Swallowing is something that most of us take for granted. We drink water when we are thirsty, and swallow our morning coffee without a second thought. Yet, dysphagia (swallowing difficulty) is a serious, costly and significant health concern, particularly for the elderly and people with neurologic injuries. Dysphagia puts individuals at risk for malnutrition, dehydration and pneumonia and adversely affects quality of life. People with dysphagia have particular difficulty swallowing thin liquids safely;the fast flow of liquids makes them difficult to control. The tongue plays a critical role in containing liquids in the mouth, and in directing and controlling flow through the pharynx (throat). We are engaged in a program of research to better understand tongue function in swallowing, particularly with respect to controlling the flow of liquids. This research is guiding the development and testing of interventions with the goal of rehabilitating tongue function, so that people with dysphagia might return to swallowing thin liquids safely. To date, we have learned that modulations of the time-scale of tongue-pressure application (tongue-pressure-timing) are a critical element in liquid swallowing. Healthy young adults modulate tongue-pressure-timing across liquids of differing viscosity. We are requesting funding for the next phase in this research, to examine tongue-pressure timing in healthy adults (young and elderly) and individuals with dysphagia. The proposed research is based on the idea that the primary purpose of tongue-pressure application to a liquid stimulus is to measure and control the flow properties of that liquid. We hypothesize that, in comparison to healthy young adults, healthy seniors and people with dysphagia will demonstrate differences in tongue-pressure timing. We expect that people with abnormal tongue-pressure timing (vs. healthy young controls) will be less able to detect differences in liquid viscosity and will show reduced tongue-pressure timing modulation in swallowing across viscosity. We specifically seek to confirm that impairments in tongue- pressure-timing co-occur with impairments in the detection of viscosity differences. We also want to conduct a preliminary test of an intervention protocol that we have developed, emphasizing the modulation of tongue- pressure-timing. We hypothesize that this intervention will: a) shift tongue-pressure timing values closer to those of healthy young adults;b) facilitate improved viscosity detection;and c) improve liquid bolus control. This study will answer a critical question for the clinical management of dysphagia, namely how large must a viscosity difference be to influence swallowing function? This will inform industry standards for the formulation of thickened liquids for dysphagia. The results of this study will support the development of evidence-based clinical protocols for tongue-pressure evaluation. Finally, this study will produce preliminary evidence of the effectiveness of tongue-pressure timing training to ameliorate bolus control difficulties in dysphagia.

Public Health Relevance

Dysphagia (swallowing difficulty) is a serious health concern for the elderly and for individuals with stroke or other neurological conditions. This study will advance our understanding of the role of tongue pressure application in swallowing, and will advise future best-practice guidelines for dysphagia assessment and intervention. The results will guide the formulation of therapeutically useful, just-thick-enough liquids and will advance our ability to address liquid bolus control difficulties, - a major component of swallowing disability.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Research Project (R01)
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Motor Function, Speech and Rehabilitation Study Section (MFSR)
Program Officer
Shekim, Lana O
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Toronto Rehabilitation Institute
Zip Code
M5 2-A2
Molfenter, Sonja M; Leigh, Chelsea; Steele, Catriona M (2014) Event sequence variability in healthy swallowing: building on previous findings. Dysphagia 29:234-42
Nagy, Ahmed; Steele, Catriona M; Pelletier, Cathy A (2014) Barium versus nonbarium stimuli: differences in taste intensity, chemesthesis, and swallowing behavior in healthy adult women. J Speech Lang Hear Res 57:758-67
Dietsch, Angela M; Solomon, Nancy Pearl; Steele, Catriona M et al. (2014) The effect of barium on perceptions of taste intensity and palatability. Dysphagia 29:96-108
Nagy, Ahmed; Molfenter, Sonja M; PĂ©ladeau-Pigeon, Melanie et al. (2014) The effect of bolus volume on hyoid kinematics in healthy swallowing. Biomed Res Int 2014:738971
Steele, Catriona M; James, David F; Hori, Sarah et al. (2014) Oral perceptual discrimination of viscosity differences for non-newtonian liquids in the nectar- and honey-thick ranges. Dysphagia 29:355-64
Molfenter, Sonja M; Steele, Catriona M (2014) Kinematic and temporal factors associated with penetration-aspiration in swallowing liquids. Dysphagia 29:269-76
Stokely, Shauna L; Molfenter, Sonja M; Steele, Catriona M (2014) Effects of barium concentration on oropharyngeal swallow timing measures. Dysphagia 29:78-82
Steele, Catriona M; Molfenter, Sonja M; Peladeau-Pigeon, Melanie et al. (2013) Challenges in preparing contrast media for videofluoroscopy. Dysphagia 28:464-7
Fei, Tiffany; Polacco, Rebecca Cliffe; Hori, Sarah E et al. (2013) Age-related differences in tongue-palate pressures for strength and swallowing tasks. Dysphagia 28:575-81
Steele, Catriona; Sasse, Caroline; Bressmann, Tim (2012) Tongue-pressure and hyoid movement timing in healthy liquid swallowing. Int J Lang Commun Disord 47:77-83