Nonepileptic seizure outcome varies by type of spell and duration of illness

Purpose: To determine whether differences in clinical manifestations of psy chogenic nonepileptic events are associated with differences in outcome and whether the length of illness before diagnosis correlates with outcome. Methods: We reviewed ictal videotapes and EEGs in 85 patients diagnosed wit h exclusively nonepileptic psychogenic seizures during inpatient CCTV-EEG m onitoring at the University of Michigan between June 1994 and December 1996 . They were classified into groups of similar ictal behaviors. Fifty-seven of these patients were available to respond to a follow-up telephone survey about their condition 2-4 years after discharge. We examined demographics, baseline EEG abnormalities, and outcome of treatment interventions. We als o evaluated whether interventions were more likely to succeed if patients w ere diagnosed early in the course of the illness. Results: We found that the largest groups consisted of patients with motion less unresponsiveness ("catatonic," n = 19) and asynchronous motor movement s with impaired responsiveness ("thrashing," n = 19), Infrequent signs incl uded tremor, automatisms, subjective events with amnesia, and intermittent behaviors. There was a higher incidence of baseline EEG abnormalities in th e thrashing group (31%) than in the catatonic group (0%). There was a highe r incidence of complete remission of spells in the catatonic group (53%) th an in the thrashing group (21%). Patients who had a more recent onset of se izures (most often within 1 year) were much more likely to have remission o f spells after diagnosis. Conclusions: Classification of nonepileptic seizures is useful in predictin g outcome and may be valuable in further investigation of this complex set of disorders.