Outcome of surgery for temporal lobe epilepsy in adults – A cohort study

INTRODUCTION: The aim of the current study was to evaluate the factors associated with post-operative outcome in patients with temporal lobe epilepsy (TLE) undergoing Surgery. METHODS: We analyzed data of 288 consecutive patients operated for drug-resistant TLE. All the patients had at least one year post surgery follow-up. Logistic regression model was used to evaluate the predictive value of different factors for outcome. RESULTS: The mean age at onset of epilepsy of the study population was 15.51 ± 9.79 years; whereas the mean age at surgery was 32.16 ± 9.45 years, with 125 (43.4%) women. The age at surgery was significantly lower in the patients with favourable outcome (30.26 ± 9.05 vs. 34.06 ± 9.85 years; p = 0.007). The mean duration of epilepsy with age of onset below 12 years was higher than the rest (19.84 ± 7.30 vs. 13.00 ± 8.45 years; p < 0.001). The histopathology showed hippocampal sclerosis in 203 (70.4%) of the patients; isolated focal cortical dysplasia was associated with unfavourable outcome (9.3% vs.2.6%; p = 0.036). The duration of follow up ranged from 1 to 10.3 years. Three patients died late in the follow up. At the last follow 73% were seizure free and Engel's favourable outcome was noted in 82%. Duration of epilepsy greater than ten years (β = 6.997; 95%CI; 2.254-21.715; p = 0.01), younger age of onset of epilepsy (β = 1.07; 95%CI; 1.014-1.132; p = 0.015) and acute post operative seizures (APOS) (β = 4.761; 95%CI; 1.946-11.649; p = 0.001) were the predictors of unfavourable outcome. CONCLUSION: Following surgery for TLE, 73% were seizure free and Engel's favourable outcome was noted in 82%. The predictors of unfavourable outcome were younger age of onset, pronged duration and of epilepsy and APOS.