Functional neuromuscular stimulation to improve severe hand dysfunction after stroke: Does inhibitory rTMS enhance therapeutic efficiency?

BackgroundNovel strategies to improve hand function after stroke are needed. Electromyography-triggered functional neuromuscular stimulation (EMG-FNMS) and repetitive transcranial magnetic stimulation (rTMS) are promising techniques to facilitate recovery of sensory-motor hand dysfunction after stroke.ObjectiveTo investigate if 1 Hz rTMS over the contralesional primary motor cortex enhances the effectiveness of EMG-triggered FNMS of the hand and finger extensors to improve severe sensory-motor hand dysfunction after stroke.Methods24 subjects with a first stroke received 10 daily sessions of 20 min EMG-triggered FNMS of the hand and finger extensors of the affected forearm preceded by 15 min of either 1 Hz rTMS (rTMS group, n = 12) or sham rTMS (control group, n = 12) over the contralesional primary motor cortex. Prior to and after each intervention motor function and spasticity were rated at both hands, and cortical excitability of the contralesional primary motor cortex was assessed.ResultsMotor function and spasticity of the affected hand were significantly improved by either intervention, whereas behavioural measures of the unaffected hand did not change. There were no significant differences between both intervention groups. Improvement of motor function of the affected hand was positively correlated with cortical excitability of the contralesional primary motor cortex after EMG-triggered FNMS preceded by 1 Hz rTMS.Conclusions1 Hz rTMS does not enhance the general effectiveness of EMG-FNMS to the wrist and finger extensors of the affected forearm after stroke. Motor recovery of the severely affected hand after stroke appears to depend on excitability of the contralesional primary motor cortex.

► Novel strategies to improve hand function after stroke are needed, repetitive transcranial magnetic stimulation (rTMS) and EMG-triggered functional neuromuscular stimulation are promising techniques. ► 1 Hz rTMS does not enhance the general effectiveness of EMG-FNMS to improve motor function of the severely affected hand after stroke. ► Motor recovery of the severely affected hand after stroke depends on excitability of the contralesional primary motor cortex.