Altered seizure patterns after temporal lobectomy

Purpose: We compared features of seizures occurring after temporal lobectomy with those of preoperative seizures in the same patients to determine whether aspects of postoperative partial seizures presage ultimate seizure control. Methods: Seizure descriptions of 100 consecutive patients who underwent anterior temporal lobectomy (ATL) were obtained by our epileptologists before and after surgery. Follow-up for seizure control for all patients was obtained for a median of 5.5 years. Results: Twenty-six of the 100 patients had at least one diurnal complex partial seizure (CPS) after lobectomy. The proportion of patients with an aura for their CPS decreased from 86% preoperatively to 58% postoperatively. Fifty-five percent had two or more aura features before surgery, as compared with 31% after lobectomy. Eleven of 18 (61%) with fewer than two postoperative aura features, as compared with 2 of 8 (25%) with two or more aura features ultimately had >90% seizure reduction postoperatively. Nineteen (95%) of 20 patients with only simple partial seizures (SPS) postoperatively ultimately obtained greater than or equal to 90% reduction, and 7 (35%) of them became seizure-free. Although generalized tonic-clonic seizures (GTCS) decreased from 70% to 39% after lobectomy, 7 (23%) of 30 patients who had not had GTCS preoperatively had at least one after lobectomy, usually while receiving a lesser amount of antiepileptic drug (AED) therapy. Among the 27 patients with residual CPS, ultimate outcome was better among patients with removal of >6 cm as measured along the inferior temporal gyrus than among those with less extensive resections. Conclusions: In addition to eliminating or reducing the frequency of temporal lobe seizures, lobectomy may simplify or eliminate the aura features of residual CPS. The number of CPS aura features correlated inversely with ultimate postoperative seizure reduction. Ultimate seizure control among patients with only SPS was better than that of patients with CPS postoperatively. First-ever GTCS may occur when AED dosages are reduced after surgery.