White Matter Abnormalities in Children with Temporal Lobe Epilepsy: A DTI and MEG Study

Abstract

The widespread propagation of synchronized neuronal firing in seizure disorders may affect cortical and subcortical brain regions. The purpose of this study was to investigate the abnormal changes of white matter in children with focal temporal lobe epilepsy (TLE) using diffusion tensor imaging (DTI) and magnetoencephalography (MEG). Eight children with clinically diagnosed TLE and eight age- and gender-matched healthy controls were studied. DTI images were obtained with a 3T magnetic resonance imaging (MRI) scanner. The epileptic foci were localized with MEG. Fractional anisotropy (FA), trace, 1-volume ratio (VR), parallel (λ||) and perpendicular (\(\lambda\bot\)) diffusivities in the genu and splenium of the corpus callosum, external capsule, anterior limbs of the internal capsule, and the posterior limbs of the internal capsule were calculated. The DTI parameters in the same brain regions between patients and controls were statistically compared. The DTI parameters of white matter between the hemisphere with seizure foci and the hemisphere without seizure foci were statistically compared. In comparison to controls, patients with epilepsy had significantly lower FA and higher trace, 1-VR, λ|| and \(\lambda\bot\) in white matter structures. There was no significant difference between the hemisphere with seizure foci and the hemisphere without seizure foci in TLE patients in terms of FA, trace, 1-VR, λ|| and \(\lambda\bot\). The results of the present study indicate that children with TLE had significant abnormalities in the white matter in the hemisphere with seizure foci. Furthermore, these abnormal changes could be identified in the hemisphere without seizure foci. Though further investigation and more patients’ data are necessary, it seems that white matter abnormalities represent an underlying predisposing factor in the development of TLE.