Cortical Thickness and Executive Functioning in Children with New Onset Epilepsy and Co-morbid Attention-Deficit/Hyperactivity Disorder

Epilepsy is a debilitating neurological disorder that impacts both adults and children. Although there is extensive research in the adult literature, its pediatric counterpart does not have the same depth of study. In addition, ADHD comorbidity is far more common in children with epilepsy. In the literature, these subjects are often combined or eliminated from the data. Neurological development and cognitive functioning were of interest in this study, particularly cortical thickness development and executive functioning in children recently diagnosed with epilepsy in the past 12 months. Children with epilepsy, children with epilepsy/comorbid ADHD, and healthy controls were compared on performance on four cognitive measures and select subtests of attention, intelligence, and executive functioning and cortical thickness development at baseline and two year follow up. Results revealed significantly decreased maximum cortical thickness at time of onset in both epilepsy groups compared to healthy controls, but little difference between the two patient groups. Cognitive performance on intelligence indicates that the epilepsy only group and healthy controls were not significantly different, but both performed better than the comorbid group. On measures of executive functioning there was a step-wise pattern in which healthy controls were significantly better than the epilepsy only group, which was significantly better than the comorbid group. Longitudinally, the cortical thickness analyses revealed a consistent trend of marginal main effects of group, but not as robust a difference at follow-up compared to baseline. On 13 of the 14 cognitive subtests analyzed, there were similar significant step-wise pattern of differences as with the executive functioning measures at baseline.