The value of closely spaced scalp electrodes in the localization of epileptiform foci: a study of 26 patients with complex partial seizures.

Twenty-seven patients with complex partial seizures were studied electrographically utilizing a large number of closely spaced scalp electrodes around the epileptogenic focus. Skull roentgenograms were made with the electrodes in place in order to relate the electrode positions to underlying brain anatomy. Field distribution maps were constructed from reference montages employing the closely spaced electrode set. Electrodes other than 10-20 were maximal most often and the single electrodes most often maximal were D9-D10, anterior temporal in location. This method of localization is of help in the evaluation of patients with complex partial seizures who may be surgical candidates.