8 research outputs found
Long-term dementia prevalence in Parkinson Disease: Glass half-full?
Introduction: Dementia occurs in up to 80% of Parkinson’s disease (PD) patients long-term, but studies reporting such high rates were published years ago and had relatively small sample sizes and other limitations.
Objective: To determine long-term, cumulative dementia prevalence rates in PD using data from two large, ongoing, prospective observational studies.
Design: Analyses of data from the Parkinson’s Progression Markers Initiative (PPMI) and a longstanding PD research clinical core at the University of Pennsylvania (Penn).
Setting: PPMI is a multi-site international study, and Penn is a single site study at a tertiary movement disorders center.
Participants: PPMI enrolls de novo, untreated PD participants at baseline, and Penn enrolls a convenience cohort from a large clinical center.
Methods: For PPMI a cognitive battery and MDS-UPDRS Part I are administered annually, and the site investigator assigns a cognitive diagnosis annually. At Penn a comprehensive cognitive battery is administered either annually or biennially, and a cognitive diagnosis is made by expert consensus.
Main Outcomes: Kaplan-Meier (KM) survival curves were fit for time from PD diagnosis to stable dementia diagnosis for each cohort, using assigned cognitive diagnosis of dementia as the primary endpoint (for both PPMI and Penn), and MoCA score <21 and MDS-UPDRS Part I cognition score ≥3 as secondary endpoints (for PPMI). In addition, cumulative dementia prevalence by PD disease duration was tabulated for each study and endpoint.
Results: For the PPMI cohort, 417 PD participants were seen at baseline; estimated cumulative probability of dementia at year 10 disease duration were: 7% (site investigator diagnosis), 9% (MoCA) or 7.4% (MDS-UPDRS Part I cognition). For the Penn cohort, 389 PD participants were followed over time, with 184 participants (47% of cohort) eventually diagnosed with dementia. The KM curve for the Penn cohort had median time to dementia diagnosis =15 years (95% CI: 13-15) disease duration; the estimated cumulative probability of dementia was 27% at year 10, 50% at year 15, and 74% at year 20.
Conclusions and Relevance: Results from two large, prospective studies suggest that dementia in Parkinson disease occurs less frequently, or later in the disease course, than often-cited previous research studies have reported