Abstracts

Rationale: There has been a debate regarding whether Benign Epilepsy with Centrotemporal Spikes (BECTS) is a truly 'benign' epilepsy; there is evidence that a subset of patients with BECTS exhibit cognitive and behavioral deficits. The age-dependent onset/remission and distinct EEG features suggest that there may be an association between atypical brain maturation and cognitive outcomes. The aim of this study was to investigate whether there are differences in grey matter (GM) volume in BECTS compared to age and gender matched typically developing children. Methods: Thirty five patients with newly-diagnosed BECTS (age: 5-12 yrs, mean SD: 7.92.0 yrs, F/M=17/18) and forty six age- and gender-matched healthy controls (age: 5-13 yrs, mean SD: 8.12.2 yrs, F/M=22/24) were included. T1-weighted MRI images with 1mm isotropic voxel resolution were acquired for all participants at the time of diagnosis of BECTS. Voxel-based morphometry was utilized to investigate GM volume differences between BECTS and controls. Age, gender and total intracranial volume were included as covariates. After creating a study-specific template and segmentation of brain tissue types, each GM was non-linearly registered to the template and smoothed. A randomize approach (5000 permutations with threshold-free cluster enhancement) was used for multiple comparisons correction. A general linear model approach was used to examine differences between groups. Neuropsychological measures, including full-scale IQ (WPPSI/WASI) and processing speed index (WPPSI/WISC) were obtained for all participants. Results: GM volume was decreased in superior frontal gyrus in the BECTS patients compared to controls at baseline (Fig. 1: p=0.0002 uncorrected). Analysis of age-related changes revealed that the BECTS patient group had significantly increased GM volume in right hippocampus, and decreased GM in bilateral superior parietal gyrus as age increased (Fig.2a and 2b: p < 0.05, corrected). In the control group, there were widespread GM volume decreases in anterior portion of brain (Fig.2c: p < 0.05, corrected). BECTS patients did not differ from controls in IQ (mean 106.65, 109.80 respectively) but they performed more poorly on processing speed (mean BECTS 95.77, controls 103.31, p=0.0029). Conclusions: This study showed that BECTS patients exhibit decreased GM volume in the superior frontal gyrus at the time of diagnosis, a region that contributes to higher cognitive functions. In addition, there is an atypical pattern of age-related increases and decreases in GM volume in BECTS; this atypical cortical developmental course may underlie cognitive problems in children with BECTS. Funding: n/a