Dementia May Occur Less Often, Develop Slower in Parkinson Disease Patients

WEDNESDAY, Aug. 7, 2024 (HealthDay News) -- For patients with Parkinson disease (PD), dementia may occur less often or develop over a longer time period than previously thought, according to a study published online Aug. 7 in Neurology.

Julia Gallagher, from the University of Pennsylvania in Philadelphia, and colleagues determined long-term dementia risk among participants from the Parkinson's Progression Markers Initiative (PPMI) multisite international study and a long-standing PD research cohort at the University of Pennsylvania (Penn). A total of 417 participants with PD were followed for the PPMI cohort, and 389 participants with PD were followed for the Penn cohort.

The researchers found that the estimated probability of dementia at year 10 disease duration was 9, 15, and 12 percent for site investigator diagnosis, according to the Montreal Cognitive Assessment, and according to the Movement Disorder Society-Unified Parkinson's Disease Rating Scale, respectively, in the PPMI cohort; 47 percent of the Penn cohort was eventually diagnosed with dementia. The median time to dementia was 15 years in the interval-censored curve for the Penn cohort, with estimated probabilities of dementia of 27, 50, and 74 percent at 10, 15, and 20 years of disease duration, respectively.

"These results provide updated, and more hopeful, estimates of long-term dementia risk in PD, suggesting a longer window to intervene to prevent or delay cognitive decline," the authors write.

Several authors disclosed ties to the biopharmaceutical industry; the PPMI is partially funded by biopharmaceutical companies.

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