Brain markers of cognitive-motor control of gait function in Parkinson's disease: links with physical activity and aerobic fitness.

PURPOSE: This narrative review synthesizes magnetic resonance imaging (MRI) evidence of (i) the associations between physical activity and/or aerobic fitness and brain markers related to cognitive function in Parkinson's disease (PD); and (ii) MRI-derived brain markers linked to gait impairment in PD. We also propose a conceptual framework describing how physical activity or fitness may support the cognitive-motor networks associated with gait.

METHODS

PubMed and Web of Science were searched for MRI studies examining the relationships between physical activity/fitness and cognition-relevant brain markers as well as MRI studies linking brain markers to gait outcomes (including cognition-related gait measures and freezing of gait).

RESULTS

Fourteen observational studies met our inclusion criteria. Higher physical activity and/or fitness were seen to be generally associated with better cognitive performance and MRI features suggestive of preserved brain integrity and connectivity within the cognitive-motor networks. Regarding gait, the reviewed evidence suggests a shift toward greater reliance on cognitive-motor control to compensate for impaired automatic motor control, which may occur when this compensatory cognitive control becomes insufficient under increased task demands.

CONCLUSION

Physical activity and fitness may contribute to gait function in patients with Parkinson's disease by supporting the cognitive-motor integration required for walking. Longitudinal and interventional studies using ecologically valid paradigms that approximate real-world (including dual-task) walking, ideally combined with wearable neuroimaging approaches, are needed to clarify how changes in physical activity or fitness are related to neural markers of gait.