Prevalence of Poststroke Cognitive Impairment

TLDR

Stroke incidence is rising with an aging population, underscoring the need for preventive strategies and poststroke surveillance to manage survivors with cognitive impairment. The study examines how the prevalence of cognitive impairment after first‑ever stroke changes over time, stratified by sociodemographic factors, vascular risk, and stroke subtype, over a 15‑year follow‑up. Researchers used a community‑based cohort of 4,212 first‑ever stroke patients from the South London Stroke Register, assessing cognition with the Abbreviated Mental Test or Mini‑Mental State Examination at baseline, 3 months, and yearly thereafter, with age‑adjusted estimates. Cognitive impairment prevalence remained high (~22%) and stable over 15 years, but increased with older age, black ethnicity, and lower socioeconomic status, and showed a progressive rise in small‑vessel occlusion and lacunar infarcts, indicating sociodemographic factors largely explain the variation.

Abstract

Background and Purpose— Stroke is a common long-term condition with an increasing incidence as the population ages. This study evaluates temporal changes in the prevalence of cognitive impairment after first-ever stroke stratified by sociodemography, vascular risk factors, and stroke subtypes, up to 15 years after stroke. Methods— Data were collected between 1995 and 2010 (n=4212) from the community-based South London Stroke Register covering an inner-city multiethnic population of 271 817 inhabitants. Patients were assessed for cognitive function using Abbreviated Mental Test or Mini-Mental State Examination at the onset, 3 months, and annually thereafter. All estimates were age adjusted to the European standard. Results— The overall prevalence of cognitive impairment 3 months after stroke and at annual follow-up remained relatively unchanged at 22% (24% [95% CI, 21.2–27.8] at 3 months; 22% [17.4–26.8] at 5 years to 21% [3.6–63.8] at 14 years). In multivariate analyses, the poststroke prevalence ratio of cognitive impairment increased with older age (2% [1–3] for each year of age), ethnicity (2.2 [1.65–2.89]-fold higher among black group) and socioeconomic status (42% [8–86] increased among manual workers). A significant, progressive trend of cognitive impairment was observed among patients with small vessel occlusion and lacunar infarction (average annual percentage change: 10% [7.9–12.8] and 2% [0.3–2.7], respectively, up to 5 years after stroke). Conclusions— The prevalence of cognitive impairment after stroke remains persistently high over time, with variations being predominantly explained by sociodemographic characteristics. Given population growth and ageing demographics, effective preventive strategies and poststroke surveillance are needed to manage survivors with cognitive impairment.