We used stepwise logistic regression analyses to test whether neurofilament contributes to a biomarker CSF panel including total, oligomeric, and phosphorylated synuclein and Alzheimer's disease biomarkers. Measures of disease severity included disease duration, UPDRS III, Hoehn Yahr stage, and MMSE. RESULTS: After correcting for age, CSF neurofilament levels were 42 higher in PD patients compared with controls P