A Critical Analysis of Electrocorticography in Temporal Lobe Epilepsy

Introduction That the changes in potential picked up by scalp, ear, pharyngeal, or sphenoidal electrodes do not adequately sample the intrinsic activity of the temporal lobe has been well documented. For that reason, and because it was thought that direct recording from the cerebral cortex might indicate the limits of an adequate resection for psychomotor epilepsy, electrocorticography was introduced. Although much has been written about the findings, few critical analyses of its value have appeared. This report concerns the results of electrocorticography in patients with temporal lobe epilepsy studied with the purpose of evaluating the technique from the surgeon's viewpoint. Clinical Material The electrocorticographic studies were made upon a series of 30 patients undergoing an operation for psychomotor seizures. Because of technical difficulties—in either operating or recording—only 29 records, made on 27 patients, are suitable for study. In 20 cases the recordings were made with the patient conscious, the surgical