Prevalence of Parkinson's disease and atypical parkinsonian syndromes in a rural Japanese district

Objectives - To investigate the prevalence of Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) in a rural Japanese district. Method - Collaboration with the medical institutions, the long-term care insurance system facilities, and the public health office. Results - The crude prevalence rates were 175 per 100 000 (95% CI: 143-206) for PD, 18 (8-28) for progressive supranuclear palsy, 17 (7-26) for multiple system atrophy (MSA), and 9 (2-16) for corticobasal degeneration. The age-adjusted prevalence rates were 109 per 100 000 (88-134), 10 (2-17), 13 (4-21), and 6 (0-12), for each condition. There was a preponderance of women with PD and of men with APS. Nine of the 116 PD patients and 7 of the 29 APS patients were newly diagnosed in this study. Conclusions - There are high prevalence rates for PD and APS and suboptimal recognition of APS. This is the first epidemiological prevalence study of MSA from Japan.