
||||
- Pituitary anomalies
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- "Deficient" diaphragma sellae
|
||||
- Dural covering of sella is incomplete (widened)
|
||||
- Leaves large opening for infundibular stalk
|
||||
- Allows intrasellar herniation of arachnoid with CSF from suprasellar subarachnoid cistern above
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Mostly incidental, asymptomatic (adults)
|
||||
- F:M = 5:1
|
||||
- Headache, visual disturbances if related to intracranial hypertension
|
||||
- Frequent endocrine abnormalities in children
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Empty sella (ES)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Herniation of suprasellar arachnoid and cerebrospinal fluid (CSF) through wide diaphragma sellae into bony sella turcica
|
||||
- Sella turcica is partially filled with CSF
|
||||
- Rarely completely empty
|
||||
- Pituitary gland
|
||||
- Almost never completely absent
|
||||
- Thin, flattened rim of residual pituitary tissue
|
||||
- Generally at posteroinferior sellar floor
|
||||
- Primary or secondary
|
||||
- Primary empty sella
|
||||
- Common normal variant (15% of brain MRs), incidental finding
|
||||
- Normal or increased CSF pressure
|
||||
- Near-normal volume of compressed pituitary tissue
|
||||
- No history of trauma, surgery, radiation
|
||||
- Patients typically endocrinologically normal
|
||||
- Secondary empty sella
|
||||
- Many etiologies
|
||||
- Surgery
|
||||
- Radiation
|
||||
- Bromocriptine therapy
|
||||
- Trauma
|
||||
- Sheehan syndrome (postpartum pituitary necrosis)
|
||||
- Pituitary apoplexy
|
||||
- Pituitary abscess
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Intrasellar CSF with pituitary gland flattened against sellar floor
|
||||
- Bony sella may be normal or large
|
||||
- ### Location
|
||||
|
||||
|
||||
- Intrasellar CSF
|
||||
- ### Size
|
||||
|
||||
|
||||
- Variable
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- Sagittal T1WI
|
||||
- Coronal T2WI
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- CSF-like herniation of CSF into bony sella
|
||||
- Bony sella typically appears normal
|
||||
- May also be moderately enlarged (secondary to pulsatile CSF)
|
||||
- Bony margins intact, not eroded/demineralized
|
||||
- ### CECT
|
||||
|
||||
|
||||
- Infundibular stalk and pituitary gland enhance normally
|
||||
- Occasionally intrasellar CSF collection may be asymmetric
|
||||
- Stalk may appear tilted to one side
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Primary empty sella
|
||||
- Fluid looks exactly like CSF
|
||||
- Stalk usually midline
|
||||
- Gland + stalk = anchor sign on coronal imaging
|
||||
- Stalk may be tilted to one side if intrasellar CSF herniation is asymmetric
|
||||
- 3rd ventricle, hypothalamus usually normal
|
||||
- Rare: Herniation of optic chiasm, anterior 3rd ventricle into sella
|
||||
- Secondary empty sella
|
||||
- Look for changes of transsphenoidal hypophysectomy
|
||||
- Defect in sellar floor
|
||||
- Fat packing
|
||||
- May cause distortion of stalk, chiasm
|
||||
- Stalk and pituitary remnant(s) may be scarred/adhesed to side or bottom of sella turcica
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Fluid exactly like CSF
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- Intrasellar fluid suppresses completely on FLAIR
|
||||
- ### DWI
|
||||
|
||||
|
||||
- No restriction
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- Primary empty sella
|
||||
- Stalk, gland enhance normally
|
||||
- No other abnormalities
|
||||
- Secondary empty sella
|
||||
- Gland and stalk may be adhesed/distorted
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Idiopathic Intracranial Hypertension](/document/idiopathic-intracranial-hypertensi-/d7a0a1b6-1d94-473c-9fe9-021443969f9f)
|
||||
- Often not truly "idiopathic" (e.g., dural venous sinus stenosis)
|
||||
- Usually obese female, 20-40 years
|
||||
- Headache, papilledema
|
||||
- Intraoptic protrusion of optic nerve head
|
||||
- Enlarged optic nerve sheaths ± empty sella
|
||||
- Ventricles may appear slit-like
|
||||
- Subarachnoid spaces (cisterns, surface sulci) may be small
|
||||
- ## Secondary Intracranial Hypertension
|
||||
|
||||
|
||||
- Increased intracranial pressure caused by
|
||||
- Obstructive hydrocephalus (intra-/extraventricular)
|
||||
- Mass (neoplasm, etc.)
|
||||
- Dilated anterior recesses of 3rd ventricle herniate into sella
|
||||
- Look for mass, evidence for transependymal CSF migration
|
||||
- [Arachnoid Cyst](/document/arachnoid-cyst/d25aaeb3-5b3c-4483-99dc-2757468eedb9)
|
||||
- Suprasellar arachnoid cyst may herniate into bony sella
|
||||
- Bony sella often enlarged, eroded/expanded
|
||||
- Look for 3rd ventricle or optic chiasm displaced by CSF-containing mass
|
||||
- Cyst walls may be visible on thin-section imaging
|
||||
- [Pituitary Apoplexy](/document/pituitary-apoplexy/43efc995-d33c-4ac1-be70-e3237eec9fc9)
|
||||
- Acute: Pituitary gland usually enlarged, not small
|
||||
- Usually hemorrhagic
|
||||
- Look for rim enhancement around periphery of enlarged, nonenhancing gland
|
||||
- Chronic: May cause empty sella
|
||||
- [Pituitary Anomalies](/document/pituitary-anomalies/09ca9b54-a3d9-43fd-a9cc-4c0212b578a1)
|
||||
- Ectopic posterior pituitary "bright spot"
|
||||
- May cause small pituitary gland
|
||||
- Infundibular stalk short, "stubby"
|
||||
- Bony sella often small, shallow appearing
|
||||
- Sella can appear partially empty
|
||||
- Persisting embryonal infundibular recess of 3rd ventricle
|
||||
- Can mimic empty sella (rare)
|
||||
- Pituitary stalk duplication
|
||||
- Rare
|
||||
- Look for 2 thin stalks
|
||||
- Sella may appear partially empty
|
||||
- [Sheehan Syndrome](/document/pituitary-apoplexy/43efc995-d33c-4ac1-be70-e3237eec9fc9)
|
||||
- Original clinical description
|
||||
- Postpartum hemorrhage
|
||||
- Pituitary necrosis
|
||||
- Lactation failure
|
||||
- Hypopituitarism
|
||||
- Anterior pituitary necrosis
|
||||
- Leaves small residual pituitary gland
|
||||
- Result = empty sella
|
||||
- May occur years after pregnancy
|
||||
- Slow clinical progression over years suggests factors other than ischemia may be involved
|
||||
- Necrosis may be caused by antihypothalamus, antipituitary antibodies
|
||||
- Pituitary autoimmunity may perpetuate hypopituitarism
|
||||
- [Epidermoid Cyst](/document/epidermoid-cyst/704c5ddf-e1f7-4a5d-a1b8-5b0e603170d9)
|
||||
- True intrasellar epidermoid cyst very rare
|
||||
- Off midline > midline
|
||||
- Usually extension from cerebellopontine angle epidermoid
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Primary empty sella
|
||||
- Deficient diaphragma sellae
|
||||
- Dural covering of sella is incomplete (widened)
|
||||
- Leaves widened dural opening for infundibular stalk
|
||||
- Allows intrasellar herniation of arachnoid with CSF from suprasellar subarachnoid cistern above
|
||||
- Compresses pituitary gland against sellar floor
|
||||
- Traction on infundibular stalk may cause alteration in visual system
|
||||
- Pulsatile CSF may gradually enlarge sella
|
||||
- Secondary empty sella
|
||||
- Common: Surgery, bromocriptine therapy, radiation
|
||||
- Less common: Pituitary apoplexy, pituitary abscess
|
||||
- Rare: Pituitary necrosis in viral hemorrhagic fever (e.g., hanta)
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Diaphragma sellae appears widened, gaping
|
||||
- Intrasellar herniation of arachnoid-containing CSF
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Incidental, usually asymptomatic
|
||||
- Headache
|
||||
- Visual disturbances 1-15%
|
||||
- Idiopathic intracranial hypertension (IIH)
|
||||
- Optic chiasm herniation into ES may cause visual symptoms
|
||||
- Endocrine disturbances
|
||||
- 20% of adults have subtle laboratory abnormalities
|
||||
- Majority (70%) of children with ES have endocrine abnormalities
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Peak incidence between 50-60 years
|
||||
- Increased CSF pressure presents earlier (30-40 years)
|
||||
- ### Sex
|
||||
|
||||
|
||||
- F:M = 5:1
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- 10-15% found incidentally on imaging
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Both primary and secondary empty sella usually benign, do not require treatment
|
||||
- If related to IIH, can result in vision loss or CSF leak
|
||||
- Hormonal replacement therapy may be required in some cases
|
||||
- Surgery (rare)
|
||||
- "Chiasmapexy" to elevate optic chiasm if severe visual disturbances caused by inferior displacement of optic chiasm into empty sella
|
||||
- CSF rhinorrhea may require surgical intervention
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Incidental, normal variant in older adults
|
||||
- Additional findings of IIH in younger females (e.g., dilated optic nerve sheaths, papilledema, dural venous sinus narrowing)
|
||||
- Look for endocrine abnormalities in children
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Intrasellar fluid follows CSF **exactly**on all sequences
|
||||
|
||||
8bb93cd6-d836-4878-89c3-865ebc070aea
|
||||
@@ -1,72 +0,0 @@
|
||||
---
|
||||
title: "Epilepsy, Adult"
|
||||
docid: "c936f9e1-b6c6-4c4a-afc6-f2e1a968a7b0"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Brain Parenchyma, General"
|
||||
- "Clinically Based Differentials"
|
||||
- "Epilepsy, Adult"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Adult-onset seizures are more likely acquired
|
||||
- Acute symptomatic seizure ≤ 1 week of brain injury
|
||||
- Remote symptomatic seizure: Beyond 1 week
|
||||
- Encephalomalacia and gliosis can also cause seizures
|
||||
- Epilepsy: When 2 or more seizures occur 24 hours apart
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Trauma**
|
||||
- Diffuse axonal injury and contusions
|
||||
- Intracranial hemorrhage (subdural hemorrhage and subarachnoid hemorrhage) can also present with seizures without parenchymal findings
|
||||
- **Stroke**
|
||||
- Most common cause in older adults
|
||||
- **Infection**
|
||||
- All cerebral and meningeal infection can cause seizure
|
||||
- Meningitis, encephalitis, and abscess
|
||||
- Look for herpes encephalitis
|
||||
- CNS tuberculosis and neurocysticercosis are common causes outside of USA
|
||||
- **Drug Use and Withdrawal**
|
||||
- Withdrawal from alcohol, benzodiazepines, barbiturates
|
||||
- Illicit drug use and drugs, which lower seizure threshold
|
||||
- **Metabolic**
|
||||
- Hyper- or hypoglycemia
|
||||
- Hyponatremia, hypocalcinemia, hypomagnesemia, hypothyroidism
|
||||
- Hyperammonemia from hepatic encephalopathy
|
||||
- Uremic encephalopathy
|
||||
- **Neoplasms**
|
||||
- Glioblastoma most common in older adults
|
||||
- Cortically based tumors primarily in older children to young adults
|
||||
- **Neurodegenerative Disease**
|
||||
- Dementia: Alzheimer
|
||||
- Demyelinating disease: Multiple sclerosis
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Oligodendroglioma, IDH-Mutant and 1p/19q-Co-Deleted**
|
||||
- 70-90% present with seizures
|
||||
- Cortically based T2-hyperintense mass, rare enhancement
|
||||
- **Mesial Temporal Sclerosis**
|
||||
- Most common cause of intractable temporal lobe seizures
|
||||
- Hippocampal atrophy and sclerosis
|
||||
- May see ipsilateral mammillary body and forniceal atrophy
|
||||
- **Paraneoplastic and Autoimmune Encephalitis**
|
||||
- Both paraneoplastic and nonparaneoplastic
|
||||
- 80% have bilateral/unilateral edema of temporal lobes
|
||||
- Limbic system most common, also brainstem, cerebellum, and spinal cord
|
||||
- **Posterior Reversible Encephalopathy Syndrome**
|
||||
- 60-75% present with seizure
|
||||
- Patchy parietooccipital cortical/subcortical T2/FLAIR hyperintense edema
|
||||
- Associated with hypertension, chemotherapy, high-dose steroids, immunomodulation, sepsis, kidney failure, preeclampsia/eclampsia, autoimmune disease
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Pleomorphic Xanthoastrocytoma**
|
||||
- 75% of patients present with seizures
|
||||
- Cortical cyst + enhancing nodule is classic
|
||||
- Reactive involvement of adjacent meninges typical: Dural tail
|
||||
@@ -1,132 +0,0 @@
|
||||
---
|
||||
title: "Epilepsy, Child"
|
||||
docid: "a342e5b5-5b98-4003-a437-6d42a483b40e"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Brain Parenchyma, General"
|
||||
- "Clinically Based Differentials"
|
||||
- "Epilepsy, Child"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Generalized seizure disorders usually nonlocalizing
|
||||
- Partial complex (focal) epilepsy usually due to focal structural abnormality [i.e., focal cortical dysplasia (FCD)]
|
||||
- Correlate with EEG results
|
||||
- High-resolution & 3T MR helpful for subtle lesions
|
||||
- 1-mm isotropic T1 for gray matter evaluation
|
||||
- 3D FLAIR imaging helpful for identifying FCD
|
||||
- PET & SPECT are often complimentary to MR in identifying seizure focus prior to surgical intervention
|
||||
- PET: Decreased interictal metabolism in seizure focus
|
||||
- SPECT: Increased ictal blood flow in seizure focus
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Idiopathic Epilepsy**
|
||||
- No structural cause found on MR
|
||||
- Generalized: May be inherited
|
||||
- Partial: Partial motor seizures, may resolve by puberty
|
||||
- **Acquired Causes**
|
||||
- Febrile seizure: Most common cause of seizure in children < 5 years
|
||||
- Simple febrile seizure < 15 minutes without recurrence does not require imaging
|
||||
- Trauma, remote stroke, or infection results in encephalomalacia &/or gliosis, which may cause epilepsy
|
||||
- Benign & malignant tumors
|
||||
- Toxic, metabolic, & drug abuse
|
||||
- **Vascular Malformation**: Arteriovenous & cavernous malformations with hemorrhage
|
||||
- **Mesial Temporal Sclerosis**
|
||||
- Most common cause of intractable temporal lobe epilepsy in adults
