Cognitive performance in community-dwelling older adults with stroke and the contribution of age and diffuse subcortical damage: a population-based study in rural Ecuador (The Atahualpa Project)

Background: Cognitive impairment is common among stroke survivors. However, there is controversy on the role of the stroke itself or the associated subcortical damage in post-stroke cognitive decline. Aim: To assess the independent contribution and the interaction of age, the stroke itself and diffuse subcortical damage in the poor cognitive performance observed in patients with stroke. Methods: Atahualpa residents aged ≥60 years were identified during a door-to-door survey and invited to undergo brain MRI for identification of stroke lesions and white matter hyperintensities (WMH) of presumed vascular origin. Cognitive performance was evaluated by the use of the Montreal Cognitive Assessment (MoCA). Using a generalized linear model, we examined the association between MoCA score, stroke and WMH, after adjusting for demographics, education, vascular risk factors, depression and edentulism. Results: Out of 311 persons aged ≥60 years, 242 (78 %) were enrolled. MRI showed strokes in 39 (16 %) and moderate-to-severe WMH in 52 (22 %) cases. Mean MoCA score was 18.5 ± 4.7 in the entire population. When participants were stratified according to the median age of the population (67 years), the generalized linear model showed that MoCA scores were not different in younger persons irrespective of the presence of stroke or WMH. In contrast, increased age associated with lower MoCA scores in persons with WMH (p = 0.002) or with both stroke and WMH (p = 0.003), but not in those with stroke without WMH (p = 0.087). Conclusions: Interaction of age and diffuse subcortical damage are major determinants for poor cognitive performance among stroke patients.