EPIDEMIOLOGY OF VASCULAR DEMENTIA

Vascular dementia (VaD) is the second commonest dementia after Alzheim er's disease (AD). Epidemiological studies of this condition suffer fr om many shortcomings related to definition of the disease, diagnostic criteria and assessment of subjects. The prevalence of VaD increases l inearly with age and varies greatly from country to country, ranging f rom 1.2 to 4.2% of people over 65 years old, even after adjustment for age and sex. The incidence of VaD is more homogeneous than prevalence and is estimated at 6-12 cases per 1,000 persons over 70 years per ye ar. The mean duration of the disease is around 5 years and survival is less than for the general population and for AD. The major risk facto rs for VaD appear to be hypertension, diabetes, heart disease and stro ke. Although some of these risk factors are modifiable, there is no st udy on efficacy of prevention of VaD.