Global cortical atrophy (GCA) associates with worse performance in the Montreal Cognitive Assessment (MoCA). A population-based study in community-dwelling elders living in rural Ecuador

Background/objective: Increasing numbers of individuals with cognitive impairment are posing economic threads to the developing world. Proper assessment of this condition may be complicated by illiteracy and cross-cultural factors. We conducted a population-based study in elders living in rural Ecuador to evaluate whether the MoCA associated with structural brain damage in less-educated populations. Methods: Atahualpa residents aged ≥60 years were identified during a door-to-door survey and invited to undergo MRI for grading GCA. Using a multivariate generalized linear model, we evaluated whether MoCA scores correlates with GCA, after adjusting for demographics, education, cardiovascular health (CVH) status, depression and edentulism. Results: Out of 311 eligible persons, 241 (78%) were enrolled. Mean age was 69.2 ± 7.5 years, 141 (59%) were women, 199 (83%) had primary school education, 175 (73%) had poor CVH status, 30 (12%) had symptoms of depression and 104 (43%) had edentulism. Average MoCA scores were 18.5 ± 4.7 points. GCA was mild in 108, moderate in 95, and severe in 26 persons. Total and most domain-specific MoCA scores were significantly worse in persons with moderate to severe GCA. In the multivariate model, mean MoCA score was associated with GCA severity (β = 2.38, SE = 1.07, p = 0.027). Conclusions: MoCA scores associate with severity of GCA after adjusting for potential confounders, and may be used as reliable estimates of structural brain damage. However, a lower cut-off than that recommended for developed countries, would be better for recognizing cognitive impairment in less educated populations.