Abstracts

Rationale: The Pediatric Epilepsy Research Consortium (PERC) is a network of US pediatric epilepsy centers that facilitates collaborative research to improve the care of children with epilepsy. The Epilepsy Surgery Subgroup was formed in 2018 to characterize the use of pediatric epilepsy surgery in the US and define current practices for candidate selection and treatment. We demonstrate the feasibility of a multicenter collaboration and report the sociodemographic and epilepsy characteristics of children presenting for epilepsy surgery evaluation in the initial interim analysis. Methods: Patients 0-18 years of age undergoing epilepsy surgery evaluation at 13 actively enrolling pediatric epilepsy centers were prospectively enrolled in a shared REDCap database. Predefined variables collected included demographics, epilepsy characteristics, presurgical treatment, evaluation, surgical therapy, and outcome of epilepsy surgery. Data was analyzed from project inception (1/1/18) to 4/30/19. Descriptive analysis of overall data was collected: sociodemographic information (insurance type, race, and ethnicity), epilepsy characteristics, and initial phase I results. Results: Two hundred forty-eight patients began evaluation for epilepsy surgery. Patients referred were more commonly Caucasian (69.7%), non-Hispanic (82.4%), with private insurance (58.6%). Most referrals came directly from the pediatric epileptologist (65.6%) or general pediatric neurologist (27.9%). Most children had early onset epilepsy, with seizure onset at less than or equal to 3 years of age in 47%, and between 3 to 8 years of age in 26%. Median time from age of onset to referral was 4 years. 13% had epilepsy for more than ten years before referral. Half had multiple seizure types (40.7% with 2 seizure types; 9% with 3 or more seizure types). The mean and median number of ASMs (anti-seizure medications) failed at the time of referral was three. Most patients were on two or more ASMs at the time of phase I evaluation (78.9%). Prior nonpharmacologic epilepsy treatments included VNS (5%), dietary therapy (8.5%), and others (9.3%: cannabidiol, resective surgery, thermal ablation, corpus callosotomy, immunotherapy, neuromodulation). The most common etiology of epilepsy was structural (congenital 36%, acquired 26%), though with unknown causes comprising 28%.At the time of interim analysis, video EEG monitoring results were available for 237 patients. Seizure onset was focal (62%), multifocal (17.3%), generalized (9.6%), and mixed generalized/focal or indeterminate (11%). Of 236 patients in whom MRI brain results were available, MRI abnormality was present in 171 patients (72%), with abnormality congruent with EEG in 77.8% of patients. Conclusions: Children with medically refractory epilepsy were enrolled in a shared database, demonstrating the feasibility of common data elements across 13 epilepsy centers in the US. This cross-sectional cohort of patients referred for epilepsy surgery evaluation demonstrates that candidates are disproportionally Caucasian, non-Hispanic, and with private insurance. Despite meeting criteria for intractable epilepsy, there remains a delay to referral and evaluation for surgical intervention for children. Early onset epilepsy was common, and about half of the patients had multiple seizure types. Evaluations are ongoing for many patients included in this study, but video EEG and MRI are components of nearly every evaluation and the majority demonstrate structural abnormalities consistent with EEG abnormalities. These and additional children will continue to be followed through the epilepsy surgery evaluation process, in order to identify and address best practices for the use of epilepsy surgery in children. Funding: No funding