[Hyperbaric oxygen for neuropsychiatric sequelae of carbon monoxide poisoning]

A broad range of neuropsychiatric abnormalities, including dementia, psychosis, and parkinsonism, as well as almost every known neurologic syndrome, can occur following carbon monoxide (CO) poisoning. These symptoms develop 2-40 days (usually 2-3 weeks), after initial exposure. There is an incidence of recurrence of up to 40%. However, in recent years the neuropsychiatric sequelae appear to have been occurring less frequently, perhaps as a direct result of the use of hyperbaric oxygen (HBO) therapy. There is no specific therapy for this complication, but up to 75% recover within 12-18 months. Myers et al. (Ann Emerg Med, 14: 1163, 1985) found HBO to be effective for the neuropsychiatric sequelae. We report a 19-year-old man who developed late psychiatric disturbances despite the use of HBO for acute CO intoxication. The neuropsychiatric symptoms, which developed 3 days after full recovery of consciousness, resolved completely when HBO therapy was reinstituted. 6 months later he was functioning normally with no neuropsychiatric symptoms.