Dysphagia (swallowing impairment) is a serious health condition seen in many age-related disease and injury processes. Although videofluoroscopy (VF) is an international "gold standard" dysphagia diagnostic exam, there is a paucity of available normative physiologic VF reference values in healthy adults across the age span to guide interpretation of these examinations. In this project, the investigators will extend previous work on the quantitative measurement of swallowing physiology from VF examinations to establish reference values for swallowing in healthy adults, and to identify clinical decision point values for differentiating healthy swallowing across the age span from disordered swallowing in several high-risk clinical populations to study dysphagia.

Dysphagia (swallowing impairment) is a serious health condition seen in many age-related disease and injury processes. Although videofluoroscopy (VF) is an international "gold standard" dysphagia diagnostic exam, there is a paucity of available normative physiologic VF reference values in healthy adults across the age span to guide interpretation of this examination. This fundamental gap in knowledge contributes to poor agreement in the identification of swallowing impairment and its underlying mechanisms. To enable better dysphagia diagnostics, there is a critical need to establish reference values for VF swallowing measures across the healthy age span.

In a previous study, the investigators developed a rigorous method for measuring swallowing physiology from VF: the Analysis of Swallowing Physiology: Events, Kinematics and Timing (ASPEKT Method). That study led to publication of initial ASPEKT reference values from 40 young healthy adults (<60 years) and preliminary analyses comparing data from healthy older adults and small cohorts of adults with dysphagia to these reference data.

In this project, the investigtors will:

• validate the ASPEKT Method healthy reference values for swallowing across the adult life span; and
• profile swallowing patho-physiology in clinical groups where dysphagia is a cause of morbidity to identify clinical decision points that can be used for diagnosis and outcome measurement.

This study will explore the following research questions:

Research Question 1: Will > 5% of healthy adult participants in a new sample show ASPEKT values outside the common reference interval calculated in a prior sample? • VF measures will be collected in a prospective sample of 280 healthy adults, controlling for sex, age, and bolus consistency. Updated reference interval boundaries for healthy swallowing will be calculated.

Research Question 2: Do specific clinical conditions present with specific patterns of swallowing pathophysiology?

• VF measures will be prospectively collected in 3 high-risk dysphagia cohorts: adults with Parkinson Disease, Chronic Obstructive Pulmonary Disease, adults in the acute stage post-stroke. Values for these clinical cohorts will be compared to age- and sex-matched reference values from healthy participants. This will delineate swallowing impairment profiles to inform clinical decision points for diagnosis.

Inclusion Criteria:

1. Healthy Volunteers: no history of swallowing difficulties.
2. Clinical cohorts: physician confirmed diagnosis of the condition of interest plus symptoms of swallowing difficult, defined as a score >/=200 on the Sydney Swallow Questionnaire.

Exclusion Criteria:

• cognitive communication difficulties that may hinder comprehension of the study documents
• known allergies to latex, due to the possibility that these items will come into contact with the oral mucosa during data collection
• current pregnancy