271 A Retrospective, Chart Review Study of the Efficacy and Safety of the RNS System in Pediatric Populations for Medically Refractory Focal Epilepsy

Abstract

INTRODUCTION: The Responsive Neurostimulation System (RNS) (NeuroPace, Mountain View) is a direct intracranial neurostimulator that is FDA-approved for adults with medically refractory focal epilepsy. There currently exists limited data regarding its efficacy and safety in pediatric populations. METHODS: A retrospective chart review was conducted of pediatric patients treated with the RNS System between January 1, 2019 and December 31, 2021 at Rady Children’s Hospital for at least one year. Data collected included percent change in median disabling seizure frequency from baseline at years 1, 2, and 3, as well as device-related serious adverse events. RESULTS: Twenty patients with medically refractory focal epilepsy were identified who had been treated with the RNS System for at least one year. Median duration of follow-up was 24 months (interquartile range [IQR]: 15-35 months) The median percent reduction in disabling seizures was 29% (N = 20, IQR = 0-84%) at 1 year, 53% (N = 12, IQR = -5-81%) at 2 years, and 67% (N = 4, IQR = 25-100%) at 3 years. 40% of patients reported a >90% reduction in median disabling seizure frequency, and 25% were seizure-free at last follow-up. Reductions in median seizure frequency were comparable based on patient age, age at seizure onset, neuroimaging findings, and prior intracranial monitoring. Zero patients experienced implant site infections. One patient (5%) required lead revision, and another patient (5%) had a spontaneous intraparenchymal hemorrhage at the generator site 2 years after implantation that resolved with expectant management. Neither of these events were associated with long-lasting neurological complications. CONCLUSIONS: The RNS System is a safe and efficacious treatment for pediatric patients with medically refractory focal epilepsy.