The association of CSF biomarkers and cognitive decline with choroid plexus volume in early Parkinson's disease

Objective This study aims to determine the link between choroid plexus (CP) volume and cognitive decline in patients with early-stage Parkinson's disease (PD) and to test whether pathological proteins in the cerebrospinal fluid (CSF) are involved in the modulation of any detrimental effects from CP volume. Methods Data on 95 early-stage PD patients with 5 years of follow-up were collected from the Parkinson's Progression Marker Initiative cohort. The patients were separated into three groups based on tertiles of baseline CP volume. We then used a linear mixed model for longitudinal analysis and conducted path analysis to investigate mediating effects. Results At baseline, the patients in both the upper and middle tertile group were older and had lower concentrations of CSF Aβ1-42 than those in the lowest tertile group. Longitudinal analysis showed that the upper tertile group suffered from a more rapid cognitive decline in the Symbol Digit Modalities test, Hopkins Verbal Learning Test (HVLT)-retention, and HVLT delayed recalled score. Furthermore, path analysis showed that the pathological effects of CP volume on the 5-year decline in memory might be partly mediated by the CSF Aβ1-42/αsyn ratio. Conclusion CP enlargement could be an independent risk factor for decreased cognition in patients with early-stage PD, and this risk may be mediated by CSF pathological proteins.