Comparative effectiveness of sleep and metrazol-activated electroencephalography

Abstract

In 210 patients with various manifestations of epilepsy, 37 per cent whowed seizure discharges in the electroencephalograms recorded while awake. The use of sleep EEG increased the incidence of such discharges to 47 per cent. In the group of 102 patients who had normal or borderline electroencephalograms while awake, 15 (14.7 per cent) demonstrated seizure discharges during sleep. Sleep recording contributed most information in the group with psychomotor seizures, and was especially valuable in demonstrating anterior temporal spike foci in these patients. In 138 of the patients, the results of sleep and Metrazol-activated EEG were compared. There was a 33 per cent incidence of seizure discharges while awake. With sleep recording, the incidence was increased to 40 per cent and with Metrazol to 62 per cent. In almost all cases, seizure discharges recorded during sleep were also observed during Metrazol activation. Metrazol induced seizure discharges in the electroencephalograms of 35 (45 per cent) of the 77 patients with normal or borderline records while awake. Sleep was successful in only 10 patients (13 per cent) of this group. Metrazol was more effective than sleep in all clinical groups except for the group with psychomotor epilepsy. The focal character of the seizure discharges in the patients with psychomotor epilepsy was best demonstrated during the sleeping state.