One researcher’s mission to restore hope to Parkinson’s patients and others with swallowing disorders includes teaching them exercises to build strength and function
The act of swallowing is deceptively complex, a symphony of physiology that relies on the split-second, seamless coordination of 26 muscles and nine cranial nerves. The ability to swallow is essential for eating and drinking, and yet about 20 million adults in the U.S. experience a condition called dysphagia — literally, difficulty swallowing.
Some people’s symptoms are so severe, they are unable to swallow food or even their own saliva.
“Swallowing is probably one of the most complex neuromotor behaviors a human being can do,” said Giselle Carnaby, PhD, MPH, CCC-SLP, a professor in the Department of Health Sciences in the School of Health Professions at The University of Texas Health Science Center at San Antonio.

“It is connected to one of the cardinal, or most important, things that humans like to do, that gives them comfort, gives them self-identity, gives them reward and socialization — which is eating. Imagine if you couldn’t eat at all or drink anything, and you had to sit and watch everybody else,” said Carnaby. “On the tree of important things that humans do, it’s second to breathing.”
A speech pathologist and public health scientist, Carnaby has spent more than three decades in
clinical practice actively researching swallowing and swallowing-related disorders and developing therapies to treat the most severe cases. She joined the faculty of the School of Health Professions in 2021 and directs the PhD in Health Sciences program, a collaboration with the university’s Graduate School of Biomedical Sciences.
Carnaby also founded the Swallowing and Upper Aerodigestive Research Laboratory, where she is conducting a study to determine whether an exercise-based dysphagia intervention — the
McNeill Dysphagia Therapy Program that was originally developed to help people recovering from stroke — can be used as a preventative intervention for people with early Parkinson’s disease.
This is not to cure Parkinson’s. It is secondary prevention, said Carnaby.
“If we can show a difference in pre- and postintervention in early Parkinson’s patients who do not have obvious difficulties with swallowing, then the conceptual background is that it should be more beneficial in patients with more significant issues,” she said.
As Carnaby explains, dysphagia in people with Parkinson’s disease increases morbidity and mortality and decreases quality of life; the progressive neuromuscular disorder causes swallowing disorders in about 80% of patients at some period over the disease.
‘We can remediate this’
Carnaby decided to pursue a career in research because she grew frustrated by unanswered
questions early in her career in her home country of Australia.
“After working for a number of years in an acute care hospital, I realized that I didn’t have any answers to any of the questions I wanted to ask, and I couldn’t find answers anywhere,” she said.
So, she chose to focus on swallowing while earning a Master of Public Health degree and then a PhD in public health. Her passion stems from witnessing the strain, serious illness and even death that dysphagia can cause and knowing that something can be done for it.
“Food nourishes the brain,” Carnaby said. Not being able to access that nutrition simply because you can’t eat opens you up to all sorts of health problems, she added.
“And it’s so, so preventable. We can remediate this. We can fix it. We can change it. There are very few cases I have run across in my history that I can’t help in some way,” Carnaby said. “I can’t think of anything more socially isolating than not being able to eat or drink anything.”
Empowering patients to rehabilitate
Carnaby is collaborating with a multidisciplinary team of researchers from the university, including Assistant Professor Megan Carreon, MA, RRT, in the Department of Respiratory Care; and Associate Professor Okeanis Vaou, MD, FAAN, in the Department of Neurology.
“What’s different here is the level of expertise and the access to the high-end study equipment we have here,” Carnaby said of the specialized imaging, swallow and lingual strength measurement and respiratory equipment that enables researchers to see, hear and measure what is happening during the study participants’ swallowing in therapy.
The program the team is researching forces the participants’ muscles to work fast and hard while progressing through a hierarchy of increasingly hard-to-swallow foods, said Carnaby, who said the process is similar to developing a workout routine.
“The best way to describe it is you go to the gym and start with a simple exercise like walking on the treadmill. Then you introduce weights, and then you are dancing and lifting your legs higher,” she said. “Every next activity is harder and more challenging and pushes your system, so you are not just growing in strength, you are growing in range and coordination and complexity of movement pattern. It layers on.”
