Electroencephalography resting-state networks in people with Stroke

Introduction The purpose of this study was to characterize resting-state cortical networks in chronic stroke survivors using electroencephalography (EEG). Methods Electroencephalography data were collected from 14 chronic stroke and 11 neurologically intact participants while they were in a relaxed, resting state. EEG power was normalized to reduce bias and used as an indicator of network activity. Correlations of orthogonalized EEG activity were used as a measure of functional connectivity between cortical regions. Results We found reduced cortical activity and connectivity in the alpha (p p = .05) and beta (p p = .03) bands after stroke while connectivity in the gamma (p = .031) band increased. Asymmetries, driven by a reduction in the lesioned hemisphere, were also noted in cortical activity (p = .001) after stroke. Conclusion These findings suggest that stroke lesions cause a network alteration to more local (higher frequency), asymmetric networks. Understanding changes in cortical networks after stroke could be combined with controllability models to identify (and target) alternate brain network states that reduce functional impairment.

Automated summary

After stroke, there is a decrease in cortical activity and connectivity, especially in the alpha and beta bands, while connectivity in the gamma band increases. Asymmetries in cortical activity, driven by a reduction in the lesioned hemisphere, are also observed after stroke.