Paired Associative Stimulation (PAS) for Stroke Rehabilitation

Comparison of Two Deep TMS Protocols With Paired Associative Stimulation (PAS) for the Treatment of Motor Impairement in Stroke Patients

Paired associative stimulation (PAS) delivered with multi-channel deep transcranial magnetic stimulation (dTMS) may enhance motor recovery in patients with first-ever ischemic stroke. This study evaluates whether dTMS-PAS targeting both primary motor cortices (M1-M1) improves upper-extremity hemiparesis when administered at the early subacute stage (up to three weeks poststroke).

Unilateral ischemic stroke disrupts the activity balance between the hemispheres, which hinder brains' recovery and treatments' efficiency. The most common and pervasive acquired postischemic stroke functional disorder is hemiparesis of the upper-extremity. The limited impact of conventional rehabilitation therapies is attributed to their inability to restore the interhemispheric balance. Thus, PAS protocol, delivered using dTMS, may benefit patients by regaining the interhemispheric balance. PAS is delivered over two different cortical brain areas, and the modulation of interhemispheric balance is determined by which area is stimulated by the first pulse and which by the second. In this study, the investigators apply a dTMS-PAS protocol over the two primary motor cortices, to restore the activity balance between M1-M1, alleviate upper-extremity hemiparesis symptoms, and promote functional recovery.

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.