Abstracts

Rationale: Focal cortical dysplasia (FCD) is a common etiology of intractable pediatric epilepsy often requiring surgical resection. Prior studies have only reported outcome based on intelligence (IQ) and adaptive functioning in relatively small samples. Furthermore, outcome data for FCD subtypes based on the more recent ILAE classification scheme (Blümcke et al.,2011) is lacking. The current study extends previous research by investigating neuropsychological outcome in a comprehensive manner in a cohort of 51 children with FCD, broken down by subtype, who underwent unilateral surgical resection for intractable epilepsy. Methods: 51 children and adolescents with FCD were evaluated pre- and post-surgically (mean age at surgery = 11.1 (5.3) years; mean age at seizure onset = 4.4 (4.7) years). Multiple neuropsychological domains were assessed, including IQ, academics, language, visual-motor, memory, attention, executive function, motor, and psychosocial functioning. We compared outcome to normative data for the whole sample, as well as by FCD subtype (I, II, and III). Effects of lateralization, age at onset, history of status epilepticus, and seizure outcome were also investigated. Results: Average interval between pre- and post-surgery testing was 1.5 years, and 55% of the sample was seizure free at follow-up. Our sample performed significantly worse than the normative population across all domains at baseline and at follow-up (all p-values < .05). Change over time, assessed using repeated measures Anova's, indicated a decrement in visual-motor integration skills post-surgery (p < .05), regardless of side of surgery. Literacy outcome, memory recall, and right-sided motor function interacted significantly with side of surgery (all p-values < .05), with children undergoing a left resection faring worse. There were no differences in outcomes by FCD subtype across any of the neuropsychological domains. Seizure freedom post-surgery was not associated with outcome, but those children with a history of status epilepticus had worse memory discriminability (p < .05) and a trend toward worse language outcome (p = .06). Conclusions: Children with FCD who undergo resection for intractable epilepsy have deficits in multiple neuropsychological domains, not just IQ and adaptive functioning, as previously reported in the literature. Furthermore, they are at increased risk for additional deficits post-surgery in the visual-motor domain, regardless of side of resection, and at increased risk for literacy and memory deficits with dominant hemisphere resection. Similar levels of dysfunction were seen across FCD subtypes, although results should be considered preliminary due to the smaller subgroup sample sizes. Comprehensive neuropsychological assessment post-surgery is indicated given continuity of deficits across areas regardless of seizure status. These data can be used to manage treatment expectations and tailor rehabilitative recommendations.