Alterations of white matter network in patients with left and right non-lesional temporal lobe epilepsy

Objectives The goal of this study was to investigate alterations of white matter (WM) network in patients with left non-lesional temporal lobe epilepsy (nl-TLE) and right nl-TLE to assess the relationship between the white matter network properties and clinical parameters. Methods T1 magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) were acquired for 45 participants, including 30 nl-TLE patients (13 left, 17 right) and 15 healthy controls. Diffusion tensor tractography was computed to model the WM structural network. The topologic properties of the WM network were obtained by graph theoretical analysis, and the between-group differences in global and nodal properties of the WM network were examined by network-based statistical analysis (NBS). The relationship between WM network properties and clinical parameters was assessed by Pearson's correlation analysis. Results NBS results indicated that patients with left and right nl-TLE experienced distinct changes of WM nodal and global network properties compared with HCs. Positive correlation coefficients were found in several regions. The structural disruptions of networks in the two nl-TLE groups were observed to be different in distribution and severity. Conclusions This study provides evidence for changes of the WM network topological properties and structural connectivity in nl-TLE patients, which provide useful insights for the understanding of disease mechanisms of TLE and improving treatment outcomes for nl-TLE. Key Points This study aims to investigate alterations of white matter (WM) network in patients with non-lesional temporal lobe epilepsy (nl-TLE). Network-based statistical analysis results indicated that patients with left and right nl-TLE experienced distinct changes ofWM nodal and global network properties compared with healthy controls. This study provides useful insights for the understanding of disease mechanisms of TLE and improving treatment outcomes for nl-TLE.