The US Food and Drug Administration (FDA) has approved the Vivistim System (MicroTransponder), a first-of-its kind vagus nerve stimulation (VNS) system intended to treat moderate-to-severe upper extremity motor deficits associated with chronic ischemic stroke.
"People who have lost mobility in their hands and arms due to ischemic stroke are often limited in their treatment options for regaining motor function," Christopher M. Loftus, MD, acting director of the Office of Neurological and Physical Medicine Devices, FDA Center for Devices and Radiological Health, said in a news release.
Approval of the Vivistim Paired VNS System "offers the first stroke rehabilitation option using vagus nerve stimulation. Used alongside rehabilitative exercise, this device may offer benefit to those who have lost function in their upper limbs due to ischemic stroke," Loftus said.
Tells Brain to "Pay Attention"
The Vivistim System is a prescription implantable device intended to be used in conjunction with intensive stroke rehabilitation.
The system stimulates the vagus nerve while the patient is undergoing a rehabilitative movement, which tells the brain to "pay attention" to that movement, the company explains on its website.
This simultaneous pairing of a specific movement with VNS strengthens motor circuits associated with the physical movement.
"Consistently pairing VNS with specific neural circuits helps rebuild those circuits and the brain relearns the commands to enable the muscles to perform specific tasks and can strengthen those muscles as well," the company notes.
The safety and effectiveness of the Vivistim System paired with stroke rehabilitation were demonstrated in a phase 3, sham-controlled study of 108 patients with long-term moderate-to-severe arm weakness after ischemic stroke.
Effectiveness was measured using the Fugl-Meyer Assessment for Upper Extremity (FMA-UE), a stroke-specific measure of motor impairment. Progress was measured as an increase in motor function from baseline after 6 weeks of therapy.
As reported at the time by Medscape Medical News, the findings were presented last year at the European Stroke Organisation-World Stroke Organisation (ESO-WSO) Conference.
Results showed that patients who received active VNS stimulation had an average score increase of 5 points on the FMA-UE, whereas patients in the sham group had an average score increase of 2.4 points (P = .001).
Additionally, 47.2% of the active stimulation group showed an improvement in FMA-UE score of six or more points 90 days post-therapy versus 23.6% of the sham group (P = .01).
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 FDA reported.
The Vivistim System was granted breakthrough device designation and was reviewed under the FDA's premarket approval pathway, which is the most stringent type of device marketing application required by the agency.
The designation was based on a determination by the FDA that the premarket approval application contained "sufficient valid scientific evidence to provide reasonable assurance that the device is safe and effective for its intended use."
Cite this: FDA OKs First Vagus Nerve Stimulation System for Stroke Rehab - Medscape - Aug 27, 2021.