Wednesday, January 24, 2007

Mimics of GBS Part II

Chemical toxins
vacor (rodenticide)ingested due to homicidal or suicidal intent. Impairs fast axon transport. Clinical findings are initially abdominal pain, nausea, vomiting, necrosis of pancreas beta cells causes hyperglycemia, rapid distal motor/sensory/Autonomic neuropathy with weakness, areflexia, dysesthesias, OH, urine retention, and cranial neuropathy, then later stupor, EEG changes, DKA, EKG changes. Long term residua often include DM and ANS dysfunction. Acute tx is gastric lavage and induced emesis.

Organophosphates -- found in malathion, parathion, dursban. 10-20 days after exposure they produce a distal axonopathy, calf cramps, extremity paresthesias and distal weaknesss. A SEPARATE syndrome is NMJ disorder with cholinergic toxicity and respiratory insufficiency.

n-Hexane solvent associated with glue sniffing and industrial exposure. Clinical includes distal sensory loss and severe weakness that progresses for months after exposure ends.

CV-- amiodorone, streptokinase
Hem-- cytarabine, suramin.

amiodoarone chronic progressive predominantly distal s-m neuropathy. NCS show distal latency prolongation and slowing to 11 m/s. Dose is 200-400 mg per day.

streptokinase-- 10-20 cases, 10-20 days after exposure, paresthesias of hands and feet, cndxn blocks, elevated CSF protein, coincident to peak SKN titers, dramatic response to IVIG.

cytarabine-- 0.6 % of cases with doses more than 200 mg/m2/d. progressive distal sensorimotor neuropathy, hours to days after last treatment.

Suramin -- PN in 40 % of patients with levels> 350 ug/ml Rarely GBS like presentation.

Churg-Strauss s-- may resemble GBS. Eosinophilia is seen. Tx with pred/MTX. Asthma, vasculitic lung involvment, eosinophilia and mononeuropathy are common but not universal.

Other cryoglobulinemia, PAN.

AIP-- Motor PN.
Diptheria ("extinct" in US, present in developing countries)
West Nile Virus
CMV polyradiculopathy
critical illness myopathy
critical illness neuropathy

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