Predictors and Long-term Outcome of Resective Epilepsy Surgery in Patients with Tuberous Sclerosis Complex: A Single-centre Retrospective Cohort Study

ABSTRACT Objective : To identify prognostic factors and long-term seizure outcomes for patients with tuberous sclerosis complex (TSC) who underwent resective treatment for epilepsy. Methods : We enrolled 81 patients with TSC who had undergone resective epilepsy surgery at Sanbo Brain Hospital, Capital Medical University, between April 2004 and June 2019. We analysed the proportion of time to seizure-freedom and plotted survival curves. Variables were compared using Mann–Whitney U, Pearson's correlation, continuity correction, and Fisher's exact chi-square tests. Prognostic predictors were analysed using log-rank (Mantel–Cox) tests and Cox regression models. Results : At the last follow-up, 48 (59.3%) patients were classified as International League Against Epilepsy Class 1 (including 14 patients who had a seizure >3 times postoperatively on the same or different day and were seizure-free at all other times). The estimated cumulative proportion of time to seizure-freedom postoperatively was 69.0% (95% confidence interval [CI] 58.8–79.2%), 61.9% (95% CI 51.1–72.7%), and 55.0% (95% CI 42.8–67.2%) at 2, 5, and 10 years, respectively. The mean time to seizure freedom was 7.24 ± 0.634 years (95% CI 6.00–8.49); en bloc resection was an essential positive predictor of postoperative seizure freedom, as was age at seizure onset, regional interictal video-electroencephalography pattern, and temporal lobe surgery. The longer the seizure-free time, the less likely a relapse. Patients who postoperatively experienced seizures remained likely to recover. Conclusions : We demonstrated the efficacy of surgical treatment for patients with TSC and intractable epilepsy. Detailed perioperative tests are a reliable predictor of postoperative seizure freedom.