The Current Research
- At Rhodes University in Memphis, TN, Dr. Gerecke et al. report that exercise can protect mice against toxic exposure. MPTP is a neurotoxin that is used as an animal model for Parkinson’s disease, as it selectively kills dopamine neurons in the substantia nigra, the same nucleus that degenerates in Parkinson’s disease. Dr. Gerecke showed that 3 months of exercise provided complete protection against MPTP-induced neurotoxicity in mice. Also, if the duration of running was limited to either 1 or 2 months, or if the amount of running daily was decreased, the protective effects of exercise was abolished. Thus, daily, sustained exercise was necessary for full protection. In addition, Gerecke performed proteomic analysis to identify possible mechanisms of this protection, and found that 3 months of exercise induces changes in proteins related to energy regulation, cellular metabolism, cytoskeleton dynamics, and intracellular signaling events.
- At the University of Pittsburgh, Dr. Zigmond et al. found that exercise reduces the impairments elicited by the dopaminergic neurotoxins as well as the loss of DA neurons. This study is focused on one of several possible explanations for the beneficial effects of exercise: an exercise-induced increase in the expression of neurotrophic factors, particularly GDNF (glial-derived neurotrophic factors). Observations indicate that GDNF can reduce the vulnerability of DA neurons, in part due to the activation of key intracellular cascades. This raises the possibility that some individuals with Parkinson's disease suffer from a reduction of these neuroprotective mechanisms, and that treatments that boost these mechanisms - including exercise - may provide therapeutic benefit.
- A review of 14 studies on treadmill training found that three studies show an immediate effect of increased walking speed, longer stride length and improved balance as early as after one treadmill session. Longer-term trials, numbering 11 in all, demonstrated not only safety, but positive benefits in gait speed, strike length and related quality of life even several weeks later.
- And at the Cleveland Clinic, Dr. Alberts et al. found that when people with Parkinson’s pedaled on a stationary bike 30% faster than their preferred “voluntary” rate (or forced exertion), they not only gained in aerobic fitness, but also showed improvement in motor function and coordination as well as manual dexterity. This improvement was retained some weeks after the exercise stopped.
- In a recent study conducted by Beth Fisher et al., researchers at the University of Southern California found that exercise may have an effect on the brain. On a day-to-day basis, people with PD who exercised moved more normally than those who did not. Based on these findings, they believe that exercise may be helping the brain to maintain old connections, form new ones and restore lost ones. They suggest that, in certain situations, the neuroplasticity created from exercise in patients with PD may actually outweigh the effects of neurodegeneration.
- The above are just some of the mounting evidence that shows that for people with Parkinson’s, exercise is an essential part of managing the disease. Many researchers are working to better understand this, what makes it happen, and how to achieve the best results and the National Parkinson Foundation is supporting their efforts.
Page reviewed by Dr. Joash Lazarus, NPF Movement Disorders Fellow, Department of Neurology at Emory University School of Medicine.