CORTICAL RESECTIONS FOR INTRACTABLE EPILEPSY OF EXTRATEMPORAL ORIGIN - EXPERIENCE WITH 17 CASES OVER 11 YEARS

Seventeen patients underwent surgery between 1981 and 1990 for intract able partial epilepsy arising outside the temporal lobe. Twelve had fr ontal seizure onset, two parietal, two occipital and one diffusely in the hemisphere. Localization was achieved using extraoperative electro corticography (ECoG) in five cases and intraoperative ECoG was employe d in 12. Fifteen patients underwent cortical resections, but two did n ot subsequently have a resection. Both of these had porencephalic cyst s. Of the 15 who had resections six (40%) were seizure free after a me an of 7.3 years. One (7%) was almost seizure free, six (40%) had worth while improvement. Pathological examination revealed oligodendroglioma in three, recurrent meningioma in one, vascular malformations in two, glial hamartoma in one and gliosis in six. One case with gliosis init ially was shown to have an underlying malignant astrocytoma 2 years la ter. All these patients had CT abnormalities prior to surgery. Two pat ients (13%) had no worthwhile improvement. Pathology in these two was ischaemic neurons and arachnoid thickening. Both had normal CT finding s preoperatively. One patient had an increased hemiparesis postoperati vely. There were three cases of postoperative infection. It is conclud ed that extratemporal resection can achieve good results for seizure c ontrol and intraoperative ECoG is an effective technique for localizin g the epileptogenic area. The presence of a structural lesion carries a particularly favourable prognosis for seizure outcome and surgery sh ould, therefore, be strongly considered in patients with intractable p artial epilepsy who have evidence of underlying structural pathology.