Results of the study were revealed on Monday at the Radiological Society of North America 2012 Scientific Assembly and Annual Meeting in Chicago.
Parkinson's DiseaseApproximately 7 to 10 million people worldwide live with Parkinson's disease, a chronic, progressive neurological disorder where part of the brain gradually becomes more damaged as the years go by. The main symptoms of the disease are movement related, and include shaking or tremor, muscle stiffness and rigidity, and slowness of physical movements (bradykinesia).
Most cases occur after the age of 50, and as the disease progresses, cognitive and behavioral problems such as dementia, may also develop.
Idea for the Study Started on a Charity RideStudy investigator Jay L. Alberts, a neuroscientist at the Cleveland Clinic Lerner Research Institute, first got the notion that exercise might be beneficial for Parkinson's patients during a 2003 charity cycle ride across Iowa, to raise awareness of Parkinson's disease. During that event he rode a tandem with a female Parkinson's patient, whose symptoms improved after the ride.
In a statement, in which he describes the finding as "serendipitous", Alberts recalls:
"I was pedaling faster than her, which forced her to pedal faster. She had improvements in her upper extremity function, so we started to look at the possible mechanism behind this improved function."
What the Researchers DidFor their study, Alberts, co-researcher Chintan Shah, and other colleagues from the Cleveland Clinic, used functional connectivity magnetic resonance imaging (fcMRI) to investigate the effect of exercise on 26 patients aged from 30 to 75 with mild to moderate Parkinson's disease.
fcMRI measures changes in blood oxygen in the brain, which enables researchers to look at how active different brain regions are and how well they connect with each other, explains Shah.
The researchers randomly assigned the patients to one of two groups. One group (13 patients) cycled at their own voluntary pace, while the other group cycled at a forced rate.
The groups completed exercise sessions on stationary bikes three times a week for 8 weeks. Both groups underwent MRI scans at the start and the end of the period, and also after four weeks of follow up.
The forced rate group had bikes fitted with specially controlled motors to make them cycle faster than their voluntary rate, as Alberts explains:
"We developed an algorithm to control a motor on the bike and used a controller to sense the patient's rate of exertion and adjust the motor based on their input."
What they FoundUsing the fcMRI data, the team then calculated brain activation and connectivity levels, and correlated them to average pedalling rates.
They found increases in task-related connectivity between the primary motor cortex and the posterior region of the brain's thalamus, and conclude that faster pedaling rate was the key factor in these improvements, which were still present at follow-up.
Some of the results were similar to patterns of activation during deep brain stimulation of Parkinson's patients, which is a costly and invasive treatment for late stage disease.
Effective, Low-Cost TherapyShah says their study suggests "forced-rate bicycle exercise is an effective, low-cost therapy for Parkinson's disease".
However, Alberts says while forced-rate pedalling appears to give better results, not all Parkinson's patients would need to do exercise so fast to see improvement:
"We're now looking at this phenomenon in patients with exercise bikes in their home; and other exercises like swimming and rowing on tandem machines may provide similar benefits," he adds.