Background
Lesion location is a major source of post-stroke neurophysiological heterogeneity, yet most electroencephalography (EEG) studies analyze patients as a single group, limiting lesion-specific biomarkers and translation. We proposed a lesion-centric, multi-scale EEG framework integrating local oscillations, inter-regional connectivity, and hemispheric asymmetry with machine learning to characterize and decode basal ganglia (P1), fronto-temporal/centrum semiovale (P2), and brainstem (P3) lesions.
Methods
Five-minute eyes-open, 128-channel resting EEG ( \(1\,\text {kHz}\) ) was recorded in 57 subacute stroke patients (P1 = 22, P2 = 18, P3 = 17) and 22 matched controls. From artifact-minimized \(90\,\text {s}\) segments, ROI-averaged power spectral density (PSD) ( \(\theta \) : 4– \(7\,\text {Hz}\) ; \(\alpha \) : 7– \(12\,\text {Hz}\) ; \(\beta _{1}\) : 12– \(16\,\text {Hz}\) ; peak \(\alpha \) frequency), current source density (CSD)-based magnitude-squared coherence, and directional BSI (dirBSI) were computed. Between-group and subgroup differences were assessed using t-tests/Wilcoxon and ANOVA/Kruskal–Wallis with Benjamini–Hochberg FDR ( \(q=0.05\) ). EEG–behavior associations were examined with Spearman correlations. For machine learning, common spatial patterns (CSP) features were classified using linear discriminant analysis (LDA) with leave-one-subject-out cross-validation. To align with clinical workflow, we report HC vs P as “stroke detection/screening” and patient-only P1/P2/P3 classification as “lesion subtype decoding for stratification” (along with pairwise P1 vs P2, P1 vs P3, and P2 vs P3 models). An EEGNet baseline was evaluated for comparison.
Results
Increased \(\alpha \) power and a leftward peak \(\alpha \) shift were observed in patients (HC: \(9.93 \pm 1.09\,\text {Hz}\) ; P: \(8.75 \pm 1.02\,\text {Hz}\) ; \(p = 6.82 \times 10^{-5}\) ). Pre-FDR, \(\theta \) -band frontal–motor connectivity was strengthened, while posterior P–O connectivity in \(\alpha \) / \(\beta _{1}\) was weakened. Ipsilesional dominance in \(\theta \) was indicated by dirBSI (HC: \(-0.026 \pm 0.101\) ; P: \(0.061 \pm 0.122\) ; \(q=0.012\) ). Across lesions, \(\beta _{1}\) power differences in central/parietal/occipital ROIs were detected pre-FDR, with higher parietal \(\beta _{1}\) in P3; \(\alpha \) -band asymmetry was stronger in P1/P2 and more symmetric in P3 ( \(q=0.028\) ). EEG–behavior correlations did not survive FDR. Using CSP+LDA, accuracies of 92.41% (HC vs P), 94.87% (P1 vs P3), 85.71% (P2 vs P3), and 82.50% (P1 vs P2) were achieved; all binary AUCs exceeded 0.85; three-class accuracy reached 85.96%.
Conclusion
This multi-scale EEG framework identifies lesion-associated neurophysiological signatures and demonstrates feasible lesion subtype decoding, supporting the potential of EEG biomarkers for objective stratification and precision neurorehabilitation.