Altered intrinsic thalamic network based on electroencephalography source-level analysis in poststroke epilepsy

This study aimed to investigate the alterations in the intrinsic thalamic network in patients with poststroke epilepsy (PSE) based on electroencephalography (EEG) source-level analysis. This retrospective observational study followed the STROBE guidelines. Thirty-nine patients with stroke and PSE and 34 patients with stroke without PSE were enrolled. These patients underwent EEG in a resting state. Source localization based on scalp electrical potentials was computed using the minimum norm imaging method and the standardized low-resolution brain electromagnetic tomography approach. To construct a functional connectivity matrix, the Talairach atlas was used to define the nodes belonging to the thalamus, and the coherence method was applied to measure brain synchronization as edges. The intrinsic thalamic network was analyzed using graph theory and compared between patients with and without PSE. EEG source-level analysis revealed notable differences in the intrinsic thalamic network between patients with and without PSE. From the undirected weighted connectivity matrix, the measure of modularity was lower in patients with PSE than in those without PSE (0.038 vs 0.106, P = .024). Additionally, modularity measures showed significant differences between the groups, as demonstrated by graph theoretical analysis using binary undirected graphs with a fixed density range of connections. This study is the first to demonstrate the alterations in the intrinsic thalamic network in patients with stroke with PSE compared to those without PSE based on EEG source-level analysis. These intrinsic thalamic network changes may be related to PSE development.