Objective: To assess patients who have had a stroke for the subsequent development of poststroke dementia (PSD) and to determine if the characteristics of delayed PSD (dPSD) vary in the long-term follow-up.
Methods: Nondemented patients were followed from 6 months after stroke onset for 4 years. Dementia was diagnosed by International Classification of Diseases-10 criteria; dementia etiology was diagnosed by the National Institute of Neurological and Communication Disorders and Stroke/Alzheimer's Disease and Related Disorders Association and National Institute of Neurologic Disorders and Stroke/Association Internationale pour la Recherche et l'Enseignement en Neurosciences criteria. Neuroimaging and neuropsychological tests were repeated annually.
Results: During a 2-year period, 191 stroke patients were enrolled. By the end of the follow-up period, 41 (21.5%) patients had developed dementia. At the Cox regression analysis, dPSD was associated with cortical atrophy (hazard ratio [HR] = 3.4, 95% CI 1.5 to 7.9), age (HR = 3.3, 95% CI 1.4 to 7.8), and multiple ischemic lesions (HR = 2.5, 95% CI 1.2 to 4.8). The Kaplan-Meier analysis showed a significant difference between the incidence of dPSD subtypes (log-rank test; p = 0.002).
Conclusions: During the 4-year follow-up, the incidence of dementia increased gradually, shifting from an Alzheimer disease-type picture in the first years to a vascular dementia type later in years 2 to 4.