Augmenting the Effects of Mirror Therapy for Stroke Rehabilitation by tDCS

This project is to evaluate and compare the impact of tDCS stimulation location on augmenting MT effects.

Mirror therapy (MT) has emerged as an effective treatment approach for stroke rehabilitation. To augment the effects of MT, one appealing approach is to combine MT with transcranial direct current stimulation (tDCS) to promote neuroplasticity. However, it remains undetermined as to how tDCS may be effectively and efficiently applied in conjunction with MT. The long term goal of this project will be to identify the optimal combination approach of MT and tDCS to enhance recovery after stroke. The stimulation timing and location of tDCS in relation to MT will be varied, and the scientific evidence will be built upon by the evaluation of comprehensive outcome measures. This project will also investigate the possible electroencephalography (EEG) physiological and motor control mechanisms, and study predictors of treatment success to identify the appropriate patient population for the hybrid regimen.

Specifically, the first aim of this project is to evaluate and compare the impact of tDCS stimulation location on augmenting MT effects. The tDCS will be applied either before or concurrently with MT, and will be applied either over primary motor cortex (M1) or premotor cortex (PMC). Outcome measures will include behavioral performances selected based on the International Classification of Functioning, Disability and Health (ICF) framework, EEG physiological measures, and kinematic control of upper extremity (UE) movements. All the outcome measures will be assessed before and immediately after the intervention, and only behavioral performances will be evaluated at 3- and 6-month follow-up. Investigators hypothesize that immediately after intervention, the participants who receive MT combined with tDCS will demonstrate greater improvements in the outcomes than those who receive MT with sham tDCS. Investigators also hypothesize that the stimulation location of tDCS will induce differential therapeutic effects on the outcome measures.

The second aim of this study is to examine the retention performance of the behavioral outcomes at 3-and 6-month follow-up. Investigators hypothesize that the beneficial effects of the hybrid therapy will be retained 3 and 6 months post intervention.

The third aim of this study is to perform subsequent analysis of exploring whether patients with primary motor cortex involved will respond to various types of treatment differently from those without primary motor cortex involved.

The fourth aim of the study is to identify the characteristics of responders for the hybrid therapy. The possible predictors of post treatment changes in behavioral (the aspects of activities and participation), EEG physiological, and kinematic measures will be determined. Investigators hypothesize that the behavioral (the aspect of motor impairment), the EEG physiological and the kinematic measures will be good predictors for the treatment outcomes.

Eligibility Criteria:
Inclusion Criteria:

1. sustained an unilateral stroke with onset ≥ 6 months;
2. UE-FMA score between 18 and 56 indicating moderate to mild motor severity;
3. aged from 45 to 85 years old; and
4. able to follow instructions and perform the tasks (Mini Mental State Examination ≥ 24).

Exclusion Criteria:

if they

1. have excessive spasticity or joint contracture of the paretic UE;
2. are enrolled in other rehabilitation experiments or drug studies;
3. have additional neurological or psychological disorders other than stroke;
4. have received Botulinum toxin injections 3 months before enrollment;
5. have unstable cardiovascular status such as uncontrolled hypertension or New York Heart Association (NYHA) Class III/IV heart failure;
6. have contradictions to tDCS including a history of epilepsy, migraine headache, uncontrolled medical status, being pregnant, having a pacemaker, or metal implanted in their head or body; and
7. have a history of drug or alcohol abuse, skin lesions on the electrode sites, brain tumor, brain injury, arteriovenous malformation (AVM), had brain surgery, other brain diseases (such as intracranial hypertension or cerebral edema), or being not suitable for using tDCS by the physician's assessment.