The Influence of Parkinson’s Disease and Neurotypical Aging on Cognitive Performance Among Volunteers for an Exercise-based Rehabilitative Intervention

PURPOSETo determine the impact of aging versus combined aging and disease on cognition in older adults with and without Parkinsons disease (PD) who were volunteers for exercise based rehabilitation research.\n\nMETHODSWe used a multiple linear regression approach to analyze cognitive outcome measures of rehabilitation volunteers with and without PD.\n\nRESULTSSignificant associations were identified between increased age and decreased performance on 8 of the 14 outcomes analyzed after controlling for false discovery rate. Of those 8 outcomes, multivariate regression analyses demonstrated an effect of disease on performance in only 4/8. In all cases, PD was associated with superior, rather than decreased performance after controlling for age. Results were unaffected by sex and education. Post-hoc comparison with available age norms demonstrated that differences between PD and Non-PD volunteers could be primarily attributed to the Non-PD group substantially underperforming versus age norms.\n\nCONCLUSIONSIn rehabilitative exercise studies using volunteers, many cognitive domains decline with increasing age, consistent with previous neuropsychological studies without a rehabilitation component. However, older \"neurotypical\" volunteers may potentially underperform PD volunteers after controlling for age. This may be an important design consideration for rehabilitation studies with cognitive outcomes.\n\nIMPLICATIONS FOR REHABILITATIONO_LIAn increasing number of rehabilitation studies incorporate cognitive outcomes.\nC_LIO_LIWhether the overall cognitive profile of rehabilitation volunteers differs from that of neurotypical aging remains to be established.\nC_LIO_LIRehabilitation volunteers with Parkinsons disease may outperform putatively neurotypical volunteers after controlling for covariates.\nC_LIO_LICognitive impairments associated with PD in neuropsychological studies may not generalize to exercise rehabilitation volunteers.\nC_LI