Improvement of Tuberous Sclerosis Epilepsy Outcomes via Resection of Symptomatic Tuber Plus Adjacent Zone
Tuberous sclerosis complex (TSC) is a frequent etiology for childhood epilepsy surgery evaluation. A retrospective, multicenter cohort, including 78 patients from 6 centers in the United States and Canada was studied to identify predictors of seizure outcome in children with TSC and intractable epilepsy who underwent resective epilepsy surgery. The authors utilized a time-to-event (TTE) measure, rather than a dichotomous outcome for seizure freedom, to increase sample size, control for follow-up variation, and place a positive value on delay in seizure recurrence. Univariate analysis of variables identified from previous meta-analyses and from expert opinion identified younger age at seizure onset, resection larger than tuberectomy, and larger predominant tuber size as factors predicting longer duration of seizure freedom. Multivariate analysis identified only resection larger than tuberectomy as an independent predictor of outcome. This is the largest multi-institutional cohort study to evaluate epilepsy surgery in TSC, and provides further evidence that the epileptogenic zone includes the area around the tuber. The statistically powerful TTE model provides strong justification for future studies.