Prodromal and Overt Parkinson's Disease Epidemiological Study in Brazil

Overview

Parkinson's Disease (PD) affects people universally, including all ethnic and socioeconomic groups, as a highly prevalent neurodegenerative disorder. However, there are several additional challenges for people living with PD in developing countries, especially those with low socioeconomic status. There is limited access to neurological care in Brazil due to an uneven distribution of neurologists and neurological facilities, which is more critical in the poorest regions. In addition, people in these vulnerable communities are more exposed to environmental pollution, including pesticides and metals used in agriculture and mining, respectively. Therefore, reliable data on the prevalence and incidence of PD in Brazil are essential to understand the proportion of this limited access to care for patients with PD, its burden in the region, and the potential role of environmental and lifestyle risk factors in PD. Unfortunately, the literature describes few epidemiological data on PD in Latin America, including Brazil, with an evident need for more information in their regions remarkably different. The investigators will carry out a population-based study in four municipalities in Brazil (Veranópolis-RS, Belém-PA, Jacobina-BA and Candangolândia-DF), comprising distinct communities in terms of ethnic groups, education levels, and environmental and lifestyle exposures, to portray the differences in Brazilian society. The present study will screen all people living in these regions aged 60 and over for parkinsonian symptoms and REM sleep behavior disorder (RBD). At least one neurologist will examine those selected to determine the diagnosis of PD or related disorders. The study also will evaluate a random sample of those individuals with a negative screen. Each participant selected after the screening will undergo clinical assessments and interview with the addition of a comprehensive questionnaire on clinical and sociodemographic data, prodromal symptoms, as well as lifestyle and environmental exposures, including occupational use and non-occupational use of pesticides and metals. An equal sample of blood and hair will be collected from individuals with PD and controls. The study will determine the prevalence of PD and related disorders in these distinct communities. An exploratory analysis also will be performed to determine the association between PD and each variable investigated.

Detailed Description: This project proposes to evaluate the prevalence of PD and other parkinsonian syndromes in four regions of Brazil. Additionally, the incidence of PD and conversion of premotor symptoms into parkinsonian syndromes will be investigated in a 5-year cohort in a population-based sample in the southern region country. The investigators will also perform an exploratory analysis to assess the effect of environmental and lifestyle risk factors on PD. Primary Purpose: To determine the prevalence of Parkinson's disease and other Parkinson's syndromes in population-based samples of people aged 60 and over in the cities of Veranópolis (RS), Belém (PA), Jacobina (BA), and the administrative region of Candangolândia (DF). Secondary Objective: For all four regions studied: To determine the overall prevalence and age- and sex-adjusted prevalence of Parkinson's disease; To determine the prevalence of other forms of parkinsonism (atypical, drug and vascular parkinsonism); To determine the prevalence of pre-motor symptoms of Parkinson's disease (REM sleep behavior disorder (RBD), constipation, hyposmia, subtle voice changes, depression in a sample of elderly individuals) To assess the association between Parkinson's disease and exposure to environmental factors: caffeine, tobacco, alcohol, pesticides, herbicides and other environmental toxicants; To evaluate the association between Parkinson's disease and biochemical and molecular biomarkers in peripheral fluids. The biological markers will be uric acid, iron, ferritin, transferrin and heavy metals; Data Analysis Methodology: The investigators will follow the STROBE statement for cross-sectional studies for data analysis and reporting of results for the study of prevalence and risk factors (Vandenbroucke et al. 2014). Data collection will be recorded in spreadsheets and digitally captured by REDCap tools (Harris et al. 2009) hosted at Hospital de Clínicas de Porto Alegre. For PD and other parkinsonian disorders, the aim will be to estimate: 1) crude prevalence, 2) age-specific prevalence, 3) gender-specific prevalence, and 4) age-adjusted prevalence rate.