Estimation of corticomuscular coherence following stroke patients

The major symptom of stroke is motor dysfunction and it is usually due to the damage in neural pathway that responsible for motor control. In this study, we investigate the functional corticomuscular coupling (FCMC) between the motor cortex and the contralateral muscles in stroke patients. First, we recorded the 59-channel electroencephalogram (EEG) and 2-channel electromyogram (EMG) of the biceps brachii (BB) / deltoid (DT) muscles in stroke subjects and healthy controls in the arm uplifting movement process. Then, the EEG and EMG time series were analyzed using time-frequency coherence for quantifying the FCMC. The results showed a lack of coherence in the γ-band (35-60 Hz) between EEG and BB (EEG-BB) and between EEG and DT (EEG-DT) of stroke subjects during the movement from waist to chest. Moreover, compared to healthy controls, the coherence of synkinetic patients was reduced at ß-band (15-35 Hz) in EEG-BB and enhanced at ß-band in EEG-DT during maintaining up to chest during maintaining up to chest. These results indicate synkinetic patients are able to induce larger scale of DT with BB than healthy controls, i.e. there was large scale of abduction with should joint.