Eligibility Criteria- INCLUSION CRITERIA:
We will include patients with thromboembolic non-hemorrhagic hemispheric lesions at least 6 months after the stroke. We will choose patients who initially had a severe motor paresis (below MRC grade 2), which subsequently recovered to the point that they have a residual motor deficit but can perform the required tasks. Assessment of the initial functional state will be taken either from patient report or medical records. As a control group, we will include age- and gender matched healthy volunteers with matched non-dominant/dominant hand (to the affected hand of the stroke patients).
Patients with more than one stroke in the medial cerebral artery territory.
Patients with bilateral motor impairment.
Patients with cerebellar or brainstem lesions.
Patients or healthy volunteers unable to perform the task (wrist or elbow flexion at least MRC grade 2).
Patients or healthy volunteers with history of severe alcohol or drug abuse, psychiatric illness like severe depression, poor motivational capacity, or severe language disturbances, particularly of receptive nature or with serious cognitive deficits (defined as equivalent to a mini-mental state exam score of 23 or less).
Patients or healthy volunteers with severe uncontrolled medical problems (e.g. cardiovascular disease, severe rheumatoid arthritis, active joint deformity of arthritic origin, active cancer or renal disease, any kind of end-stage pulmonary or cardiovascular disease, or a deteriorated condition due to age, uncontrolled epilepsy or others).
Patients or healthy volunteers with increased intracranial pressure as evaluated by clinical means.
Patients with unstable cardiac arrhythmia.
Patients or healthy volunteers with h/o hyperthyroidism or individuals receiving drugs acting primarily on the central nervous system.
Patients or healthy volunteers with more than moderate to severe microangiopathy, polyneuropathy, diabetes mellitus, or ischemic peripheral disease.
Patients or healthy volunteers with diseased or damaged skin over the face or scalp.
Patients or healthy volunteers who have professionally practiced playing a keyboard musical instrument or trained as a typist.