Stroke patients often lose strength in their arms and hands, and while physical therapy can allow for some improvement, oftentimes results will stagnate. However, in a recent international, multi-center clinical trial, patients with moderate to severe arm weakness received rehabilitation paired with vagus nerve stimulation (VNS) that achieved positive results.
The trial consisted of 53 participants with arm weakness 9 months to 10 years post-stroke who received the VNS, along with 55 patients with the same conditions who received a placebo treatment. This trial was led by MicroTransponder and was published in The Lancet.
The treatment consisted of a surgical procedure that implanted a wire into the neck and wrapped around the vagus nerve. The wire was connected to a pulse generator implanted in the chest. During therapy, a therapist activates the pulse generator.
The device is believed to work by releasing brain neuromodulators which help connect motor circuits associated with movement. This allows the brain to relearn tasks patients were capable of pre-stroke by helping restore communication throughout the brain.
All patients received six weeks of in-clinic therapy to work on grasping, reaching, simulated eating, and opening and closing containers. After the six weeks patients completed daily at-home therapy.
Lead neurosurgeon of the study and Director of the University of Southern California Neurorestoration Center Dr. Charles Liu stated, “This is incredibly exciting news for everyone involved in stroke rehabilitation and functional restoration and represents a unique intersection between neurosurgery and neurorehabilitation…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.”
Treating stroke patients is not the only application for VNS. This treatment has already been used to treat epilepsy and is beginning to treat patients with depression as well. Researchers plan to study treating other cases of functional restoration in the future.
VNS is opening doors that will enable researchers to provide patients with new solutions for long term conditions, allowing patients who have lost hope in regaining functional strength to retrain their brains and gain control over their bodies once again.