MDS 2009: Forced Exercise Provides Benefit Similar to Levodopa in Parkinson's Disease
June 15, 2009 (Paris, France) - Patients with Parkinson's disease (PD) who exercise on a stationary tandem bicycle with a healthy partner during a single 40-minute session experience a 35% improvement in motor function and increased brain activation similar to that found with levodopa treatment, new research shows.
The study, by researchers at the Cleveland Clinic in Ohio, found that maintaining a steady rate of 80 to 90 revolutions per minute (rpm) on the bicycle not only improved function in lower extremities but also in upper extremities.
The improvement was dramatic and similar to that achieved by levodopa therapy, said 1 of the researchers, Jay L. Alberts, PhD, from the Center for Neurological Restoration at the Lerner Research Institute, in Cleveland.
"It looks like there are global effects in terms of the improvement in motor function," he told Medscape Neurology. "It suggests to us that maybe we're changing central motor function or maybe we're actually changing brain function through something very noninvasive."
The study was presented during the Movement Disorder Society's 13th International Congress of Parkinson's Disease and Movement Disorders.
A previous published study by this Cleveland research group found that the same forced exercise intervention administered 3 times a week for 8 weeks provided a similar 35% improvement in motor function.
"Couple these new findings with our longer-term data, and for us it's very encouraging," said Dr. Alberts. "Maybe if we can alter brain function, we can potentially alter the course and potentially slow the progression of this disease."
For the study, researchers selected 11 male and female patients ranging in age from mid 50s to early 70s who had mild to moderate PD but no cardiac concerns. They tested these patients under 3 random conditions: not on medication, on medication (levodopa), and not on medication but completion of the forced-exercise intervention.
When on a stationary bicycle, PD patients normally pedal at a sustained rate of about 40 to 60 rpm. In this intervention, however, the patients sat on the back of a tandem bicycle while a healthy young adult trainer occupied the front seat and regulated the pedaling rate, ensuring that it remained between 80 to 90 rpm for 40 minutes.
Researchers monitored each patient's heart rate and made sure it stayed within 60% to 80% of his or her age-determined target range.
Patients also performed a force-tracking task and a bilateral finger-tapping task to demonstrate their level of control and coordination. Similar grasping tasks are necessary to perform daily activities such as buttoning a shirt or tying shoe laces, said Dr. Alberts.
The researchers found that the forced exercise and the levodopa produced similar significant reductions in Unified Parkinson's Disease Rating Scale (UPDRS III) motor scores, 35% with exercise and 38% with levodopa. Data from functional magnetic resonance imaging (fMRI) showed increased activation in the supplementary motor area (SMA) and primary motor cortex (M1) regions of the brain in response to both interventions.
"In terms of the fMRI data, we found that there was an increase in the level of cortical activation in the 2 motor areas - the SMA and the primary motor cortex - and this increase in activation looks very similar to the increase you see when you administer L-dopa," said Dr. Alberts.
For the force-tracking task and bilateral finger tapping, motor performance was 35% better following forced exercise compared with no exercise.
"Overdriving" Central Nervous System
These findings suggest that the exercise and the drug treatment elicit the same underlying mechanisms that provide similar symptomatic relief from PD symptoms, said Dr. Alberts.
The researchers surmise that the exercise may facilitate central motor control processes in Parkinson's patients. "For lack of a better word, we may be 'overdriving' the central nervous system by providing an increase in the quantity and quality of sensory information provided to the patient," said Dr. Alberts.
He added that this type of intervention could also be carried out on a treadmill, but it may be riskier and less practical than on a tandem bike. "We can't increase someone's walking rate 30% without having them in a harness and even then, I think you'll find that their feet would be dragging."
The next step in this line of research, he said, is to develop a motor-assisted cycle that will allow patients to do this type of exercise at home.
Many Beneficial Effects
Asked for a comment, Kapil D Sethi, MD, professor of neurology and director of the movement disorders program at the Medical College of Georgia, in Augusta, said the research highlights additional benefits of exercise. "Exercise has many beneficial effects both physical and psychological," he told Medscape Neurology. "There is evidence in the animal models and now in humans that exercise may have beneficial effects in PD. The exact mechanism is unclear, and the exact paradigm is unknown."
Mark Hallett, MD, from the National Institute of Neurological Disorders and Stroke, in Bethesda, Maryland, added in a press release that the finding of similarities between exercise and drug treatment "is certainly interesting and may indicate that exercise, in the short term, causes dopa release."
Dr. Alberts has no disclosures. Dr. Sethi is a member of the editorial advisory board for Medscape Neurology. He has disclosed he has served as an advisor or consultant to and received grants for clinical research from Boehringer Ingelheim Pharmaceuticals, Schering-Plough, GlaxoSmithKline, Allergan, Novartis Pharmaceuticals, and Solvay. He owns stock, stock options, or bonds in and has received grants for educational activities from Pfizer and Elan Pharmaceuticals.
Movement Disorder Society's 13th International Congress of Parkinson's Disease and Movement Disorders: Abstract LB-13. Presented June 10, 2009.