Main idea: Lower diffusivity along with the perivascular space, represented by lower ALPS-index, indicates impairment of the glymphatic system in PD patients. The correlation between elevated plasma nuclear DNA levels and lower ALPS-index supports the notion that PD patients may exhibit increased oxidative stress associated with glymphatic system microstructural alterations.
Parkinson’s disease (PD) is a common neurodegenerative disease associated with the accumulation of misfolded proteins and increased neuroinflammation. This study was to evaluate glymphatic system activity and its relationship with systemic oxidative stress status in PD patients. Magnetic resonance imaging and neuropsychological tests were conducted on PD patients. Oxidative stress status was assessed by plasma DNA level. Differences in ALPS-index among the subgroups were assessed and further correlated with cognitive functions. The PD-MCI and PDD groups showed significantly lower ALPS-index compared to normal controls. The ALPS-index was inversely correlated with plasma nuclear DNA, mitochondrial DNA levels, and cognitive scores.