A novel therapy involving vagus nerve stimulation (VNS) paired with rehabilitation was approved to treat chronic moderate to severe upper extremity motor deficits after ischemic stroke, the Friday.
"Today's approval of the Vivistim Paired VNS System offers the first stroke rehabilitation option using vagus nerve stimulation," said Christopher 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."
Vivistim is the first system of its kind approved to help stroke patients move their arms and hands. It stimulates the vagus nerve through an implantable pulse generator placed just under the skin in the chest. Attached to the pulse generator is a wire that leads to electrodes placed on the left side of the neck.
The FDA's decision was based on the pivotal of 108 patients with moderate-to-severe arm weakness at least 9 months after ischemic stroke. Participants were randomized into a study (53 patients) or control (55 patients) group; each was asked to complete 300-400 physical therapy exercises for 90 minutes a day, three times a week for 6 weeks.
The control group received a very low level of VNS for the first five of the 300-400 exercises and no stimulation for the rest of each session. The treatment group received the appropriate amount of VNS throughout all 90-minute sessions.
At 6 weeks, the on the Upper Extremity Fugl-Meyer Assessment (), a stroke-specific measure of motor impairment. The control group had an average score increase of 2.4 points. At 90 days after in-clinic therapy, 47.2% of the treatment group saw an improvement of 6 or more points on the FMA-UE, compared with 23.6% of controls.
Adverse events included 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 said.
Patients should discuss any prior medical history of the following with their health provider: other concurrent forms of brain stimulation; current diathermy treatment, depression or suicidality; schizophrenia, schizoaffective disorder, or delusional disorders; rapid cycling bipolar disorder; previous brain surgery or central nervous system injury; progressive neurological diseases other than stroke; cardiac abnormalities; respiratory diseases or disorders; ulcers; vasovagal syncope; and pre-existing hoarseness.
Accompanying the implantable components of the Vivistim system are clinician software preloaded onto a laptop and a wireless transmitter to be used by a healthcare provider only. The system also may be used at home with a magnet that can be passed over an implanted pulse generator.
Vivistim, a prescription device, is not approved for other use, the FDA added, and should not be used in patients with vagotomy. The system is manufactured by MicroTransponder.