|
||||
- 2-hit hypothesis suggests initial injury with inherent vulnerability to neuronal injury
|
||||
- Hippocampal atrophy & gliosis
|
||||
- May see ipsilateral mammillary body & forniceal atrophy
|
||||
- Look for associated FCD, especially in the ipsilateral temporal lobe (FCD type IIIa)
|
||||
- **Migrational Anomalies**
|
||||
- **Focal cortical dysplasia**
|
||||
- Newest classification Blumcke et al 2011
|
||||
- Type I: Mild blurring of gray-white junction with mild increased T2 signal of subcortical white matter
|
||||
- More common in temporal lobes, difficult to detect
|
||||
- Type II: Moderate blurring of gray-white junction & increased T2 signal of subcortical white matter
|
||||
- Typically frontal lobes
|
||||
- Type IIb includes more dysmorphia & balloon cells: Highly associated with transmantle sign & easier to detect on MR
|
||||
- Transmantle sign: T2-hyperintense comet tail from ventricle to cortex; best seen on FLAIR
|
||||
- Type III: Associated with another lesion: Mesial temporal sclerosis, tumor, vascular malformation, acquired injury
|
||||
- **Polymicrogyria**
|
||||
- Small, pebbly, cobblestone, or micronodular-appearing gyri
|
||||
- Common migrational malformation with heterogeneous causes
|
||||
- TORCH infection (particularly CMV) is common cause of polymicrogyria & seizures
|
||||
- Diffuse or bilateral polymicrogyria more likely genetic/syndromic
|
||||
- **Heterotopic gray matter**
|
||||
- Gray matter nodules within deep white matter follow gray matter signal on all MR sequences
|
||||
- Subependymal most common location
|
||||
- Can be found incidentally in patients without seizures
|
||||
- Diffuse subependymal heterotopia is X-linked
|
||||
- **Schizencephaly**
|
||||
- Cleft extending from cortical surface to ventricular ependyma, gray matter lined
|
||||
- Outpouching or "dimpling" of lateral ventricular contour "points" to cleft
|
||||
- May be unilateral or bilateral
|
||||
- Open lipped: CSF in cleft; commonly bilateral
|
||||
- Closed lipped: No CSF with apposed walls, usually unilateral
|
||||
- **Septo-Optic Dysplasia Plus Syndrome**
|
||||
- Septum pellucidum absence + optic nerve hypoplasia ± pituitary dysfunction
|
||||
- When SOD is associated with schizencephaly &/or polymicrogyria, it is referred to as SOD Plus
|
||||
- **Tuberous Sclerosis Complex**
|
||||
- Burden of cortical dysplasias (i.e., tubers) correlates with seizure burden
|
||||
- T2-hyperintense cortical/subcortical tubers: Similar imaging to type IIb FCD
|
||||
- Cortical tubers also similar in histology to FCD type IIb with balloon cells
|
||||
- Subependymal nodules can enhance & calcify
|
||||
- 10-15% develop subependymal giant cell astrocytoma at foramen of Monro
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **Cortically Based Glioneuronal Tumors**
|
||||
- Associated cortical dysplasia with tumor common (type IIIb)
|
||||
- **Ganglioglioma**
|
||||
- Most common cause of tumor-associated temporal lobe epilepsy
|
||||
- Cystic/solid cortically based mass
|
||||
- Ca⁺⁺ (~ 50%); enhancement (~ 50%)
|
||||
- Temporal lobe most common site
|
||||
- **Dysembryoplastic neuroepithelial tumor**
|
||||
- Discrete T2-hyperintense "bubbly" cortical mass
|
||||
- Medial temporal lobe most common
|
||||
- Enhancement may occur (~ 10%) but is less common than ganglioglioma
|
||||
- **Holoprosencephaly**
|
||||
- Spectrum of failure of cleavage of midline cerebral hemispheres & telencephalon from diencephalon
|
||||
- Monoventricle due to absence of septum pellucidum
|
||||
- Complete to partial absence of other midline structures: Falx & corpus callosum
|
||||
- Fusion of fornices, thalami, & basal ganglia
|
||||
- Incomplete separation of frontal lobes
|
||||
- More severe cases may include large dorsal cyst
|
||||
- **Hemimegalencephaly**
|
||||
- Unilateral hemispheric overgrowth
|
||||
- Dysplastic enlarged ipsilateral ventricle
|
||||
- Associated with genetic/syndromic diseases
|
||||
- **Sturge****-****Weber Syndrome**
|
||||
- Unilateral trigeminal (V1 & V2) distribution facial port-wine stain
|
||||
- Ipsilateral malformation of cortical & pial veins = leptomeningeal enhancement
|
||||
- Ipsilateral enlarged choroid plexus, hemiatrophy late finding
|
||||
- Gyriform Ca⁺⁺ increases over time
|
||||
- **Status Epilepticus**
|
||||
- Seizure > 5 minutes or > 1 seizure within 5-minute period
|
||||
- Higher likelihood for irreversible brain damage
|
||||
- 1/2 are associated with known history of epilepsy
|
||||
- Increased T2 signal of predominantly cortex with swelling & possible decreased diffusion
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Lissencephaly Type 1: Subcortical Band Heterotopia**
|
||||
- "Smooth" brain lacking normal gyri; thick cortex
|
||||
- Can see subcortical smooth gray matter band in many cases
|
||||
- LIS1: Posterior predilection of lissencephaly
|
||||
- DCX (double cortex): X-linked
|
||||
- Females: Primarily diffuse band heterotopia
|
||||
- Males: Diffuse lissencephaly, more severe phenotype
|
||||
- **Lissencephaly Type 2**
|
||||
- Congenital muscular dystrophy: Walker-Warburg, Fukuyama, & muscle-eye-brain
|
||||
- Diffuse polymicrogyria (cobblestone lissencephaly) particularly frontal lobes & sylvian fissures
|
||||
- Cerebellar polymicrogyria, cysts, vermian hypoplasia, hypomyelination, & eye abnormalities can be seen
|
||||
- **Rasmussen Encephalitis**
|
||||
- Likely autoimmune inflammation of unilateral cerebral hemisphere
|
||||
- Typically at least mesial temporal lobe & insula affected
|
||||
- Hemiatrophy late
|
||||
@@ -1,6 +1,42 @@
|
||||
---
|
||||
title: "Finger-in-Glove Sign"
|
||||
docid: "81c5db2f-b8f6-4092-bcd2-ffb8aa3ab18a"
|
||||
authors:
|
||||
- key: "fa682303-6426-4b97-8c60-783051febb88"
|
||||
value: "Jorge Alberto Carrillo-Bayona, MD"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Chest"
|
||||
slug: "chest"
|
||||
treeNodeId: "23b17a2b-c629-4f3b-b960-0bfdc5d138ca"
|
||||
-
|
||||
name: "Differential Diagnosis"
|
||||
slug: "differential-diagnosis"
|
||||
treeNodeId: "41e2b114-bb5b-4430-86a8-4c667ef0f50a"
|
||||
-
|
||||
name: "Airways"
|
||||
slug: "airways"
|
||||
treeNodeId: "dbd08dc8-069b-455c-af2f-73376c667e07"
|
||||
-
|
||||
name: "General Imaging Patterns"
|
||||
slug: "general-imaging-patterns"
|
||||
treeNodeId: "569ccd87-4cb8-4a9e-83f4-c8ac16b26c5e"
|
||||
-
|
||||
name: "Finger-in-Glove Sign"
|
||||
slug: "finger-in-glove-sign"
|
||||
treeNodeId: null
|
||||
category: "Chest"
|
||||
documentVersionId: "b09d26e0-dd26-493f-a120-ba11c7e04745"
|
||||
imageCount: 8
|
||||
isBookmarked: false
|
||||
isComparable: false
|
||||
isInCompareCart: false
|
||||
lastUpdated: "02/10/20"
|
||||
pageDescription: "Finger-in-Glove Sign"
|
||||
pageKeywords: "Chest, Differential Diagnosis, Airways, General Imaging Patterns, Finger-in-Glove Sign"
|
||||
pageTitle: "Finger-in-Glove Sign | STATdx"
|
||||
enhancedTitle: "Finger-in-Glove Sign"
|
||||
type: "DDX"
|
||||
breadcrumbs:
|
||||
- "Chest"
|
||||
- "Differential Diagnosis"
|
||||
@@ -68,3 +104,46 @@ breadcrumbs:
|
||||
- Patients < 15 years of age (70%)
|
||||
- Most frequent location: Right lower lobe bronchus and bronchus intermedius
|
||||
- Adults: Chronic clinical course, recurrent pneumonia
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
**Allergic Bronchopulmonary Aspergillosis**
|
||||
*PA chest radiograph of a patient with asthma and allergic bronchopulmonary aspergillosis shows right basilar tubular opacities <img src='/img/arrows/CS.png'/> corresponding to mucoid impaction in dilated airways.*
|
||||
|
||||
|
||||
**Allergic Bronchopulmonary Aspergillosis**
|
||||
*PA chest radiograph of a patient with asthma and allergic bronchopulmonary aspergillosis shows right basilar tubular opacities <img src='/img/arrows/CS.png'/> corresponding to mucoid impaction in dilated airways.*
|
||||
|
||||
|
||||
**Allergic Bronchopulmonary Aspergillosis**
|
||||
*Coronal NECT of the same patient shows right basilar branching tubular opacities that correspond to right lower lobe bronchiectasis with intrinsic mucus plugs <img src='/img/arrows/CS.png'/>. Impacted mucus may exhibit high attenuation. Allergic bronchopulmonary aspergillosis is due to hypersensitivity to fungal antigens.*
|
||||
|
||||
|
||||
**Congenital Bronchial Atresia**
|
||||
*Coronal CECT of a 27-year-old man with bronchial atresia shows a nonenhancing left upper lobe tubular opacity that corresponds to an atretic bronchus impacted with mucus <img src='/img/arrows/CS.png'/>.*
|
||||
|
||||
|
||||
**Congenital Bronchial Atresia**
|
||||
*Coronal CECT of the same patient shows focal air-trapping <img src='/img/arrows/CS.png'/> in the left upper lobe distal to the impacted atretic bronchus and mucocele. Bronchial atresia most frequently affects the left upper lobe apicoposterior bronchus. Affected patients are typically asymptomatic.*
|
||||
|
||||
|
||||
**Bronchiectasis**
|
||||
*Axial NECT of a 20-year-old man with cystic fibrosis shows multifocal bronchiectasis <img src='/img/arrows/CS.png'/>, bronchial wall thickening, and soft tissue tubular opacities that correspond to impacted mucus <img src='/img/arrows/CO.png'/> within dilated peripheral airways.*
|
||||
|
||||
|
||||
**Bronchiectasis**
|
||||
*Axial NECT of a 34-year-old-man with primary ciliary dyskinesia and Kartagener syndrome shows bilateral upper lobe branching tubular opacities <img src='/img/arrows/CS.png'/> that correspond to impacted mucus within bronchiectatic airways. Note coexistent situs inversus and right aortic arch <img src='/img/arrows/WC.png'/>.*
|
||||
|
||||
|
||||
**Malignant Airway Neoplasm**
|
||||
*Axial CECT of a patient with a history of chronic cough and blood-tinged sputum shows a polylobular middle lobe soft tissue mass <img src='/img/arrows/CO.png'/> that exhibits an endobronchial component <img src='/img/arrows/CS.png'/> and obstructs a small airway in the middle lobe. Carcinoid tumor was diagnosed at surgery.*
|
||||
|
||||
|
||||
**Malignant Airway Neoplasm**
|
||||
*Sagittal CECT of the same patient shows the centrally obstructing carcinoid tumor and peripheral mucoid impaction <img src='/img/arrows/CS.png'/>. Carcinoid tumor is a low-grade malignant neoplasm with frequent endobronchial involvement.*
|
||||
|
||||
|
||||
-215
@@ -1,215 +0,0 @@
|
||||
---
|
||||
title: "Fragile X-Associated Tremor/Ataxia (FXTAS)"
|
||||
docid: "4778fafe-9873-4c28-8f4f-299c00c72b50"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Acquired Toxic/Metabolic/Degenerative Disorders"
|
||||
- "Dementias and Degenerative Disorders"
|
||||
- "Fragile X-Associated Tremor/Ataxia (FXTAS)"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Fragile X-associated tremor/ataxia syndrome (FXTAS)
|
||||
- X-linked progressive neurodegenerative disorder characterized by 55-200 CGG trinucleotide repeats in *FMR1* gene
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Ventricular and sulcal prominence: Global volume loss
|
||||
- WM and brainstem hyperintensities
|
||||
- MCP atrophy with symmetric hyperintensities: MCP sign
|
||||
- Decreased MCP width may be first notable sign
|
||||
- Splenium of corpus callosum atrophy with hyperintensity: Corpus callosum splenium sign
|
||||
- High sensitivity but lower specificity than MCP sign
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- **Middle cerebellar peduncle sign**
|
||||
- Neurodegenerative, metabolic, cerebrovascular, inflammatory and demyelinating disorders
|
||||
- **Corpus callosum splenium sign**
|
||||
- Normal aging, radiation therapy
|
||||
- Cytotoxic/transient splenial lesions
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- Premutation expansions (55-200 CGG repeats) in 5' untranslated region of *FMR1* gene, located on X-chromosome
|
||||
- **Radiological criteria**
|
||||
- Major: White matter lesions in brainstem or MCP sign
|
||||
- Minor: Cerebral white matter lesions, moderate to severe generalized brain atrophy
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Kinetic tremor, cerebellar gait ataxia, cognitive dysfunction
|
||||
- Usually > age 50
|
||||
- Diagnosis confirmed by molecular genetic testing
|
||||
- Progressive and severe neurodegenerative disease
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Fragile X-associated tremor/ataxia syndrome (FXTAS)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- X-linked progressive neurodegenerative disorder characterized by 55-200 CGG trinucleotide repeats in *FMR1* gene
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Generalized brain atrophy with hyperintensities in brainstem or middle cerebellar peduncle (MCP)
|
||||
- ### Location
|
||||
|
||||
|
||||
- Brainstem and middle cerebellar peduncles
|
||||
- Cerebral white matter (WM), corpus callosum
|
||||
- ### Size
|
||||
|
||||
|
||||
- MCP atrophy, global atrophy
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Moderate to severe generalized brain atrophy
|
||||
- MCP atrophy with subtle hypodensities
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Subtle hypointensity in MCP with atrophy
|
||||
- Corpus callosum splenium hypointensity
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- Ventricular and sulcal prominence: Global volume loss
|
||||
- WM and brainstem hyperintensities
|
||||
- Putaminal rim hyperintensity
|
||||
- MCP atrophy with symmetric hyperintensities: MCP sign
|
||||
- Decreased MCP width may be first notable sign
|
||||
- Splenium of corpus callosum atrophy with hyperintensity: Corpus callosum splenium sign
|
||||
- High sensitivity but lower specificity than MCP sign
|
||||
- ### T2* GRE
|
||||
|
||||
|
||||
- No hemorrhage
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- No enhancement
|
||||
- ### MRS
|
||||
|
||||
|
||||
- Decreased NAA/Cr and Ch/Cr in MCP
|
||||
- DTI
|
||||
- Reduced fractional anisotropy (FA) in corpus callosum
|
||||
- Associated with increasing FXTAS symptom severity
|
||||
- Reduced FA in MCP
