Cognitive Function and Mortality in a Community-based Elderly Cohort of First-ever Stroke Survivors and Control Subjects

Objective

We sought to determine the frequency and incidence of cognitive impairments not dementia, dementia, and mortality in first-ever stroke survivors and control subjects.

Methods

We conducted a longitudinal follow-up of a cohort of first-ever stroke survivors (n=98) and age-/sex-matched control subjects (n=92).

Results

At baseline, 37 stroke survivors and 4 control subjects fulfilled Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for dementia. From baseline to follow-up, 6 new patients in the nondemented stroke cohort and 4 patients in the stroke-free cohort developed dementia, giving an incidence of 3.97 (95% confidence interval [CI] 1.46-8.65) and 1.78 (95% CI 0.49-4.57), respectively. The stroke cohort had a more than 2-fold increased risk for developing dementia (relative risk=2.14, 95% CI 0.64-7.13). The cumulative rate of mortality in the stroke cohort was 11.03 per 100 person-years (95% CI 7.7-15.3) and in the stroke-free cohort it was 3.47 per 100 person-years (95% CI 1.13-8.1). The risk for mortality after controlling for dementia cases at baseline was more than 2.5 times that of the stroke-free cohort.

Conclusions

A first-ever stroke increases the risk of developing dementia, Mortality in our stroke cohort was still higher than that observed in the stroke-free cohort. Improved survival poststroke may be contributing to an increased risk for cognitive impairment or dementia in this population.

Key Words: Dementia, epidemiology, vascular cognitive impairment, mortality