Rural or urban living and Parkinson's disease

Prevalence, distribution and future projections of Parkinson disease in Brazil: insights from the ELSI-Brazil cohort study

Background

There is limited epidemiological data regarding Parkinson's disease (PD) prevalence in Brazil, which hinders adequate public health policies planning and patient care. This study aimed to investigate the distribution, prevalence, and clinical characteristics of PD among older adults in Brazil.

Methods

This cross-sectional study used data from the ELSI-Brazil cohort, a Brazilian nationally representative study of individuals aged 50 and older. Data were collected through door-to-door surveys with standardized questionnaires. PD diagnosis was based on self-reported data. We calculated PD prevalence in the general population and specific age groups, studied its association with clinical variables, and projected PD prevalence in Brazil from 2024 to 2060.

Findings

A total of 9881 respondents were included in this study, and 93 reported a medical diagnosis of PD. The crude prevalence of PD among Brazilians aged 50 or more was 0.84% (95% CI: 0.64%-1.09%), with an age- and sex-standardized prevalence of 0.86% (95% CI: 0.62%-1.10%). Men were more affected than women (OR: 2.35, 95% CI: 1.35-4.08; p < 0.01), and the prevalence was higher in older age groups, from 0.39% in those aged 50-59 years to 2.75% in those 80 years and older. PD individuals had higher rates of stroke, depression, functional dependency, and were more likely to need walking support or be bedridden. Projections indicated that PD cases in Brazil will rise from 535,999 (95% CI: 309,963-922,948) in 2024 to 1,250,638 (95% CI: 734,660-2,117,585) by 2060.

Interpretation

This study reveals the prevalence and distribution of PD in Brazil, showing many patients with advanced disease and suggesting underdiagnosis in early stages. There is a need for better diagnostic accuracy, improved access to neurologists, and comprehensive public health strategies to manage the rising prevalence and healthcare demands of PD in Brazil.

Funding

This study did not receive any funding. The ELSI-Brazil cohort was funded by the Ministry of Health of Brazil.

Conjugal Parkinsonism and Parkinson disease: a case series with environmental risk factor analysis

PD occurring in married couples, "conjugal PD" represents a unique opportunity to study environmental risk factors for PD due to the shared environment. This retrospective study of non-related married individuals who both presented to the Washington University Movement Disorders Center between 1994 and 2005 investigated the clinical presentation, therapy response, and disease course in conjugal PD subjects. In addition, an occupational, residential, and environmental survey was administered to elucidate potential shared environmental risk factors. Eighteen married subjects had a clinical picture suggestive of idiopathic Parkinson disease. Average age of motor symptom onset was 66.1 (+/-6.22) years in women, 63.4 (+/-7.87) years in men. Subjects cohabitated an average of 39.9 years prior to motor symptom onset in the first affected spouse and an average of nine years elapsed prior to symptom onset in their partner. Disease course in conjugal pairs varied substantially. Seventeen out of eighteen subjects reported at least one environmental exposure of interest. Concordant exposures were residential, non-occupational pesticide and heavy metal exposure, each reported by 77.8% (7/9) of couples. Multiple exposures were reported by 88.9% (16/18) of subjects, most often residential agricultural chemical and heavy metal in combination. This case series of conjugal PD suggests that combined residential exposures may be important in the pathogenesis of idiopathic PD. Larger conjugal PD studies may permit stratification of concordant environmental exposures to determine dose responsiveness and relative contributions to PD risk.

Prognostic factors for the progression of Parkinson's disease: a systematic review

The purpose of this systematic review is to summarize studies that describe the course of Parkinson's disease (PD) and to identify factors that predict change in motor impairment, disability, and quality of life. A literature search was conducted in MEDLINE, EMBASE, CINAHL, and Web of Science limited to the English, French, German, Spanish, and Dutch language. Reports were selected if the study involved subjects with PD, the outcome measures described impairment, disability, or quality of life and follow-up was at least 6 months. All included studies were scored for methodological quality. Data were extracted and summarized in a best evidence synthesis. We screened 1,535 titles and abstracts, of which 27 fulfilled our inclusion criteria. A meta-analysis to quantitatively aggregate progression scores of motor impairment and disability was not possible because of the wide variety of outcome measures used and the heterogeneous study populations. Limited evidence is found for lower UPDRS-ME at baseline, dementia and SE < 70% as prognostic factors for future motor impairment. There is strong evidence for higher age at onset and higher PIGD-score; and limited evidence for higher bradykinesia-score, non-tremor dominant subtype, symmetrical disease at baseline, and depression as prognostic factors for progression of disability. Prognostic factors were identified for impairment and disability. The literature on prognosis in PD is not fulfilling the high methodological standards applied nowadays. There is a need for prospective cohorts of PD patients assembled at a common early point in the disease with long time follow-up.

Epidemiology of Parkinson's disease

This chapter discusses the epidemiology of Parkinson's disease (PD). Classically, PD refers to progressive parkinsonism caused by loss of pigmented aminergic brainstem neurons without an identifiable cause, while parkinsonism refers simply to the syndrome of bradykinesia, resting tremor, rigidity and postural reflex impairment. Over nearly two centuries, Parkinson's clinical description has provided the framework for clinical investigations, including epidemiologic ones. Descriptions of PD were limited to selected clinical settings until the middle of the 20th century. Since then, epidemiologic approaches have been used not only to investigate the population distribution of PD, but also as a way to glean clues as to the cause of this “idiopathic” disorder. Because PD is relatively infrequent, a large base population must be surveyed to identify sufficient numbers of cases for a study. In some instances, PD cases can be identified through health service rosters within defined geographic areas or in enumerated populations. In others, cases of PD are sought independently of the health care system, such as through door-to-door surveys. While the latter approach is theoretically least likely to exclude cases, the time and cost involved are also greatest using this approach.

Movement disorders in Latin America

The authors review some particularities of movement disorders (MDs) in the ethnically diverse population of Latin America. Although idiopathic diseases are evenly prevalent, access to treatment encounters difficulties that are worth discussing. Infectious-parasitic diseases observed throughout the continent occasionally present as MDs, and will be individually reviewed. Inherited MDs with regional foci of increased prevalence, particularly spinocerebellar ataxias, will also be considered. Whereas there is no treatment for genetic disorders, most of the other conditions are preventable or amenable to adequate treatment. Hope for better health standards for the Latin American population lies in profound social and political changes that are still to come.