Induction of partial epileptic seizures by flumazenil

Purpose: This study addressed the efficacy of flumazenil (FMZ) to induce or activate interictal or ictal epileptic discharges in patients with medical ly intractable partial epilepsies. Methods: Flumazenil, 1 mg, was injected intravenously in 67 patients underg oing presurgical monitoring for epilepsy surgery, 49 of whom had been treat ed with benzodiazepines (BZDs) before flumazenil was given. Continuous vide o electroencephalogram (EEG) monitoring with surface or intracranial electr odes was used to evaluate interictal EEG activity, ictal discharges, and th e occurrence and semiology of clinically manifest epileptic seizures. Results: Interictal epileptiform potentials did not change in frequency or distribution after FMZ. In patients not pretreated with BZDs, epileptic sei zures could not be provoked. In eight of the 49 patients pretreated with BZ Ds, epileptic seizures occurred within 30 min of FMZ application. Seizure s emiology and regional EEG onset were identical to seizures recorded without FMZ. Patients operated on according to seizure-onset localization with FMZ had a >75% reduction in seizure frequency or became seizure free. Conclusions: Seizure induction by FMZ seems to be a valid method for evalua ting seizure semiology and localization of the seizure-onset zone during pr esurgical monitoring of patients with medically intractable localization-re lated epilepsies.