Cough According to Stimulus Type in PD

The study will be completed in one visit, and take about an hour. All study procedures are done in the investigators quiet clinical research area at the Center for Movement Disorders and Neurorestoration (Room 7). If participants agree to be in this research study, after participants sign the informed consent form, the investigators will ask participants some questions related to participants health history. These questions include:

Do participants have a history of any breathing disorders or diseases (asthma, emphysema/chronic obstructive pulmonary disease (COPD), etc), or severe chest injury?

• Do participants have any history of stroke, or any neurologic disease besides Parkinson's disease?
• Have participants smoked in the last 5 years?
• Have participants had any chest infections within the last 5 the weeks?
• Do participants have a history of head and neck cancer?
• Are participants allergic to capsaicin, hot peppers, Zostrix cream, or other medicines?

The investigators will ask these questions to make sure participants do not have a history of any illnesses that would affect their ability to cough or that would make it unsafe for them to participate. If participants answer yes to any of these questions, they will not be able to continue in the study.

Next, the investigators will begin to measure participants reflex cough. First, the investigators will attach a small microphone with a clip to participants shirt that will record participants cough responses. The investigators will have participants inhale a "hot pepper" vapor at five different concentrations. The hot pepper vapors will be separately delivered through a mouthpiece attached to a hand-held nebulizer (a device that makes vapors out of liquids). The investigators will deliver each type of vapor to participants 3 times each for a total of 15 presentations. After inhaling each vapor and coughing if participants need to, the investigators will ask participants to rate their urge to cough using a scale of 0-10, with 0 equaling no urge to cough, and 10 equaling the greatest urge to cough. If participants do not cough to any of the vapors, the investigators will present one final stronger dose. There will be a 2 minute break in between each presentation of the vapor, and water will be available at all times throughout the study. This will take approximately 40 minutes.

Next, the investigators will continue to measure participants reflex cough using a slightly different test. The investigators will have participants inhale water vapor (fog) and a low concentration of hot pepper vapor. Both types of vapor will be in separate nebulizers, like the ones the investigators just used. For these vapors, participants will breathe in and out through the nebulizer's mouthpiece until participants cough, or for up to 1 minute. The investigators will try each one 3 times, for a total of 6 tries.

Inclusion criteria

• Within age limits
• For PD group: confirmed diagnosis of idiopathic parkinson's disease

Exclusion criteria

• Uncontrolled hypertension
• Difficulty complying due to neuropsychological dysfunction (i.e., severe depression)
• Allergy to capsaicin or hot peppers
• History of head or neck cancer
• Neurological disorders other than PD (i.e., stroke, etc.)

• control participants only: any history of neurologic disorders including PD
• History of smoking in the last 5 years
• Breathing disorders or diseases