Long-term video-EEG monitoring revisited. The value of interictal and ictal video-EEG recording, a follow-up study.

Between October 1990 and November 1992, 100 patients were monitored at the University of Gent Epilepsy Monitoring Unit. Sixty-three patients were referred for refractory epilepsy, 38 of whom were entered in the epilepsy surgery protocol. Thirty-seven patients were evaluated for the diagnosis of attacks of uncertain origin. Average duration of monitoring was 3.5 days (2-15 days). Prolonged interictal EEG was recorded in all patients. Ictal EEG was obtained in 63 patients; the average number of recorded episodes was 3 (1-15). Pre-monitoring tentative seizure diagnosis was available in 81 patients, 59 of whom had clinical attacks. Premonitoring diagnosis was confirmed in 31 patients and revised in 28 patients. As a result of the monitoring session, anticonvulsant medication was started in 10 patients, changed in 47, stopped in 5 and left unchanged in 23 patients. Twelve patients underwent surgery. Average follow-up after monitoring was 17 months (4-30 months). Four patients were lost to follow-up; 2 patients died of an underlying disease. In the nonsurgical group (85 patients), 60 patients became seizure-free or experienced significant reduction in seizure frequency. Outcome was unrelated to the availability of ictal recording. While prolonged interictal EEG monitoring is mandatory in the successful management of patients with refractory epilepsy, ictal video-EEG monitoring is very helpful but not indispensable, except in patients enrolled for epilepsy surgery or suspected of having pseudoseizures.