Transient ictal psychosis.

Transient psychotic episodes may result from continuous cerebral epileptiform discharges unaccompanied by clinically observed seizures. Such episodes may mimic depressive, hysterical and schizophrenic psychosis and delirium. I describe two patients here and review eight patient histories from the literature. Diagnosis is established by use of electroencephalography during the psychotic episode. Correct diagnosis is essential because specific treatment is available and additional episodes may be prevented by appropriate long-term anticonvulsant therapy.