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- Brain MR without contrast
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- Add coronal T2/FLAIR MR
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Middle Cerebellar Peduncle Sign
|
||||
|
||||
|
||||
- **Neurodegenerative**
|
||||
- Multiple systemic atrophy (MSA), olivopontocerebellar atrophy, spinocerebellar ataxia
|
||||
- **Metabolic**
|
||||
- Adrenoleukodystrophy, Wilson disease, hypoglycemia
|
||||
- **Cerebrovascular**
|
||||
- Infarcts, PRES, pontine infarct with wallerian degeneration of MCPs
|
||||
- **Inflammatory and demyelinating**
|
||||
- Multiple sclerosis, ADEM, Behçet disease
|
||||
- ## Corpus Callosum Splenium Sign
|
||||
|
||||
|
||||
- Normal aging, radiation therapy
|
||||
- Cytotoxic /transient splenial lesions
|
||||
- Seizure- &/or drug-related, viral encephalitis, metabolic derangement
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- Premutation expansions (55-200 CGG repeats) in untranslated region of *FMR1* gene, located on X-chromosome
|
||||
- Full mutation (> 200 CGG repeats) leads to neurodevelopmental disease fragile X syndrome (FXS)
|
||||
- 2 main molecular mechanisms
|
||||
- Toxic gain of function of expanded CGG-repeat *FMR1*mRNA → binding/sequestration of CGG-binding proteins
|
||||
- CGG repeat-associated non-AUG-initiated (RAN) translation → polyglycine peptide toxic to cells
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- Diagnostic criteria for FXTAS: Clinical, radiological, and pathological
|
||||
- **Radiological criteria**
|
||||
- Major criteria: WM lesions in brainstem or MCP sign
|
||||
- Minor criteria: Cerebral WM lesions, moderate to severe generalized brain atrophy
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Diffuse, spongy degeneration of WM
|
||||
- Eosinophilic intranuclear inclusions in neurons and astrocytes with cortex and cerebellum
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Kinetic tremor, cerebellar gait ataxia, cognitive dysfunction
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- Psychiatric disorders common
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- Usually > age 50
|
||||
- More common among male patients who are hemizygous for premutation (40%) than female patients who are heterozygous for premutation (8-16%)
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Diagnosis confirmed by molecular genetic testing
|
||||
- Progressive and severe neurodegenerative disease
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Symptomatic and supportive
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Patient presenting with ataxia and tremor with symmetric middle cerebellar peduncle hyperintensities (MCP sign)
|
||||
|
||||
863ab378-3ef7-4994-a374-6fc4bb8249e5
|
||||
@@ -1,265 +0,0 @@
|
||||
---
|
||||
title: "Frontotemporal Dementia"
|
||||
docid: "9f9eda8c-7e3c-4292-9861-4b8abc2c6474"
|
||||
breadcrumbs:
|
||||
- "Nuclear Medicine"
|
||||
- "Central Nervous System"
|
||||
- "Neurodegeneration"
|
||||
- "Frontotemporal Dementia"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Frontotemporal dementia (FTD): Progressive neurodegenerative disorder of frontal/anterior temporal lobes
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- F-18 FDG PET
|
||||
- Helps differentiate between FTD and other causes of dementia
|
||||
- Glucose hypometabolism
|
||||
- Initially in frontal lobes progressing to temporal lobes
|
||||
- Anterior cingulate also commonly hypometabolic
|
||||
- Left-sided asymmetry could suggest underlying primary progressive aphasia (PPA)
|
||||
- Hypometabolism within motor strip (precentral gyrus) could suggest motor neuron disease FTD (FTD-MND)
|
||||
- Perfusion SPECT
|
||||
- Similar pattern of frontal hypoperfusion as F-18 FDG PET
|
||||
- Potentially less sensitive than F-18 FDG PET
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Progressive changes in behavior, language, or motor function depending upon subtype
|
||||
- Memory is less dominant clinical feature in FTDs
|
||||
- No current disease-modifying treatment for FTD, only symptomatic therapy
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- Clinical therapy decisions depend on proper diagnosis
|
||||
- FTD important to distinguish from Alzheimer disease (AD) because AD medications do not slow progression of FTD and can worsen symptoms
|
||||
- Amyloid-targeting therapies (ATTs) have no role in treating FTDs
|
||||
- Image analysis
|
||||
- If hypometabolism is anterior-predominant (e.g., frontal, anterior temporal, anterior cingulate), this favors FTD
|
||||
- Amyloid PET can also help exclude AD pathology
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Frontotemporal dementia (FTD)
|
||||
- Alzheimer disease (AD)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Progressive neurodegenerative disorder of frontal/anterior temporal lobes
|
||||
- Typically subdivided into categories based on underlying molecular aggregates [TDP-43 (50%), tauopathy without amyloid (40%), and FET protein family (10%)] and main functional deficit (cognitive and behavior, language, or motor)
|
||||
- Behavioral variant FTD (bvFTD) (formerly Pick disease)
|
||||
- Commonly characterized by behavioral disinhibition, apathy, loss of sympathy, hyperorality, executive deficits
|
||||
- Most commonly seen with TDP-43 aggregation, initially described with intracellular τ inclusions (Pick bodies)
|
||||
- Prosopagnosia (inability to recognize familiar faces) has been described with right temporal variant FTD
|
||||
- Language variant FTD [FTD-primary progressive aphasia (PPA)]
|
||||
- Includes 2/3 subtypes of PPA, semantic variant PPA (svPPA) and nonfluent agrammatic variant PPA (nfvPPA)
|
||||
- svPPA is predominantly seen with TDP-43 pathology and nfvPPA with τ pathology
|
||||
- Other PPA variant, logopenic variant (lvPPA), is atypical AD variant (amyloid and τ positive)
|
||||
- Motor neuron disease FTD (FTD-MND)
|
||||
- Includes amyotrophic lateral sclerosis (FTD-ALS; 95% TDP-43) as well as atypical parkinsonian syndromes of progressive supranuclear palsy (PSP; tauopathy) and corticobasal degeneration (CBD; tauopathy)
|
||||
- ALS classically presents with both upper motor neuron signs (spasticity, rigidity, hyperreflexia), lower motor neuron signs (muscle fasciculations, muscle atrophy), and nonmotor signs (behavioral disturbances), as seen with bvFTD (30% of cases)
|
||||
- PSP usually presents with bradykinesia, rigidity, **vertical gaze palsy**, dysphagia, dysarthria
|
||||
- CBD presents with parkinsonism, dystonia, apraxia, executive dysfunction, aphasia, "alien limb" phenomenon
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- F-18 FDG PET/CT
|
||||
- Glucose hypometabolism initially in frontal lobes with progression to include regions of temporal/parietal lobes
|
||||
- Anterior cingulate cortex, frontal insula, caudate nuclei, thalamus may also have hypometabolism bilaterally
|
||||
- Relative sparing of motor cortex, except in FTD-MNDs, specifically ALS and CBD, which can show hypometabolism
|
||||
- Hemispheric metabolic asymmetry may be present
|
||||
- Hypometabolism occurs before atrophy visually evident on CT/MR
|
||||
- Most sensitive diagnostic tool currently available
|
||||
- Glucose hypometabolism worsens with disease progression
|
||||
- May be used to distinguish between FTD and AD
|
||||
- AD often shows hypometabolism in posterior cingulate/temporoparietal regions, spared with FTD
|
||||
- 50% of patients with behavioral or dysexecutive AD variant do not show typical parietal and posterior cingulate hypometabolism
|
||||
- Amyloid PET can be helpful in this situation if considering amyloid-targeting therapies (ATTs)
|
||||
- Attenuation correction CT can show
|
||||
- Preferential atrophy of frontal/temporal lobes
|
||||
- Increased CSF space surrounding medial temporal lobes
|
||||
- Enlargement of lateral ventricles
|
||||
- Perfusion SPECT
|
||||
- Pattern is similar to F-18 FDG PET with decreased radiotracer activity in frontal/temporal lobes
|
||||
- SPECT generally has less sensitivity and quantitative potential compared to PET
|
||||
- More sensitive than structural MR in detecting early changes
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- F-18 FDG PET helps to differentiate between FTD and other causes of dementia, e.g., AD and Lewy body dementia (LBD)
|
||||
- Correlates with disease progression
|
||||
- Amyloid PET can help exclude AD variants that can mimic FTDs, such as lvPPA
|
||||
- I-123 ioflupane scan can help in cases of suspected PSP or CBD, which will show decreased/abnormal uptake
|
||||
- CT/MR documents atrophy of mainly frontal/temporal lobe structures
|
||||
- Look for reversible causes of dementia, e.g., normal-pressure hydrocephalus
|
||||
- Motor band sign with T2* hypointensity of precentral gyri or T2/FLAIR hyperintensity of corticospinal tracts in ALS
|
||||
- F-18 FDG PET
|
||||
- Patient preparation
|
||||
- Patient should fast, stop IV fluids containing dextrose, and stop parenteral feeding for 4-6 hours
|
||||
- Blood sugar should be < 150-200 (mg/dL)
|
||||
- Patient should be placed in quiet, dimly lit room prior to and after injection (30 min)
|
||||
- Radiopharmaceutical: F-18 FDG
|
||||
- Dose: 5-20 mCi (185-740 MBq)
|
||||
- Dosimetry: Urinary bladder receives largest dose
|
||||
- Image acquisition: Image 30-60 min after injection
|
||||
- SPECT
|
||||
- 2nd-line study if F-18 FDG PET is not available/reimbursed
|
||||
- Patient preparation
|
||||
- Patient should be placed in quiet, dimly lit room prior to and after injection (30 min)
|
||||
- Radiopharmaceutical
|
||||
- Tc-99m exametazime (HMPAO)
|
||||
- Tc-99m ethyl cysteinate dimer (ECD)
|
||||
- Dose: 15-30 mCi (555 MBq to 1.1 GBq)
|
||||
- Dosimetry
|
||||
- Tc-99m HMPAO: Kidneys receive highest dose
|
||||
- Tc-99m ECD: Bladder wall receives highest dose
|
||||
- Image acquisition
|
||||
- Optimal imaging time for Tc-99m HMPAO: 90 min post injection
|
||||
- Optimal imaging time for Tc-99m ECD: 45 min post injection
|
||||
- ## Artifacts and Quality Control
|
||||
|
||||
|
||||
- Immobilize patient's head to decrease motion, attenuation correction artifacts
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Alzheimer Disease](/document/alzheimer-disease/2aad3ac4-44fd-43e5-8e50-a86987483af3)
|
||||
- Most common cause of dementia generally leading to impairments in episodic memory and other cognitive domains
|
||||
- Related to aggregation of amyloid-β and τ proteins; therefore, positive on amyloid PET
|
||||
- Behavioral and dysexecutive variants of AD
|
||||
- Clinical presentation with less memory impairment and more behavioral disinhibition/loss of executive function
|
||||
- Can be clinically indistinguishable from bvFTD
|
||||
- 50% of cases show F-18 FDG hypometabolism in precuneus and posterior cingulate gyrus (similar to classic AD); 50% show frontal hypometabolism with parietal sparing similar to FTD
|
||||
- Must consider amyloid PET in these cases; prerequisite for ATTs
|
||||
- lvPPA
|
||||
- Predominant language loss with spared memory that can mimic other PPAs
|
||||
- Sentence repetition and single-word meaning usually preserved
|
||||
- Often have mild cognitive impairments outside of language (more than seen with svPPA or nfvPPA)
|
||||
- F-18 FDG hypometabolism shows more parietal involvement than other PPAs; amyloid PET can be helpful if considering ATTs
|
||||
- ## Limbic-Predominant Age-Related TDP-43 Encephalopathy
|
||||
|
||||
|
||||
- Newly recognized neurodegenerative disease with predominant memory deficits related to hippocampal dysfunction
|
||||
- Typically in patients > 80 years
|
||||
- Often slower decline than AD, though can commonly be comorbid with AD, accelerating disease progression
|
||||
- F-18 FDG PET shows marked hippocampal hypometabolism with less severe involvement of precuneus and posterior cingulate
|
||||
- MR often shows marked hippocampal sclerosis
|
||||
- ## Vascular Dementia
|
||||
|
||||
|
||||
- 2nd most common cause of dementia
|
||||
- Caused by impaired blood supply to brain regions
|
||||
- Global atrophy with diffuse white matter lesions (infarcts)
|
||||
- Lesions generally correlate with cognitive symptoms
|
||||
- ## Lewy Body Dementia
|
||||
|
||||
|
||||
- Commonly presents with hallucinations, sleep disturbances, and parkinsonian motor features
|
||||
- F-18 FDG PET hypometabolism in occipital cortex
|
||||
- Cardiac MIBG demonstrates sympathetic denervation (CBD and PSP do not demonstrate denervation)
|
||||
- Positive α-synuclein skin test (CBD and PSP are tauopathies)
|
||||
- ## Psychiatric Illness
|
||||
|
||||
|
||||
- Bipolar disorder, schizophrenia, obsessive compulsive disorder
|
||||
- ## Reversible Dementias
|
||||
|
||||
|
||||
- Mass lesions (brain tumor), head trauma, normal-pressure hydrocephalus, vitamin B12 deficiency, hypothyroidism, infections (neurosyphilis, Lyme disease)
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Heterogeneous pathologic and clinical subtypes
|
||||
- Resulted from disease naming related to clinical presentation, before etiology/pathology was well understood
|
||||
- Pathologic subtypes of FTD are classified based upon pattern of protein accumulation in groups encompassing disorders of frontotemporal lobar degeneration
|
||||
- Etiology uncertain but associated with 3 major protein aggregates
|
||||
- τ (microtubule-associated protein)
|
||||
- TDP-43 (transactive response DNA binding protein of 43kD)
|
||||
- FET protein family, including FUS (tumor-associated protein; fused in sarcoma)
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- Autosomal dominant inheritance in 10-25% of FTD cases
|
||||
- c9orf72 most common genetic mutation in familial FTD and familial ALS
|
||||
- *SOD1*(superoxide dismutase) gene mutation in 10% of familial ALS with specific treatment, intrathecal tofersen
|
||||
- Positive family history of FTD is only known risk factor
