Predictors of postoperative long-term seizure outcome in pediatric patients with focal cortical dysplasia type II at a German tertiary epilepsy center

Abstract

OBJECTIVE Focal cortical dysplasia (FCD) is a common cause of early-onset intractable epilepsy, and resection is a highly sufficient treatment option. In this study, the authors aimed to provide a retrospective analysis of pre- and postoperative factors and their impact on postoperative long-term seizure outcome. METHODS The postoperative seizure outcomes of 50 patients with a mean age of 8 ± 4.49 years and histologically proven FCD type II were retrospectively analyzed. Furthermore, pre- and postoperative predictors of long-term seizure freedom were assessed. The seizure outcome was evaluated based on the International League Against Epilepsy (ILAE) classification. RESULTS Complete resection of FCD according to MRI criteria was achieved in 74% (n = 37) of patients. ILAE class 1 at the last follow-up was achieved in 76% (n = 38) of patients. A reduction of antiepileptic drugs (AEDs) to monotherapy or complete withdrawal was achieved in 60% (n = 30) of patients. Twelve patients (24%) had a late seizure recurrence, 50% (n = 6) of which occurred after reduction of AEDs. A lower number of AEDs prior to surgery significantly predicted a favorable seizure outcome (p = 0.013, HR 7.63). Furthermore, younger age at the time of surgery, shorter duration of epilepsy prior to surgery, and complete resection were positive predictors for long-term seizure freedom. CONCLUSIONS The duration of epilepsy, completeness of resection, number of AEDs prior to surgery, and younger age at the time of surgery served as predictors of postoperative long-term seizure outcome, and, as such, may improve clinical practice when selecting and counseling appropriate candidates for resective epilepsy surgery. The study results also underscored that epilepsy surgery should be considered early in the disease course of pediatric patients with FCD type II.