Reorganized Functional Networks Underlie Working Memory Deficits After Right-Hemispheric Stroke

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Working memory (WM) is crucial for cognition, but stroke often impairs it.
• Traditional lesion mapping misses large-scale brain network changes impacting WM post-stroke.

Purpose of the Study:

• Investigate working memory (WM) deficits in right hemisphere (RH) stroke patients using functional connectivity (FC) analysis.
• Examine the relationship between frontoparietal network FC and WM performance in RH stroke survivors.

Main Methods:

• Utilized resting-state fMRI for seed-to-voxel FC analysis in 34 RH stroke patients and 35 controls.
• Assessed WM performance using verbal and spatial N-back tasks.
• Correlated FC measures with WM task accuracy.

Main Results:

• Stroke patients displayed altered FC-WM associations compared to controls.
• Reduced intrahemispheric FC in RH correlated with lower WM performance.
• Enhanced interhemispheric FC showed a positive association with WM accuracy, indicating compensatory mechanisms.

Conclusions:

• Working memory deficits post-stroke result from altered brain network dynamics, not just focal damage.
• Reduced intrahemispheric connectivity may be compensated by interhemispheric recruitment.
• Findings emphasize early network reorganization's role in cognitive recovery after stroke.