Findings by Dr. Teresa Kimberley affirm ”watershed moment” tying effectiveness of nerve stimulation with rehabilitation

Sean Hennessey

A new study led by MGH Institute researcher Dr. Teresa Kimberley has found that targeted brain stimulation therapy, combined with rigorous rehabilitation therapy, leads to sustained limb movement that is double that of someone who receives the therapy alone.

Dr. Kimberley is presenting her one-year data findings this week at the International Stroke Conference in Phoenix, which runs February 7-9. Calling it the “durability of effect,” she says it demonstrates that connecting a brain stimulation device to the vagus nerve – which runs from the brain and down the neck to the stomach – paired with rehabilitation therapy, can improve movement, function and quality of life.

“We saw the benefit of this pairing after 90 days, which was exciting,” said Kimberley. “The question was – could it be maintained over a year? The answer is yes. This is a watershed moment for rehabilitation science.

“These long-term, pivotal results enhance our long-term results from an earlier pilot study where we showed that patients continue to improve or maintain their gains up to three years after starting vagus nerve stimulation therapy paired with rehabilitation. As a clinician, it is surprising to see someone with chronic stroke – stroke that in many ways is a progressive disease – continue to improve and not show a decline.”

Over a year, the researchers looked at 74 stroke survivors aged 22 – 80 years old who had a stroke between nine months and ten years ago and had limited movement in their hands and arms.

“This helps to alleviate concern about whether or not vagus nerve simulation is a worthwhile intervention for stroke survivors to have,” said Kimberley.  “There’s always some nervousness about having something implanted into one’s body and whether it’s worth it. I understand that. This shows that people who benefit maintain the gains.”

Julie Hahnke suffered a stroke seven years ago and was part of the trial. She says of the fifteen different research studies since then, the VNS pairing by far made the greatest difference in her recovery.

“This study made the therapy full-on!” said Hahnke.  “A stroke survivor needs constant therapy to make any kind of progress towards long-term rehabilitation. Getting better has been my top priority during the last seven years, and I’ve made tremendous progress. It’s worth it!”

Kimberley’s team compared results using a control group that received a sham or fake stimulation and a group that got the real stimulation. The study was blinded, meaning neither the participants nor the researchers knew who was in which group. Over the course of six weeks, the participants with the real device implanted received  “nerve zaps” three times per week, stimulating the vagus nerve; combined with the rehabilitation therapy, it helped the brain create or strengthen new neural pathways like building a bridge to bypass a damaged road.

Following that, the sham group underwent the same six weeks of intense physical therapy with real stimulation as the other group. Both groups were sent home for a year of in-home exercise that was combined with daily stimuli to the vagus nerve. The implant, inserted just under the skin in the upper chest area, is activated when a magnet is swiped over the area, sending a “nerve zap” to the brain while the person does their exercises.

“This is quite impressive in the rehabilitation world because most studies don't follow people for a year - they might do three or six months,” said Kimberley. “And when we do follow people after a year, people’s movements generally decrease. So, maintaining an improvement for up to a year is quite a notable impact for people with stroke.”

Hahnke agrees but says stroke survivors need to put in the work.  

“If you’re not sure about the surgery, you have to ask yourself whether you’ll do the therapy afterwards,” said Hahnke. “If not, don’t bother. If you will, then this is the single best treatment for you!”

Kimberley, director of the Institute’s Brain Recovery Lab, began working on pairing Vagus Nerve Stimulation (VNS) with physical therapy concept a decade ago and helped develop the rehabilitation protocol the FDA says was necessary to pair with the Vivistim Paired VNS during rehabilitation therapy to improve upper extremity motor function.

Last year, thanks to the collaborative efforts of Mass General Brigham’s research and clinical institution, the first patient on the East Coast had the device implanted at Massachusetts General Hospital then underwent rehabilitation therapy at Spaulding Rehabilitation Hospital.

Kimberly says her latest research should set the stage for further developments in stroke recovery.

“This study focused on the arm but there's no reason why this wouldn't also work for gait, balance, speech difficulties, and cognition,” she said. “It opens the door wider now for this to be explored and provide a more comprehensive boost to therapy for people with stroke. It has the potential to address all of their impairments.”

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