To determine whether resting-state functional connectivity within motor-related brain regions predicts upper extremity motor function in individuals with chronic stroke.

Stroke remains a leading cause of long-term disability, often resulting in persistent motor deficits that affect independence and quality of life despite advanced rehabilitative therapies. Recovery of motor function depends on adaptive reorganization of distributed cortical, subcortical, and cerebellar networks. Resting-state functional MRI (rs-fMRI) provides a noninvasive method to assess intrinsic neural activity that reflects the functional integrity of these networks. Characterizing resting-state connectivity within motor circuits may reflect functional status and guide rehabilitation strategies.

Participants with chronic ischemic stroke and upper extremity weakness underwent rs-fMRI prior to enrollment in a neuromodulation study. Whole-brain functional connectivity matrices were generated in the Talairach space using 144 predefined regions. A bilateral five-node motor network was defined, including the primary motor cortex, (M1) premotor cortex, supplementary motor cortex, basal ganglia, and dentate nucleus. Mean intra- and interhemispheric connectivity among these nodes was computed for each participant. Upper extremity motor function was assessed using the Fugl-Meyer Upper Extremity (FM-UE) scale. Pearson correlation was performed between mean motor network connectivity and FM-UE scores.

Resting-state motor connectivity showed positive but non-significant associations with FM-UE scores. Contralesional M1 connectivity demonstrated the strongest correlation (r = 0.78, p = 0.12; β = 6.94, 95% CI [–3.21, 17.09]), followed by interhemispheric (r = 0.74, p = 0.16) and overall motor mean connectivity (r = 0.72, p = 0.17). Ipsilesional M1 connectivity showed a weaker, non-significant relationship (r = 0.37, p = 0.54). Spearman correlations (ρ = 0.6–0.8) supported these trends.

Although not statistically significant due to limited sample size, consistent positive trends suggest that greater contralesional and interhemispheric coupling within motor circuits may support improved upper extremity function.