Different patterns of white matter changes after successful surgery of mesial temporal lobe epilepsy

• Main Authors: Wei Li, Dongmei An, Xin Tong, Wenyu Liu, Fenglai Xiao, Jiechuan Ren, Running Niu, Yingying Tang, Baiwan Zhou, Du Lei, Yuchao Jiang, Cheng Luo, Dezhong Yao, Qiyong Gong, Dong Zhou
• Format: Article
• Language: English
• Published: Elsevier 2019-01-01
• Series: NeuroImage: Clinical
• Online Access: http://www.sciencedirect.com/science/article/pii/S2213158218303796

Objectives: To explore the dynamic changes of white matters following anterior temporal lobectomy (ATL) in mesial temporal lobe epilepsy (MTLE) patients who achieved seizure-free at two-year follow-up. Methods: Diffusion tensor imaging (DTI) was obtained in ten MTLE patients at five serial time points: before surgery, three months, six months, 12 months and 24 months after surgery, as well as in 11 age- and sex-matched healthy controls at one time point. Regions with significant postoperative fractional anisotropy (FA) changes and their dynamic changes were confirmed by comparing all preoperative and postoperative data using Tract-Based Spatial Statistics (TBSS). Results: After successful ATL, significant FA changes were found in widespread ipsilateral and contralateral white matter regions (P <.05, FWE correction). Ipsilateral external capsule, cingulum, superior corona radiate, body of corpus callosum, inferior longitudinal fasciculus, optic radiation and contralateral inferior cerebellar peduncle, inferior longitudinal fasciculus showed significant FA decrease at three months after surgery, without further changes. Ipsilateral superior cerebellar peduncle and contralateral corpus callosum, anterior corona radiate, external capsule, optic radiation showed significant FA decrease at three months follow up but increase later. Ipsilateral cerebral peduncle and contralateral middle cerebellar peduncle showed significant FA decrease at three months follow up, with further decrease after that. While ipsilateral posterior limb of internal capsule, retrolenticular part of internal capsule and contralateral posterior corona radiate showed significant FA increase after surgery. Conclusions: FA changes after successful ATL presented as four distinct patterns, reflecting different structural adaptions following epilepsy surgery. Some FA increases indicated the reversibility of preoperative diffusion abnormalities and the possibility of structural reorganization, especially in the contralateral hemisphere. Keywords: Mesial temporal lobe epilepsy, Anterior temporal lobectomy, Hippocampal sclerosis, Diffusion tensor imaging, Reorganization