Both the body and brain benefit from exercise: Potential win‐win for Parkinson's disease patients

Abstract

Review Of: Erickson KI, Voss MW, Prakash RS, et al. Exercise training increases size of hippocampus and improves memory. Proc Natl Acad Sci U S A. 2011;108:3017-3022 and The motor symptoms of Parkinson's disease (PD) lead to functional impairment and place patients at increased risk of significant adverse outcomes (eg, falls and hip fractures). Reviews of clinical trials have concluded that exercise in PD is beneficial for physical functioning, health-related quality of life, strength, postural stability, balance, and gait speed.1,2 A recent comparative controlled study found that PD patients undergoing exercise training with the LSVTV R BIG technique had approximately 5 points of improvement in their UPDRS motor score after 16 weeks.3 This benefit was superior to 2 other groups that were walking or performing a self-directed home exercise program (their UPDRS motor scores actually worsened slightly).It is not clear if exercise training in PD has benefits that extend beyond improvement in motor function, however. This is particularly relevant in PD, a disease with frequently disabling nonmotor symptoms, including dementia (PDD) 4 and mild cognitive impairment (PD-MCI). 5 The neural substrate of cognitive decline in PD appears complex, but hippocampal atrophy has been associated with cognitive decline in PD patients. [6][7][8] Erickson et al 9 recently conducted a single-blind, randomized, controlled trial of exercise training in 120 healthy, older adults. The investigators predicted that 1 year of moderateintensity aerobic exercise (ie, walking with a target heart rate zone of 60%-75% of maximum heart rate reserve) 3 days per week would increase hippocampal size, which in turn would be associated with increased brain-derived neurotrophic factor (BDNF) and improved spatial memory. This hypothesis was based on previous preclinical and clinical research demonstrating that exercise improves cognitive abilities and hippocampal cell proliferation and survival, which may in part be mediated by increased BDNF production.The results of the study were compelling and can be summarized as follows: (1) The aerobic exercise group had an increase in bilateral hippocampal volumes (specifically the anterior hippocampus) over 1 year, whereas the control group had a decrease in hippocampal volume (consistent with normal aging), and the difference was statistically significant. No such changes were seen in the control brain regions. (2) In the entire sample, improvement over time in aerobic fitness (increase in VO 2 max) was positively correlated with increase in hippocampal volume. (3) In the LSVTV R BIG exercise group, increases in serum BDNF were positively correlated with increased hippocampal volume, specifically the anterior hippocampus. (4) In the exercise group, increased hippocampal volume was positively correlated with improvements in spatial memory performance.Research suggests that exercise training offers substantial motor benefits for PD patients, and ongoing randomized clinical trials are assessing its impact on no...