Abstracts

Rationale: There is little prospective information regarding patterns of brain development in children with epilepsy compared to healthy controls. In this investigation we used quantitative MRI volumetrics to examine prospective 2-year neurodevelopmental changes in total cerebral and lobar gray and white matter volumes in children with idiopathic epilepsies versus healthy controls. Methods: To date, 25 children with new onset epilepsy and 21 first degree cousin controls, 8-18 years of age, have completed baseline and prospective (2-year) quantitative MR volumetrics using a well known software system (BRAINS-2). Images were obtained on a 1.5 Tesla GE Signa MR scanner. Manual inspection and correction of the output of the neural network tracing was conducted. The brain images were then volume rendered using local utilities, producing tissue volumes for regions of interest within the brain. Because all measurements were obtained in the image space of the subject and not normalized, ICV was used as a co-variate in the analysis. The dependent variables included total and segmented tissue volumes for frontal, temporal, parietal, and occipital lobes; as well as total cerebral gray and white matter. Results: From baseline to two year follow-up, healthy controls showed a significant reduction in total cerebral gray (p=.001) and significant increase in cerebral white matter (p=.01) volumes. Children with new onset children showed a similar significant decline in cerebral gray matter (p=.008) but the growth in cerebral white matter was not significant (p=.15) Examining segmented lobar volumes, healthy controls showed a significant decrease in gray matter in the frontal (p< .01) and parietal (p=.009) but not temporal (p=.12) or occipital (p=.96) lobes. Similar trends were evident among the epilepsy subjects with significant gray matter reductions in frontal (p<.001) and parietal (p=.013) but not temporal (p=.56) or occipital (p=.91) lobes. Healthy controls showed significant increases in white matter volumes across the frontal (p=.013), parietal (p=.008), and temporal (p=.003) lobes but not occipital (p=.75) lobe. Children with epilepsy showed significant white matter increase only in frontal (p=.026), but not parietal (p=.07), temporal (p=.24) or occipital (p=.11) lobes.Conclusions: At this early stage of data acquisition, healthy controls exhibit well described changes in segmented tissue volumes with decreasing gray matter and increasing white matter volumes, the changes most evident in frontal and parietal lobes. Patients with new onset epilepsies exhibit similar changes in gray matter but less significant volumetric increase in white matter. These findings raise the possibility of altered patterns of brain development in non-lesional pediatric epilepsy, but data acquisition will be ongoing. (Source of funding: NINDS RO1-44351).