Paired Associative Stimulation (PAS) for Stroke Rehabilitation

Inclusion Criteria: * The diagnosis of stroke is based on computed tomography (CT) or magnetic resonance imaging (MRI). * The diagnosis of first acute ischemic stroke in unilateral hemisphere within 3 weeks after onset. * Clinically evident arm hemiparesis attributable to acute ischemic stroke. * Age of 18-85 years. * The ability to sign a informed consent. Exclusion Criteria: * Any previous stroke. * Minor stroke with non-disabling deficit or rapidly improving neurological symptoms. * Prior participation in the present study, or planned participation in another therapeutic trial, prior to the final assessment in this trial. * Current participation in another study with an investigational drug or device. * Women known to be pregnant, lactating or having a positive or indeterminate pregnancy test. * Any intracranial surgery, intraspinal surgery, or serious head trauma (any head injury that required hospitalization) within the past 3 months prior to participation in the current study. * Presence or history of intracranial neoplasm (except small meningiomas) or arteriovenous malformation. * Intracranial aneurysm, unless surgically or endovascularlytreated more than 3 months prior to participation in the current study. * Seizure at the onset of stroke or a history of epilepsy. * Life expectancy less than 3 months. * Cardiac pacemakers, implanted medication pumps, intracardiac lines, or acute, unstable cardiac disease. * Other serious illness, e.g., severe hepatic, cardiac, or renal failure. * Acute myocardial infarction or complex disease that may confound treatment assessment. * Cognitive or verbal impairment that prevented understanding of or cooperation with the research study. Under the following medical conditions, treatment was stopped, and patients were excluded from the study: * Acute worsening of \> 4 points on the NIH stroke scale (NIHSS). * Acute symptoms of headache nausea and vomiting suggestive of possible sICH. * Occurrence of seizures. * Appearance of a new ventricular arrhythmia, tachycardia, fibrillation etc. or a new life-threatening supraventricular arrhythmia (e.g., rapid atrial fibrillation or supraventricular tachycardia). * Symptomatic bradycardia - heart rate less than 50 beats per min.