White Matter Changes in a Model of Temporal Lobe Epileptogenesis: A Combined Diffusion Tensor Imaging and Histopathology Study

Willem Maarten Otte^1,2, Pieter van Eijsden¹, W. S. van der Hel¹, O. van Nieuwenhuizen¹, Rick M. Dijkhuizen², R A. de Graaf³, Kees P.J. Braun¹

Although epilepsy is considered to be a grey matter disease, diffusion tensor imaging (DTI) studies have demonstrated that white matter is affected. However, interpretation of DTI findings is often complicated by the lack of histology. We characterized white matter changes longitudinally during epileptogenesis using DTI and histology in a rat model of temporal lobe epilepsy (TLE). Our analysis demonstrated significant reduction in Lambda1 of the corpus callosum at four weeks, before spontaneous seizures occur. Histology confirmed that myelin was affected at four weeks, but normalizes. Axonal integrity was not affected. Diffusion properties behave different during epipileptogenesis than in TLE.