Exercise has potential to improve non-motor as well as motor symptoms of Parkinson’s disease (PD), including cognitive function, researchers report in the Journal of Parkinson’s Disease.

It is widely acknowledged that physical exercise improves motor symptoms such as tremor, gait disturbances, and postural instability. However, the effect of exercise on non-motor symptoms in PD, especially cognitive function, is less clear.
The underlying neurophysiological mechanisms for cognitive decline in PD are not completely understood, but an accumulation of amyloid plaques, mitochondrial dysfunction, and neurotransmitter changes are all suggested to contribute, according to a media release from IOS Press.
In the study, investigators from the Institute of Movement and Neurosciences, German Sport University, Cologne, Germany, and the VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Queensland, Australia conducted a comprehensive literature review. The review included studies that investigated the effects of coordination exercise, resistance exercise, and aerobic exercise on domain-specific cognitive function in patients with PD.
“Physical exercise is generally associated with increased cognitive function in older adults, but the effects in individuals suffering from PD are not known,” lead investigator Tim Stuckenschneider, MA, explains.
The researchers identified 11 relevant studies published before March 2018 that included a combined total of more than 500 patients with PD with a disease severity from stages 1 to 4 on the Hoehn & Yahr scale, which is used to describe the symptom progression of PD. In four studies, positive effects of exercise on cognition (memory, executive function, and global cognitive function) were shown with no negative effect of exercise on any cognitive domain. Furthermore, disease severity was generally improved by exercise interventions.
All modes of exercise are associated with improved cognitive function in individuals with PD, the investigators conclude. However, no clear picture of which exercise mode is most effective emerged as they may influence cognitive function differently. Aerobic exercise tended to improve memory best, but different forms of exercises such as treadmill training or stationary bike training may have different effects, although both are considered aerobic exercise.
Future studies are needed that directly compare the effects of different exercise modes, as the number of high-quality research projects is still limited, the release explains.
“The potential of exercise to improve motor and non-motor symptoms is promising and may help to decelerate disease progression in individuals affected by PD,” Stuckenschneider observes.
“Exercise therapy needs to be, and often already is, an essential part of therapy in individuals with PD. However, it is mostly used to treat motor symptoms. As part of a holistic therapy, the potential of exercise to maintain or improve non-motor symptoms such as cognitive function in individuals with PD needs to be acknowledged, and the most effective treatment options need to be defined”
“This will not only help practitioners to recommend specific exercise programs, but also ultimately improve the quality of life of the individual. Our work shows that ‘exercise is medicine’ and should routinely be recommended for people with PD to help combat both the physical and cognitive challenges of the disease,” he concludes.
[Source(s): IOS Press, Science Daily]