Methods: We conducted a single‐center retrospective study with 108 DN PD patients, assessed by the MDS‐UPDRS and MoCA scores, and the measurement of CSF total alpha‐synuclein (alpha‐syn), total and phosphorylated‐181 tau (t‐tau, p‐tau), amyloid‐beta42 and amyloid‐beta40 (ABeta42, ABeta40) levels, p‐tau/t‐tau, ABeta42/ABeta40, and p‐tau/ABeta42 ratios. Here, MAPT is linked to Parkinson disease.