Outcome of lesionectomy in medically refractory epilepsy due to non-mesial temporal sclerosis (non-MTS) lesions

ObjectivesTo analyze the seizure outcome of lesionectomy for refractory epilepsy secondary to non-mesial temporal sclerosis (non-MTS) lesions.MethodsSixty-eight patients with non-MTS lesions (M:F = 42:26; age at onset: 11.7 ± 9.6 years; age at surgery: 21.1 ± 9.4 years), who underwent lesionectomy for refractory epilepsy were analyzed. The age at onset, frequency/type of seizure, MRI findings, video-EEG, histopathology and Engel's grading at 1 year/last follow up were recorded.ResultsThe duration of epilepsy at surgery was 9.9 ± 6.9 years. The location of lesions were: temporal: 41 (60.3%); frontal: 21 (30.9%); parietal: 6 (8.8%). The type of lesionectomies performed were temporal 41 (60.3%), extra-temporal: 25 (36.8%), temporo-frontal and temporo-parietal: 1 (1.5%) patient each. The histopathological diagnosis were neoplastic: 32 (47.1%), cortical dysplasia: 19 (27.9%), other focal lesions: 17 (25%). At mean follow up of 2.9 ± 2.1 years (median: 2.6 years), outcome was – Engel's class I: 43 (63.2%), IIa: 14 (20.6%), III: 7 (10.3%), IV: 4 (5.9%). Good seizure control (Engel's class I/IIa) was achieved in 57 (83.8%) patients. The good prognostic markers included temporal seizures, extended lesionectomy and AEDs after surgery while poor prognostic marker was gliotic lesion on histopathology.ConclusionFollowing lesionectomy due to non-MTS lesions, seizure freedom (Engel I) was noted in about 63.2% of patients, which is comparable to other series and reiterates the effectiveness of lesionectomy for seizure control.