Abstracts

Rationale: Benign childhood epilepsy with centrotemporal spikes (BCECTS) is one of the common localized-related idiopathic epileptic syndromes in children. Increase of interhemispheric connectivity can be associated with brain maturation and cognitive development in childhood age. Since corpus callosum is a major tract for interhemispheric connection, quantification of white matter integrity in corpus callosum using diffusion tensor imaging (DTI) can reflect normal and abnormal cognitive development in this age group. The purpose of this study was to investigate DTI changes in corpus callosum and their relationship with cognitive dysfunctions in children and adolescence with BCECTS. We hypothesized that DTI analysis of corpus callosum would reflect abnormal cognitive development in these patients.Methods: Nineteen subjects with BCECTS and 25 normal subjects aged 6 to 16 year were included in this study (mean 10.46 2.61 year-old). Neuropsychological tests were assessed with Korean version of the Wechsler Intelligence Scale for Children (K-WISC-III), the Stroop and Trail-making tests (TMT), the verbal and non-verbal memory tests, the verbal fluency and Boston naming tests. DTI was obtained with 15 directions, 2 mm slice thickness, b-value 1000 s/mm2, 2mm x 2mm in axial resolution from all subjects. DTI was analyzed using FMRIB s software library (FSL) software (www.fmrib.ox.ac.uk/fsl). Values of fractional anisotropy (FA) and mean diffusivity (MD) in corpus callosum were calculated based on Mori s white matter atlas implanted in FSL from each patient. Results were compared in younger and older age (6 to 11 vs. 12 to 16 year-old) groups in both patients and controls to test age effects on FA and MD values.Results: Increase in FA values with increasing age were observed in body of corpus callosum in normal subjects (r=0.51, P=0.009), but not in BCECTS patients. Significant FA reduction in genu and body in patients were found only in older age group (P = 0.003 and 0.008, respectively). Patients with BCECTS had lower full-scale IQ scores compared to control subjects (98.95 15.54 vs. 112.35 10.64; P = 0.001). FA values in genu of corpus callosum showed positive correlation with full-scale IQ in all subjects after controlling for age (P=0.011). FA values in body of corpus callosum were positively correlated with Boston Naming test in all subjects (P=0.005). Conclusions: These findings suggest that DTI analysis of corpus callosum would be helpful to understand underlying mechanisms involving cognitive impairments in epilepsy patients especially in children and adolescence. Decreased intelligence and naming abilities in patients with BCECTS could be related with altered maturation of corpus callosum. Changes of white matter tract integrity might play a role for cognitive development and brain maturation in this age group.