Prolongation of the P-300 latency associated with hydrogen sulfide exposure.

Three patients exposed to hydrogen sulfide developed persistent cognitive impairment, as suggested by the P-300 event-related potential and measured by neuropsychological testing. Routine neurological and physical examinations were unremarkable, although the patients were sufficiently impaired so as to be unable to work. The P-300 event-related potential and neuropsychological testing proved to be important in the detection of cognitive dysfunction following acute hydrogen sulfide exposure. The three patients with neurocognitive dysfunction were acutely exposed to hydrogen sulfide. The incidents occurred independently and under different circumstances. Each patient was evaluated at the Northern California Occupational Health Clinic, San Francisco, examined neurologically and neuropsychologically, and evaluated with a P-300 event-related potential. Each patient had persistent neurological symptoms, neuropsychological deficit, and abnormally prolonged P-300 latencies.