Parkinson's Autonomic Responses to Treadmill Walking

This study will require the PD subjects to attend three testing days, lasting approximately 1
hour. PD subjects will report for two exercise testing sessions, with each session separated
by 7 days. The age-matched, healthy subjects will only be required to attend two testing days
consisting of one day for paperwork and anthropometric measurements, and one day for exercise
testing, each lasting approximately 1 hour. PD subjects will be randomly assigned, in a
counterbalanced manner, to either an "on-medication" or "off-medication" group for days two
and three of testing. All subjects with PD will complete both exercise testing days.

Day 1: The subject will read and sign the informed and audio-visual consent forms and
complete a health questionnaire, PAR-Q, and mini-mental survey. The subject will also
complete the ACSM risk stratification screening questionnaire. Anthropometric measures will
be taken to include, waist circumference, height, and weight. The subject will then be
introduced to various test procedures which will be utilized throughout the experiment. Each
subject will be familiarized with the treadmill and harness support system. The harness
support system will be emplaced to ensure the safety of the PD patients due to the inherent
fall risk associated with a progressive decline in motor control often seen in this
population. The subject will walk on the treadmill at gradually increasing speeds until he or
she indicates, by a prearranged signal, that a comfortable walking speed has been attained.
Then the treadmill grade will be raised 2% every 30 seconds so the subject can feel what it
is like to walk during a progressive test. This will last no longer than five minutes. PD
subjects will also be given instruction as to which group (on, or off-medication) they have
been assigned to, and how to prepare for the follow-on tests.

Off-Medication Testing Day: Subjects will complete a blood draw and a motorized treadmill
VO2peak¬ test. Subjects are expected to arrive fasted (no food or drink for the past 12
hours) and having refrained from antiparkinsonian medication(s) for the past 24 hours. The
subject will first be seated and given a 5 minute rest period. Following this rest period the
phlebotomist will insert a catheter into the median cephalic vein in the antecubital (bend in
the arm) region on the subject's arm. One vial (3 cc) of venous blood will be drawn prior to
exercise testing and an identical draw will take place immediately following exercise
testing. All blood specimens will be tested and analyzed at the University of Miami Miller
School of Medicine. Then subject will then be allowed to eat a predetermined meal at the lab
before returning to exercise. Following the meal, the subject will be asked to return to a
seated resting position for an additional 5 minute period. During this time, gel electrodes
will be applied on the subject for the purposes of ECG and heart/blood flow monitoring and
measurements. Following this rest period, blood flow will be measured for an additional 5
minutes while the subject remains quietly seated. Next, the subject will be attached to the
harness support system for the treadmill exercise test. For the metabolic assessment portion
of the test, the subject will be fitted with a mask covering the nose and mouth, in which an
airflow sensor will be attached to measure gas content during respirations. The test will
start with a 4 minute warm-up at a speed dictated by the subject. By the end of the warm up,
the subject will have reached a speed that both they and instructor agree upon which meets
the requirements for moderate-intensity exercise. The speed will no longer be adjusted at
this point. Percent grade will start at 2.5 percent and will be increased by 2.5 percent
every 3 minutes until the subject has met the criterion for a peak exercise test, or has
requested to stop. BP and HR will be monitored every minute of testing using an automatic
electronic BP assessment machine (BPTRU, Coquitlam, BC), manual sphygmomanometer and
stethoscope, and electronic ECG software (Cardiosoft, GE Healthcare), respectively.
Successful completion of the test will be determined using the following criteria from the
American College of Sports Medicine (ACSM): (1) plateau in VO2, (2) maximal HR within 10
beats per minute of an age predicted maximum, (3) a respiratory exchange ratio of >1.15, (4)
respirations > 50 breaths per minute, (5) a rating of perceived exertion (RPE) ≥ 18. In
addition to these criteria we will use ACSM indications for termination of an exercise test
which include:

Absolute Indications

1. Suspicion of a myocardial infarction or acute myocardial infarction (heart attack)

2. Onset of moderate-to-severe angina (chest pain)

3. Signs of poor perfusion (circulation or blood flow), including pallor (pale appearance
to the skin), cyanosis (bluish discoloration), or cold and clammy skin

4. Severe or unusual shortness of breath

5. Central Nervous System (CNS) symptoms e.g., ataxia (failure of muscular coordination),
vertigo (an illusion of dizzying movement), visual or gait (pattern of walking or
running) problems, confusion

6. Technical inability to monitor the ECG

7. Patient's request (to stop) Relative Indications

1. Any chest pain that is increasing 2. Physical or verbal manifestations of shortness of
breath or severe fatigue 3. Wheezing 4. Leg cramps or intermittent claudication (grade 3 on a
4-point scale) 5. Hypertensive response (SBP >260 mm Hg; DBP>115 mm Hg) 6. Pronounced ECG
changes from baseline (>2 mm of horizontal or down sloping ST- segment depression, or >2 mm
of ST-segment elevation (except in aVR) 7. Exercise-induced bundle branch block that cannot
be distinguished from ventricular tachycardia 8. Less serious arrhythmias (abnormal heart
rhythms) such as supraventricular tachycardia On-Medication Testing Day: Procedures for the
on-medication day will be identical to those used for the off-medication day testing. Each
day, following the completion of exercise testing, subjects will be required to remain under
lab personnel supervision until HR returns to within 10 beats of resting, and systolic BP
returns to within 20 mmHg of resting. HR recovery will be measured continuously following
exercise to determine how quickly it returns to baseline. This is a useful measure in
determining autonomic function and the progression of PD symptoms.

Inclusion Criteria:

Men and women can be included in the study if these potential participants are between 50
and 85 years of age and meet the following criteria:

- Have received clearance from a primary physician to perform a peak exercise test.

- Will be able to walk on a motorized treadmill with supporting harness system.

- Are Individuals with PD having recently had a diagnosis of Stage 1, or 2, or 3 on the
Hoehn and Yahr scale and can present the research team with evidence from the
potential participant's physician stating the diagnosis.

Or,

- The potential participant is a healthy individual with no unresolved cardiovascular,
neuromuscular, and/or musculoskeletal disease.

Exclusion Criteria:

Men and women will be excluded from participation if the individual:

- Has been advised by a physician not to exercise.

- Is currently participating, or within the past 3 months has participated, in an
exercise training program.

- Is currently on any cardiac or blood pressure medication.

- Has any additional neurological disorder.

- Is considered to be at high risk for cardiovascular disease as determined by the -
American College of Sports Medicine (ACSM) risk stratification screening questionnaire
or their primary physician.

- Is unable to provide informed consent.

- has a Mini-mental score less than 18.

- Is pregnant.

- Is currently a prisoner.