Abstract
In this study, we used Electromyogram (EMG) triggered electrical stimulation (ETES) to move unilateral hand synchronously with contralateral voluntary hand movement while performing mirror therapy and investigated the effects on motor evoked potential (MEP) induced by transcranial magnetic stimulation (TMS) in healthy subjects. The MEP was recorded from three muscles in the right arm;extensor carpi radialis (ECR), flexor carpi radialis (FCR) and first dorsal interosseous (FDI). The subjects performed 6 tasks as below:observation of a mark with only left hand extension movement (Task1), observation of resting right hand added to Task1 (Task2), observation of mirror reflection of left hand movement added to Task1 (Task3), observation of a mark and right hand movement induced by ETES (Task4), observation of moving right hand added to Task4 (Task5), and observation of mirror reflection of left hand movement added to Task4 (Task6). In ECR, mean amplitude of MEP (AMEP) in Task 4 and Task 6 showed a significant increase comparing to Task 1. In FCR, statistically significant differences were not found. In FDI, the AMEP in Task 2 and Task 5 showed a significant increase comparing to Task 1. These results suggested that ETES combined with mirror therapy had a possibility to activate excitability of the primary motor cortex corresponding to the muscle that was electrically moved.
