Forland MG, et al. - During this study, experts examined if cerebrospinal fluid (CSF) total α-synuclein concentrations changed over time and correlated with motor and cognitive function in Parkinson's disease (PD). Based on the results, it was determined CSF total α-synuclein levels did not distinguish PD patients from controls. Hence, the clinical utility of total α-synuclein was not supported as a single diagnostic or prognostic biomarker in PD.