Parkinsonism and Parkinson's disease in the elderly: a community-based survey in Brazil (the Bambuí study).

Several community-based surveys on the prevalence of Parkinsonism and Parkinson's disease have been conducted worldwide, with variations on their methodology and results. The objective of this study is to assess the prevalence of Parkinsonism and its causes in a cohort of individuals age 64 years or older in Bambuí, a Brazilian town. In phase I, 1,186 people older than 64 years responded to a 9-question screening questionnaire for Parkinsonism. In phase II, all subjects who scored > or = 2 points on the test were examined independently by at least 2 movement disorder-trained physicians. A movement disorder senior specialist excluded or confirmed the diagnosis in all suspected cases. The response rate was high for both phases (96% for phase I and 94% for phase II). The prevalence rate per 100 population over 64 years of age in this group was 7.2% for Parkinsonism of all types (n = 86). The most frequent causes were idiopathic Parkinson's disease and drug-induced Parkinsonism, with prevalence rates of 3.3% (n = 39) and 2.7% (n = 32), respectively. The prevalence of vascular Parkinsonism was 1.1% (n = 13). We found 1 case of posttraumatic Parkinsonism and another with multiple system atrophy. In this first population-based study of Parkinsonism conducted in Brazil, the prevalence in a cohort of elderly subjects was higher than the observed in other populations worldwide, especially because of the high rates of drug-induced and vascular Parkinsonism. The prevalence of Parkinson's disease was similar to that observed in elderly people in door-to-door surveys in other American, European, and Eastern countries.