Electroacupuncture improves upper-limb motor function and modulates sensorimotor network connectivity in subacute...

Electroacupuncture (EA) has been shown to facilitate post-stroke motor recovery; however, the underlying neurophysiological mechanisms remain insufficiently understood. This study aimed to investigate how EA modulates sensorimotor network (SMN) connectivity and to explore its relationship with upper-limb motor recovery in patients with subacute stroke.

Fifty patients with subacute stroke were randomly assigned to the EA group or sham EA (SEA) group. All participants received 18 treatment sessions over 3 weeks in addition to standard rehabilitation. Upper-limb motor function and daily living ability were assessed before and after treatment. Resting-state electroencephalography (EEG) was recorded before and after the intervention. Functional connectivity (FC) within the SMN was calculated using phase-locking value (PLV) in the alpha (8-13 Hz) and beta (13-30 Hz) bands. Graph-theoretical metrics were analyzed, and partial least squares regression (PLSR) was used to evaluate associations between FC alterations and motor improvement.

After treatment, the EA group showed significantly greater improvement in upper-limb motor function than the SEA group, as indicated by a significant group × time interaction for the Fugl-Meyer Assessment for Upper Extremity (FMA-UE) and greater between-group gains in change scores (p < 0.05). For the Modified Barthel Index (MBI), significant main effects of time and group were observed, but the group × time interaction was not significant, although Week 3 scores were higher in the EA group (p < 0.05). EEG analysis showed that alpha-band SMN FC significantly increased after EA, whereas no significant changes were observed in the SEA group (p < 0.05). Between-group comparisons revealed higher post-treatment alpha-band FC in the EA group, predominantly involving interhemispheric connections (p < 0.05). In the EA group, PLSR explained 68.7% of the variance in motor improvement (R²  = 0.687; RMSE = 7.68), whereas no valid predictors were identified in the SEA group. No significant differences were found in global network topology metrics (p > 0.05).

EA improved upper-limb motor recovery in patients with subacute stroke and was accompanied by selective enhancement of alpha-band functional connectivity within the sensorimotor network. These findings suggest that EA may promote post-stroke motor recovery through frequency-specific reorganization of recovery-relevant sensorimotor circuits.

https://www.chictr.org.cn/bin/project/edit?pid=199590, Chinese Clinical Trial Registry (Registration number: ChiCTR2300077420).