Disparities in Connectivity Profiles Between Structural and Functional Networks in Patients With Temporal Lobe Epilepsy

Temporal lobe epilepsy (TLE) is one of the most prevalent forms of epilepsy. Recent advancements in research have increasingly categorized TLE as a network disorder, focusing on its network characteristics. Prior studies predominantly examined changes in connectivity properties within a single network, with limited attention to the distinctions between different connectivity networks. Both structural and functional connectivity serve as quantitative measures of connection strength among network nodes, yet they differ significantly. Functional connectivity (FC) highlights short-term cooperation among nodes, whereas structural connectivity (SC) underscores long-term cumulative effects of structural alterations. In this study, we constructed a comprehensive spectrum of structural and functional network connectivity in TLE patients and investigated the modulatory impact of seizure duration on both types of connectivity. Our findings indicate that the functional and structural connectivity of the brain displays inconsistent coupling patterns and heterogeneity. Specifically, we observed pervasive reductions in both structural and functional connectivity. As seizure duration increased, SC decreased, particularly in regions adjacent to the lesion. Additionally, there was a general decline in FC. However, we noted a significant increase in abnormal FC between nodes of the default mode network near the midline as seizure duration prolonged. These results suggest that the evolutionary patterns of structural and functional connectivity may differ in patients with TLE, indicating potential network reorganization.