Transcranial Direct Current Stimulation for Post-stroke Motor Recovery

Each subject must meet all of the following criteria to participate in this study: 1. 18-80 years old; and 2. First-ever unihemispheric ischemic stroke radiologically verified and occurred within the past 30-180 days; and 3. \>10° of active wrist extension, \>10° of thumb abduction/extension, and \> 10° of extension in at least 2 additional digits; and 4. Unilateral limb weakness with a Fugl-Meyer Upper Extremity score of ≤ 54 (out of 66) to avoid ceiling effects; and 5. An absolute difference of FM-UE scores between the two baseline assessments that is ≤ 2 points indicating stable motor impairment; if subject is not stable, then he/she will be invited for a reassessment after 7-14 days (but no more than 3 reassessments); and 6. Pre-stroke mRS ≤2; and 7. Signed informed consent by the subject or Legally Authorized Representative (LAR). Each Subject who meets any of the following criteria will be excluded from the study: 1. Primary intracerebral hematoma, subarachnoid hemorrhage or bi-hemispheric or bilateral brainstem ischemic strokes; 2. Medication use at the time of study that may interfere with tDCS, including but not limited to carbamazepine, flunarizine, sulpiride, rivastigmine, dextromethorphan; 3. Other co-existent neuromuscular disorders (pre- or post-stroke) affecting upper extremity motor function; 4. Other neurological disorders (pre- or post-stroke) affecting subject's ability to participate in the study; 5. Moderate to severe cognitive impairment defined as Montreal Cognitive Assessment (MOCA) score \< 18/30; 6. History of medically uncontrolled depression or other neuro-psychiatric disorders despite medications either before or after stroke that may affect subject's ability to participate in the study; 7. Uncontrolled hypertension despite medical treatment(s) at the time of randomization, defined as SBP≥185 mmHg or DBP≥110 mmHg (patient can be treated, reassessed and randomized later); 8. Presence of any MRI/tDCS/TMS risk factors including but not limited to: 8a) an electrically, magnetically or mechanically activated metallic or nonmetallic implant including cardiac pacemaker, intracerebral vascular clips or any other electrically sensitive support system; 8b) a non-fixed metallic part in any part of the body, including a previous metallic injury to eye; 8c) pregnancy (effects of MRI, TMS, and tDCS on the fetus are unknown); 8d) history of seizure disorder or post-stroke seizure; 8e) preexisting scalp lesion under the intended electrode placement or a bone defect or hemicraniectomy; 9. Planning to move from the local area within the next 6 months; 10. Life expectancy less than 6 months; 11. Has received Botulinum toxin injection to the affected upper extremity in the past 3 months prior to randomization or expectation that Botulinum will be given to the Upper Extremity prior to the completion of the last follow-up visit; 12. Concurrent enrollment in another investigational stroke recovery study; 13. Doesn't speak sufficient English to comply with study procedures; 14. Expectation that subject cannot comply with study procedures and visits.