It is the same with swallowing.
“It is developmental over a period of time, forcing the mechanism to work in ways it is not normally being used,” she said.
The therapy program combines motor control elements so that motor function is changed as patients build strength. Patients practice at home. They and their families are trained on the intensive therapy so that they can return to the methods as needed after leaving the therapy setting.
“The patient takes it home with them, and it lives with them, and it changes their behavior from the ground up,” Carnaby said.
Changing minds
The conventional thinking in health care regarding swallowing disorders holds that swallowing is a reflex that will return, and that until then, the priority should be keeping patients safe, Carnaby said. The typical treatment for swallowing disorders often is one of managing the swallowing disorder rather than actively seeking to rehabilitate it.
“Years ago, we used to modify diets and keep patients on easy-to-eat, mushy foods,” she said. “This is the reverse of that.”
The exercise-based approach used in the Parkinson’s study is customized to each patient. The decision to work with people with Parkinson’s disease was an intentional choice to flip the original timing of the therapy on its head.
“What we are doing with the Parkinson’s patients is saying, ‘Let’s take this idea of rehabilitation and this intensive rehabilitation program that we know works, and let’s provide it as a preventative,” she said. “Teach it up front and then maybe we will extend the period of time where their swallowing is normal and easy for them.
“If we can make them safer and more effective functional feeders for longer, we save costs, save hospitalizations, save stress, save morbidity. There are lots of benefits.”
Carnaby is treating patients under research protocol, and she continues to hear from people around the world who are seeking help for severe dysphagia that has not been treated successfully. Although stroke, head and neck cancer and Parkinson’s disease are some common conditions that increase the risk of swallowing disorders, age is another risk factor, as are a range of other conditions for which Carnaby sees potential for helping people maintain or regain their swallowing fitness.
“We’re slowly changing people’s minds about how you do this sort of intervention and with different populations,” she said.
Untangling your tongue: A patient’s perspective
Although it has been 18 years since Carlos González was diagnosed with Parkinson’s disease, he only began to experience problems with swallowing about two years ago.
González and his wife, AnnaMaria Ornelas, are always seeking to learn more about treatment options for

Parkinson’s. When they learned that Professor Giselle Carnaby, PhD, MPH, CCC-SLP, was giving a presentation on a swallowing intervention for people with Parkinson’s, they hurried home — from their boxing group for people with Parkinson’s — to freshen up and attend. After hearing Carnaby speak, they were on board.
“We didn’t even think twice,” Ornelas said. “We said, ‘This is what we need to do.’”
“I’m always willing to try something new and different,” González said. “It made a lot of sense to me.”
Carnaby is researching the effectiveness of an exercise-based dysphagia intervention for people with Parkinson’s disease who are experiencing the swallowing disorder called dysphagia. She believes the approach may help prolong their swallowing proficiency before it becomes significantly affected by the progression of their disease.
When González joined the study in 2024, he underwent imaging and other assessments, including the measurement of his swallowing frequency. Over the course of 12 sessions, he learned a specific method for eating that includes paying attention to his breathing and swallowing and employing strategies for clearing food from his throat. He built up his strength and technique by working through a hierarchy of foods that are increasingly difficult to eat, with one of the hardest being a Cobb salad.
“I think my tongue began to untangle itself,” he said of the changes he noticed. He compared the intervention to a workout, but one that is calibrated depending on the food being eaten.
“What Dr. Carnaby is doing is a whole new technique,” he said. “She describes it as doing a pushup.”
Before beginning the program, González carried a folded napkin to wipe his mouth because his slower rate of swallowing caused him to drool. He also would cough frequently to clear food lodged in his throat. Both issues subsided with treatment, he said.
At the end of the program, González took a test of sorts: He had to consume 400 calories of a meal of his choice in 30 minutes. As he worked his way through a pile of breaded chicken strips and fries, Carnaby monitored his progress and offered encouraging reminders.
“Swallow hard and fast,” she said. “Less is more with this kind of stuff. Keep it as simple as possible.”