|
||||
- 30-50% of individuals with bvFTD have positive family history
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Progressive changes in behavior, personality, language, &/or motor function, depending upon clinical subtype
|
||||
- Disinhibition, apathy, loss of sympathy, hyperorality, dysexecutive behaviors
|
||||
- Bradykinesia, rigidity, tremor, spasticity, hyperreflexia, fasciculations, muscle atrophy in motor subtypes
|
||||
- Loss of language comprehension, including word meaning or agrammatism in language subtypes
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- FTD is composed of 3 main clinical subtypes
|
||||
- bvFTD
|
||||
- Most common, accounting for ~ 1/2 of cases
|
||||
- Progressive decline in social function with personality changes, often with disinhibition
|
||||
- Language presentation (PPA)
|
||||
- Including variants svPPA and nfvPPA
|
||||
- Motor presentation
|
||||
- ALS, PSP, CBD
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Mean of onset: 50-60 years
|
||||
- ~ 10% > 70 years
|
||||
- Younger onset than AD, which is generally > 65 years
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Insidious onset of behavioral and cognitive dysfunction
|
||||
- More significant behavioral, language, executive functioning impairment than memory
|
||||
- Slowly progressive with eventual functional impairment
|
||||
- Median survival ~ 8-10 years after diagnosis; varies widely based upon underlying pathology
|
||||
- Median survival in ALS is 2-5 years
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- No current disease-modifying treatment for FTD
|
||||
- ALS with *SOD1*mutation can be treated with intrathecal tofersen (6.5-month increase in median survival at 3 years)
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- FTD important to distinguish from AD because AD medications do not slow progression of FTD and can worsen symptoms
|
||||
- FTDs are not amenable to ATTs due to lack of underlying amyloid pathology
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- When analyzing images, use surface projections and normative dataset comparison to increase sensitivity
|
||||
|
||||
c96633b0-f435-4b0a-9f06-702857dfe4c4
|
||||
-313
@@ -1,313 +0,0 @@
|
||||
---
|
||||
title: "Frontotemporal Lobar Degeneration"
|
||||
docid: "49510d0e-acf7-45cb-9eb1-53f8193b0b6d"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Acquired Toxic/Metabolic/Degenerative Disorders"
|
||||
- "Dementias and Degenerative Disorders"
|
||||
- "Frontotemporal Lobar Degeneration"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Clinical subtypes
|
||||
- Behavioral variant frontotemporal dementia **(bvFTD)**
|
||||
- Primary progressive aphasia syndromes **(PPA)**
|
||||
- Semantic variant **(sv-PPA)**: Previously known as semantic dementia
|
||||
- Nonfluent/agrammatic variant **(nfv-PPA)**: Previously known as progressive nonfluent aphasia
|
||||
- Logopenic variant **(lv-PPA)**
|
||||
- Frontotemporal dementia with motor symptoms
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Early
|
||||
- PET shows frontotemporal ↓ glucose metabolism
|
||||
- Late: Frontotemporal atrophy with knife-like gyri on MR
|
||||
- Subtypes have characteristic cortical atrophy patterns
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Alzheimer dementia (AD)
|
||||
- Vascular dementia
|
||||
- Corticobasal ganglionic degeneration (CBD)
|
||||
- Dementia with Lewy bodies (DLB)
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Clinical syndromes (some overlap)
|
||||
- **bvFTD**: Disinhibition, apathy & loss of empathy, hyperorality, & compulsive behavior
|
||||
- **sv-PPA**: Impaired single-word comprehension & object naming with preserved fluency, repetition, & grammar
|
||||
- **nfv-PPA**: Effortful speech production of phonemes (linguistic units of sound) & orofacial apraxia
|
||||
- **lv-PPA**: Impaired word finding & repetition with errors in speech & naming
|
||||
- Younger age group than AD
|
||||
- FTLD most common cause of early-onset (< 65 years) dementia
|
||||
- Median survival: 6-11 years from symptom onset & 3-4 years from diagnosis
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Frontotemporal lobar degeneration (FTLD)
|
||||
- Clinical subtypes
|
||||
- Behavioral variant frontotemporal dementia **(bvFTD)**
|
||||
- Primary progressive aphasia syndromes **(PPA)**
|
||||
- Semantic variant **(sv-PPA)**: Previously known as semantic dementia
|
||||
- Nonfluent/agrammatic variant **(nfv-PPA)**: Previously known as progressive nonfluent aphasia
|
||||
- Logopenic variant**(lv-PPA)**: Has Alzheimer pathology & is not included as 1 of 3 clinical FTD syndromes
|
||||
- Frontotemporal dementia (FTD) with motor symptoms
|
||||
- Corticobasal degeneration (CBD)
|
||||
- Progressive supranuclear palsy (PSP)
|
||||
- FTD with motor neuron disease
|
||||
- FTD with amyotrophic lateral sclerosis (ALS)
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Pick disease no longer used
|
||||
- Referred to pathologic variant with Pick bodies
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Heterogeneous family of neurodegenerative disorders characterized by focal lobar degeneration of frontal &/or temporal lobes
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Structural & functional imaging are supportive but not diagnostic of FTD
|
||||
- PET showing frontotemporal ↓ glucose metabolism
|
||||
- Anterior frontotemporal atrophy with knife-like gyri
|
||||
- ### Location
|
||||
|
||||
|
||||
- Anterior temporal/frontal lobes, orbitofrontal cortex, medial temporal region
|
||||
- Relative sparing of parietooccipital lobes
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Knife blade appearance of atrophic gyri
|
||||
- ± marked asymmetry
|
||||
- May have worst atrophy in dominant hemisphere
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Frontal lobe atrophy often most prominent feature
|
||||
- ↑ size of frontal horns (larger than rest of lateral ventricles)
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Atrophy of frontal & temporal lobes, often asymmetric
|
||||
- Knife-like gyri with normal signal
|
||||
- Dilated frontal sulci reflecting atrophy
|
||||
- Relative sparing of parietooccipital lobes
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- ± hyperintensity in frontotemporal white matter (WM)
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- ± hyperintensity in frontotemporal WM
|
||||
- ### MRS
|
||||
|
||||
|
||||
- ↓ NAA glutamate + glutamine (neuronal loss), ↑ myoinositol (↑ glial content) in frontal lobes
|
||||
- ↓ NAA in posterior cingulate gyri
|
||||
- Reflects ↓ neuronal population, viability
|
||||
- ± lactate peak in frontal lobes
|
||||
- MR voxel-based morphometry
|
||||
- Subtypes have characteristic cortical atrophy patterns
|
||||
- Frontal vs. temporal, left vs. right help discriminate
|
||||
- **bvFTD**: Atrophy of frontal & temporal lobes
|
||||
- Anterior insula, anterior cingulate, orbitofrontal cortex, & amygdala (early changes occur in right hemisphere)
|
||||
- **sv-PPA**: Typically anterior temporal lobe atrophy (asymmetric to left)
|
||||
- Entire temporal lobe can be involved
|
||||
- Ventromedial & superior frontal lobes
|
||||
- Right temporal atrophy as disease progresses
|
||||
- **nfv-PPA**: Selective left posterior frontoinsular region
|
||||
- **lv-PPA**: Predominant atrophy of left posterior temporal cortex & parietal lobe
|
||||
- DTI
|
||||
- Widespread damage to WM tracts reported
|
||||
- **bvFTD**: Uncinate fasciculus, inferior longitudinal fasciculus, & anterior commissural fibers
|
||||
- **sv-PPA**: Inferior longitudinal & uncinate fasciculi
|
||||
- **nfv-FTD**: Left superior longitudinal fasciculus
|
||||
- **lv-PPA**: Widespread dorsal & ventral WM tracts
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- ### PET
|
||||
|
||||
|
||||
- Functional imaging more sensitive than MR in early-stage disease
|
||||
- FDG PET: ↓ metabolic activity in frontotemporal cortex
|
||||
- Amyloid PET helps differentiate FTLD from Alzheimer disease (AD)
|
||||
- HMPAO-SPECT
|
||||
- Sensitive technique for early detection of FTD
|
||||
- Occurs before atrophy is evident
|
||||
- **bvFTD**: ↓ perfusion frontal & anterior temporal lobes
|
||||
- Asymmetric, left or right dominant
|
||||
- **sv-PPA**: Prominent anterior temporal hypoperfusion, left > right
|
||||
- **nfv-PPA**: Asymmetric frontal hypoperfusion often involving insular cortex
|
||||
- **lv-PPA**: ↓ perfusion in left parietal inferior lobule & posterolateral temporal lobe
|
||||
- SPECT perfusion deficits predominantly in frontal & anterior temporal lobes with preserved perfusion posteriorly
|
||||
- Helps distinguish FTD from AD
|
||||
- Reduced frontal perfusion is not specific to FTD but also occurs in some cases of schizophrenia, depression, HIV encephalopathy, Creutzfeldt-Jakob disease, AD
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- PET/SPECT; MR voxel-based morphometry
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- Routine T1WI, T2WI, coronal T2WI MR
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Alzheimer Disease](/document/alzheimer-disease/f71f5cf5-b1af-4c6d-b145-b4c10eec7b58)
|
||||
- Parietal & temporal cortical atrophy with disproportionate hippocampal volume loss
|
||||
- Increased rate of atrophy in FTD compared to AD
|
||||
- Often coexisting microvascular disease, WM hyperintensities, microhemorrhages
|
||||
- Amyloid imaging (11C-labeled Pittsburgh Compound-B) helps to differentiate AD from other dementias
|
||||
- [Vascular Dementia](/document/vascular-dementia/f59dab57-c511-4369-8fcc-592421a4b8d1)
|
||||
- 2nd most common dementia (15-30%)
|
||||
- WM & deep gray lacunae
|
||||
- Hyperintense lesions on T2WI & focal atrophy is suggestive of chronic infarcts
|
||||
- [Corticobasal Degeneration](/document/corticobasal-degeneration/23f97d4e-8724-4229-b9f8-08f63906ebd8)
|
||||
- Prominent extrapyramidal, cortical symptoms
|
||||
- Severe frontoparietal atrophy contralateral to more severely affected clinically
|
||||
- Atrophy of paracentral structures
|
||||
- [Dementia With Lewy Bodies](/document/dementia-with-lewy-bodies/e8e46d1d-46d2-4e5a-880f-f025a84c5871)
|
||||
- Hypometabolism of entire brain, especially visual cortex
|
||||
- Visual & auditory hallucinations, paranoid delusions
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Tau protein (hyperphosphorylated microtubular protein) or TDP-43 (TAR DNA-binding protein-43)
|
||||
- Rare cases change on fused-in-sarcoma (FUS) protein
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- FTD is highly heritable without clear inheritance pattern
|
||||
- 25-40% of FTD is familial, > 50% of bvFTD is autosomal dominant
|
||||
- Mutations in following 3 genes together constitute 15% of FTD cases
|
||||
- Most common: Hexanucleotide expansion in chromosome 9 open reading frame 72 (*C9orf72*) gene
|
||||
- Microtubule-associated protein tau (*MAPT*) gene
|
||||
- Granulin precursor (*GRN*) gene
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- Histopathologic classification of FTLD based on abnormal inclusions
|
||||
- FTLD-tau: Tau inclusion (hyperphosphorylated tau protein)/Pick bodies
|
||||
- FTLD-TDP: Tau-negative & TDP-43-positive inclusions (subtypes: Type A, B, C, & D)
|
||||
- FTLD-FUS: Tau-/TDP-negative & FUS-positive inclusions
|
||||
- FTLD-ALS/dipeptide repeats (DPR): TDP-negative DPR protein aggregates
|
||||
- FTLD-ni: No inclusions
|
||||
- FTD clinical syndromes correlate with brain atrophy patterns & not with pathologic subtypes
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Gross atrophy of frontal &/or anterior temporal lobes
|
||||
- Firm cortical gray matter (gliosis) &/or basal ganglia atrophy
|
||||
- Soft, retracted subcortical WM
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Loss of pyramidal neurons & microvacuolar degeneration in layer II & III of frontal & temporal cortex
|
||||
- Subjacent WM shows axonal & myelin loss
|
||||
- FTLD-related tauopathies
|
||||
- Pick disease: Prototypical tauopathy of FTLD
|
||||
- Characterized by Pick bodies: Solitary, round or oval, argyrophilic inclusions in cytoplasm of neurons
|
||||
- Commonly found in dentate gyrus of hippocampus, amygdala, frontal & temporal neocortex
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Personality, behavior, & language changes
|
||||
- Memory loss, confusion, cognitive & speech dysfunction, apathy, & abulia
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- **bvFTD**: Disinhibition, apathy & loss of empathy, hyperorality, & compulsive behavior
|
||||
- 15-20% may develop concomitant motor neuron disease (MND)
|
||||
- **sv-PPA**: Impaired single-word comprehension & object naming with preserved fluency, repetition, & grammar
|
||||
- **nfv-PPA**: Effortful speech production of phonemes (linguistic units of sound) & orofacial apraxia
|
||||
- **lv-PPA**: Impaired word finding & repetition with errors in speech & naming
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- More common cause of early-onset (midlife) dementia
|
||||
- Mean age of onset is 58 years; rare < 40 & > 75 years
|
||||
- Peak incidence 45-65 years
|
||||
- ### Sex
|
||||
|
||||
|
||||
- bvFTD & sv-FTD: Male preponderance
|
||||
- nfv-PPA: Female predominance
|
||||
- ### Ethnicity
|
||||
|
||||
|
||||
- Familial forms of Pick complex dementias particularly common in people of Scandinavian origin
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- FTLD more common cause of early-onset (< 65 years) dementia
|
||||
- Age > 65 years account for 20-25% of cases of FTLD
|
||||
- Prevalence: 3.5-15/100,000 person-years
|
||||
- FTLD accounts for ~ 5% of all pathologic diagnoses in patients with dementia
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Insidious onset of behavioral & cognitive dysfunction
|
||||
- Speech & language disturbance are often more profound than memory disorder
