The ratios of various cerebrospinal fluid (CSF) proteins have greater value than that of these proteins alone in predicting short- to mid-term progression toward dementia in individuals with Parkinson disease (PD), according to research published in Movement Disorders.

The researchers relied on data from 281 individuals with PD taken from the Parkinson’s Progression Markers Initiative database as an exploratory cohort. The replication cohort consisted of 40 patients without base dementia recruited from the Movement Disorders unit at the University Hospital Donostia in San Sebastián, Spain. The ratios of Amyloid ß1-42, total tau, threonine-181 phosphorylated tau, and α-synuclein in the CSF were also assessed over the length of the study.

In the Parkinson’s Progression Markers Initiative database cohort, the total tau/amyloid ß1-42, total tau/α-synuclein, total tau/amyloid ß1-42+α-synuclein, and amyloid ß1-42/total tau ratios were linked with increased risk of progression to dementia over a 3-year follow-up. In the replication cohort, the total tau/α-synuclein and total tau/amyloid ß1-42 +α-synuclein ratios were linked with progression to dementia over a 41-month follow-up. 

To evaluate whether the ratios were better predictors of progression toward dementia than clinical appraisal, the researchers used logistic regression models for the Montreal Cognitive Assessment score and presence of mild cognitive impairment, total tau/α-synuclein, and total tau/Aß1-42+α-synuclein. The results indicated that ratios were more reliable predictors of dementia than clinical assessments.

The researchers concluded that the results “indicate that the ratios of different CSF proteins have a superior value to that of these proteins alone in predicting short- to mid-term progression of dementia in PD.” They stressed the need for more research regarding the utility of these ratios as biomarkers for dementia in patients with PD.

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Disclosures: Multiple authors declare affiliations with pharmaceutical companies. See reference for a complete list of disclosures.


Delgado-Alvarado M, Dacosta-Aguayo R, Navalpotro-Gómez I, et al. Ratios of proteins in cerebrospinal fluid in Parkinson’s disease cognitive decline: prospective study [published online November 13, 2018]. Mov Disord. doi: 10.1002/mds.27518