Abstracts

Rationale: Children with new onset and chronic epilepsy but no other neurological or neuroradiological abnormalities have abnormal gray and white matter fronto-temporal volumes (FTV) compared to healthy controls (HC) (1-3). Birth weight, an indirect measure of the health of intrauterine environment and prenatal adversities (4), is related to total brain and caudate volumes in HC (5). This study compared the relationship between birth weight and FTV in children with two epilepsy syndromes to that of HC. Methods: 39 children with localization related epilepsy and complex partial seizures (CPS), 20 children with childhood absence epilepsy (CAE), and 29 HC, aged 6-14.5 years underwent MRI scans at 1.5T. Tissue was segmented and frontal parcellations of inferior frontal gyrus (IFG), orbital frontal gyrus (OFG), dorsolateral prefrontal cortex (DLPFC)), and temporal lobe (TL) gray and white volumes (GMV, WMV) were computed. Mothers provided birth weight and pregnancy/delivery complication information through an abbreviated version of the Yale Neuropsychoeducational Assessment Scales (6). Perinatal and demographic variables, other than ethnicity, were unrelated to birth weight and FTV. ANCOVAs, controlling for age, gender, and ethnicity were used to determine group differences in birth weights and volumetric measures. General linear models, with the regional volumes as the dependent variables and group, birth weight and interaction of group x birth weight as predictors, were estimated to determine if the 3 groups differed in the relationships between FTV and birth weight. ANCOVAs, controlling for the same variables, were then performed to examine lateralization effects for brain regions that demonstrated significance. Given an association of FTV with IQ and seizure variables (1, 2), we examined their possible mediating or moderating role on the findings.Results: The three groups had birth weights in the normal range (2.5 3.5 Kg) and similar FTVs. The ANCOVAs revealed a significant birth weight by diagnosis interaction for both IFG GMV (F(2,73) = 4.81, p =.01) and IFG WMV (F(2,75) = 4.17, p =.02) (Figure 1). Birth weight of the HC was unrelated to FTVs. However, higher birth weight was significantly related to larger IFG GMV (t = 2.87, p = .005) and IFG WMV (t = 1.59, p = .05) in the CPS and to a trend for lower IFG WMV in the CAE (t = -1.96, p = .055). Lateralization, IQ, and seizure variables were unrelated to the findings.Conclusions: The study s findings suggest that perinatal adversity might contribute to abnormal IFG structure and function in CPS and CAE. They are particularly important given the role of this brain region in the basic and higher-level language skills (7) that are impaired in CPS and CAE children (8, 9).