Incidence of Parkinson's disease and atypical parkinsonism: Russian population-based study.

Data on the incidence of Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) in East European countries and Asia are limited. The objective of this prospective population-based study was to determine the incidence of PD and APS in the Russian population. The study area was a large district of Moscow with a population of 1,237,900 inhabitants. Multiple sources of case ascertainment were used to identify incident cases of PD and APS between July 2006 and December 2008. All incident cases were examined by a specialist and followed up prospectively to confirm the diagnosis. The age-standardized incidence rates per 100,000/year were 9.03 [95% confidence interval (CI) 8.01-10.15] for PD, 0.11 (95% CI 0.03-0.23) for multiple system atrophy, 0.14 (95% CI 0.08-0.21) for progressive supranuclear palsy, and 0.02 (95% CI 0.01-0.12) for corticobasal degeneration. The age-standardized male-to-female ratio of PD was 0.87 for all ages and 1.46 for those aged 60 and older. A high proportion of new cases with PD (34%) and APS (50%) had comorbid depressive symptoms. Given the rapid growth of the elderly population in Eastern Europe and Asia, the epidemiology of PD and APS in these regions should be investigated in greater depth. The incidence of PD in our study was slightly lower than in studies of Western populations and the male-to-female ratio was closer to those reported in studies from Asia. The clinical implication of our study is that it highlights the need for better diagnosis and treatment of depression in early stages of PD.