Impact of VNS With Rehab on Gait Post-Stroke

The Impact of Vagus Nerve Stimulation Paired With Rehabilitation on Lower Limb and Gait Functions After Ischemic Stroke

This is a prospective, double-blinded, randomized controlled study to evaluate the impact of Vagus Nerve Stimulation (VNS) therapy on lower limb function.

Stroke is a major cause of disability worldwide and currently there is a lack of effective treatments to improve functional capacity of patients with long-term disability. Vagus Nerve Stimulation (VNS) is FDA-approved for rehabilitation of upper limb deficits in patient with stroke. The device (including Vagus nerve electrodes and chest generator) is permanently implanted prior to the beginning of rehabilitation as standard of care. It is activated by patients and physical therapists during a period of 4.5 months of in-clinic and home therapy. However, so far there have been no approved neuromodulation treatments to improve lower limb functions and gait, which are key for patients' quality of life and their ability to integrate with work and social cycles.

This project will evaluate the impact of VNS on lower limb functions as measured by clinical and laboratory-based analyses of gait in stroke survivors. Patients with both upper and lower limb deficits will be included in this project. After the completion of the standard upper limb VNS-rehabilitation protocol, patients will be double-blindly randomized into 2 groups: a) lower limbs and gait rehabilitation with VNS ON for the duration of therapy; b) lower limbs and gait rehabilitation with VNS OFF.

Based on prior experience with upper limb deficits, we hypothesize that rehabilitation therapy coupled with VNS neuromodulation will elicit functional improvements in lower limb deficits and gait.

Inclusion Criteria:

• Approved for Vagus Nerve Stimulation (VNS) and rehabilitation therapy
• ≥22 years and ≤ 80 years
• Only patients who elect to undergo VNS therapy for stroke-related upper limb deficits
• Residual active movement in the affected limb's thumb and other 2 fingers
• Stroke-related deficits in the lower limbs and gait with a Functional Ambulation Category (FAC) ≥3
• Able to follow simple instructions and independently walk short distances with or without external support or leg orthoses, but without manual contact with another person

Exclusion Criteria:

• Intact lower limb functions (Fugl-Meyer score=34)
• Not a candidate for VNS therapy according to FDA guidelines
• Pregnant patients