Prevalence and incidence of Parkinson’s disease and other forms of parkinsonism in a cohort of elderly individuals in Southern Brazil: protocol for a population-based study

IntroductionParkinsonism is one of the most common neurological disorders affecting the elderly. Several population-based studies have determined the epidemiology of parkinsonism, mainly Parkinson’s disease (PD), but there is still little evidence in the Brazilian population. This protocol study aims to assess the prevalence and incidence of cases of PD and other parkinsonian syndromes in a 5-year cohort in a population-based study in the southern region of Brazil.Methods and analysisA prospective population-based longitudinal study, with a cohort of development of cases of parkinsonism, divided into two phases: in phase I, two questionnaires to screen for parkinsonism (Tanner’s questionnaire), Rapid Eyes Movement (REM) sleep behaviour disorder (REM Sleep Behavior Disorder Single-Question Screen) and a short interview will be conducted with all elderly residents of Veranópolis (the first longevity Brazilian county located in the Rio Grande do Sul, Brazil) aged 60 or over. The positive screened cases will be examined independently by at least two movement disorder-trained physicians and prevalence will be determined. A comprehensive evaluation of prodromic symptoms, risk factors and clinical characteristics will be carried out. Subjects with subtle parkinsonism and a sample of healthy subjects will be followed for 5 years in a developmental cohort of parkinsonism cases. For crude incidence, all individuals admitted at the beginning of the study will be re-evaluated.Ethics and disseminationThe study was approved by the research ethics committee of the Hospital de Clínicas de Porto Alegre (protocol n° 4.095.609). All participants provide their informed consent before evaluations. Findings from this survey will be disseminated through peer-reviewed publications and will be presented at conferences.