Exercise is a Protective Factor for Motor and Cognitive Function in Early-Stage Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disease with no known cure. Previous research has identified aerobic exercise as a non-pharmacological therapeutic option to potentially reverse or slow the progression of motor decline. However, the impact of regularly maintaining aerobic activity on domains of cognition remains poorly understood. Here, the primary goal was to identify which cognitive domains may be more responsive to aerobic exercise to better understand its therapeutic benefits on motor and cognitive function in early-stage PD. Independent groups included exercising and non-exercising early-stage PD patients compared to matched non-Parkinson's healthy controls (NPHC). Neurocognitive testing revealed that PD exercise subjects made significantly fewer errors on Trail-Making Test (TMT) B (p < .05; cognitive flexibility, attention) than the non-exercise group and performed comparably to NPHC. The longer number of years PD subjects regularly exercised the better their cognitive flexibility, attention (TMT A and B; p < .001) and visuospatial memory (CLOX2, p < .05). Several significant relationships emerged between motor (Timed Up and Go, Gait speed, and 6-minute Walking Test) and cognitive flexibility, attention (TMT-A, p=0.001; TMT-B, p=0.000), and verbal fluency (FAS, p=0.009; Animal Naming, p=0.002). In summary, PD subjects maintaining a regular aerobic regimen of activity show better motor function, cognitive flexibility, attention, verbal and visuospatial memory than their sedentary counterparts. Future directions include translating these findings using a genetic PD rat model to further elucidate the neural mechanisms underlying exercise-related cognitive and motor performance.