Lateral extratemporal resections in adults.

The presurgical evaluation in cases of extratemporal epilepsy is much less stereotypic than it is for mesial temporal lobe epilepsy. The finding of even a tiny structural lesion may be relevant but needs verification that it matches the seizure onset zone. Often invasive analysis is necessary to produce such evidence and to assess the relationship to adjacent eloquent cortex. Invasive analysis exposes the patient to an additional surgical procedure and to the morbidity associated with it. Therapeutic resections may comprise lesionectomy, topectomy, or lobectomy. Epileptogenic cortex that coincides with indispensable eloquent cortex can be treated with multiple subpial transections. A large variety of lesions may be epileptogenic, ranging from posttraumatic gliosis, over dysplasias and vascular malformations, to low-grade tumors. Intraoperative monitoring of adjacent brain functions under anesthesia or awake surgery may be used. Unless a circumscribed lesionectomy is possible, results in extratemporal epilepsy tend to be less favorable than in mesial temporal lobe epilepsy.