Research

The Swallowing Rehabilitation Research Laboratory (SRRL) is directed by Catriona Steele and has funding from several agencies including the National Institutes of Health (NIH). There are several main foci of research in the lab:

Establishing Reference Values for Healthy Swallowing

A videofluoroscopy is an x-ray assessment of swallowing, in which an x-ray movie is recorded of food or liquid moving through the mouth and throat. Interpretation of this assessment involves measurements of airway protection, residue remaining behind in the throat after the swallow, and the timing and extent of the movements of various structures in the throat. These measures may vary due to things like the food or liquid consistency, sip size and head position. Our lab is leading work to define the expected values of a comprehensive set of x-ray measures in healthy swallowing, according to food and liquid consistency. This work will help clinicians to determine when measures in patients fall outside the range of values seen in healthy swallowing, and also to determine when treatment techniques are effective.

In addition to establishing reference values for healthy swallowing, the lab is using the same methods to determine the patterns of impairment seen in several different disease conditions. These include studies in people with Stroke, Parkinson Disease, Chronic Obstructive Pulmonary Disease, Amyotrophic Lateral Sclerosis (ALS), and Laryngeal Cancer.

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Treatment outcome studies

Since receiving her Ph.D. in 2003, Professor Steele has conducted several studies investigating treatment outcomes for dysphagia. These studies have focused on treatment methods employing exercise such as tongue-pressure resistance training.

Tongue Pressure: Professor Steele’s work on tongue pressure continues to support the need for refinements to tongue pressure training methods. Results from a previous multi-site randomized trial funded by the Heart and Stroke Foundation of Ontario were disseminated in the following publication: Steele, C. M., et al. (2016). A randomized trial comparing two tongue-pressure resistance training protocols for post-stroke dysphagia (link). We recently concluded a small trial looking at Tongue Pressure Training Protocol for Swallowing Impairment Post-Stroke (link to protocol).

Viscosity & Texture Modification

Professor Steele has a long-standing interest in the use of texture modified foods and thickened liquids to address swallowing impairment.  Her work in this area focuses on characterizing the viscosity of liquids used in dysphagia assessment and management, including barium stimuli, and liquids thickened with both starch-based and xanthan-gum-based thickening agents. Professor Steele collaborates with Professor Ben Hanson (University College London) in making measurements of liquid flow characteristics.

Additionally, Professor Steele was a founding member of the Board of Directors of the International Dysphagia Diet Standardisation Initiative.  This international task force is committed to developing definitions for terminology used to describe texture modified foods and liquids, and guidelines to facilitate the preparation of quality products for patients with dysphagia.  Professor Steele led a large systematic review project for IDDSI, to synthesize evidence from the literature regarding the effects of viscosity and other textural characteristics on human swallowing.

Expert analysis of videofluoroscopies for other research groups

Professor Steele’s lab provides consulting services to other research groups, including independent analysis of videofluoroscopy data for other studies. Current contracts include videofluoroscopy analysis for studies of swallowing impairment and treatment outcome in hereditary neurodegenerative disease.