Study to quantify benefits of aerobic exercise in managing Parkinson's symptoms

Daniel Corcos has studied Parkinson's disease for more than 20 years. For most of the past 10, he has focused on the effects of exercise.

"It became obvious several years ago that exercise really was good for people with Parkinson's disease," said Corcos, who is professor of kinesiology and nutrition at the University of Illinois at Chicago. "Not only is it good for the heart, the brain, and muscles in the same way it is for healthy people, it also modifies signs and symptoms of Parkinson's disease."

Now as a co-principal investigator of a four-year, $3 million National Institute of Neurological Disorders and Stroke grant, he will try to quantify the benefits of aerobic exercise in managing symptoms in persons with recently diagnosed Parkinson's disease.

At this April's annual meeting of the American Academy of Neurology, Corcos will report the finding that two years of weight training can significantly and progressively improve motor symptoms of Parkinson's disease as compared to alternatives such as stretching and balancing. Those exercises produced no improvements after six months.

The results suggest that long-term weight training could be considered as an important component in managing Parkinson's disease, he said.

In the planned study of aerobic exercise, Corcos and co-investigator Margaret Schenkman of the University of Colorado-Denver will compare patients newly diagnosed with the disease who will be assigned to one of three groups. The first group will maintain whatever their current activity level is. The second will do 30 minutes of endurance exercise on a treadmill four times a week at between 60 and 65 percent of maximum heart rate. The third group will do a more vigorous workout at between 80 to 85 percent of their maximum heart rate.

"Our first aim is just to test the feasibility of whether they can exercise at both the moderate and high dose (rates)," Corcos said. "Then we'll ask, does exercise at one or the other dose modify symptoms of the disease?"

Half the study patients will be recruited at Rush University Medical Center and will be tested at UIC. A quarter will be tested at the University of Colorado-Denver, and another fourth at the University of Pittsburgh.

While medication such as levodopa usually shows initial effectiveness in treating Parkinson's symptoms, the benefits wear off in half of users within five years and in 90 percent after a decade. Participants in Corcos' and Schenkman's study will not have started any medication.

Using a clinical measurement tool called the Unified Parkinson's Disease Ratings Scale, the researchers will note how each exercise group manages symptoms such as slow movement, tremor, rigidity and abnormal postural reflexes.

If the study finds a particular level of endurance exercise lessens symptoms, Corcos plans a new study-phase to learn if exercise is actually neuro-protective. Evidence suggests exercise can be effective therapy, he says, though much research remains to be done.

"Any treatment that reduces the amount of medication is beneficial to a patient, because they'll get a longer and better response from their medication," Corcos said. "The goal of our work is to help Parkinson's disease patients lead a better life until a cure is found."