ALTERED SEIZURE PATTERNS AFTER TEMPORAL LOBECTOMY

Purpose: We compared features of seizures occurring after temporal lob ectomy with those of preoperative seizures in the same patients to det ermine whether aspects of postoperative partial seizures presage ultim ate 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 seizur e control for all patients was obtained for a median of 5.5 years. Res ults: 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% postop eratively. Fifty-five percent had two or more aura features before sur gery, as compared with 31% after lobectomy. Eleven of 18 (61%) with fe wer 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 parti al seizures (SPS) postoperatively ultimately obtained greater than or equal to 90% reduction, and 7 (35%) of them became seizure-free. Altho ugh generalized tonic-clonic seizures (GTCS) decreased from 70% to 39% after lobectomy, 7 (23%) of 30 patients who had not had GTCS preopera tively had at least one after lobectomy, usually while receiving a les ser amount of antiepileptic drug (AED) therapy. Among the 27 patients with residual CPS, ultimate outcome was better among patients with rem oval of >6 cm as measured along the inferior temporal gyrus than among those with less extensive resections. Conclusions: In addition to eli minating or reducing the frequency of temporal lobe seizures, lobectom y may simplify or eliminate the aura features of residual CPS. The num ber of CPS aura features correlated inversely with ultimate postoperat ive seizure reduction. Ultimate seizure control among patients with on ly SPS was better than that of patients with CPS postoperatively. Firs t-ever GTCS may occur when AED dosages are reduced after surgery.