Mechanisms of acupuncture-regulated cortical plasticity after stroke based on TMS-EEG-MEP integration.

BACKGROUND: Stroke disrupts cortical excitability, inhibition, and network connectivity, contributing to persistent motor deficits. OBJECTIVE: To determine whether acupuncture modulates cortical reactivity, functional connectivity, and corticospinal output after stroke using an integrated transcranial magnetic stimulation–electroencephalography–motor evoked potential (TMS–EEG–MEP) framework in a retrospective cohort. METHODS: Clinical and neurophysiological data from 200 patients with first-ever ischemic stroke (100 acupuncture; 100 control) were analyzed at baseline, 4 weeks, and 8-week follow-up. Primary mechanistic outcomes included changes in the TMS-evoked N100 component, global mean field power (GMFP), motor network connectivity quantified by the weighted phase lag index (wPLI), and motor evoked potential (MEP) amplitude. Secondary outcomes included upper-limb motor function (Fugl-Meyer Assessment–Upper Extremity, FMA-UE), activities of daily living (Barthel Index), and neurological impairment (NIH Stroke Scale). RESULTS: Compared with controls, acupuncture was associated with greater increases in N100 amplitude and GMFP, strengthened M1–supplementary motor area connectivity (wPLI), enhanced oscillatory activity in the theta–beta frequency range, and increased MEP amplitudes with reduced motor thresholds (all p < 0.01). Changes in functional connectivity (ΔwPLI), intracortical facilitation (ΔICF), and MEP amplitude jointly predicted improvements in motor function (R² = 0.72, p < 0.001). CONCLUSIONS: Acupuncture was associated with enhanced cortical reactivity, strengthened motor-network coupling, and facilitated corticospinal excitability. Integrated TMS–EEG–MEP markers may serve as mechanistic, hypothesis-generating endpoints for stroke rehabilitation.