|
||||
- Median survival 6-11 years from symptom onset & 3-4 years from diagnosis
|
||||
- Currently no FDA-approved disease-modifying drugs available for treatment of FTD
|
||||
- Some patients develop artistic talents during course of dementia (disinhibition of "creative" brain areas)
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- Other common forms of dementia (AD, dementia with Lewy bodies)
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Bilateral frontal lobe atrophy should make one consider diagnosis of FTD
|
||||
- Bilateral asymmetric anterior temporal lobe atrophy: sv-PPA
|
||||
- ## Reporting Tips
|
||||
|
||||
|
||||
- Report pattern of cortical volume loss
|
||||
|
||||
69c47a04-dd7a-4a23-a55b-21542ccce82a
|
||||
+181
@@ -0,0 +1,181 @@
|
||||
---
|
||||
title: "Fusiform Arterial Enlargement"
|
||||
docid: "31d50b93-b057-4da3-86b5-4cc8fb0bc806"
|
||||
authors:
|
||||
- key: "2bca6b86-1eca-4e93-b997-4e18913686a7"
|
||||
value: "Hediyeh Baradaran, MD, MS"
|
||||
- key: "f184750a-90b4-47a7-907b-23b05d70357a"
|
||||
value: "Chang Yueh Ho, MD"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Brain"
|
||||
slug: "brain"
|
||||
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
||||
-
|
||||
name: "Differential Diagnosis"
|
||||
slug: "differential-diagnosis"
|
||||
treeNodeId: "a7fdd139-664e-4bb8-8d18-400e4733ff60"
|
||||
-
|
||||
name: "Arteries"
|
||||
slug: "arteries"
|
||||
treeNodeId: "f5fee8ee-062f-41f2-b449-efcca9fb78f9"
|
||||
-
|
||||
name: "Anatomically Based Differentials"
|
||||
slug: "anatomically-based-differentials"
|
||||
treeNodeId: "9955b05e-9840-401a-b3da-4039f8b22a35"
|
||||
-
|
||||
name: "Fusiform Arterial Enlargement"
|
||||
slug: "fusiform-arterial-enlargement"
|
||||
treeNodeId: null
|
||||
category: "Brain"
|
||||
documentVersionId: "b01387a5-2f90-4a92-9429-acfca70e11a5"
|
||||
imageCount: 15
|
||||
isBookmarked: false
|
||||
isComparable: false
|
||||
isInCompareCart: false
|
||||
lastUpdated: "02/22/23"
|
||||
pageDescription: "Fusiform Arterial Enlargement"
|
||||
pageKeywords: "Brain, Differential Diagnosis, Arteries, Anatomically Based Differentials, Fusiform Arterial Enlargement"
|
||||
pageTitle: "Fusiform Arterial Enlargement | STATdx"
|
||||
enhancedTitle: "Fusiform Arterial Enlargement"
|
||||
type: "DDX"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Differential Diagnosis"
|
||||
- "Arteries"
|
||||
- "Anatomically Based Differentials"
|
||||
- "Fusiform Arterial Enlargement"
|
||||
---
|
||||
# ESSENTIAL INFORMATION
|
||||
|
||||
- ## Key Differential Diagnosis Issues
|
||||
|
||||
|
||||
- Ectasia = elongated/tortuous artery
|
||||
- Fusiform aneurysm
|
||||
- Long-segment fusiform arterial dilatation
|
||||
- Can be acute (dissecting) or chronic (atherosclerosis, nonatherosclerotic vasculopathy)
|
||||
- ## Helpful Clues for Common Diagnoses
|
||||
|
||||
|
||||
- **Dolichoectasia**
|
||||
- Dilated/elongated arteries ± slow flow
|
||||
- Vessel layers intact
|
||||
- Older patients, chronic hypertension
|
||||
- Vertebrobasilar > internal carotid artery (ICA)
|
||||
- Ectasia often extends into branches
|
||||
- **Atherosclerotic Fusiform Aneurysm**
|
||||
- Thick wall ± organized thrombus
|
||||
- Variable slow flow
|
||||
- **Dissecting Aneurysm/Pseudoaneurysm**
|
||||
- Focal arterial dilatation
|
||||
- Trauma = most common etiology
|
||||
- Next to hard/fixed structures (bone, dura)
|
||||
- **Nonaneurysmal Dissection**
|
||||
- Vertebral > basilar > ICA
|
||||
- Lacks changes of atherosclerosis in other vessels
|
||||
- Can be spontaneous or traumatic
|
||||
- ## Helpful Clues for Less Common Diagnoses
|
||||
|
||||
|
||||
- **CNS Vasculitis**
|
||||
- Involves multiple vessels
|
||||
- Alternating stenoses and fusiform dilatations
|
||||
- **Inherited Connective Tissue Disorders**
|
||||
- Abnormal connective tissue involves vessel walls
|
||||
- Aneurysm and dissections
|
||||
- Thoracic aorta most common location
|
||||
- **HIV Infection**
|
||||
- Vasculopathy may be present in children or adults
|
||||
- Multifocal fusiform enlargement involving supraclinoid ICA and basilar artery
|
||||
- No consistent infectious agent isolated
|
||||
- ## Helpful Clues for Rare Diagnoses
|
||||
|
||||
|
||||
- **Giant Serpentine Aneurysm**
|
||||
- Large, partially thrombosed mass
|
||||
- Distal branches arise from aneurysm dome
|
||||
- Lacks definable neck
|
||||
- ICA/middle cerebral artery > vertebrobasilar artery
|
||||
- **Atypical Saccular Aneurysm**
|
||||
- Arises from vessel bifurcations
|
||||
- Long "aspect ratio" → fusiform appearance
|
||||
- Often multilobulated, bizarre
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
**Dolichoectasia**
|
||||
*Axial CT shows fusiform dilatation and tortuosity of the basilar artery <img src='/img/arrows/CS.png'/> in an octogenarian related to dolichoectasia. Fusiform dolichoectasia is a common finding in the vertebrobasilar arteries in older patients.*
|
||||
|
||||
|
||||
**Dolichoectasia**
|
||||
*Axial CT shows fusiform dilatation and tortuosity of the basilar artery <img src='/img/arrows/CS.png'/> in an octogenarian related to dolichoectasia. Fusiform dolichoectasia is a common finding in the vertebrobasilar arteries in older patients.*
|
||||
|
||||
|
||||
**Dolichoectasia**
|
||||
*Axial CT shows fusiform dilatation and tortuosity of the basilar artery <img src='/img/arrows/CS.png'/> in an octogenarian related to dolichoectasia. Fusiform dolichoectasia is a common finding in the vertebrobasilar arteries in older patients.*
|
||||
|
||||
|
||||
**Atherosclerotic Fusiform Aneurysm**
|
||||
*Coronal CTA shows fusiform dilatation <img src='/img/arrows/CS.png'/> of the right supraclinoid internal carotid artery (ICA). Irregularity from atherosclerotic disease can be seen of the M1 segment of the middle cerebral artery <img src='/img/arrows/CO.png'/>. No significant mural thrombus was noted in this fusiform aneurysm.*
|
||||
|
||||
|
||||
**Dissecting Aneurysm/Pseudoaneurysm**
|
||||
*Dissecting pseudoaneurysm in the V4 segment of the right vertebral artery seen on 3D TOF MRA <img src='/img/arrows/WS.png'/>, T2 <img src='/img/arrows/BS.png'/>, and T1 pre- <img src='/img/arrows/CS.png'/> and post <img src='/img/arrows/CO.png'/> DANTE VWI sequences shows peripheral enhancement, suggestive of instability.*
|
||||
|
||||
|
||||
**Ehlers-Danlos**
|
||||
*3D MIP MRA of the vertebrobasilar arteries in a teenage female with a history of type 4 Ehlers-Danlos shows fusiform dilatation of the vertebral artery <img src='/img/arrows/CS.png'/>. The affected gene is COL3A1, and this specific type of Ehlers-Danlos has a higher risk of aneurysm and vascular rupture.*
|
||||
|
||||
|
||||
**Marfan Syndrome**
|
||||
*Axial MIP from CT arteriography shows fusiform dilatation of the left middle cerebral artery bifurcation <img src='/img/arrows/CS.png'/> in this child with a history of Marfan syndrome.*
|
||||
|
||||
|
||||
**Familial Thoracic Aneurysm &/or Dissection**
|
||||
*Coronal MIP reformat from CT arteriography shows bilateral fusiform aneurysms of supraclinoid ICAs <img src='/img/arrows/CS.png'/>. This patient also had thoracic aortic aneurysm, which is consistent with familial thoracic aortic aneurysm and dissection and is associated with a mutation of ACTA2. This gene is responsible for a component of vascular smooth muscle.*
|
||||
|
||||
|
||||
**HIV Infection**
|
||||
*Axial T2WI MR shows strikingly enlarged middle cerebral arteries <img src='/img/arrows/CS.png'/> in this child with congenital HIV/AIDS (an uncommon but well-recognized cause of pediatric fusiform arteriopathy). The stroke-like presentations of HIV infection may relate to vasculopathies, including large-vessel aneurysmal vasculopathy.*
|
||||
|
||||
|
||||
**Giant Serpentine Aneurysm**
|
||||
*Axial NECT demonstrates a giant serpentine aneurysm in the basilar artery <img src='/img/arrows/WC.png'/> with associated mural thrombus <img src='/img/arrows/CC.png'/> seen on sagittal CTA.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
**Dolichoectasia**
|
||||
*Sagittal T1WI MR shows an elongated basilar artery with a slow-flow, thickened wall <img src='/img/arrows/WS.png'/>. The apex of the tortuous basilar artery indents the hypothalamus, 3rd ventricle <img src='/img/arrows/WO.png'/>.*
|
||||
|
||||
|
||||
**Dolichoectasia**
|
||||
*Axial T2WI MR shows an elongated, tortuous basilar artery with a thickened arterial wall <img src='/img/arrows/BS.png'/>, typical for atherosclerosis-associated fusiform ectasia.*
|
||||
|
||||
|
||||
**Atherosclerotic Fusiform Aneurysm**
|
||||
*Lateral angiography shows a large fusiform middle cerebral artery aneurysm <img src='/img/arrows/BS.png'/> that extends into smaller, more distal branches <img src='/img/arrows/BO.png'/>. This is an unusual example because of the location (ICA, middle cerebral artery).*
|
||||
|
||||
|
||||
**Nonaneurysmal Dissection**
|
||||
*Axial T1WI MR shows an enlarged right vertebral artery with high signal intensity <img src='/img/arrows/WS.png'/> as well as an absent flow void of the left vertebral artery <img src='/img/arrows/WC.png'/>.*
|
||||
|
||||
|
||||
**Ehlers-Danlos Syndrome**
|
||||
*Anteroposterior oblique view of the left vertebral angiogram shows focal elongations and widening of the basilar artery <img src='/img/arrows/BS.png'/> in a 6-year-old child with Ehlers-Danlos type 4.*
|
||||
|
||||
|
||||
**Giant Serpentine Aneurysm**
|
||||
*Axial MRA submentovertex view shows an unusual nonatherosclerotic giant serpentine fusiform aneurysm. The patent channel <img src='/img/arrows/WS.png'/> lies within the clot in the partially thrombosed <img src='/img/arrows/WO.png'/> lumen.*
|
||||
|
||||
|
||||
**Atypical Saccular Aneurysm**
|
||||
*Lateral angiography in 30-year-old man with a subarachnoid hemorrhage shows an elongated, bizarre-appearing, multilobulated aneurysm <img src='/img/arrows/BS.png'/> with long aspect ratio, tit-like projections.*
|
||||
|
||||
@@ -1,204 +0,0 @@
|
||||
---
|
||||
title: "Granular Cell Tumor"
|
||||
docid: "da976b04-85a3-4bf8-ac81-e579f081293e"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Anatomy-Based Diagnoses"
|
||||
- "Sella and Pituitary"
|
||||
- "Neoplasms"
|
||||
- "Granular Cell Tumor"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Neoplasms that arise from pituicytes, specialized glial cells of neurohypophysis or infundibulum
|
||||
- Rare low-grade, nonendocrine neoplasms of sellar region
|
||||
- Formerly called pituicytoma; granular cell tumor of neurohypophysis
|
||||
- Part of 2017 WHO spectrum of thyroid transcription factor 1 (TTF-1) expressing pituitary tumors of posterior lobe
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Enhancing, well-circumscribed sellar/suprasellar or infundibular mass
|
||||
- 1.5-6.0 cm
|
||||
- CT: Sellar/suprasellar mass with hyperattenuation
|
||||
- Rarely calcification may be present
|
||||
- Best imaging tool: C+ MR with high-resolution imaging through sellar region
|
||||
- Consider granular cell tumor if sellar/suprasellar mass appears separate from anterior pituitary gland
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Pituitary macroadenoma
|
||||
- Lymphocytic hypophysitis
|
||||
- Pituicytoma
|
||||
- Spindle cell oncocytoma
|
||||
- Rathke cleft cyst
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- WHO grade 1
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Commonly asymptomatic (small lesions)
|
||||
- Visual field deficit related to optic chiasm compression is most common presenting feature
|
||||
- Less common symptoms: Panhypopituitarism, galactorrhea, amenorrhea, decreased libido, neuropsychological changes
|
||||
- Typically present in adulthood, 5th-6th decades
|
||||
- Generally benign clinical course
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Granular cell tumor (GCT)
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Formerly called pituicytoma; granular cell tumor of neurohypophysis
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Neoplasms that arise from pituicytes, specialized glia of neurohypophysis or infundibulum
|
||||
- Rare low-grade, nonendocrine neoplasms of sellar region
|
||||
- Part of 2017 WHO spectrum of thyroid transcription factor1 (TTF-1) expressing pituitary tumors of posterior lobe
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Enhancing, well-circumscribed sellar/suprasellar or infundibular mass
|
||||
- ### Location
|
||||
|
||||
|
||||
- Sellar and suprasellar or infundibular mass
|
||||
- ### Size
|
||||
|
||||
|
||||
- 1.5-6.0 cm
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Lobulated and well circumscribed
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Sellar/suprasellar mass with hyperattenuation
|
||||
- Rarely calcification may be present
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Sellar/suprasellar mass isointense to gray matter
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- Enhancement may be homogeneous or heterogeneous
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- C+ MR with high-resolution imaging through sellar region
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Pituitary Macroadenoma](/document/pituitary-microadenoma/283f3068-d369-4f79-bf01-0f2b82c6e49b)
|
||||
- Sellar and suprasellar enhancing mass
|
||||
- Arises from adenohypophysis
|
||||
- May be indistinguishable
|
||||
- [Lymphocytic Hypophysitis](/document/lymphocytic-hypophysitis/f30774c3-cbd0-4ab3-b3d1-e0574106db1f)
|
||||
- May be indistinguishable from macroadenoma
|
||||
- May present as infundibular mass
|
||||
- Typically pregnant or postpartum females
|
||||
- [Pituicytoma](/document/pituicytoma/d6e481d5-7742-4354-8dfe-4f04286a709a)
|
||||
- May be intrasellar or suprasellar mass
|
||||
- May be separate from adenohypophysis
|
||||
- [Spindle Cell Oncocytoma](/document/spindle-cell-oncocytoma/1557bfb2-8315-4782-9a1e-4e70d6d20c4e)
|
||||
- Imaging mimics macroadenoma
|
||||
