Peripheral neuropathy following a single exposure to arsenic. Clincal course in four patients with electrophysiological and histological studies.

Four patients are described who developed a peripheral neuropathy 10 days to 3 weeks after ingestion of a single dose of arsenic. All improved slowly, but after 6 to 8 years 3 of them still had abnormal neurological symptoms and signs. Electrophysiological studies showed reduction of motor conduction velocity and marked abnormalities of sensory nerve action potentials. The findings suggest that conduction is abnormal in at least some surviving nerve fibres. Sural nerve biopsies from 2 patients showed axonal degeneration, which was at an early stage in some fibres, even 10 weeks after intoxication.