Outcomes of Early-Life Focal Cortical Dysplasia–Related Epilepsy

Abstract

Background and Objectives – Focal cortical dysplasia (FCD) is the most common cause of surgically treatable drug-resistant epilepsy (DRE) in children. Surgical outcomes are poorly defined in early-onset FCD-DRE. The purpose of this study was to evaluate clinical and presurgical characteristics relating to surgical outcomes in early-life (seizure onset <4 months old) FCD-DRE.Methods – A multicenter prospective cohort was analyzed from the Pediatric Epilepsy Research Consortium (PERC) Surgery Database to identify patients with pathologically confirmed FCD-DRE and seizure onset younger than 4 months old. Clinical characteristics, presurgical workup, and surgical intervention and outcomes data were collected and analyzed. Primary outcome was to evaluate whether earlier surgery is associated with seizure freedom; secondary outcomes evaluated clinical/presurgical predictors of seizure freedom and safety.Results – Thirty-one patients with FCD-DRE were identified from 18 PERC centers. Median age at seizure onset was 2.4 months (interquartile range 1.2–3.6 months). Four patients had focal to bilateral tonic-clonic seizures (FBTCS); 35% (n = 11) had epileptic spasms. Median age at phase 1 referral was 2.0 years (0.7–4.0 years). Median age at surgery was 2.6 years (1.1–5.5 years). Pathology was type II, 65% (n = 20); type I, 26% (n = 8); and type III, 6% (n = 2). Seizure freedom was achieved in 65% (n = 20) with median follow-up 2.5 years (1.3-4 years). Age at seizure onset/referral/surgery, surgery type, and experiencing FBTCS were not associated with seizure-free outcome. Type IIB pathology had 89% (n = 8) seizure-free outcome. Epileptic spasms had 45% seizure-free outcome. Transient neurologic deficits occurred in 2 patients, and an expected neurologic deficit in 1 (visual field cut from occipital lobectomy). There were no deaths.Discussion – This study finds high rates of seizure-free outcome in epilepsy surgery for early-onset FCD-DRE across all pathologies and procedures with minimal complication rates and no deaths. Focal cortical dysplasia type IIB is associated with very high rates of seizure-free outcome. Epileptic spasms were associated with lower seizure-free outcome. The study also fails to confirm a high rate of multilobar unilateral hypoplasia with severe epilepsy in children, a type I FCD variant that has been reported as a common etiology of early-life FCD.