Predictors of Surgical Failure in Pediatric Lesional Temporal Lobe Epilepsy Surgery

Abstract

Background: Epilepsy surgery can potentially cure pharmacoresistant temporal lobe epilepsy (TLE) in children. However, surgical failures, where patients continue to experience seizures, still exist. We evaluated outcomes in pediatric patients after resective temporal lobe surgery to identify risk factors for failure.

Methods: Data on pediatric patients with TLE who underwent surgery were prospectively collected at our institution. Minimum follow-up (FU) was three years after surgery. Resections were stratified into extended resections, i.e., anterior temporal lobectomies, and sparing resections, i.e., lesionectomies and selective amygdalohippocampectomies. Ongoing seizures and relapses within the first three years were considered surgical failures.

Results: We included 96 patients after 43 sparing and 52 extended resections from 1993 to 2019 with a median FU of 10.1 years (range 3.0 to 28.3 years). Pathohistology most frequently revealed epilepsy-associated tumors (44.8%), hippocampal sclerosis (37.5%), and focal cortical dysplasias (12.5%). One year postoperatively, 69.8% were seizure free, increasing to 78.5% after five and 72.9% after 10 years. Sparing resections increased the odds for surgical failure in a multivariate analysis (odds ratio: 4.63, P = 0.006). Preoperative focal onset to bilateral tonic-clonic seizures increased the likelihood of seizure relapses (hazard ratio: 3.89, P = 0.006) and contributed to higher odds of surgical failure (odds ratio: 2.79, P = 0.002).

Conclusions: Pediatric patients with TLE undergoing surgery have high rates of long-lasting favorable seizure outcomes. Resection strategy is a prognostic factor for early surgical success in favor of larger resections. Relapses were more frequent in children with focal onset to bilateral tonic-clonic seizures beforesurgery.

Keywords: Epilepsy surgery; Long-term outcome; Pediatric epilepsy; Temporal lobe epilepsy.