Catriona Steele
Ph.D., CCC-SLP, SLP(C), CASLPO

Like breathing or blinking, swallowing is something healthy people do automatically, countless times each day. Although the exact mechanism is still a mystery, swallowing is a complex process involving 25 pairs of muscles firing in sequence. When accident or disease interfere with this process, the results can be devastating.

People with degenerative diseases like Parkinson's disease or head and neck cancers are prone to swallowing disorders (also known as dysphagia). So are stroke survivors and older people. Studying the causes and treatments of swallowing disorders is the research focus of Dr. Catriona Steele, a Scientist at Toronto Rehab.

"In very serious cases, people can't eat or drink at all - or even swallow their own saliva," says Dr. Steele. "Even for people with less severe symptoms, dysphagia can mean a lifelong diet of pureed and thickened liquids. Obviously a disorder like this has huge social and quality-of-life implications." Serious swallowing problems can even lead to fatal pneumonia.

To learn what causes dysphagia, Dr. Steele is studying the behaviour of a key component of the swallowing process: the tongue. "Using state-of-the-art equipment that measures tongue movement, we are trying to find out why people with Parkinson's disease often have difficulty swallowing.

"We are also trying to distinguish changes in swallowing caused by normal aging from those caused by disease. We've learned that older people are already at a disadvantage when it comes to swallowing. When a disease affects their ability to swallow, they are less able to compensate."

Treatments for dysphagia are still evolving. Dr. Steele is particularly interested in a new technique called EMG (electromyography) biofeedback.

In EMG, electrodes are attached to the skin of the neck. They "read" muscle activity and display the results on a computer screen. This allows patients to receive immediate feedback about an automatic activity. Using this feedback, they can consciously relearn how to swallow.

"We've found EMG can definitely help some people relearn control over the muscles that control swallowing. For instance, we have taught some stroke survivors with dysphagia how to swallow in just a couple of weeks. They went from being unable to swallow to being able to eat at least some foods.

"We're still studying this technique but so far, we've had very promising results - even with hard-to-help individuals, including patients with head and neck cancer. These people need to be persistent, but we have seen some real success stories."

A speech pathologist by training, Dr. Steele has long been interested in swallowing disorders. She became interested in biofeedback therapy after reading about the results other researchers were obtaining with the technique.

"I love learning more about these mysteries," she says. "I'm also motivated by my clinical background. I want to be able to do better for my patients. With biofeedback, we have the potential to change people's lives."