Abstracts

Differential engagement of the neural network for language tasks in epilepsy patients as compared to normal controls is associated with adaptive changes in language representation due to disease effects. To investigate differences in activation between epilepsy patients and controls using an fMRI category decision task., We studied 16 patients (11 Males; age 6-12) and 16 age and gender matched healthy controls (all right handed), using whole brain 3T fMRI (EPI BOLD) and an auditory category decision task [ndash] press button if word belongs to category-- employing a box car design. Data was analyzed with SPM2. Performance data was analyzed using independent t-tests. Patient activation patterns were also compared against a larger normative dataset that includes 52 (30 Males; age 4-12 years) healthy volunteers., Random effects group analysis revealed no consistent pattern of activation for patients at a strict threshold. In contrast, matched controls showed medial superior frontal gyrus (SFG) and left-lateralized inferior frontal gyrus (IFG) activation (FWE corrected, p = .05). Due to the variability within the patient group, no significant group differences were detected with a two sample t-test. However, on individual visual inspection, patients showed significantly more (X² = 11.22, p[lt].01) bilateral and temporal activation (15/16, (93.75%)) compared to controls (6/16(37.5%)). Task performance was comparable for accuracy (Patient Mean = 75%, Normal Mean = 77%, p=.76) and reaction time (Patient Mean = 1099ms, Normal Mean = 1123ms, p=.48). Comparison to normative data revealed that patients[apos] activation patterns were similar to younger age group maps that showed greater bilateral (ages 7-9 normative group map) and temporal activation (ages 4-6 normative group map)., Pediatric epilepsy patients engage more of the language neural network than normal controls to perform the task with comparable speed and accuracy. These patterns of activation are similar to patterns seen in younger normal individuals, which suggest that epilepsy patients persist in utilizing a functionally immature network., (Supported by R01 NS44280 NINDS.)