Respiratory Kinematics of Cough in Healthy Older Adults and Parkinson's Disease

If the participant agrees to participate, the investigators will first test pulmonary (lung) function. Next, the investigators will test voluntary and reflex cough. After this first round of cough testing, the investigators will ask participants to cough long and hard during voluntary and reflex cough testing. Finally, the investigators will view the larynx (voice box) with an endoscopic camera inserted through the nose. This test is done to see if there are any changes in the larynx that may influence cough.

Inclusion criteria

• Age 55-85 years
• Ability to provide informed consent

For participants with Parkinson's disease (PD):

• Diagnosis of PD (Hoehn & Yahr stages II-IV) by a University of Florida Movement Disorders fellowship trained neurologist having completed a clinical assessment of each participant's PD severity and arriving at the diagnosis of PD by applying strict United Kingdom brain bank criteria.

Exclusion criteria

Participants with PD:

• History of neurological disorders other than PD (e.g. multiple sclerosis, stroke, brain tumor, etc)

Healthy older adults:

• History of neurological disease including PD
• History of head and neck cancer
• History of breathing disorders or disease (i.e. chronic obstructive pulmonary disease, asthma)
• History of smoking for more than 5 years at any one time (as this reduces the sensitivity to capsaicin)
• History of chest infection the last 5 weeks
• Failure of a screening test of pulmonary function (e.g. forced expiratory volume in one second/forced vital capacity<75%)
• Difficulty complying due to neuropsychological dysfunction (i.e. severe depression)