{"id":4987,"date":"2010-12-26T18:37:12","date_gmt":"2010-12-26T23:37:12","guid":{"rendered":"http:\/\/insidesurgery.com\/?p=4987"},"modified":"2011-04-07T17:17:54","modified_gmt":"2011-04-07T21:17:54","slug":"charcotmarietooth-disease","status":"publish","type":"post","link":"https:\/\/insidesurgery.com\/2010\/12\/charcotmarietooth-disease\/","title":{"rendered":"Charcot-Marie-Tooth Disease"},"content":{"rendered":"
1)<\/strong> heterogeneous group of hereditary peripheral neuropathies 2)<\/strong> type 1 – most common; marked by demyelination 3)<\/strong> type 2 – less severe clinically; lacks demyelination 4)<\/strong> type 3 (Dejerine-Sottas disease) – infantile onset; severe symptoms 5)<\/strong> type 4 – rare; X-linked recessive 6) frequency for all variants combined is 1\/2,500<\/p>\n Signs and Symptoms<\/strong><\/p>\n 1)<\/strong> onset is in adolescence with both motor and sensory deficits 2)<\/strong> distal extremity weakness 3)<\/strong> distal atrophy 4)<\/strong> decreased deep tendon reflexes 5)<\/strong> high stepping gait 6)<\/strong> frequent falls 7)<\/strong> abnormal feet (commonly pes cavus or high arches)<\/p>\n Characteristic Test Findings<\/strong><\/p>\n EMG<\/em> – 1) type 1 – decreased nerve-conduction velocity 2) type 2 – normal or only slightly decreased nerve-conduction velocity<\/p>\n Histology\/Gross Pathology<\/strong><\/p>\n 1)<\/strong> type 1 – axonal degeneration, segmental demyelination, onion bulbs, and nerve hypertrophy 2)<\/strong> type 2 – distal axonal degeneration only<\/p>\n Associated Conditions<\/strong><\/p>\n 1)<\/strong> focal segmental glomerulosclerosis 2)<\/strong> destructive arthritis<\/p>\n Inheritance\/Epidemiology<\/strong><\/p>\n 1)<\/strong> autosomal dominant 2)<\/strong> most common peripheral hereditary neuropathy 3)<\/strong> type 1A – gene deficit is duplication-type defect on chromosome 17 (likely involves peripheral myelin protein 22) 4)<\/strong> type 1B – gene defect on chromosome 1 (likely involves myelin protein zero) 5)<\/strong> type 1A most common variant<\/p>\n Tips for USMLE<\/strong><\/p>\n all drugs with known neurologic side effects should be avoided (e.g., vincristine, metronidazole) Pathophysiology 1) heterogeneous group of hereditary peripheral neuropathies 2) type 1 – most common; marked by demyelination 3) type 2 – less severe clinically; lacks demyelination 4) type 3 (Dejerine-Sottas disease) – infantile onset; severe symptoms 5) type 4 – rare; X-linked recessive 6) frequency for all variants combined is 1\/2,500 Signs and Symptoms 1) […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[63],"tags":[3788,2149,3790,3791,3789,435],"yoast_head":"\n
\nPathophysiology<\/strong><\/p>\n
\n<\/p>\n","protected":false},"excerpt":{"rendered":"