VNS During Rehabilitation for Improved Upper Limb Motor Function After Stroke

Inclusion criteria

• History of ischemic stroke that occurred at least 4 months prior to enrollment, but not more than 24 months prior
• Age >30 years and <80 years
• Right or left sided weakness of upper extremity
• UEFM score within designated range.
• At least 10 degrees of wrist extension, 10° of thumb abduction/extension, and at least 10° of extension in at least 2 additional digits

Exclusion criteria

• History of hemorrhagic stroke
• Any deficits in language or cognitive functioning that hinders participation, for example, (aphasia) or unable to follow 2 step commands.
• Significant sensory loss.
• Presence of ongoing dysphagia or aspiration difficulties.
• Active major neurological or psychiatric diagnosis that would likely interfere with study protocol including prior history of brain lesions (including dementia, etc.), and current alcohol abuse, drug abuse, or epilepsy.
• Subject receiving any therapy (medication or otherwise) at study entry that would interfere with VNS (e.g. drugs that interfere with neurotransmitter mechanisms). Additionally, no psychoactive medications - including nicotine - may be used during the acute study.
• Prior injury to vagus nerve - either bilateral or unilateral (e.g., injury during carotid endarterectomy)
• Severe depression
• Not considered candidate for a device implant surgery (history of adverse reactions to anesthetics, poor surgical candidate in surgeon's opinion, etc.)
• Any other implanted device such as a pacemaker or other neurostimulator; any other investigational device or drug
• Medical or mental instability (diagnosis of personality disorder, psychosis, or substance abuse)
• Pregnant or plan on becoming pregnant or breastfeeding during the study period
• Currently require, or likely to require, diathermy during the study duration
• Any health problem requiring surveillance with MRI imaging
• Active rehabilitation within 4-weeks prior to therapy
• Botox injections or any other non-study active rehabilitation of the upper extremity 4-weeks prior to and during therapy
• Severe spasticity of the upper limb