Trial Information

Effect of Task on Oral Pressure Dynamics During Swallowing

The tongue enacts complex mechanical events during swallowing, the most important of which
is the propulsion of a bolus from the oral cavity to the pharynx. Successful bolus
transport requires the tongue to interact with other oral structures, especially the hard
palate, to generate sufficient impulsive force or pressure gradients that drive the bolus
toward the oropharynx. Our knowledge of deglutitive lingual pressure dynamics is at best
incomplete. The available data on oral tongue pressure phenomena are based exclusively on
commanded single swallows. Oral pressure changes during other important everyday eating
activities (e.g., cup drinking) have not been studied to date. Past investigations revealed
that rapid sequential swallowing during continuous drinking, in contrast to commanded
discrete swallows, had unique tongue-palate contact patterns, surface electromyographic
response characteristics, and hyoid displacement profiles. Given the different
biomechanical properties and motor strategies, we hypothesize that oral lingual pressure
profiles for sequential swallowing are also different, that sequential swallows require less
impulsive force, and that selected dysphagic patients, especially those whose swallowing
deficits are associated with reduced tongue strength, will perform sequential swallows more
efficiently than they do discrete swallows. This protocol, therefore, proposes to test
these hypotheses in healthy individuals of different ages, and in patients with reduced
tongue strength and oral-oropharyngeal dysphagia associated with neurologic disorders,
musculoskeletal diseases, or head and neck cancer. Our goals are to: (a) acquire a better
and more complete understanding of normal tongue pressure phenomena as a function of
swallowing tasks, (b) characterize the interrelationship between task-induced lingual
pressure differences and result of clinical diagnostic tests of swallowing function in
patient populations, and (c) differentially identify the profiles of dysphagic patients who
can and those who cannot benefit from sequential swallowing as a compensatory/rehabilitative
strategy.