Chronic inorganic mercury induced peripheral neuropathy

We report the clinical features, electrophysiological studies, and morphome tric analysis of sural nerve pathology in a patient with polyneuropathy due to inorganic mercury intoxication. He developed slowly progressive general ized paralysis of all limbs after 3 months ingestion of herb drugs which co ntained mercuric sulfate. Electrophysiologic studies revealed axonal polyne uropathy involving both motor and sensory fibers. Sural nerve biopsy demons trated axonal degeneration with demyelination and a predominant loss of lar ge myelinated fibers. His muscle strength showed only mild improvement afte r 2 years' follow-up. We concluded that inorganic mercury exposure may indu ce severe axonal sensorimotor polyneuropathy in humans and that neurologica l deficits may persist in severe cases.