Monday, April 25, 2011

4 aminopyridine toxicity mimicking autoimmune limbic encephalitis

Neurology 72; 2009: 1100-1101
A 22 year old man ingested 30 tablets of 4-AP. He was agitated but oriented, flushed, mildly febrile, hypertensive.  EEG showed spikes and polyspikes and waves. CSF was normal.   MRI showed bitemporal hyperintensity on T2 imaging as well as affecting anterior cingulum.  Cardiac EF initially was 24 % but recovered.  He awoke to be mute and amnestic.  He recovered over one year but still had short term memory problems.   

differential diagnosis of long segment myelopathy suggesting NMO

Compression/ spondylitic myelopathy-- pearl- check enhancing scan for signet ring sign 

zoster myelitis-- history of shingles

paraneoplastic-- history of cancer

infective-helminth-- prior "Wells" syndrome, with eosiniphilia

cord AVM- history of worsening with Vasalva, singing, defecation, also check blood sensitive sequences and MRA cord

Sjogren's-- controversial, check CSF NMO as well as serum

B12 deficiency-- posterior cord

copper deficiency-- also posterior cord

stroke-- can affect almost any part of cord

multiple sclerosis/transverse myelitis-- check brain MRI

GBS/CIDP-- may be difficult to differentiate clinically, check nerve roots for radiculitis on MRI

CMV radiculitis -- in immunocompromised


Sunday, April 03, 2011