Functional Impairment in Individuals With Prodromal or Unrecognized Parkinson Disease

Abstract

ImportanceDaily functioning in individuals with prodromal Parkinson disease requires more detailed description.ObjectiveTo evaluate whether functional limitations exist in individuals with Parkinson disease prior to diagnosis compared with the general population.Design, Setting, and ParticipantsThis case-control study used Medicare-linked data from the National Health and Aging Trends Study (NHATS), a longitudinal survey in the US, for a random subsample of Medicare beneficiaries aged 65 years or older, with Black and older individuals oversampled by design. Patients with incident Parkinson disease were defined as having 2 or more Medicare diagnoses from January 2011 to December 2017, with Medicare eligibility 2 or more consecutive years prior to the first diagnosis. Controls were defined as individuals with Medicare eligibility at a baseline year and 2 or more years prior, with no Parkinson disease diagnosis. Analyses were conducted from November 2021 to June 2022.ExposuresResponses to survey questions addressing dexterity, eating, mobility, mood, pain, sleep, speech, strength, and vision.Main Outcome and MeasuresAssociations between survey responses and Parkinson disease diagnosis in the first year of diagnosis (baseline) and up to 3 years prior to diagnosis (ie, during the prodromal phase) were examined using logistic regression.ResultsA total of 6674 participants were included. The participant numbers and case prevalence each year varied from 3492 to 5049 and from 700 to 1180 per 100 000 population, respectively. The median age groups were 75 to 79 years and 80 to 84 years, and the percentage of females varied from 48.21% (27 of 56 cases) to 59.98% (2079 of 3466 controls) across all years, with similar proportions among cases and controls. Individuals with prodromal Parkinson disease were less likely to report being able to walk 6 blocks (odds ratio [OR], 0.34; 95% CI, 0.15-0.82), stand independently from a kneeling position (OR, 0.30; 95% CI, 0.11-0.85), or lift a heavy object above one’s head (OR, 0.36; 95% CI, 0.15-0.87) and were more likely to report imbalance (OR, 2.77; 95% CI, 1.24-6.20) 3 years prior to diagnosis.Conclusions and RelevanceThe findings suggest that individuals with prodromal or unrecognized Parkinson disease may have greater impairment in activities involving mobility and strength up to 3 years prior to diagnosis compared with the general population. Identification of prodromal disease may facilitate earlier intervention to improve function.

Perspectives of People At-Risk on Parkinson’s Prevention Research

“…Because α -synucleinopathy diseases like Parkinson’s can have a long prodromal stage, many people exhibit various non-motor and subclinical motor manifestations for several years, adding to the challenge of diagnosing this complex disease during its insidious onset [ 88 ]. A recent case-control study using random sampled survey data from the National Health and Aging Trends Study (NHATS) found that unrecognized, prodromal Parkinson’s is connected to significant problems with mobility and strength compared to the general population up to three years prior to diagnosis [ 89 ].…”

Perspectives of People At-Risk on Parkinson's Prevention Research

“…[77] A recent case-control study using random sampled survey data from the National Health and Aging Trends Study (NHATS) found that unrecognized, prodromal Parkinson's is connected to significant problems with mobility and strength compared to the general population up to three years prior to diagnosis. [78] Encouraging the at-risk population to participate in clinical studies during the prodromal stage to monitor the onset of symptom development is critical to identifying interventions that can slow, stop, or reverse disease progression prior to a traditional diagnosis of PD. Yet, many at-risk individuals do not feel supported when communicating their concerns.…”

Functional Impairment Preceding Parkinson Disease Diagnosis—What’s in a Prodrome?

“…Another caveat regarding diagnostic certainty is that, while the authors excluded participants with diagnostic codes for atypical parkinsonism or vascular parkinsonism, there are always uncertainties regarding how well diagnostic and billing codes accurately reflect clinical reasoning. For example, someone with subtle clinical findings that may suggest progressive supranuclear palsy (but are not yet clear enough for clinical confirmation) might be given the clinical diagnosis of parkinsonism that can be assigned the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10) code G20, the same code as PD.…”

“…Given the rising importance attached to prodromal PD research, the results of a case-control study by Miller-Patterson and colleagues in this issue of JAMA Neurology are of particular interest and raise new questions regarding how early motor dysfunction begins in PD. Using data from the National Health and Aging Trends Study, a longitudinal survey of Medicare beneficiaries, the authors aimed to evaluate evidence of functional limitations in the years preceding newly diagnosed PD. They examined responses to a self-reported questionnaire that all participants in the study completed annually.…”