- Enhancing sellar and suprasellar mass
|
||||
- [Rathke Cleft Cyst](/document/rathke-cleft-cyst/8f1561f7-92a7-485c-a0ae-2e2d5c8c1628)
|
||||
- Nonenhancing cystic sellar &/or suprasellar lesion
|
||||
- Intracystic nodule in up to 75%
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Associated abnormalities
|
||||
|
||||
|
||||
- Granular cell tumors have been found in associated with adenomas
|
||||
- Small granular cell clusters have been found in up to 17% of autopsy series
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- WHO grade 1
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Lobulated, well-circumscribed mass, soft but rubbery
|
||||
- More firm than pituitary adenoma
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Densely packed polygonal cells with abundant granular eosinophilic cytoplasm
|
||||
- Electron microscopy: Cytoplasm is filled with phagolysosomes containing electron-dense material and membranous debris
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Commonly asymptomatic (small lesions)
|
||||
- Visual field deficit related to optic chiasm compression
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- Panhypopituitarism, galactorrhea, amenorrhea, decreased libido, neuropsychological changes
|
||||
- Rarely diabetes insipidus
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Typically present in adulthood, 5th-6th decades
|
||||
- ### Gender
|
||||
|
||||
|
||||
- F:M = 2:1
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Rare (~ 150 reported cases)
|
||||
- Generally benign clinical course
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Surgical resection
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Consider granular cell tumor if sellar/suprasellar mass appears separate from anterior pituitary gland
|
||||
|
||||
55b6bf2f-c975-435a-972b-a42c5b4cbe6d
|
||||
+295
@@ -0,0 +1,295 @@
|
||||
---
|
||||
title: "Guillain-Barr\u00e9 Spectrum Disorders"
|
||||
docid: "c1f52a65-920e-4e28-8a75-07dfa208f290"
|
||||
authors:
|
||||
- key: "b2e6dabb-ee1c-42a4-a332-9f0814c1c607"
|
||||
value: "Surjith Vattoth, MD, FRCR"
|
||||
breadcrumbs:
|
||||
-
|
||||
name: "Brain"
|
||||
slug: "brain"
|
||||
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
||||
-
|
||||
name: "Diagnosis"
|
||||
slug: "diagnosis"
|
||||
treeNodeId: "51c00394-446e-4a38-94af-d3b1d14d34e8"
|
||||
-
|
||||
name: "Pathology-Based Diagnoses"
|
||||
slug: "pathology-based-diagnoses"
|
||||
treeNodeId: "d9d3a8ed-f21b-4831-8c77-591a3500ef77"
|
||||
-
|
||||
name: "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
slug: "infectious-inflammatory-and-demyel-"
|
||||
treeNodeId: "7210f860-fe5f-4a2d-81cc-4fe06c769607"
|
||||
-
|
||||
name: "Inflammatory and Demyelinating Disease"
|
||||
slug: "inflammatory-and-demyelinating-dis-"
|
||||
treeNodeId: "62ab4dc3-dbf6-45a9-8532-f0e962aa62dc"
|
||||
-
|
||||
name: "Guillain-Barr\u00e9 Spectrum Disorders"
|
||||
slug: "guillain-barr-spectrum-disorders"
|
||||
treeNodeId: null
|
||||
category: "Brain"
|
||||
documentVersionId: "52016b28-7710-43a4-8cca-e659ab8227cf"
|
||||
imageCount: 5
|
||||
isBookmarked: false
|
||||
isComparable: true
|
||||
isInCompareCart: false
|
||||
lastUpdated: "06/12/20"
|
||||
pageDescription: "Guillain-Barr\u00e9 Spectrum Disorders"
|
||||
pageKeywords: "Brain, Diagnosis, Pathology-Based Diagnoses, Infectious, Inflammatory, and Demyelinating Disease, Inflammatory and Demyelinating Disease, Guillain-Barr\u00e9 Spectrum Disorders"
|
||||
pageTitle: "Guillain-Barr\u00e9 Spectrum Disorders | STATdx"
|
||||
enhancedTitle: "Guillain-Barr\u00e9 Spectrum Disorders"
|
||||
type: "DX"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Infectious, Inflammatory, and Demyelinating Disease"
|
||||
- "Inflammatory and Demyelinating Disease"
|
||||
- "Guillain-Barr\u00e9 Spectrum Disorders"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Guillain-Barré syndrome (GBS), Miller Fisher syndrome (MFS), Bickerstaff brainstem encephalitis (BBE)
|
||||
- **Classic GBS**: Acute-onset, rapidly progressive, ascending sensorimotor neuropathy; absent or ↓ tendon reflexes
|
||||
- **Clinical variants of GBS**: Pure motor, paraparetic, bilateral facial palsy with paraesthesias, pharyngeal-cervical-brachial (PCB) variants and MFS
|
||||
- **Other disorders often included in GBS spectrum** (controversial): Pure sensory variant, pure sensory ataxia, BBE
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Cauda equina (CE) nerve root enhancement in > 80%
|
||||
- Isolated ventral CE in 17%, both ventral and dorsal in 65%
|
||||
- Enhancement intensity of ventral CE ≥ dorsal CE
|
||||
- Pial surface of distal cord/conus variable enhancement
|
||||
- Pediatric GBS and MFS: CN enhancement in > 80%
|
||||
- CNIII, CNVI, CNVII most common; others like CNII (and optic chiasm), CNV, CNXI, CNXII
|
||||
- BBE: Brainstem T2 hyperintensities, may involve cerebellar peduncles and cerebellum
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Subacute or chronic demyelinating polyneuropathies (SIDP/CIDP)
|
||||
- CSF metastatic seeding, infections, arachnoiditis
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- 6 temporally associated pathogens: *Campylobacter jejuni*, Cytomegalovirus (CMV), Hepatitis E virus, *Mycoplasma pneumoniae*, Epstein Barr virus (EBV), and Zika virus
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Motor weakness and sensory signs in legs progressing to upper limbs and cranial muscles
|
||||
- GBS spectrum/clinical variants with various findings
|
||||
- Serum anti-GQ1b antibodies in up to 90% of MFS, 70% of BBE, and 8% of classic GBS
|
||||
- Anti-GM1 antibodies more characteristic of classic GBS
|
||||
- Intravenous immunoglobulins and plasma exchange therapy
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- Consider GBS, variants or overlap syndromes in MR with ventral > dorsal cauda equina nerve root enhancement
|
||||
- Look for cranial nerve root enhancement in MFS
|
||||
- Look for brainstem signal abnormalities in BBE
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Guillain-Barré syndrome (GBS), Miller Fisher syndrome (MFS), Bickerstaff brainstem encephalitis (BBE)
|
||||
- Acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor sensory axonal neuropathy (AMSAN)
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Immune-mediated peripheral nerves and nerve roots disorder, usually triggered by infections
|
||||
- **Classic GBS**: Acute-onset, rapidly progressive, ascending sensorimotor neuropathy; absent or ↓ tendon reflexes
|
||||
- Initially in legs, progressing to arms and cranial muscles
|
||||
- Usually reach maximum disability within 2 weeks
|
||||
- **Electrophysiological subtypes**: **AIDP, AMAN, AMSAN**
|
||||
- **Clinical variants of GBS**: Do not characteristically progress to classic GBS pattern of sensory loss and weakness
|
||||
- Usually not "pure"; often partial overlap with classic GBS or other variants
|
||||
- **Pure motor variant**: Motor weakness; no sensory signs
|
||||
- **Paraparetic variant**: Paresis in lower limbs only
|
||||
- **Bilateral facial palsy with paraesthesias variant**: Weakness limited to cranial nerves; ↓ reflexes
|
||||
- **Pharyngeal-cervical-brachial (PCB) variant**: PCB muscle weakness, no lower limb weakness
|
||||
- **MFS**: Ophthalmoplegia, areflexia, ataxia
|
||||
- 15% overlap classic GBS
|
||||
- Incomplete forms: **Acute ataxic neuropathy** (isolated ataxia); **acute ophthalmoplegia**
|
||||
- **Other disorders often included in GBS spectrum**:****Due to similar clinical or pathophysiological features
|
||||
- Inclusion in GBS spectrum debatable as these do not fulfil GBS diagnostic criteria
|
||||
- **Pure sensory variant**: Overlapping clinical features of classic GBS, except motor signs and symptoms
|
||||
- **Pure sensory ataxia**: Overlap with MFS
|
||||
- **BBE**: Initially ophthalmoplegia, ataxia, areflexia (like MFS), later brainstem dysfunction, e.g., ↓ consciousness and pyramidal tract signs; often overlap classic GBS
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Cauda equina (CE) nerve root enhancement > 80%
|
||||
- Isolated ventral CE 17%, both ventral and dorsal 65%
|
||||
- Enhancement intensity of ventral CE ≥ dorsal CE
|
||||
- Pial surface of distal cord/conus variable enhancement
|
||||
- Pediatric GBS and MFS: Cranial nerve enhancement > 80%
|
||||
- CNIII, CNVI, CNVII most common; others like CNII (and optic chiasm), CNV, CNXI, CNXII
|
||||
- Entire spinal cord T2-hyperintense posterior column described as delayed-onset finding in MFS case
|
||||
- BBE: Brainstem T2 hyperintensities, may involve cerebellar peduncles and cerebellum
|
||||
- Enhance only rarely; extremely rare, patchy spinal cord involvement described
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- May see slight nerve root thickening
|
||||
- Brainstem hyperintensities in BBE
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- Ventral > dorsal nerve root enhancement
|
||||
- Cranial nerve enhancement
|
||||
- ## Ultrasonographic Findings
|
||||
|
||||
|
||||
- Enlarged nerves/roots during first 3 weeks, improve later
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- MR of lumbar spine with contrast
|
||||
- MR of brain with contrast if MFS or BBE suspected
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Infections
|
||||
|
||||
|
||||
- Bacterial or granulomatous meningitis
|
||||
- Nerve root enhancement in minority of enterovirus D68 acute flaccid myelitis
|
||||
- ## CSF Metastatic Seeding
|
||||
|
||||
|
||||
- Nodular nerve root thickening and enhancement
|
||||
- ## Subacute or Chronic Demyelinating Polyneuropathies
|
||||
|
||||
|
||||
- Slower onset, protracted course
|
||||
- CIDP: Nadir 2 months; SIDP: 4-8 weeks
|
||||
- ## Arachnoiditis
|
||||
|
||||
|
||||
- Secondary to hemorrhage, surgery, chemicals, chemotherapy (like vincristine), radiation
|
||||
- ## Vasculitic Neuropathy
|
||||
|
||||
|
||||
- Polyarteritis nodosa, Churg-Strauss syndrome
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- Infection in 6 weeks prior to onset in 2/3; triggering immune response causing GBS
|
||||
- 6 temporally associated pathogens: *Campylobacter jejuni*, Cytomegalovirus (CMV), Hepatitis E virus, *Mycoplasma pneumoniae*, Epstein Barr virus (EBV), and Zika virus
|
||||
- Absence of preceding illness does not exclude GBS
|
||||
- Infections and other immunological stimuli (immunobiologicals like tumour necrosis factor antagonists, immune checkpoint inhibitors or type I interferons, surgery, amlgnancy) may be subclinical
|
||||
- Serum antibodies against gangliosides in axolemma and other peripheral nerve components
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Peripheral nerve and nerve root complement activation, macrophage infiltration, and edema
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Motor weakness and sensory signs in legs progressing to upper limbs and cranial muscles
|
||||
- Low back pain common symptom
|
||||
- GBS spectrum/clinical variants with various findings
|
||||
- Respiratory failure and mechanical ventilation in 20%
|
||||
- Autonomic nervous system involvement with cardiac arrhythmias and unstable blood pressure
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- Serum **anti-GQ1b** antibodies in up to 90% of MFS, 70% of BBE, and 8% of classic GBS
|
||||
- **Anti-GM1** antibodies more characteristic of classic GBS
|
||||
- Should not wait for antibody test results to start treatment when GBS is suspected
|
||||
- Albumino-cytological dissociation: Classic GBS finding
|
||||
- ↑ CSF protein and normal CSF cell count
|
||||
- Protein levels normal in 30-50% during 1st week and 10-30% during 2nd week
|
||||
- Mild CSF pleocytosis (10-50 cells/μl) can be seen in GBS, but should exclude infectious polyradiculitis
|
||||
- Electrodiagnostic studies not required to diagnose GBS; might be normal during 1st week, mild or variant disease, initial proximal weakness, or slow progression
|
||||
- GBS: Sensorimotor polyradiculoneuropathy or polyneuropathy: ↓ conduction velocities, sensory and motor evoked amplitudes, abnormal temporal dispersion &/or partial motor conduction blocks
|
||||
- GBS: Typical "sural sparing" pattern: Normal sural sensory nerve action potential, but abnormal or absent median and ulnar sensory nerve action potentials
|
||||
- MFS: Normal or only ↓ amplitude of sensory nerve action potentials
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- 1-2 per 100,000 person-years; M > F; ↑ with age
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Rapid progression, nadir within 2 weeks; mortality 3-10%
|
||||
- GBS plateau phase (days to weeks or months); then recovery
|
||||
- 60-80% walk independently after 6 months
|
||||
- GBS typically monophasic illness, but relapses in 2-5%
|
||||
- Treatment-related fluctuation (TRF): Deterioration after intial stability/improvement on therapy
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Intravenous immunoglobulin for 5 days (0.4 g/kg daily)
|
||||
- Plasma exchange for 5 sessions (200-250 mL/kg)
|
||||
- If TRF, repeat same treatment
|
||||
- If no initial response or incomplete recovery, currently no evidence to support repeat treatment
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- GBS, variants or overlap syndromes in MR showing ventral > dorsal cauda equina nerve root enhancement
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Look for cranial nerve root enhancement in MFS
|
||||
- Look for brainstem signal abnormalities in BBE
|
||||
|
||||
5e867f2a-de7e-44dd-83cf-67453b9125d2
|
||||
|
||||
|
||||
## Images
|
||||
|
||||
|
||||
### Selected Images
|
||||
|
||||
|
||||
*Axial T1 C+ MR of the lumbar spine in a patient with Guillain-Barré syndrome (GBS) shows the characteristic ventral cauda equina (CE) nerve root enhancement <img src='/img/arrows/CS.png'/> and slight thickening.*
|
||||
|
||||
|
||||
