Prevalence of early dementia after first-ever stroke: a 24-year population-based study.

BACKGROUND AND PURPOSE No data about temporal change in the prevalence of poststroke dementia are available. We aimed to evaluate trends in the prevalence of early poststroke dementia. METHODS From 1985 to 2008, overall first-ever strokes occurring within the population of the city of Dijon, France (150 000 inhabitants) were recorded. The presence of dementia was diagnosed during the first month after stroke, according to Diagnostic and Statistical Manual of Mental Disorders, Third and Fourth Editions criteria. Time trends were analyzed according to 4 periods: 1985 to 1990, 1991 to 1996, 1997 to 2002, and 2003 to 2008. Logistic regression was used for nonmultivariate analyses. RESULTS Over the 24 years, 3948 first-ever strokes were recorded. Among patients with stroke, 3201 (81%) were testable of whom 653 (20.4%) had poststroke dementia (337 women and 316 men). The prevalence of nontestable (mostly due to death) patients declined from 28.0% to 10.2% (P<0.0001). Multivariate analysis revealed significant temporal changes in the prevalence of poststroke dementia; prevalence in the second and fourth periods was, respectively, almost half and twice that in the first period. The prevalence of poststroke dementia associated with lacunar stroke was 7 times higher than that in intracerebral hemorrhage but declined over time as did prestroke antihypertensive medication. Age, several vascular risk factors, hemiplegia, and prestroke antiplatelet agents were associated with an increased prevalence of poststroke dementia. CONCLUSIONS This study covering a period of 24 years highlights temporal changes in the prevalence of early dementia after first-ever stroke. These changes may be explained by concomitant determinants of survival and incidence such as stroke care management or prestroke medication.