UC trial tests tongue exercises to improve swallowing function after stroke

Source: www.uc.edu
Author: Tim Tedeschi

Up to three-quarters of all stroke survivors have some form of difficulty swallowing (dysphagia) after a stroke. Dysphagia frequently leads to entry of food or liquid into the lungs and has significant impacts on patients’ overall health and quality of life.

In the most severe cases, patients are no longer able to eat or drink at all or can die from aspiration pneumonia. Because eating and drinking are pivotal to participating in life socially, dysphagia can also lead to depression.

A new trial at the University of Cincinnati Gardner Neuroscience Institute, funded by a $660,000 National Institutes of Health (NIH) grant, will test an at-home tongue endurance exercise to improve patients’ swallowing function.

Research background
Speech language pathologist and trial principal investigator Brittany Krekeler, PhD, said swallowing issues can sometimes be a “hidden” disorder, because it is usually secondary to other diseases.

“You hurt for these patients when they can’t enjoy eating and drinking, and swallowing disorders can be a burden on family members as well,” said Krekeler, assistant professor and clinician-scientist at the UC College of Medicine’s Dysphagia Rehabilitation Laboratory. “From working with these patients clinically, we see how much it means for patients to be able to eat and drink again.”

Krekeler said research into improving swallowing function is relatively new, as historically the problem was addressed by giving feeding tubes to patients with post-stroke dysphagia. But feeding tubes can fall out, can get infected and prevent patients from being able to enjoy sitting down to a meal with loved ones, she said.

Because studying swallowing disorders is both difficult and expensive, there are still few evidence-based practices to improve swallowing function.

“Treating dysphagia is like an artform, so depending on what therapist you go to, you’ll get a different approach,” Krekeler said. “Current treatment approaches are really a mixed bag depending on what institution you’re at and what therapist you’re seeing.”

This trial is part of a larger effort to take out the guesswork and provide concrete evidence-based recommendations on what approaches will be most effective.

Trial details
Tongue exercise is a common component of therapy for these patients, often focused on improving total tongue strength, which Krekeler said is similar to maxing out how much weight you can lift at the gym at one time. This trial will test a different approach by focusing on tongue endurance, which is more like lifting a smaller weight many times in a row.

“When we swallow, we don’t press our tongue as hard as we can each time, rather we generate sub-maximal pressure with each swallow, and we do it repeatedly throughout the day and throughout a meal,” she said. “It’s more about being able to do a lot of movement with the tongue throughout a meal versus pressing really hard, which is not really what we do in swallowing.”

The study will enroll patients who have trouble swallowing three to six months after their stroke. Krekeler said it is a unique time when the brain has increased neuroplasticity, or the ability to change and adapt following an injury like a stroke. Often times when she sees patients in the clinic, Krekeler said it is a year or more following their stroke and there is less opportunity for improvement.

“We are seeing people in this trial when they’re done with their acute stroke but they’re still not fully recovered because we hope to jump in during that time and build on neuroplasticity to get them better before they are out of that window of recovery,” she said. “It’s kind of a magical period.”

Patients enrolled in the study will receive a device with a pressurized bulb that connects to their phone or tablet through Bluetooth to give them real-time feedback about how hard they are pressing the bulb with their tongue. Participants in the trial will press their tongue to the bulb, with the device recording the number of times they do so and if they meet their goal. They’ll complete the exercises three times a day for eight weeks, with their goal increasing as they build endurance.

“We think that learning how to use the device might actually be part of the therapy, and in our field, we haven’t really looked at the learning curve in terms of using your tongue to do something new,” Krekeler said. “To investigate this potential learning effect, we’re also doing MRIs on a small subset to see what changes occur in the brain with learning how to use a tongue device.”

Swallow studies before and after the eight weeks will also help measure the changes in swallow function before and after the trial.

“Besides regaining the ability to walk and be mobile after a stroke, being able to swallow food and water without choking or having substances go into the lungs with very bad consequences is the most important day-to-day activity that patients value,” said Joseph Broderick, MD, director of the UC Gardner Neuroscience Institute, co-principal investigator of the national coordinating center for the NIH StrokeNet and professor in UC’s Department of Neurology and Rehabilitation Medicine. “Improving the recovery of swallowing after stroke would be a great advance in the care of stroke patients.”

The trial is expected to enroll 60 patients over five years, and patients will receive compensation. Participants will be recruited from UC and other health care providers in the Tristate area.

Krekeler said while she is focused on stroke patients, there is potential for the knowledge gained in the trial to be applied to swallowing issues stemming from other conditions including head and neck cancer and Parkinson’s disease.

“This is just the beginning of building a body of research to try to figure out what combination of interventions is best to recover swallowing function,” Krekeler said. “We don’t think tongue endurance exercise is the only component of therapy that’s important, but this is a starting point. We really want to see if this makes a bigger change than strength training.”