Abstracts

Rationale: Imaging studies of language in children with epilepsy report reduced and/or abnormal lateralization of language during silent verb generation tasks (Lilywhite et al., 2009; Yuan et al., 2006) and neuroradiological abnormalities in those with linguistic deficits (Byars et al., 2007). However, there have been no studies on language and subtle structural abnormalities, such as brain volumes, in medically treated children with epilepsy of average intelligence and no neuroradiological findings. Therefore, this study compared the relationship between language skill and fronto-temporal volumes in language-related regions in children with epilepsy with average IQ scores to those of normal children of comparable age and gender distribution. Methods: Age appropriate versions of the Test of Language Development (TOLD)-2 (Newcomer & Hammil, 1988) administered to 69 children with epilepsy and 34 normal children, aged 6.6-15.5 years, generated Spoken Language Scores (SLQ). Study subjects underwent brain magnetic resonance imaging (MRI) scans at 1.5 Tesla. Tissue was segmented and total brain, frontal lobe, frontal parcellations and temporal lobe volumes were computed. Results: ANCOVAs controlling for age, gender, and ethnicity demonstrated significantly lower mean SLQ scores (p<.0001), smaller orbital frontal gyrus gray matter volumes (p<.02), and a trend for smaller dorsolateral prefrontal gray matter volumes (p<.09) in the epilepsy compared to the normal group. Within the normal group, regression analyses revealed an association of higher mean SLQ with larger total brain volume (p < .05), both gray (p < .03) and white matter volumes (p < .08), as well as with gray (p < .05) and white matter dorsolateral prefrontal volumes (p < .04). However, higher mean SLQ scores were associated with larger gray matter volumes of the inferior frontal gyrus (p < .04) and the temporal lobe (p<.002) in the epilepsy group. Conclusions: This first study of language skill and fronto-temporal volumes in pediatric epilepsy highlights discrepancies in both brain regions and structure (gray, white matter) involved in the linguistic skills of children with epilepsy with average intelligence compared to normal children. These findings suggest that dorsolateral prefrontal gray and white matter do not support skills involved in SLQ in the epilepsy subjects. They also imply a possible shift of language function to inferior frontal gyrus and temporal lobe gray matter in the children with epilepsy.