*Axial T1 C+ MR of the lumbar spine in a patient with Guillain-Barré syndrome (GBS) shows the characteristic ventral cauda equina (CE) nerve root enhancement <img src='/img/arrows/CS.png'/> and slight thickening.*
|
||||
|
||||
|
||||
*Sagittal T1 C+ FS MR of the lumbar spine in a patient with GBS shows CE nerve root enhancement, more intense in ventral <img src='/img/arrows/CS.png'/> than dorsal <img src='/img/arrows/CC.png'/> CE. Also note enhancement of the pial surface of the distal cord/conus <img src='/img/arrows/CO.png'/>. GBS is an immune-mediated peripheral nerves and nerve roots disorder, usually triggered by infections.*
|
||||
|
||||
|
||||
*Coronal angled T1 C+ MPRAGE MR reformat in a patient with Miller Fisher syndrome (MFS) shows mild thickening and enhancement of right facial (CNVII) <img src='/img/arrows/CC.png'/> and bilateral trigeminal (CNV) <img src='/img/arrows/CS.png'/> nerves.*
|
||||
|
||||
|
||||
*Axial FLAIR MR in a patient with BBE shows hyperintense signal in the pons <img src='/img/arrows/CS.png'/>, middle cerebellar peduncles <img src='/img/arrows/CC.png'/>, and cerebellum <img src='/img/arrows/CO.png'/>. Both MFS and BBE may initially show ophthalmoplegia, ataxia, and areflexia, the differentiating feature being reduced consciousness and other brainstem signs in BBE later.*
|
||||
|
||||
|
||||
### Additional Images
|
||||
|
||||
|
||||
*Axial FLAIR MR in a patient with Bickerstaff brainstem encephalitis (BBE) shows abnormal hyperintense signal in the pons <img src='/img/arrows/CS.png'/>. Both MFS and BBE initially present with ophthalmoplegia, ataxia and areflexia; the differentiating feature being development of brainstem dysfunction in BBE later (reduced consciousness and pyramidal tract signs).*
|
||||
|
||||
-295
@@ -1,295 +0,0 @@
|
||||
---
|
||||
title: "Hypertrophic Olivary Degeneration"
|
||||
docid: "78257543-6d52-4879-84b1-445f3611d996"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Pathology-Based Diagnoses"
|
||||
- "Acquired Toxic/Metabolic/Degenerative Disorders"
|
||||
- "Dementias and Degenerative Disorders"
|
||||
- "Hypertrophic Olivary Degeneration"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- Inferior olivary nucleus (ION) degeneration
|
||||
- Unique type of transsynaptic neuronal degeneration
|
||||
- Olivary deafferentation thought to be source of ensuing hypertrophic olivary degeneration (HOD)
|
||||
- Usually caused by primary lesions in dentato-rubro-olivary pathway (Guillain-Mollaret triangle)
|
||||
- Triangle of Guillain-Mollaret defined by 3 anatomic structures
|
||||
- Red nucleus (RN)
|
||||
- ION ipsilateral to RN
|
||||
- Contralateral dentate nucleus (DN) of cerebellum
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- ION initially hypertrophies rather than atrophies
|
||||
- 3 distinct MR stages in HOD
|
||||
- Hyperintense signal without hypertrophy of ION: Within first 6 months of ictus
|
||||
- ↑ signal + ION hypertrophy: Between 6 months & 3-4 years after ictus
|
||||
- Only ION hyperintensity: Begins when hypertrophy resolves (can persist indefinitely)
|
||||
- MR also detects primary lesion located in ipsilateral CTT, SCP or contralateral DN
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Vertebrobasilar perforating artery infarct
|
||||
- Demyelination (multiple sclerosis, microvascular disease)
|
||||
- Amyotrophic lateral sclerosis
|
||||
- HIV/AIDS
|
||||
- Rhombencephalitis
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Palatal myoclonus (palatal "tremor"), ocular myoclonus
|
||||
- Usually develops 10-11 months after primary lesion
|
||||
- Clinical symptoms (tremors) rarely improve
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Abbreviations
|
||||
|
||||
|
||||
- Hypertrophic olivary degeneration (HOD)
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Pseudohypertrophy of inferior olivary nucleus
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Transsynaptic degeneration of inferior olivary nucleus (ION), usually caused by primary lesions in dentato-rubro-olivary pathway (DROP) also called anatomic triangle of Guillain & Mollaret (GMT)
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- T2-hyperintense, nonenhancing enlargement of ION
|
||||
- ### Location
|
||||
|
||||
|
||||
- GMT is defined by 3 anatomic structures
|
||||
- Red nucleus (RN)
|
||||
- ION ipsilateral to RN
|
||||
- Contralateral dentate nucleus (DN) of cerebellum
|
||||
- Central tegmental tract (CTT or rubro-olivary pathway) connects RN to ipsilateral ION
|
||||
- Superior cerebellar peduncle (SCP, dentato-rubral tract) connects DN to contralateral RN
|
||||
- Inferior cerebellar peduncle (olivo-cerebellar pathway) connects ION to contralateral cerebellar cortex & contralateral DN
|
||||
- 4 patterns of HOD in relation to primary lesion
|
||||
- Ipsilateral HOD: Primary lesion is limited to brainstem (CTT)
|
||||
- Contralateral HOD: Primary lesion is in cerebellum (DN or SCP)
|
||||
- Bilateral HOD: Primary lesion involves midline/paramedian brainstem affecting brachium conjunctivum
|
||||
- Bilateral HOD: Primary lesion involves both unilateral brainstem & cerebellum
|
||||
- ### Size
|
||||
|
||||
|
||||
- Variable (time-dependent) size of affected ION
|
||||
- Normal in acute stage
|
||||
- ↑ (hypertrophy) from 6 months to 3-4 years
|
||||
- ↓ (atrophy) in advanced stage (> 3-4 years)
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Unique type of transsynaptic neuronal degeneration
|
||||
- ION initially hypertrophies rather than atrophies
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- May show acute primary injury (e.g., hemorrhage) in tegmentum
|
||||
- HOD typically not depicted on CT
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Acute phase: Normal ION
|
||||
- Shows primary lesion in brainstem (cerebellum or tegmentum)
|
||||
- After HOD ensues
|
||||
- Enlargement confined to ION, isointense to slightly hypointense to gray matter
|
||||
- Slightly ↑ olivary T1 signal also reported
|
||||
- ± residual primary lesion
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- 3 distinct MR stages in HOD
|
||||
- Hyperintense signal without hypertrophy of ION: Within first 6 months of ictus
|
||||
- Both ↑ signal & hypertrophy of ION: Between 6 months & 3-4 years after ictus
|
||||
- ↑ signal only in ION: Begins when hypertrophy resolves & can persist indefinitely
|
||||
- Axial MR: Disappearance of pre- & postolivary sulci in hypertrophic stage
|
||||
- MR also detects primary lesion located in ipsilateral central tegmental tract or contralateral DN
|
||||
- Old hematomas: Low-signal areas on T2WI revealing hemosiderin deposition
|
||||
- ± ↓ size of contralateral ION with higher than normal signal intensity
|
||||
- ± mild to severe atrophic changes of cerebellar cortex contralateral to HOD
|
||||
- ### PD/intermediate
|
||||
|
||||
|
||||
- High signal intensity of ION better detected on PD images than on T2WI
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- Similar to T2WI
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- No contrast enhancement of degenerated ION
|
||||
- DTI
|
||||
- ↑ radial diffusivity, ↑ mean diffusion & ↓ fractional anisotropy in GMT components reflecting demyelination
|
||||
- ↑ fractional anisotropy & ↑ axial diffusivity in ION reflect rearrangement of regenerating axons & shrunken neurons
|
||||
- ## Nuclear Medicine Findings
|
||||
|
||||
|
||||
- ### PET
|
||||
|
||||
|
||||
- Focal glucose hypermetabolism in medulla of patients with HOD
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- MR
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- T2WI (include coronal or sagittal sections)
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- ## Other Causes of High T2 Signal Intensity in Anterior Part of Medulla
|
||||
|
||||
|
||||
- [Demyelination related to multiple sclerosis](/document/multiple-sclerosis/7892b2a2-f52a-4d7f-9858-a326f2b7ab04)
|
||||
- Tumor (astrocytoma, metastasis, lymphoma)
|
||||
- Lesions involving corticospinal tract
|
||||
- Wallerian degeneration, adrenoleukodystrophy
|
||||
- [Amyotrophic lateral sclerosis](/document/amyotrophic-lateral-sclerosis-als/23de52b7-d9bd-441c-a18c-95c8afccb470)
|
||||
- Vertebrobasilar perforating artery infarct
|
||||
- Most medullary infarctions occur in posteroinferior cerebellar artery territory & involve posterolateral medulla (e.g., vertebral artery dissection)
|
||||
- Alternatively, medullary infarcts could be related to perforating branches of anterior spinal or vertebral arteries & have paramedial location
|
||||
- Infectious/inflammatory processes
|
||||
- [Tuberculosis](/document/tuberculosis/6e389773-2150-4299-9ce2-0b83b13c2119)
|
||||
- [Sarcoidosis](/document/neurosarcoid/fef69139-0019-4be3-9bdc-e26bc3644251)
|
||||
- HIV/AIDS
|
||||
- [Rhombencephalitis](/document/miscellaneous-encephalitis/1c3c0881-4046-46a1-90fc-371941c0cf2c)
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Transsynaptic degeneration caused by interruption of pathways composing GMT
|
||||
- Olivary deafferentation thought to be source of ensuing HOD
|
||||
- Primary lesions usually located in contralateral DN or ipsilateral CTT
|
||||
- Focal brainstem insults that may lead to dentato-rubral-olivary pathway interruption
|
||||
- Ischemic infarction, demyelination
|
||||
- Hemorrhage (related to hypertensive disease, occult cerebrovascular malformation, or diffuse axonal injury following severe head trauma)
|
||||
- Cavernous malformation
|
||||
- ### Associated abnormalities
|
||||
|
||||
|
||||
- Primary brainstem insult
|
||||
- Most commonly pontine hemorrhage from trauma (including surgery), hypertension, tumor, & infarction
|
||||
- Olivary enlargement: Histologically unusual vacuolar cytoplasmic degeneration → hypertrophy related in part to ↑ number of astrocytes
|
||||
- After onset of primary lesion
|
||||
- Vacuolar cytoplasmic degeneration in 6-15 months
|
||||
- Gliosis follows at 15-20 months
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- 6 phases of pathologic change
|
||||
- No olivary changes within first 24 hours
|
||||
- Degeneration of olivary amiculum (white matter capsule at olive periphery) at ≥ 2-7 days
|
||||
- Olivary hypertrophy (mild enlargement with neuronal hypertrophy, no glial reaction) at 3 weeks
|
||||
- Maximal olivary enlargement (hypertrophy of neurons & astrocytes) at 8.5 months
|
||||
- Olivary pseudohypertrophy (neuronal dissolution with prevailing large gemistocytic astrocytes) after 9.5 months
|
||||
- Olivary atrophy (neuronal disappearance with olivary atrophy & prominent degeneration of amiculum olivae) after 3-5 years of primary lesion
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Focal swelling of ION
|
||||
- Unilateral HOD
|
||||
- Asymmetric enlargement of anterior medulla
|
||||
- "Pallor" in contralateral DN
|
||||
- Atrophy of contralateral cerebellar cortex
|
||||
- Bilateral HOD: More difficult to observe
|
||||
- No left-right asymmetry
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Changes in hypertrophic degenerated ION
|
||||
- Hypertrophic, thickened neurites
|
||||
- Vacuolation of neurons
|
||||
- Fibrillary gliosis
|
||||
- Demyelination & astrocytic proliferation of WM
|
||||
- In contralateral cerebellar cortex
|
||||
- ↓ number of Purkinje cells
|
||||
- Contralateral DN reduced in size, possibly due to
|
||||
- Iron depletion secondary to axonal iron transport block
|
||||
- Loss of cells in nucleus
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Symptomatic palatal tremor/myoclonus
|
||||
- Rhythmic involuntary movement of soft palate, uvula, pharynx, & larynx
|
||||
- Severe myoclonus may also affect cervical muscles & diaphragm
|
||||
- ± dentato-rubral tremor (Holmes tremor)
|
||||
- 2-5 Hz rest, postural, & kinetic tremor of upper extremity
|
||||
- May occur before onset of palatal tremor
|
||||
- Symptoms of cerebellar or brainstem dysfunction
|
||||
- Associated with acute lesion within triangle of Guillain-Mollaret
|
||||
- Ocular myoclonus & nystagmus
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- Palatal myoclonus (palatal "tremor")
|
||||
- Usually develops 10-11 months after primary lesion
|
||||
- Virtually all patients who develop palatal myoclonus after brain insult will have HOD
|
||||
- Not all HOD patients develop palatal myoclonus
|
||||
- May result from hypermetabolism of ION
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Rare; reported in all ages, both sexes
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- After primary brainstem injury, olivary hypertrophy typically appears in delayed fashion
|
||||
- May occur between 3 weeks to 11 months (usually within 4-6 months)
|
||||
- Maximum hypertrophy at 5-15 months
|
||||
- Olivary hypertrophy typically resolves in 10-16 months
|
||||
- Olivary hyperintensity on T2WI may persist for years after resolution of hypertrophy
|
||||
- Finally ION undergoes atrophy
|
||||
- Clinical symptoms (tremors) rarely improve
|
||||
- Self-limiting disease & can be managed by symptomatic treatment
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Avoid misdiagnosis of tumor or multiple sclerosis
|
||||
- Bilateral & symmetrical lesions in ION argue against subacute infarct & vertebral artery dissection
|
||||
|
||||
16a22041-bb55-47a8-b601-8617efdb98ad
|
||||
@@ -1,308 +0,0 @@
|
||||
---
|
||||
title: "Hypothalamic Hamartoma"
|
||||
docid: "7f85487f-9497-44a9-b884-b98e50d41018"
|
||||
breadcrumbs:
|
||||
- "Brain"
|
||||
- "Diagnosis"
|
||||
- "Anatomy-Based Diagnoses"
|
||||
- "Sella and Pituitary"
|
||||
- "Congenital"
|
||||
- "Hypothalamic Hamartoma"
|
||||
---
|
||||
# KEY FACTS
|
||||
|
||||
- ## Terminology
|
||||
|
||||
|
||||
- a.k.a. tuber cinereum hamartoma
|
||||
- Nonneoplastic; congenital gray matter heterotopia
|
||||
- ## Imaging
|
||||
|
||||
|
||||
- Hypothalamic mass contiguous with tuber cinereum
|
||||
- Located between mammillary bodies and infundibulum
|
||||
- Can be sessile or pedunculated ("collar button")
