Fig. 1. Schematic diagram of path analyses for cognitive status and motor symptoms.

Vascular risk factors (hypertension, diabetes mellitus, and dyslipidemia), autonomic risk factors (OH, SH), RBD, and APOE ε4 status were entered as predictors. BGdPVS, WMdPVS, and total WMH were entered as mediators. Age, sex, years of education, disease duration, levodopa-equivalent dosage, CCSIT score, and the presence of depression were entered as covariates. Numbers on the paths are the standardized coefficients that were statistically significant. Abbreviations: BG basal ganglia, dPVS dilated perivascular spaces, CCSIT Cross-Cultural Smell Identification Test, HTN hypertension, OH orthostatic hypotension, RBD REM sleep-behavior disorder, SH supine hypertension, WM white-matter, WMH white matter hyperintensities.