POSTICTAL PSYCHIATRIC EVENTS DURING PROLONGED VIDEO-ELECTROENCEPHALOGRAPHIC MONITORING STUDIES

Background: Postictal psychiatric events presenting as postictal psych otic events and postictal nonpsychotic events are known to occur follo wing seizure clusters. Accordingly, patients undergoing prolonged vide o-electroencephalographic (EEG) monitoring studies may be at increased risk of experiencing a postictal psychiatric event, as they often hav e hurries of seizures during these studies. Objectives: To determine t he annual incidence and clinical characteristics of postictal psychoti c events and postictal nonpsychotic events in video-EEG monitoring stu dies in patients with partial seizure disorders and to identify potent ial pathogenic factors. Results: Thirteen patients met the criteria fo r a postictal psychiatric event during the 18-month study period, 10 p resenting as postictal psychotic events and three as postictal nonpsyc hotic events. The annual incidence of postictal psychiatric events at our monitoring unit for 1988 was 7.8%, 6.4% presenting as postictal ps ychotic events and 1.4% as postictal nonpsychotic events. Seven patien ts had their first-ever postictal psychiatric event during the monitor ing study. In 12 of the 13 patients, the postictal psychiatric events mimicked well-defined psychiatric entities of shorter duration (mean, 66.5 hours); they appeared 12 to 72 hours after the last seizure and r emitted spontaneously or with the use of low-dose psychotropic medicat ion. No significant differences in EEG, neuroradiologic, psychiatric, medical, or psychosocial data were found between the patients with pos tictal psychiatric events and a group of 13 age-matched control patien ts. Follow-up data of comparable duration were available in nine patie nts with postictal psychiatric events and nine controls. Psychiatric e vents were reported more frequently by patients with postictal psychia tric events than by control patients (P=.03). In three patients, posti ctal psychiatric events converted to interictal events. Conclusion: Th ese findings suggest that monitoring studies increase the risk for pos tictal psychiatric events, which neurologists need to be familiar with , as they represent important morbidity associated with these studies.