Stroke survivors who received vagus nerve stimulation (VNS) combined with rehabilitation had better arm and hand function, according to the results of a new study.
In the international, multi-center clinical trial, 53 participants with moderate to severe arm weakness nine months to 10 years post-stroke received rehabilitation paired with VNS. Fifty-five patients within the same parameters received a sham stimulation. The randomized, triple-blind trial was funded by medical device company MicroTransponder and published in The Lancet.
Those receiving the nerve stimulation had a wire inserted into their neck that wrapped around the vagus nerve. The wire was then connected to a pulse generator device implanted in the chest. Those receiving the sham received placebo implants.
After the surgical procedure, all patients received six weeks of in-clinic therapy, which included tasks such as reaching and grasping, simulated eating, and opening and closing containers. After the in-clinic period, patients continued treatment with a course of daily home therapy.
When the two patient groups were compared, those receiving the nerve stimulation showed improvements were two to three times greater than those who received sham, according to the researchers at the University of Southern California Keck School of Medicine in Los Angeles.
“This is incredibly exciting news for everyone involved in stroke rehabilitation and functional restoration and represents a unique intersection between neurosurgery and neurorehabilitation,” said Dr. Charles Liu, the lead neurosurgeon of the study and director of the USC Neurorestoration Center at the medical school. “These study results are the first of their kind, and open up new possibilities for stroke patients, allowing them to reclaim more arm function even years after having a stroke.”
The VNS device is thought to work by triggering the release of brain neuromodulators — which regulate the body’s responses — to strengthen motor circuits in the brain associated with movement, enabling the brain to effectively relearn tasks. VNS is already used widely for the treatment of epilepsy and plays an increasing role in the treatment of severe depression.
“For too long, stroke patients have faced limited options for recovery,” Liu said in a news release. “This new treatment signifies a breakthrough that could be life-changing for many stroke patients and also represents an approach that will certainly be explored for many other functional restoration applications in the future.”