Visualizing physical improvement helps dysphagia sufferers
When speech-language pathologist Sarah Szynkiewicz and a group of colleagues launched a study aimed at helping aging adults perform exercises to improve their ability to swallow through increased tongue strength, one aspect of their research clearly stood out. The study’s participants thought about the exercises without actually performing them physically.
The technique is known in clinical research circles as mental practice using motor imagery and, in simple terms, it involved asking participants to visualize using their tongues to complete the exercise protocol. Szynkiewicz, an assistant professor of language-speech-hearing at the University of South Florida Sarasota-Manatee campus, led a team of researchers whose goal was to help reverse a common condition in older adults, reduced tongue strength, which can lead to dysphagia, or difficulty swallowing.
They hope to eventually show that the technique can be widely implemented as a therapeutic treatment for individuals suffering from dysphagia, which typically emerges as a symptom of a primary cause such as stroke, Alzheimer’s disease or Parkinson’s disease that damages the part of the brain that controls the swallowing mechanism.
The results of the six-week feasibility study, funded by a USF Sarasota-Manatee campus pilot research grant, were encouraging. Six healthy, typically aging female participants between 53 years old and 78 years old all “significantly increased their tongue strength compared to baseline,” the researchers wrote in an article appearing in the June 2019 issue of the “Journal of Speech, Language and Hearing Research.”
The aspect of the study that made it unique—their hypothesis that mental practice of a physical exercise can produce measurable results—is rooted in sports exercise science, Szynkiewicz said. For example, golf teachers sometimes instruct novice players to visualize hitting a golf ball at a target before actually stepping up to the tee and making a swing. Similar approaches to transforming a mental image into an executable action can be found in other sports, but the concept is the same: Mental practice has been shown to activate and train similar areas of the brain as actual movement without actually moving anything.
“Motor imagery is creating a representation of a motor task in your mind and mental practice refers to repetitive practice of the motor imagery task,” Szynkiewicz said. “Historically, in the physical and occupational therapy worlds, research has found that physical exercise plus mental practice leads to better motor outcomes than just strength training alone. It approaches rehabilitation in a more holistic way, because you’re not just focusing on the physical part, you’re also focusing on the cognitive part. In both cases, you’re activating similar neural pathways, so the combination of physical and mental therapy allows the patient to achieve more repetitions with less fatigue.”
For the tongue strengthening research, Szynkiewicz used a specially designed device, the Iowa Oral Performance Instrument, to measure maximum tongue strength. Measurements were taken at the beginning and end of the study and at two other increments during the six-week period. The research protocol involved participants practicing only using mental practice of the motor imagery, simulating the act of exerting tongue pressure against food items of varying hardness such as a Jell-O cube, a grape or a piece of licorice or marshmallow. They performed the mental practice three times a day three days each week at home.
With the study’s findings supporting the initial viability of mental practice to reverse loss of tongue strength, the researchers already have begun to expand their work.
“The first study tells us more about how mental practice might contribute to increased tongue strength in a healthy, aging adult,” Szynkiewicz said. “We’ve since completed a larger pilot study in both men and women that confirms these results. The next step we’re planning is a grant proposal to look at this in Parkinson’s disease patients who have swallowing issues and decreased tongue strength. From there, that will help us get a better idea of how this works in the disordered population.”
- John Dudley
(Above) Sarah Szynkiewicz tests a student’s tongue strength using the Iowa Oral Performance Instrument.
Research: USF Sarasota-Manatee Campus
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Practice Makes Perfect
To test whether mental practice would increase tongue strength, Szynkiewicz instructed patients to imagine pressing their tongue against food items. Each week, the patient would choose a harder food item that would require more pressure. Below are example foods and the peak tongue pressures measured in the study. By the sixth week, tongue strength improved by a mean of 13 kPa* from visualization alone.