|
||||
- Size ranges from few mm to several cm
|
||||
- Isointense with gray matter on T1WI
|
||||
- Can be slightly hyperintense on T2/FLAIR
|
||||
- Large lesions can be heterogeneous, contain cysts
|
||||
- No enhancement on T1 C+
|
||||
- ## Top Differential Diagnoses
|
||||
|
||||
|
||||
- Chiasmatic/hypothalamic astrocytoma
|
||||
- Craniopharyngioma
|
||||
- Ectopic posterior pituitary
|
||||
- Lipoma
|
||||
- Germinoma
|
||||
- Langerhans cell histiocytosis
|
||||
- ## Pathology
|
||||
|
||||
|
||||
- Mature but dysplastic neuronal ganglionic tissue
|
||||
- ## Clinical Issues
|
||||
|
||||
|
||||
- Infant with epilepsy or precocious puberty
|
||||
- Cognitive, neuropsychiatric comorbidities common
|
||||
- Older children with precocious puberty
|
||||
- Often tall, overweight, with advanced bone age
|
||||
- Shape, size of hamartoma often predicts symptoms, presentation
|
||||
- Large, sessile lesions → seizures
|
||||
- Small, pedunculated lesions → central precocious puberty
|
||||
- ## Diagnostic Checklist
|
||||
|
||||
|
||||
- If hypothalamic mass in seizure imaging, think hypothalamic hamartoma; if enhancement present, consider astrocytoma
|
||||
|
||||
# TERMINOLOGY
|
||||
|
||||
- ## Synonyms
|
||||
|
||||
|
||||
- Tuber cinereum hamartoma, diencephalic hamartoma
|
||||
- ## Definitions
|
||||
|
||||
|
||||
- Nonneoplastic congenital gray matter heterotopia in region of tuber cinereum of hypothalamus
|
||||
|
||||
# IMAGING
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Best diagnostic clue
|
||||
|
||||
|
||||
- Nonenhancing hypothalamic mass contiguous with tuber cinereum
|
||||
- ### Location
|
||||
|
||||
|
||||
- Tuber cinereum of hypothalamus
|
||||
- Located between pons/mammillary bodies and hypothalamic infundibulum
|
||||
- ### Size
|
||||
|
||||
|
||||
- Variable, few mm to giant (3-5 cm)
|
||||
- ### Morphology
|
||||
|
||||
|
||||
- Sessile or pedunculated mass
|
||||
- Similar in density/intensity to gray matter
|
||||
- ## Radiographic Findings
|
||||
|
||||
|
||||
- ### Radiography
|
||||
|
||||
|
||||
- ± suprasellar calcifications, eroded dorsum, enlarged sella (rare)
|
||||
- ## CT Findings
|
||||
|
||||
|
||||
- ### NECT
|
||||
|
||||
|
||||
- Homogeneous suprasellar mass
|
||||
- Isodense → slightly hypodense
|
||||
- Cysts and calcification are uncommon
|
||||
- ± patent craniopharyngeal canal (very rare)
|
||||
- ### CECT
|
||||
|
||||
|
||||
- No pathologic enhancement
|
||||
- ## MR Findings
|
||||
|
||||
|
||||
- ### T1WI
|
||||
|
||||
|
||||
- Mass located between mammillary bodies and infundibulum
|
||||
- Isointense → slightly hypointense to gray matter
|
||||
- ### T2WI
|
||||
|
||||
|
||||
- Isointense → slightly hyperintense (secondary to fibrillary gliosis)
|
||||
- ### PD/intermediate
|
||||
|
||||
|
||||
- Hyperintense to CSF, slightly hyperintense to gray matter
|
||||
- ### FLAIR
|
||||
|
||||
|
||||
- Isointense → slightly hyperintense to gray matter
|
||||
- ### T1WI C+
|
||||
|
||||
|
||||
- Nonenhancing; if enhancing, consider other diagnosis
|
||||
- ### MRS
|
||||
|
||||
|
||||
- ↓ NAA and NAA/Cr, mild ↑ Cho and Cho/Cr, ↑ myoinositol (mI) and mI/Cr
|
||||
- ↓ NAA and ↑ Cho indicate reduced neuronal density and relative gliosis, respectively, compared to normal gray matter
|
||||
- ↑ mI/Cr correlates with ↑ glial component and lesion T2 hyperintensity
|
||||
- ## Imaging Recommendations
|
||||
|
||||
|
||||
- ### Best imaging tool
|
||||
|
||||
|
||||
- Multiplanar MR imaging
|
||||
- ### Protocol advice
|
||||
|
||||
|
||||
- Thin-section sagittal and coronal T2W1, T1WI C+ MR
|
||||
|
||||
# DIFFERENTIAL DIAGNOSIS
|
||||
|
||||
- [Craniopharyngioma](/document/craniopharyngioma/00e66680-6731-4287-b5a1-3f0b3f09053b)
|
||||
- Most common suprasellar mass in children
|
||||
- Variable signal intensity cysts (90%), calcifications (90%), and enhancement (90%)
|
||||
- Longstanding lesion, frequently with short stature and pituitary abnormalities
|
||||
- ## Chiasmatic/Hypothalamic Astrocytoma
|
||||
|
||||
|
||||
- 2nd most common pediatric suprasellar mass [± neurofibromatosis type 1 (NF1)]
|
||||
- Hyperintense on T2WI MR ± contrast enhancement (heterogeneous, often vigorous)
|
||||
- Optic pathway or hypothalamus ± optic tract extension
|
||||
- ## Ectopic Posterior Pituitary
|
||||
|
||||
|
||||
- Ectopic hyperintense focus on T1WI MR
|
||||
- Often located along median eminence of hypothalamus
|
||||
- No normal orthotopic posterior pituitary hyperintensity
|
||||
- [Germinoma](/document/germinoma/078b68a2-67de-457e-818a-63655cec95aa)
|
||||
- Thickening, abnormal enhancement of pituitary stalk rather than tuber cinereum
|
||||
- Diabetes insipidus common
|
||||
- ± multicentric: Suprasellar, pineal, thalamus, basal ganglia
|
||||
- Early leptomeningeal metastatic dissemination
|
||||
- [Langerhans Cell Histiocytosis](/document/langerhans-cell-histiocytosis-skul-/5bfd61b0-b320-46f4-b785-6c69daa8523c)
|
||||
- Thickening, abnormal enhancement of pituitary stalk rather than tuber cinereum
|
||||
- Diabetes insipidus common
|
||||
- Look for lytic bone lesions in typical locations
|
||||
- [Lipoma](/document/lipoma-brain/1bdb974e-8346-4730-9b1c-dea7b70b844d)
|
||||
- Hyperintense fat signal on T1WI MR
|
||||
- Hypointense on STIR or fat-saturated sequences
|
||||
|
||||
# PATHOLOGY
|
||||
|
||||
- ## General Features
|
||||
|
||||
|
||||
- ### Etiology
|
||||
|
||||
|
||||
- Neuronal migration anomaly (occurs between gestational days 33-41)
|
||||
- Affects normal hypothalamic regulation of autonomic, endocrine, neurologic, behavioral functions
|
||||
- Pathogenesis of precocious puberty-induced sexual precocity
|
||||
- ± luteinizing hormone-releasing hormone (LHRH) granules in hamartoma/connecting axons in some
|
||||
- Activating astroglial-derived factors in tumors may stimulate endogenous LHRH secretion if no intratumoral LHRH granules
|
||||
- Shape and size of hamartoma postulated to predict symptoms
|
||||
- Large, sessile lesions → seizures
|
||||
- Small, pedunculated lesions → central precocious puberty (CPP)
|
||||
- Presentation with both seizures and CPP common
|
||||
- ### Genetics
|
||||
|
||||
|
||||
- *GLI3*mutation
|
||||
- Pallister-Hall syndrome (PHS)
|
||||
- Hamartoma or hamartoblastoma of tuber cinereum; often large mass
|
||||
- Digital malformations (short metacarpals, syndactyly, polydactyly)
|
||||
- Other midline (epiglottis/larynx) and cardiac/renal/anal anomalies
|
||||
- Greig cephalopolysyndactyly syndrome (GCPS)
|
||||
- ## Staging, Grading, & Classification
|
||||
|
||||
|
||||
- Valdueza classification
|
||||
- Pedunculated, CPP or asymptomatic
|
||||
- Originates in tuber cinereum
|
||||
- Originates in mammillary bodies
|
||||
- Sessile, hypothalamus displaced, seizures
|
||||
- More hypothalamic dysfunction and abnormal behavior
|
||||
- ## Gross Pathologic & Surgical Features
|
||||
|
||||
|
||||
- Mature neuronal ganglionic tissue projecting from hypothalamus, tuber cinereum, or mammillary bodies
|
||||
- Pedunculated or sessile, rounded or nodular
|
||||
- ## Microscopic Features
|
||||
|
||||
|
||||
- Well-differentiated neurons interspersed with glial cells, myelinated/unmyelinated axons, variable amounts of fibrillary gliosis
|
||||
- Hamartoblastomas include primitive undifferentiated cells
|
||||
- Rare reports of cysts, necrosis, calcifications, fat
|
||||
|
||||
# CLINICAL ISSUES
|
||||
|
||||
- ## Presentation
|
||||
|
||||
|
||||
- ### Most common signs/symptoms
|
||||
|
||||
|
||||
- Luteinizing hormone-releasing hormone (LHRH) dependent CPP presenting at very young age
|
||||
- Refractory symptomatic mixed seizure types, including gelastic seizures
|
||||
- Gelastic seizures are recurrent automatic bursts of laughter without mirth
|
||||
- Presentation usually encompasses both epileptic seizures and encephalopathy with behavioral cognitive impairment
|
||||
- May progress to partial epilepsy, partial complex seizures, generalized tonic clonic seizures
|
||||
- Rarely occur in conjunction with focal cortical dysplasia or hypothalamic astrocytoma
|
||||
- Other seizure types frequent with hypothalamic hamartoma (HH); always look for HH in child with epilepsy
|
||||
- ### Other signs/symptoms
|
||||
|
||||
|
||||
- Depression, anxiety common in adult HH patients
|
||||
- ### Clinical profile
|
||||
|
||||
|
||||
- Infant with gelastic seizures or precocious puberty
|
||||
- Older children with precocious puberty; tall, overweight, and advanced bone age
|
||||
- ## Demographics
|
||||
|
||||
|
||||
- ### Age
|
||||
|
||||
|
||||
- Usually present between 1-3 years of age
|
||||
- ### Sex
|
||||
|
||||
|
||||
- No predilection; some reports M > F
|
||||
- ### Ethnicity
|
||||
|
||||
|
||||
- No predilection
|
||||
- ### Epidemiology
|
||||
|
||||
|
||||
- Of histologically verified lesions, 3/4 have precocious puberty and 1/2 have seizures
|
||||
- Up to 33% of patients with CPP have HH
|
||||
- ## Natural History & Prognosis
|
||||
|
||||
|
||||
- Size should remain stable; if growth is detected, surgery/biopsy is indicated
|
||||
- Postsurgical hypothalamic complications include headache, mental slowing, and weight gain
|
||||
- Symptomatic lesions: Sessile > > pedunculated
|
||||
- Sessile lesions nearly always symptomatic
|
||||
- Syndromic patients generally do poorly
|
||||
- ## Treatment
|
||||
|
||||
|
||||
- Medical: Hormonal-suppressive therapy, treat seizures
|
||||
- Surgical: If medical therapy failure or rapid lesion growth
|
||||
- Endoscopic or transcallosal surgical resection
|
||||
- Recent studies have shown stereotactic laser ablation to have equivalent efficacy to open surgery with fewer complications
|
||||
- Stereotactic radiosurgery and Gamma Knife surgery also potential options
|
||||
- Newer, less invasive techniques include magnetic resonance imaging-guided laser interstitial thermal therapy (MRgLITT)
|
||||
|
||||
# DIAGNOSTIC CHECKLIST
|
||||
|
||||
- ## Consider
|
||||
|
||||
|
||||
- If hypothalamic mass identified in seizure imaging, think HH
|
||||
- ## Image Interpretation Pearls
|
||||
|
||||
|
||||
- Classic = nonenhancing hypothalamic mass
|
||||
- Isointense to gray matter on T1WI, slightly ↑ signal on T2WI/FLAIR
|
||||
- Hypothalamic astrocytoma, Langerhans cell histiocytosis (LCH), germ cell tumor all show some contrast enhancement
|
||||
|
||||
1e636dc4-6e35-473c-a03d-2ed82f71d5bc
|
||||
BIN
Binary file not shown.
|
After Width: | Height: | Size: 106 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 111 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 115 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 100 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 113 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 108 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 112 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 108 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 117 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 113 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 52 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 91 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 90 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 121 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 117 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 251 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 130 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 64 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 109 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 94 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 121 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 53 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 103 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 136 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 99 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 86 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 106 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 100 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 75 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 98 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 84 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 9.6 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 6.3 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 7.5 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 9.9 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 8.3 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 122 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 122 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 122 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 122 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 9.3 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 9.3 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 8.9 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 6.6 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 97 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 97 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 97 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 8.1 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 8.8 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 110 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 6.9 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 93 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 93 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 93 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 93 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 124 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 9.2 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 100 KiB |
BIN
Binary file not shown.
|
After Width: | Height: | Size: 100 KiB |
Some files were not shown because too many files have changed in this diff Show More
Reference in New Issue
Block a user