Effect of aerobic exercise on cognition and sendentary behavior in persons with Parkinson disease

Parkinson disease (PD) progressively impairs individuals of physical function and cognitive capacity promoting sedentary behavior. Participation in regular exercise improves executive function in elderly persons. However, no studies have observed the impact of exercise on cognitive function or sedentary behavior in people with PD. The purposes of this study were to examine the effect of aerobic exercise on cognitive function and sedentary behavior in persons with PD. Both mode (self paced versus forced) and intensity (≤60 rpm versus >60 rpm) of exercise were investigated. We recruited 20 participants for our 12-week aerobic exercise intervention with 1-month follow-up. Executive function was measured by the Repeatable Battery for the Assessment of Neuropsychological Status(TM) (RBANS(TM)) and dual tasks (TUG manual and TUG cognitive ). Sedentary behavior was determined by physical activity level (volume and intensity) as gathered by the StepWatch(TM) Activity Monitor (SAM). Mann Whitney U tests were selected to analyze the difference between groups--both mode of exercise and intensity. Friedman's Analysis of Variance (ANOVA) test was used to analyze groups across time to determine the impact of our intervention. Wilcoxon Signed Ranks test was used post-hoc. There were no differences between exercise modes for cognitive function or physical activity. Differences with TUG manual were observed across time (X2 =9.69, p =0.01) for all participants. Specifically, TUGmanual scores were different between posttest and 1-month follow-up (z=-2.38, p =0.017) and between baseline and 1-month follow-up (z=-2.83, p =0.005). RBANS(TM) had differences between post-test and 1-month follow-up (z=-2.876, p =0.004) with post-hoc analysis. No differences were observed for the low pedal rate group on cognition over time. For the high pedal rate group, TUGcognitive scores were significantly different over time (X 2 =7.14, p =0.03) but not after post-hoc analysis. Our aerobic exercise intervention failed to minimize sedentary behavior. However, improvements were observed across time for all participants with executive function, specifically dual tasking during gait. While individuals with a high pedal rate may have benefitted from the intervention, the low pedal rate participants achieved clinically relevant improvement and reduced their fall risk. The exercise intervention may be a valuable adjunct for a multidimensional approach to maximize function in persons with PD.