The effects of electromyography-controlled functional electrical stimulation on upper extremity function and cortical perfusion in stroke patients

Objective: The relation was investigated between hemiparetic arm function improvement and brain cortical perfusion (BCP) change during voluntary muscle contraction (VOL), EMG-controlled FES (EMG-FES) and simple electrical muscle stimulation (ES) before and after EMG-FES therapy in chronic stroke patients. Methods: Sixteen chronic stroke patients with moderate residual hemiparesis underwent 5. months of task-orientated EMG-FES therapy of the paretic arm once or twice a week. Before and after treatment, arm function was clinically evaluated and BCP during VOL, ES and EMG-FES were assessed using multi-channel near-infrared spectroscopy. Results: BCP in the ipsilesional sensory-motor cortex (SMC) was greater during EMG-FES than during VOL or ES; therefore, EMG-FES caused a shift in the dominant BCP from the contralesional to ipsilesional SMC. After EMG-FES therapy, arm function improved in most patients, with some individual variability, and there was significant improvement in Fugl-Meyer (FM) score and maximal grip strength (GS). Clinical improvement was accompanied by an increase in ipsilesional SMC activation during VOL and EMG-FES condition. Conclusion: The EMG-FES may have more influence on ipsilesional BCP than VOL or ES alone. Significance: The sensory motor integration during EMG-FES therapy might facilitate BCP of the ipsilesional SMC and result in functional improvement of hemiparetic upper extremity.