Can device, size of stick of gum, help stroke patients regain balance?

November 21, 2023
Man wearing a baseball cap puts a device in his mouth. A harness is helping to support him, as is a woman standing beside him. She has a long dark ponytail.
Research associate Shraddha Srivastava, Ph.D., checks the support harness on stroke survivor Chad Wentzel as he prepares to walk with a device on his tongue designed to stimulate cranial nerve endings. Photos by Sarah Pack

A device the size of a stick of gum that goes on the tongue could make an important difference in the life of some stroke patients – if it does well in a clinical trial underway at the Medical University of South Carolina. Chad Wentzel, a family landscape company manager from Summerville, is among the first participants. He had a stroke several years ago. 

“Four-and-a-half years, almost five now – January will be five years. I'm willing to do anything to get better,” Wentzel said.

So he agreed to participate in the trial to test whether a device called the Portable Neuromodulation Stimulator, or PoNS, can stimulate areas of the brains of stroke survivors that help maintain physical balance. The study combines PoNS therapy with balance training and breathing exercises to try to improve walking stability.

A man attached to a harness walks with the help of two women. 
Occupational therapist Danielle Feerst and research associate Shraddha Srivastava, Ph.D., help Chad Wentzel place his feet properly during a balance exercise. The device remains on his tongue.

The research is the brainchild of Steven Kautz, Ph.D., chair of the Department of Health Sciences and Research at MUSC. He read about research that led to an earlier version of the device in a book called “The Brain That Changes Itself” by Norman Doidge, M.D. 

Doidge wrote about a woman whose balance was damaged by the overuse of the antibiotic gentamicin. Researchers used a plastic strip with electrodes placed on her tongue to send balance signals to her nervous system. According to Doidge, it was life-changing for the patient.

Steve Kautz 
Dr. Steven Kautz

Helius Medical Technologies Inc., the company that makes the device now known as PoNS, has Food and Drug Administration approval for use of the device with physical rehabilitation exercise to help people with another issue: mild to moderate symptoms of multiple sclerosis.

So could it also help people with balance problems due to strokes? Its mechanism looks promising to Kautz. 

“The part of the electrode that's on the tongue provides electrical stimulation that then activates the nerves in the tongue that talk to many other places in the brainstem and ascending and descending pathways. And so it's thought to affect the transmission of information between the brain and the movements, which has the potential to improve balance in this population,” Kautz said.

“Balance is, in a lot of ways, a brainstem-controlled activity. And so it's not surprising that that there could be influences on balance if people receive this stimulation while they're practicing walking and balance activities.”

The PoNS study is one of several efforts underway at MUSC to try to help stroke survivors. To put into perspective the strength of MUSC’s stroke care, MUSC Health remains the only Comprehensive Stroke Center in the Lowcountry. Other key innovations: 

  • Kautz is leading a separate study on using transcranial magnetic stimulation to assess how well the brain and certain muscles are communicating after a stroke.
  • MUSC Health recently became the first site in the Carolinas to use vagus nerve stimulation to try to help a stroke patient recover more of the use of his right hand.
  • MUSC researchers partnered with Charleston County Emergency Services to test the use of a portable magnetic resonance imager in an ambulance to try to speed the diagnosis of strokes and guide early treatment decisions.

There’s a good reason for all of this emphasis on stroke patients. “Stroke is the leading cause of disability in the country in terms of a neurological condition, and with us being in the buckle of the stroke belt, we have a lot of need in our community,” Kautz said. 

“We have the Center of Biomedical Research Excellence and Stroke Recovery with a lot of people with expertise. And we've done a lot of work with neuromodulation in many different ways. And so this PoNS study was right in our wheelhouse of a new neuromodulation approach that hadn't been tried yet in a realistic way in stroke,” Kautz said.

“There's one study in Australia in stroke that showed that it worked in stroke patients, similar to the way it does in multiple sclerosis. So there is a little bit of evidence there, but that study was done in a hospital where they had people that could do it multiple times a day, and that kind of thing that just doesn't translate to the American health care system.”

His study is designed to translate into real-world care. It brings in participants three days a week for one month and they then do three days a week for two months at home in order to receive three months of training. Each session lasts an hour, including walking, balancing and meditative breathing – all with the tongue device activated.

A woman in a bright orange sweater takes the blood pressure of a man whose back is to the camera. He is wearing a gold baseball cap. 
Occupational therapist Danielle Feerst takes Chad Wentzel’s blood pressure.

“It's a low amount of current. And so we don't expect any adverse events. There's no sort of known side effects that we have reason to suspect. But that's part of doing a study like this; this just hasn't been done to that many people. And these people have lots of comorbid issues at the same time that can cause them to have upticks in pain and other things,” Kautz said.

Those issues are part of what the study takes into account. 

Kautz also said that while he is a paid consultant for the company that makes the device, he is not being directly paid for the PoNS trial. “It's experimental. So as hopeful as we are for it, there are no guarantees that it's going to be beneficial. But we think it's an exciting possibility. We won't know the answer for around a year before we collect all the data and then can unblind because it's a blinded study where people could be getting the sham or they could be getting real stimulation. Bottom line is that we think it's exciting.”

Wentzel is hopeful enough to travel from Summerville to downtown Charleston each week, even though neither he nor the therapists he’s working with know if he’s getting the real deal or a placebo. He had this advice for other stroke survivors. “Just keep on going and do everything you can do. Every day.”

The trial is still looking for more participants. For further information, email Shraddha Srivastava or call 843-792-6165.