Motor Excitability Study of High Definition Transcranial Direct Current Stimulation (HD-tDCS) in Chronic Stroke

Study Overview
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Brief Summary
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High definition tDCS will be conducted to both stroke and healthy subjects on primary motor cortex area to explore the motor excitability changes before and after stimulation. In next stage, a randomized control trial with 20-session training will be conducted to evaluate the effectiveness of transient modulation of cortical excitability through multisite HD-tDCS with EMG driven robot hand training, a sham stimulation with EMG-driven robot hand training will be applied as control group.

Official Title
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Motor Excitability Study of High Definition Transcranial Direct Current Stimulation (HD-tDCS) in Chronic Stroke

Conditions
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Stroke

Intervention / Treatment
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* Device: HD-tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Sufficient cognition to follow simple instructions, as well as understand the content and purpose of the experiment; Have moderate to severe motor disability at the paretic upper limb (assessed by Fugl-Meter Assessment (FMA), and Action Research Arm Test (ARAT)); Hemiparesis resulting from a single unilateral lesion of the brain with onset at least 6 months before data collection Exclusion Criteria: Severe hand spasticity, open hand wound or hand deformity; Visual field deficits; Aphasia, neglect, and apraxia; History of alcohol, drug abuse or epilepsy; Bilateral infracts; Uncontrolled medical problems; Serious cognitive deficits [Mini-Mental State Examination (MMSE) < 21]; Major depression Metal implants inside body MRI, TMS and tDCS contraindications

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Anode HD-tDCS<br>The center anode is fixed on the ipsilesional primary motor cortex and the 4 surrounding cathode electrodes will be placed about 6 cm to the center. | Device: HD-tDCS<br>* Different stimulation protocols will be applied to the primary motor cortex of stroke patients. After 20-minute stimulation, EMG-driven robot hand training will be conducted.<br>|
| Experimental: Cathode HD-tDCS<br>The center cathode is fixed on the contralesional primary motor cortex and the 4 surrounding anode electrodes will be placed about 6 cm to the center. | Device: HD-tDCS<br>* Different stimulation protocols will be applied to the primary motor cortex of stroke patients. After 20-minute stimulation, EMG-driven robot hand training will be conducted.<br>|
| Placebo Comparator: Sham HD-tDCS<br>The center anode is fixed on the ipsilesional primary motor cortex and the 4 surrounding cathode electrodes will be placed about 6 cm to the center. | Device: HD-tDCS<br>* Different stimulation protocols will be applied to the primary motor cortex of stroke patients. After 20-minute stimulation, EMG-driven robot hand training will be conducted.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electroencephalography (EEG) and Electromyography (EMG) | It is used to investigate the changes in corticomuscular coherence for studying connectivity between the brainwave using EEG and the affected hand muscles using EMG. In addition, EMG will be used to detect muscle activation change and muscle co-contraction pattern alteration. | Before intervention, During intervention, After intervention, 6-month after intervention | 
| Action Research Arm Test (ARAT) | The ARAT is a 19-item measure divided into 4 sub-tests (grasp, grip, pinch, and gross arm movement) to assess upper limb functioning | Before intervention, After intervention, 6-month after intervention | 
| Fugl-Meyer Assessment Upper Extremity (FMA-UE) | It is used to evaluate and measure upper-limb recovery in post-stroke hemiplegic patients, and items are scored on a 3-point ordinal scale | Before intervention, After intervention, 6-month after intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Magnetic Resonance Imaging (MRI) | It is used to identify neural correlates of stimulation-induced behavioral gains for investigating tDCS-induced changes in brain activations | Before intervention, After intervention, 6-month after intervention | 
| Transcranial Magnetic Stimulation (TMS) | It is used to measure the changes in interhemispheric imbalance and corticospinal excitability | Before intervention |