Recent findings bring hopeful news for individuals diagnosed with Parkinson’s disease: the likelihood of developing dementia may not be as high or may manifest later than previously anticipated. This reassessment comes from a study detailed in the August 7, 2024, online issue of Neurology®, the American Academy of Neurology medical journal.
Dr. Daniel Weintraub of the University of Pennsylvania, Philadelphia, a lead author of the study, emphasized the profound impact of a concurrent diagnosis of a movement disorder and cognitive impairment on patients and their families. He remarked, “These findings offer more optimistic projections about the long-term risk of dementia in Parkinson’s patients, suggesting a prolonged opportunity to implement preventive or delaying strategies against cognitive deterioration.”
Historically, research suggested that approximately 80% of Parkinson’s patients would develop dementia within 15 to 20 years post-diagnosis. However, these earlier studies, although pivotal in highlighting cognitive decline in Parkinson’s disease, were based on small sample sizes and older data, which prompted the need for updated research, according to Weintraub.
The recent study involved analyzing data from two extensive, forward-looking studies. The international segment of the study included 417 participants, averaging 62 years old, all newly diagnosed with Parkinson’s disease and yet to commence treatment at the time of their enrolment. The other part of the research, conducted at the University of Pennsylvania, followed 389 individuals diagnosed with Parkinson’s at an average age of 69, typically six years before the beginning of the study. Researchers monitored the participants to ascertain the development of dementia.
Results from the international study indicated only a 9% probability of participants developing dementia ten years post-diagnosis. The study based in Pennsylvania presented a more varied outlook; it noted a 27% chance of developing dementia ten years after diagnosis, a 50% risk at 15 years, and a considerable 74% at 20 years post-diagnosis. Factors such as older age at diagnosis, male gender, and a lower educational level were associated with increased dementia risk in the Pennsylvania study.
It’s important to note a limitation in these studies: participants were predominantly educated, white individuals actively engaged in a research study, which may not comprehensively represent the broader population. This caveat suggests the need for further research to encompass a more diverse demographic to fully understand dementia’s trajectory in Parkinson’s disease across different populations.
More information: Julia Gallagher et al, Long-Term Dementia Risk in Parkinson Disease, Neurology. DOI: 10.1212/WNL.000000000020969
Journal information: Neurology Provided by American Academy of Neurology
