Spikes immediately after electroconvulsive therapy in psychotic patients.

The goal of this study was to assess the spikes systematically and to clarify an epileptc abnormality induced by electroconvulsive therapy (ECT). Our subjects were 20 psychotic patients with no spikes on prior EEGs. ECT was performed by applying electrical current to both sides of the patient's temple every 2 or 3 days for a period of between 1-4 weeks. The first EEG examination was performed either on the day that the ECT course was completed or on the following day. Subsequent EEG examinations were performed at intervals of 2 or 3 days. Thirteen of the 20 patients showed spikes. There were no significant differences in age, gender, diagnosis, or type of ECT. Patients with spikes had significantly more ECT sessions than those without spikes. The spikes were present in the frontal, temporal and central areas, predominantly frontal, anterior temporal and mid-temporal region, and almost disappeared in 1-3 weeks. The occurrence of spikes immediately after ECT was demonstrated. Although this abnormality was transient, it could indicate that in humans ECT causes the early stage of kindling phenomenon as a result of repeated application, and that the temporal lobe seems to play a major role in order to induce the phenomenon.