The Effect of Non-invasive Brain Stimulation rTMS on Hand Muscles in Chronic Stroke Patients.

Inclusion criteria: 1. Age \>=21 years old of any race or gender 2. First-ever ischemic or hemorrhagic stroke (neuroimaging verified) at least 3 months from stroke onset 3. Unilateral arm weakness measured by FM-UM scale \<= 62 out of 66 4. Inducible rest motor threshold and testing motor threshold recorded from the affected first dorsal interosseous (FDI) muscle from the study subject Exclusion criteria 1. Bilateral strokes (infarcts and/or hematoma) 2. Other co-existent neuromuscular disorders affecting upper extremity motor impairment. 3. History of medically uncontrolled depression or other neuropsychiatric disorders despite medications either before or after a stroke that may affect the subject's ability to participate in the study. 4. 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). 5. Presence of any MRI/rTMS risk factors including but not limited to: 1. an electrically, magnetically, or mechanically activated metallic or nonmetallic implant including cardiac pacemaker, intracerebral vascular clips or any other electrically sensitive support system. 2. a non-fixed metallic part in any part of the body, including a previous metallic injury to the eye. 3. history of seizure disorder before stroke or seizure after stroke. 4. preexisting scalp lesion or bone defect or hemicraniectomy. 6. Concurrent enrollment in another interventional stroke recovery study. 7. Concerns that the subject cannot comply with study procedures and visits. 8. Pregnant individuals