Regional variability in the prevalence of cerebral white matter lesions: an MRI study in 9 European countries (CASCADE).

White matter lesions (WML) on MRI of the brain are common in both demented and nondemented older persons. They may be due to ischemic events and are associated with cognitive and physical impairments. It is not known whether the prevalence of these WML in the general population differs across European countries in a pattern similar to that seen for coronary heart disease. Here we report the prevalence of WML in 1,805 men and women drawn from population-based samples of 65- to 75-year-olds in ten European cohorts. Data were collected using standardized methods as a part of the multicenter study CASCADE (Cardiovascular Determinants of Dementia). Centers were grouped by region: south (Italy, Spain, France), north (Netherlands, UK, Sweden), and central (Austria, Germany, Poland). In this 10-year age stratum, 92% of the sample had some lesions, and the prevalence increased with age. The prevalence of WML was highest in the southern region, even after adjusting for differences in demographic and selected cardiovascular risk factors. Brain aging leading to disabilities will increase in the future. As a means of hypothesis generation and for health planning, further research on the geographic distribution of WML may lead to the identification of new risk factors for these lesions.