Psychogenic seizures. A study of 42 attacks in six patients, with intensive monitoring.

Intractable complex partial seizures and seizures of unknown type were studied in 78 patients, six of whom were found to have psychogenic seizures. Evaluation by intensive monitoring included simultaneous six-hour telemetered EEG and videotape recordings and daily determination of plasma antiepileptic drug levels. Diagnosis was determined by assessment of four major criteria: deviation of seizures from characteristics of known seizure types, absence of epileptiform activity in the ictal EEG, absence of slowing in the postictal EEG, and relation of seizure frequency to decreasing plasma concentrations of antiepileptic drugs. No single criterion is sufficient for an unequivocal diagnosis of psychogenic seizures.