USA: Older adults with unrecognized Parkinson's disease may have more significant impairment in activities involving strength and mobility up to 3 years before diagnosis than the general population, states a case-control study of Medicare beneficiaries. Identifying prodromal disease may facilitate earlier intervention to improve function.
Daily functioning in people with prodromal Parkinson's disease needs a more detailed description. Considering this, Cameron Miller-Patterson from the University of Pennsylvania in Philadelphia and colleagues aimed to evaluate whether functional limitations exist in individuals with Parkinson's disease before diagnosis compared with the general population in their study published in JAMA Neurology.

They addressed the question, Are aspects of daily functioning more likely to be impaired in people with prodromal Parkinson's disease compared with the general population?
The researchers used Medicare-linked data from a longitudinal survey in the US, NHATS (National Health and Aging Trends Study), for a random sample comprising Medicare beneficiaries aged 65 years or above, with Older and Black individuals oversampled by design.
Parkinson's disease patients were defined as having two or more Medicare diagnoses from 2011 to 2017, with Medicare eligibility two or more consecutive years before the first diagnosis. Controls were defined as people with Medicare eligibility at a baseline year and two or more years prior, with no diagnosis of Parkinson's disease. Data was taken from the response to survey questions addressing eating, dexterity, pain, mood, mobility, strength, speech, sleep, vision, and strength.
The researchers examined associations between survey responses and diagnosis of Parkinson's disease in the first year of diagnosis (baseline) and up to 3 years before diagnosis (i.e. during the prodromal phase). The study included a total of 6674 participants.
The researchers reported the following findings:
Each year, the case prevalence and participant numbers varied from 700 to 1180 and from 3492 to 5049 per 100 000 populations.
The median age groups were 80 to 84 years and 75 to 79 years, and the females' percentage varied from 48.21% to 59.98% across all years, with similar proportions among controls and cases.
People with prodromal Parkinson's disease were less likely to report being able to walk six blocks (odds ratio [OR], 0.34), stand independently from a kneeling position (OR, 0.30), or lift a heavy object above one's head (OR, 0.36) and were more likely to report imbalance (OR, 2.77) 3 years before diagnosis.
"The findings indicate that people with unrecognized or prodromal Parkinson's disease may have motor symptoms up to 3 years before diagnosis compared to the general population," the researchers wrote.
"Identifying prodromal disease may facilitate earlier intervention for improvement in function," they concluded.
Reference:
Miller-Patterson C, Hsu JY, Willis AW, Hamedani AG. Functional Impairment in Individuals With Prodromal or Unrecognized Parkinson Disease. JAMA Neurol. Published online December 19, 2022. doi:10.1001/jamaneurol.2022.4621