This study will examine tongue strength and endurance, how the tongue applies pressure
during swallowing, and how the chin muscles react during swallowing in healthy volunteers
and in patients with dysphagia (difficulty swallowing). The information from this study may
be helpful in developing better treatments for people with swallowing problems.
Healthy volunteers who have no history of speech, swallowing or breathing problems and
patients who have difficulty swallowing because of a neurologic disorder, musculoskeletal
disease or head and neck cancer that caused tongue weakness and dysphagia may be eligible
for this study. Such medical conditions may include stroke, Parkinson's disease, multiple
sclerosis corticobasal degeneration, progressive supranuclear palsy, Gaucher's disease,
leukodystrophy, cerebral palsy, myositis, or mouth, throat or neck cancer. Volunteers who
have not participated in a NIH protocol for 1 year will be screened with a brief medical
history and physical examination. Dysphagic patients not currently enrolled in a NIH
protocol will also have a brief medical history and physical examination. In addition, they
will have a modified barium swallow to determine the nature and degree of their swallowing
Participants will have a 15-minute examination of movements of their tongue, lips and jaw
and will fill out a questionnaire about their swallowing ability. They will then begin the
tongue pressure test. To monitor and record tongue pressure, a thin rubber strip with
air-filled pressure bulbs will be attached to the roof of the mouth with dental adhesive.
The pressure bulbs are connected to an external pressure-reading device. In addition, a
small plastic pad with adhesive backing will be placed under the chin. Electrodes (wires)
attached to the pad record chin muscle activities.
With the pressure bulbs and chin electrodes in place, the patient will perform tongue
pressure tasks to test tongue strength, how long the patient can maintain a certain tongue
pressure, and how fast tongue pressure drops. The tasks include saliva swallows, water
swallows and cup-drinking.
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.
- INCLUSION CRITERIA:
Eligible healthy volunteers must:
1. be at least 21 years of age;
2. have no speech, swallowing, or respiratory problems;
3. be in good general health;
4. not be on medications that would adversely affect swallowing ability.
Eligible dysphagic patients must:
1. be at least 21 years of age;
2. have a neurologic disorder (e.g., CVA, PD, PSD, CBD, MS, Gaucher, leukodystrophy,
cerebral palsy), musculoskeletal disease (e.g., polymyositis), or head and neck
cancer that has caused impairments in tongue function and swallowing;
3. present with oral or oropharyngeal dysphagia without aspiration based on results of
the standard modified barium swallow study.
4. have sufficient auditory comprehension and cognitive skills to follow test
instructions and understand the nature of the study.
For healthy volunteers:
1. History of swallowing problems or other conditions that adversely affect swallowing
function, tongue motility and control, hearing, language, and cognition.
2. On medication (e.g., anticholinergics, antidepressants) that adversely affects
swallowing function, tongue movement, comprehension, or cognition.
3. Oral dryness that interferes with swallowing.
4. Unsatisfactory performance status, as judged by the examining speech-language
pathologist, that indicates poor compliance for the planned tasks (e.g., undiagnosed
oral motor deficits).
For dysphagic patients:
1. Aspiration, as identified via the modified barium swallow study.
2. Pregnancy, as determined via a urine pregnancy test prior to the MBS test.