Resting-state Functional Connectivity After Occipital Stroke

Area of Science:

• Neuroscience
• Neuroimaging
• Rehabilitation

Background:

• Stroke can lead to reorganization of cortical networks, impacting functional connectivity (FC).
• Resting-state functional magnetic resonance imaging (rsfMRI) is a key tool for assessing these network changes.
• Understanding FC alterations is crucial for developing effective stroke rehabilitation strategies.

Purpose of the Study:

• To investigate the effects of repetitive transcranial alternating current stimulation (rtACS) on functional connectivity (FC) in chronic occipital stroke patients.
• To compare FC patterns between stroke survivors with visual field defects and healthy controls.
• To evaluate the impact of rtACS on network parameters using rsfMRI.

Main Methods:

• A randomized, sham-controlled study involving 16 chronic occipital stroke patients and 12 healthy controls.
• rsfMRI scans were acquired at baseline, after two weeks of rtACS/sham, and after a two-month follow-up.
• Multivariate regression and graph theory were employed to analyze FC and network properties.

Main Results:

• No significant differences in whole-network FC or graph parameters were observed between stroke patients and controls at baseline.
• Centrality eigenvector differed in perilesional regions, suggesting localized connectivity modifications.
• rtACS treatment did not lead to systematic changes in prediction accuracy or network parameters compared to sham treatment.

Conclusions:

• Whole-network FC in chronic occipital stroke patients is comparable to healthy individuals.
• rtACS, in this context, did not demonstrate a significant effect on functional connectivity.
• Localized connectivity differences in perilesional areas warrant further investigation.