RESECTIVE SURGERY FOR MEDICALLY INTRACTABLE EPILEPSY ASSOCIATED WITH SCHIZENCEPHALY

Four adults with unilateral (three cases) or bilateral (one case) closed schizencephaly, medically intractable epilepsy, and otherwise normal neurological examinations are presented. Three were examined preoperatively with magnetic resonance imaging and one with computerized tomography. Scalp electroencephalographic (EEG) studies in all four patients and electrocorticography via intracranial electrodes in two showed seizure origin in the cleft regions in two patients and in the ipsilateral temporal lobe in the other two. Temporal lobectomy was performed in the two patients with temporal lobe foci. Resection of superficial pachygyria around the cleft was performed in one patient. The authors conclude that the abnormal cortical mantle lining schizencephalic clefts may be epileptogenic. Alternatively, temporal allocortex may become the source of seizures. Therefore, these patients require careful EEG monitoring of the entire ipsilateral hemisphere as well as the cleft region.