Long-term dementia risk in Parkinson Disease

Long-term dementia risk in Parkinson Disease
Neurology; Julia Gallagher, Caroline Gochanour, Chelsea Caspell-Garcia, Roseanne D Dobkin, Dag Aarsland, Roy N Alcalay, Matthew J Barrett, Lana Chahine, Alice S Chen-Plotkin, Christopher S Coffey, Nabila Dahodwala, Jamie L Eberling, Alberto J Espay, James B Leverenz, Irene Litvan, Eugenia Mamikonyan, James Morley, Irene H Richard, Liana Rosenthal, Andrew D Siderowf, Tatyana Simuni, Michele K York, Allison W Willis, Sharon X Xie, Daniel Weintraub, Parkinson's Progression Markers Initiative; 9/24
It is widely cited that dementia occurs in up to 80% of patients with Parkinson disease (PD), but studies reporting such high rates were published over two decades ago, had relatively small samples, and had other limitations. We aimed to determine long-term dementia risk in PD using data from two large, ongoing, prospective, observational studies. Participants from the Parkinson's Progression Markers Initiative (PPMI), a multisite international study, and a long-standing PD research cohort at the University of Pennsylvania (Penn), a single site study at a tertiary movement disorders center, were recruited. Results from two large, prospective studies suggest that dementia in PD occurs less frequently, or later in the disease course, than previous research studies have reported.