Overview

There is increasing evidence that the usage and delivery of energy to the brain, known as brain energetics, is altered in people with Parkinson's disease (PD). This project will explore whether exercise has a positive impact on brain energetics using functional Magnetic Resonance Imaging (fMRI) and Positron Emission Tomography (PET) brain scanning in PD subjects.

PD subjects will be scanned before and after a supervised exercise program to investigate the effect of exercise on brain energetics. In a separate study, the investigators will also scan healthy volunteers to compare brain energetics in the healthy brain with the brain energetics data in PD subjects acquired in this study.

Eligibility

Inclusion Criteria:

1. Idiopathic PD according to UK Brain Bank criteria (modified to permit inclusion of subjects with a family history)
2. Mild to moderate Parkinsonism (Hoehn & Yahr stages I-III)
3. Currently exercise less than 120 minutes per week (PD non-exercisers)

General exclusion criteria:

1. atypical Parkinson syndrome (progressive supranuclear palsy, multiple system atrophy, drug-induced etc.);
2. significant osteoporosis or arthritis;
3. history of cancer within 5 years of study participation;
4. high dose of radiation from other procedures within the year;
5. not able to tolerate being off PD medication for up to 24 hours;
6. a female subject who is breast-feeding or pregnant;
7. current or past substance use problems;
8. serious head injury with loss of consciousness for ≥ 5 minutes;
9. people with other chronic diseases such as diabetes, kidney problems, high blood pressure, other known neurological disorders, or heart diseases;
10. people who report having a significant respiratory disorder (e.g. asthma, chronic obstructive pulmonary disease (COPD)) or using home oxygen will be excluded to avoid discomfort or breathing difficulties from respiratory manipulations.
11. current or past neurological disorder (e.g. strokes, seizures, neurodegenerative disease other than Parkinson's disease);
12. current or past psychiatric disorders (e.g. depression, anxiety disorders);
13. severe claustrophobia (a fear of closed in spaces);
14. weight of more than 158kg (347 lbs);
15. inability to lay still for up to 90 minutes;
16. are not medically cleared to exercise;
17. certain medications or conditions may impact participant's ability to participate and these will be discussed on a case by case basis with the participant and the study team.

MRI-specific exclusion criteria:

1. Machinist or metalworkers;
2. cardiac pacemakers, wires, or defibrillator;
3. past injury where a piece of metal lodged in your eye or orbit;
4. ferromagnetic aneurysm clip;
5. artificial heart valve;
6. electrical stimulator for nerves or bones;
7. ear or eye implant;
8. implanted drug infusion pump;
9. coil, catheter, or filter in any blood vessel;
10. orthopedic hardware (artificial joint, plate, screws);
11. other metallic prostheses;
12. shrapnel, bullets, or other metal fragments;
13. dentures, braces, or retainer;
14. surgery (brain or otherwise), tattoos, or injection into a joint in the last 6 weeks;
15. pierced body parts (other than earrings) or tattooed eyeliner;
16. non-MRI safe intrauterine device (IUD).

        Subjects may be excluded following study enrollment if they meet any of the following
        exclusion criteria:
          1. significant cognitive impairment or depression;
          2. significant or unstable cardiovascular or respiratory disease - all subjects will
             undergo a screening aerobic exercise test;
          3. failure to comply with the exercise intervention program by not completing at least 60
             of the 72 exercise classes.