Fran Lowry

November 27, 2012

CHICAGO — Pedaling fast on a stationary bike, at speeds of 75 to 80 rpm, appears to benefit patients with Parkinson's disease, according to a study presented here at the Radiological Society of North America 98th Scientific Assembly and Annual Meeting.

"Exercise can really help. Patients can take control of their disease and take an active role in managing it by doing something simple and incorporating it into their daily lives," Chintan Shah, MS, from the Cleveland Clinic in Ohio, told reporters at a press briefing.

Chintan Shah

The study was inspired by a serendipitous observation by study coauthor Jay L. Alberts, PhD, a neuroscientist at the Cleveland Clinic Lerner Research Institute.

Dr. Alberts, an avid cyclist, rode a tandem bicycle across Iowa with a Parkinson's disease patient to raise awareness of the disease. At the end of the ride, he noticed that the patient had experienced improvements in her symptoms.

"I was pedaling faster than her, which forced her to pedal faster. She had improvements in her upper extremity function, so we decided to look at the possible mechanism behind this improved function," Dr. Alberts said in a statement.

The Cleveland Clinic researchers randomly assigned 26 patients with Parkinson's disease to voluntary-rate exercise, during which the patient pedaled a stationary bicycle at their own rate, or to forced-rate exercise, during which a trainer in the front seat of a tandem bicycle controlled the pedaling rate. Exercise sessions were 3 times a week for 8 weeks.

The forced-rate pedaling was at least 30% faster than the voluntary-rate pedaling.

After 8 weeks of exercise therapy, the forced-rate group showed a 35% improvement in symptoms; there was no improvement in the voluntary-rate group.

Shah and colleagues used functional connectivity magnetic resonance imaging (fcMRI) to determine the effect of cycling on patients with Parkinson's disease.

"By measuring changes in blood oxygenation levels in the brain, fcMRI allows us to look at the functional connectivity between different brain regions," Shah explained.

The patients underwent fcMRI scans at baseline, at the end of the 8 weeks of exercise therapy, and 4 weeks later.

The researchers calculated brain activation and connectivity levels from the fcMRI results and correlated the data with the average pedaling rate.

The results showed increases in task-related connectivity between the primary motor cortex and the posterior region of the brain's thalamus.

Faster pedaling was the key factor related to these improvements, Shah said.

"People who pedal faster tend to also strengthen the connection between the thalamus and their primary motor cortex, which helps control movement," he explained.

The researchers also saw negative correlations in the cortical regions of the brain.

"It is thought that these regions help patients with Parkinson's disease compensate for the defects that they have in their motor system. Patients who pedaled faster ended up needing less compensation from these areas," Shah noted.

After 4 weeks of follow-up without exercise, the positive correlation between faster pedaling in the thalamus and the negative correlation in the cortical areas was still evident.

Pedaling Fast Is Key

Dr. Michael Phillips

"It appears that a key factor in improving motor function and pattern of activation in the brain is to pedal at a relatively high rate — for example, greater than 80 rpm," principal investigator Michael Phillips, MD, from the Cleveland Clinic, told Medscape Medical News.

"The difficult thing about this is being able to get to a rate that does the most good for you. There are motorized bikes available that will help people get up to 80 rpm. It looks like there is benefit to most forms of exercise, but the most benefit was when people pedaled faster, and that's very difficult for people with Parkinson's," Dr. Phillips said.

How the physical activity of pedaling affects Parkinson's disease "is the real question," he added.

"Part of the reason we did the imaging study was to see which portion of the brains changed. We are just starting to figure out where things are. This initial finding suggests to us that there's an alternation in the degree of connection between the cortex and deep brain structures; that may be what is causing this to happen," Dr. Phillips said.

Dr. Max Wintermark

"I was extremely interested to learn that you can improve diseases such as Parkinson's disease with exercise. Not to have to take medications or have invasive surgical treatment is great," Max Wintermark, MD, from the University of Virginia in Charlottesville, told Medscape Medical News.

"It was also interesting to learn that not every exercise is the same; the type of exercise that you do is quite important.... We still don't understand exactly how exercise can influence the way your brain is connected. Studies such as this one are our first step toward better understanding how the brain works," said Dr. Wintermark, who was not involved in the study.

The study was supported by the National Institutes of Health. Mr. Shah, Dr. Alberts, and Dr. Phillips have disclosed no relevant financial relationships. Dr. Wintermark reports financial relationships with General Electric.

Radiological Society of North America (RSNA) 98th Scientific Assembly and Annual Meeting: Abstract LL-NRS-MO3C. Presented November 26, 2012.