Vagus Nerve Stimulation System Approved for Post Stroke Rehabilitation Therapy

The Food and Drug Administration has approved the MicroTransponder Vivistim Paired VNS System (Vivistim System) to treat moderate to severe upper extremity motor deficits associated with chronic ischemic stroke using vagus nerve stimulation (VNS).

The Vivistim System features an implantable pulse generator (IPG) that is placed under the skin in the patient’s chest and generates a mild electrical pulse. A lead wire is attached to the IPG and is implanted under the skin leading up to electrodes that are placed on the left side of the neck. The VNS system also includes clinician software preloaded onto a laptop and a wireless transmitter. Health care providers are able to input IPG settings (eg, amplitude, frequency, pulse width) as well as record stimulation history and the movements performed. 

The approval was based on efficacy and safety data from a randomized, sham-controlled study (ClinicalTrials.gov Identifier: NCT03131960) in 108 patients with moderate to severe arm weakness after at least 9 months following an ischemic stroke. Patients were randomly assigned 1:1 to receive either the Vivistim System or sham stimulation, in addition to rehabilitation therapy. The primary efficacy outcome was mean change in impairment measured by the Fugl-Meyer Assessment-Upper Extremity (FMA-UE) score.

Findings demonstrated that patients in the Vivistim System group achieved a mean score increase of 5 points compared with 2.4 points in the control group (difference, 2.6; 95% CI, 1.0-4.2; P =.0014). Moreover, 47.2% of patients in the Vivistim System group had an improvement of at least 6 points in the FMA-UE score 90 days post therapy vs 23.6% of those in the control group. 

As for safety, adverse events included, but were not limited to, dysphonia, bruising, falling, general hoarseness, general pain, hoarseness after surgery, low mood, muscle pain, fracture, headache, rash, dizziness, throat irritation, urinary tract infection and fatigue. The Vivistim System should not be used in patients with vagotomy.

“Today’s approval of the Vivistim Paired VNS System offers the first stroke rehabilitation option using vagus nerve stimulation,” said Christopher M. Loftus, MD, acting director of the FDA’s Center for Devices and Radiological Health’s Office of Neurological and Physical Medicine Devices. “Used alongside rehabilitative exercise, this device may offer benefit to those who have lost function in their upper limbs due to ischemic stroke.”

The Vivistim System is a prescription device that can be used in both clinical and at-home settings. For at-home rehabilitation use, patients will need to be trained on how to use the Vivistim System at home.

References

1. FDA approves first-of-its-kind stroke rehabilitation system. News release. US Food and Drug Administration. Accessed August 27, 2021. https://www.prnewswire.com/news-releases/fda-approves-first-of-its-kind-stroke-rehabilitation-system-301364373.html. 
2. Dawson J, Liu CY, Francisco GE, et al. Vagus nerve stimulation paired with rehabilitation for upper limb motor function after ischaemic stroke (VNS-REHAB): a randomised, blinded, pivotal, device trial. The Lancet. Published online April 24, 2021. doi.org/10.1016/S0140-6736(21)00475-X.