Abstracts

Rationale: While the co-existence of psychiatric comorbidity in pediatric epilepsy has been described in the literature, the link between brain function and psychiatric comorbidity has not been well studied. These results are from an ongoing prospective, cross sectional study of well-characterized medically treated pediatric epilepsy patients and matched controls performing a battery of neurocognitive tests including tasks of executive function, behavioral assessment, and structural and functional magnetic resonance imaging. Methods: We report results from 26 pairs of pediatric epilepsy patients and age and gender matched control subjects (n=52). Average age of the children was 12.3 years (SD 2.97), and gender was 42% female. Mean IQ of the patient group was 97.9(SD 11.7) and mean duration of disease was 3.5 years. Patients were on no more than two anti epilepsy medications. Epilepsy type in the patient group included complex partial (n=19), primary generalized (n=4), simple partial (n=1) and benign focal epilepsy (n=2). Control subjects’ mean IQ was 108 (SD 12.2, p<0.01 compared to patient group), and all control subjects were free of psychiatric diagnoses and had no history of neurological disorders. Participants performed oculomotor tasks that measured sensorimotor control (visually guided saccade task), response inhibition (antisaccade) and spatial working memory (oculomotor delayed response task). Comprehensive psychiatric assessment including a diagnostic psychiatric interview (KSADs -PL) and the Behavior Rating Inventory of Executive Function (BRIEF). A subset of the cohort underwent whole brain fMRI scanning on a 3T magnet and completed an antisaccade task and DTI scanning. Results: The rate of psychiatric diagnoses in the epilepsy patient group was elevated at 57% including attention deficit disorder (n=10) and anxiety and/or depression (n=5) and conduct disorder (n=1). Results indicate similar performance for controls and epilepsy groups in both the VGS and ODR tasks but impaired performance in the AS task. These results indicate intact basic sensorimotor function and working memory aspects of executive function but impaired response inhibition. General executive performance in the BRIEF was related to the incidence of having psychiatric comorbidity. Functional imaging (fMRI and DTI) results will also be discussed. Conclusions: The results of this ongoing study indicate a neurobiologically linked relationship between executive functioning and psychiatric comorbidity in pediatric epilepsy patients. Further neuroimaging studies will elucidate brain circuitry that may be vulnerable to epilepsy mediated effects.