Abstract
Background: There is a need for biomarkers of dementia in PD. Objectives: To determine if the levels of the main CSF proteins and their ratios are associated with deterioration in cognition and progression to dementia in the short to mid term. Methods: The Parkinson's Progression Markers Initiative database was used as an exploratory cohort, and a center-based cohort was used as a replication cohort. Amyloid ss 1-42, total tau, threonine-181 phosphorylated tau, and alpha-synuclein in the CSF and the ratios of these proteins were assessed. Results: In the Parkinson's Progression Markers Initiative cohort (n = 281), the total tau/amyloid ss 1-42, total tau/alpha-synuclein, total tau/amyloid ss 1-42+alpha-synuclein, and amyloid ss 1-42/total tau ratios were associated with a risk of progression to dementia over a 3-year follow-up. In the replication cohort (n = 40), the total tau/alpha-synuclein and total tau/amyloid ss 1-42+alpha-synuclein ratios were associated with progression to dementia over a 41-month follow-up. Conclusion: Ratios of the main proteins found in PD patient brain inclusions that can be measured in the CSF appear to have value as short- to mid-term predictors of dementia. (c) 2018 International Parkinson and Movement Disorder Society