Among the 795,000 individuals who sustain a stroke annually in the United States, 65% continue to experience moderate-to-severe impairments in one hand six months or more, which limits their ability to perform daily tasks. Currently there is dearth of understanding of the mechanisms of motor recovery after stroke. Understanding the mechanisms can potentially lead to the development of interventions to improve motor performance after stroke. The proposed study will examine how synchronously pairing brain and hand stimulation repeatedly affects the plasticity of the brain and motor performance after stroke. The knowledge gained from this study can be useful to develop interventions to improve hand movement after moderate-severe stroke.

Inclusion Criteria:

1. Male or female (either right or left handed) with unilateral hemiparesis after stroke;
2. Stroke onset of at least six months prior to the time of participation;
3. Ability to elicit motor evoked potential in the Extensor digitorum communis (EDC) muscle
4. Ability to grasp, as indicated by a score of at least 1 (out of 2) on the finger mass flexion and cylindrical grasp items of Upper Extremity Fugl-Meyer scale
5. age between 18-80 years

Exclusion Criteria:

1. Presence of severe aphasia , measured by cognitive and/or language impairments that preclude the ability to follow simple instructions;
2. Excessive spasticity of wrist and finger muscles, defined as a Modified Ashworth Score more than or equal to 3, which may limit the ability to open the hand/fingers;
3. Diagnosis of neurological disorders other than stroke, which may confound the results;
4. Has touch and proprioceptive sensory deficits determined via a score of 0 on the position sense section (section H) of the Fugl Meyer Upper Extremity assessment proprioception, which may limit the ability to report excessive amount of tingling due to hand stimulation
5. History of seizure or epilepsy as the effects of TMS are not tested in individuals with seizures or epilepsy;
6. Orthopaedic/musculoskeletal conditions (eg, arthritis) affecting the upper extremity, which may limit the ability to move the affected hand
7. Presence of metallic implants in the head or neck for TMS;
8. Currently or planning to become pregnant, as the effects of TMS are not tested not pregnant women;
9. Difficulty maintaining alertness or remaining still for MRI;
10. Ferromagnetic metallic implants, pacemakers, other implanted devices, or ventilators (for MRI);
11. Bodyweight > 300 lbs due to MRI scanner dimensions
12. Psychiatric diagnosis according to the criteria of the Diagnostic and Statistical Manual of Mental Disorder, Fifth Edition (DSM-V), or who are on psychotropic medication, which may confound the results
13. Cognitive impairments, defined as a score of < 23 on the Mini Mental Status Examination, which may limit the ability to follow the commands in the study
14. Excessive pain > equal to 5 on Visual Analog Scale in the more-affected upper extremity, which may limit the ability to participate in the study
15. History of schizophrenia, Bipolar disorder (type I or II) [Answer yes to questions 16 and items of the (hypo) maniac module of the The Mini International Neuropsychiatric Interview], current moderate, severe depression (Scores of >10 on Patient Health Questionnaire-9) and other neurological or medical conditions that could confound results.
16. Life expectancy less than the duration of the study
17. Hemispatial neglect, which may limit the ability to pay attention to the affected hand
18. Participating in concurrent therapy, which may confound the results
19. We will exclude children because although stroke may occur in children, the protocol is addressing stoke in adults and the devices are not approved for use in children

From enrollment until the end of 6 weeks

There were no serious adverse events or any other adverse events reported. There was no all-cause mortality reported.