Abstracts

Rationale: Children with epilepsy have been found to have cognitive impairment early in the course of their disease. Cognitive morbidity is often under-recognized in clinical settings and thus represents a missed opportunity for obtaining special educational services and remediation early in the course of epilepsy. Utilizing computerized testing could potentially identify those at risk and who would benefit from more extensive neuropsychological testing. Our hypothesis was that a computerized test battery would detect impairments in executive function in a cohort of patients with epilepsy with well-controlled disease compared to typically developing youth.Methods: Participants were thirty-nine non-lesional, medically treated pediatric epilepsy patients with normal IQ, ages 8-17 years, and individually matched community controls. All patients had normal neurological examinations and no MRI findings to account for seizures. Participants completed cognitive testing including the Cambridge Neuropsychological Test Automated Battery (CANTAB). Participants performed the following tasks: motor latency, delayed visual memory, sequence recall, and planning.Results: Average age for all participants was 12.45 years ( 2.55). Mean duration of epilepsy for the patient group was 3.67 years (SD 2.83). The majority of patients were on monotherapy and 40 percent of the cohort had less than 5 lifetime seizures including patients with partial (n=23) and generalized onset (n=16) epilepsy. There was no significant group difference for the motor latency and planning task. The epilepsy group showed impaired performance in the delayed visual memory and sequence recall tasks (t (76) = 3.42, p .001, t (76) = 3.40, p .001). However, epilepsy subtype, ADHD comorbidity, disease duration, antiepilepsy medication effects, and IQ did not predict patient performance. There was a modest association in the patient group between nonverbal IQ measures and sequence memory performance. Although there was no significant age by group interaction, performance lags in patients were more marked at older ages compared to younger ages. Strategy formation was more common in the patient group compared to controls for the delayed visual memory and sequence recall tasks.Conclusions: Computerized cognitive testing in epilepsy patients is well tolerated and detects impaired performance on delayed visual recognition and sequence recall which was not predicted by clinical factors, medication, or comorbidity. A greater degree of impairment was found in older youth, suggesting that executive skills undergoing maturation during this stage of development may be particularly vulnerable to epilepsy-mediated effects. While strategy formation was common in patients, helping patients develop more effective techniques may optimize functioning in academic settings. Impairment at older ages warrants further investigation into the developmental consequences of epilepsy during adolescence and impact on longer term outcomes.