Pedaling for Parkinson's

January 7, 2008 8:47:11 AM PST
According to neuroscientist Jay Alberts, Ph.D., of the Cleveland Clinic, past animal studies have shown great benefits for exercise in terms of improving Parkinson's disease function. But these positive results haven't been replicated in human studies. Dr. Alberts says, "A lot of human studies haven't shown significant improvements in motor function using the various human interventions, such as weight training or other types of exercise training." But the animal studies used a paradigm called "forced exercise" -- where the animal is forced to exercise at a rate that's faster than its voluntary rate. After taking a group bike ride across Iowa in 2003, Dr. Alberts realized the concept of forced exercise may be the key to bridging the gap between the positive animal studies and the inconclusive human ones.

FORCED EXERCISE: During the Iowa bike ride, Dr. Alberts rode on a tandem bike with a person who had Parkinson's. The patient was forced to pedal much faster than she would have normally -- between 80 RPMs and 90 RPMs as opposed to between 50 RPMs and 60 RPMs. Dr. Alberts explains, "In many ways, this tandem was like a type of forced exercise paradigm that was being used in the tandem studies." Then in 2006, Dr. Alberts rode again with another Parkinson's patient. This patient depended on a surgically implanted device called deep brain stimulation to control his symptoms. If the device is turned off, his symptoms return immediately. Dr. Alberts and the patient went on a 50-mile tandem bike ride with the stimulator turned off, and to their delight, the patient had no symptoms. These observations led to Dr. Alberts testing the theory out clinically.

UNDER STUDY: In his study at the Cleveland Clinic, Dr. Alberts has patients come in over a period of eight weeks, three days a week for a one-hour tandem bike ride session. Results show after the eight weeks, patients have on average a 30-percent improvement in their symptoms. Two weeks after the study is over, patients still have about a 20-percent improvement. Dr. Alberts says with medication patients typically have slightly less improvement. And with deep brain stimulation, patients have between about 30 and 40 percent improvement, which is about the same. But as he points out, "If you stop taking medication, the disease symptoms come back within a few hours, and these often have side effects. And with deep brain stimulation, you turn the stimulator off and the symptoms come back almost immediately." He says he's excited by the fact that the symptomatic improvement from tandem exercise is sustained for weeks. He does add that he doesn't see tandem exercise as something that would replace deep brain stimulation but instead could be used as an adjunct.

HOW IT WORKS: Patients are working the lower half of their body -- yet symptoms in their upper half improve. Dr. Alberts says, "That suggests that we're changing the way the brain is actually functioning." He's now trying to figure out what underlying mechanism is responsible for the improvement. He and his colleagues are looking at patients' functional MRI brain scans to look for differences before and after the therapy. They suspect that because Parkinson's patients have a decreased neural drive, they may not be able to drive their system sufficiently, and forced exercise augments their central nervous system, leading to biochemical changes and actually helping the disease itself, rather than just the symptoms.

ADVANTAGES: As Dr. Alberts explains, forced exercise is "a very simple intervention that doesn't require a lot of fancy equipment, and it doesn't require medications ... We all know that exercise is good for you. And if we can improve brain function, to me that's pretty exciting."


Erica Foreman, Public Relations Specialist, The Cleveland Clinic,