Surgical Strategies in Patients with the Supplementary Sensorimotor Area Seizure

ABSTRACT

OBJECTIVE: This study was designed to analyze surgical strategies for patients with intractable supplementary sensorimotor area(SSMA) seizures. METHODS: Seventeen patients who had surgical treatment were reviewed retrospectively. Preoperatively, phase I (non-invasive) and phase II (invasive) evaluation methods for epilepsy surgery were done. Seizure outcome was assessed with Engel's classification. The mean follow-up period was 27.2 months (from 12 months to 54 months). RESULTS: An MRI identified structural abnormality in eight patients and 3D-surface rendering revealed abnormal gyration in three. PET, SPECT, and surface EEG could not delineate the epileptogenic zone. Video-EEG monitoring with a subdural grid or depth electrodes verified the epileptogenic zone in all patients. Surgical procedures consisted of a resection of the SSMA and simultaneous callosotomy in two patients, a resection of the SSMA extending to the adjacent area in seven, a resection of a different area without a SSMA resection in seven, and a callosotomy in one. Seizure outcomes were class I in 11 (65%), class II in five (29%), class III in one (6%). CONCLUSION: In patients with intractable SSMA seizure, surgery was an excellent treatment modality. Precise delineation of the epileptogenic zone based on multimodal diagnostic methods can provide good surgical outcomes without neurological complications.