Can a screening questionnaire accurately identify mild Parkinsonian signs?

Mild Parkinsonian Signs: A Systematic Review of Clinical, Imaging, and Pathological Associations

Mild parkinsonian signs (MPS) have been widely studied during the past 3 decades and proposed as a risk marker for neurodegenerative disease. This systematic review explores the epidemiology, clinical and prognostic associations, radiological features, and pathological findings associated with MPS in older adults free from neurodegenerative disease. We find that MPS as currently defined are strongly associated with increasing age and increased risk of development of Parkinson's disease (PD), all-cause dementia, disability, and death. Positive associations with later PD are found mainly in younger populations and those with other features of prodromal PD. There are currently no consistent radiological findings for MPS, and pathological studies have shown that MPS, at least in the oldest old, are often underpinned by mixed neuropathologies, including those associated with Alzheimer's disease, cerebrovascular disease, nigral neuronal loss, and Lewy bodies. Different subcategories of MPS appear to convey varying risk and specificity for PD and other outcomes. MPS overall are not specific for parkinsonian disorders and, although associated with increased risk of PD, can reflect multiple pathologies, particularly in older individuals. "Mild motor signs" appears a more appropriate term to avoid prognostic and pathological implications, and larger future studies to prospectively examine outcomes and associations of specific MPS subcategories are required. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Improved diagnosis of Parkinson's disease from a detailed olfactory phenotype

Objective

To assess the predictive potential of the complete response pattern from the University of Pennsylvania Smell Identification Test for the diagnosis of Parkinson's disease.

Methods

We analyzed a large dataset from the Arizona Study of Aging and Neurodegenerative Disorders, a longitudinal clinicopathological study of health and disease in elderly volunteers. Using the complete pattern of responses to all 40 items in each subject's test, we built predictive models of neurodegenerative disease, and we validated these models out of sample by comparing model predictions against postmortem pathological diagnosis.

Results

Consistent with anatomical considerations, we found that the specific test response pattern had additional predictive power compared with a conventional measure – total test score – in Parkinson's disease, but not Alzheimer's disease. We also identified specific test questions that carry the greatest predictive power for disease diagnosis.

Interpretation

Olfactory ability has typically been assessed with either self‐report or total score on a multiple choice test. We showed that a more accurate clinical diagnosis can be made using the pattern of responses to all the test questions, and validated this against the “gold standard” of pathological diagnosis. Information in the response pattern also suggests specific modifications to the standard test that may optimize predictive power under the typical clinical constraint of limited time. We recommend that future studies retain the individual item responses for each subject, and not just the total score, both to enable more accurate diagnosis and to enable additional future insights.

Parkinsonian signs are a risk factor for falls

BACKGROUND

Parkinsonian signs are common, non-specific findings in older adults and associated with increased rates of dementia and mortality. It is important to understand which motor outcomes are associated with parkinsonian signs.

OBJECTIVES

To determine the role of parkinsonian signs on fall rates among older adults.

METHODS

We conducted a longitudinal study of primary care patients from the University of Pennsylvania Health System. Adults over 55 years were assessed at baseline through surveys and a neurological examination. We recorded falls over the following 2 years. Parkinsonian signs were defined as the presence of 2 of 4 cardinal signs. Incident falls were compared between subjects with and without parkinsonian signs, and modified Poisson regression used to adjust for potential confounders in the relationship between parkinsonian signs and falls.

RESULTS

982 subjects with a mean age of 68 (s.d. 8.8) years participated. 29% of participants fell and 12% exhibited parkinsonian signs at baseline. The unadjusted RR for falls among individuals with parkinsonian signs was 1.36 (95% CI 1.05-1.76, p=0.02). After adjusting for age, cognitive function, urinary incontinence, depression, diabetes, stroke and arthritis, individuals with parkinsonian signs were still 38% more likely to fall than those without parkinsonian signs (RR 1.38, 95% CI 1.04-1.82; p=0.03). Falls among those with parkinsonian signs were more likely to lead to injury (53% vs 37%; p=0.04).

CONCLUSIONS

Parkinsonian signs are a significant, independent risk factor for falls. Early detection of this clinical state is important in order to implement fall prevention programs among primary care patients.

The prevalence of Parkinson's disease: a systematic review and meta-analysis

Parkinson's Disease (PD) is a common neurodegenerative disorder. We sought to synthesize studies on the prevalence of PD to obtain an overall view of how the prevalence of this disease varies by age, by sex, and by geographic location. We searched MEDLINE and EMBASE for epidemiological studies of PD from 1985 to 2010. Data were analyzed by age group, geographic location, and sex. Geographic location was stratified by the following groups: 1) Asia, 2) Africa, 3) South America, and 4) Europe/North America/Australia. Meta-regression was used to determine whether a significant difference was present between groups. Forty-seven studies were included in the analysis. Meta-analysis of the worldwide data showed a rising prevalence of PD with age (all per 100,000): 41 in 40 to 49 years; 107 in 50 to 59 years; 173 in 55 to 64 years; 428 in 60 to 69 years; 425 in 65 to 74 years; 1087 in 70 to 79 years; and 1903 in older than age 80. A significant difference was seen in prevalence by geographic location only for individuals 70 to 79 years old, with a prevalence of 1,601 in individuals from North America, Europe, and Australia, compared with 646 in individuals from Asia (P < 0.05). A significant difference in prevalence by sex was found only for individuals 50 to 59 years old, with a prevalence of 41 in females and 134 in males (P < 0.05). PD prevalence increases steadily with age. Some differences in prevalence by geographic location and sex can be detected.

Prevalence of Parkinson's disease in a rural village of coastal Ecuador. A two-phase door-to-door survey

Occupational exposure to toxic solvents increases the odds for having Parkinson's disease (PD). We performed a door-to-door survey to assess PD prevalence in Atahualpa, a rural village of coastal Ecuador where more than 50 % of men work as carpenters, being in contact with toxic solvents under poor safety settings. During Phase I, rural doctors screened all Atahualpa residents aged ≥40 years with a questionnaire directed to identify those with PD. In Phase II, neurologists evaluated individuals who screened as suspected cases of PD, as well as a random sample of negative individuals to assess possible false negative cases. As a result, the census yielded 642 Atahualpa residents aged ≥40 years. An affirmative response to the questionnaire was obtained in seven persons. Neurological examination confirmed the diagnosis of PD in two of them (both carpenters). Examination of 14 non-suspected individuals disclosed no further PD patients. Prevalence of PD in Atahualpa residents aged ≥40 years was 312 per 100,000 which increased to 671 per 100,000 when only people aged ≥60 years was considered. Job-specific prevalence was 1,470 per 100,000 in carpenters. In conclusions, PD prevalence in Atahualpa is similar to that reported from other regions. However, we noted an increase in PD prevalence when only carpenters were considered. Unsafe occupational exposure to toxic substances may counterbalance the apparently lower risk of PD in the non-industrialized world.