Locus Coeruleus Influence on Cognitive Function via the Glymphatic System in Parkinson's Disease

Motivation: The underlying mechanism of locus coeruleus (LC) in cognitive function of Parkinson’s disease (PD) has not been clearly elucidated. Goal(s): To investigate the relationship among LC degeneration, cognitive function, and the glymphatic system in PD. Approach: All participants underwent neuromelanin-sensitive magnetic resonance imaging (NM-MRI) and diffusion tensor image scanning. The whole brain glymphatic activity was measured using diffusion along the perivascular space (ALPS) index, while LC degeneration was estimated using the NM contrast-to-noise ratio of LC (CNRLC). Results: Mediation analysis demonstrated that the ALPS index acted as a significant mediator between CNRLC and the MoCA score in PD subjects. Impact: These findings enhance our grasp of how the LC noradrenergic system influences cognitive function through the glymphatic system. This research offers a promising starting point for exploring potential therapies and further research into cognitive impairment in Parkinson's disease.