José Biller, MD, Loyola University, Maywood, Illinois, and colleagues conducted a study that included 331 volunteers aged 60 years and older who live in Atahualpa, a small rural village in coastal Ecuador. The subjects were given cognitive tests and brain MRIs. The MRIs were examined for 4 main components of small vessel disease (SVD). Evidence of microbleeds and minor strokes, then were added to create a total SVD score. The score ranges from zero points (no SVD) to 4 points (severe SVD).
The study found that that 61% of the subjects had zero points on the total SVD score, 20% had 1 point, 12% had 2 points, 5% had 3 points, and 2% had 4 points. The higher the SVD score, the greater the cognitive decline.
The researchers also found that each individual component of SVD predicted cognitive decline as well as the total SVD score did.
Cognitive decline was measured by a Spanish version of the Montreal Cognitive Assessment test. Subjects were asked to do basic cognitive tasks such as counting backwards from 100 by sevens, repeating back a list of words, identifying drawings of animals and naming in one minute as many words as possible that begin with N.
The finding that 39% of the older adults have at least 1 component of SVD indicates the condition is common in the region. This prevalence makes Atahualpa a suitable population for studying the effect of SVD on cognitive performance, according to the authors.
The study is part of the ground-breaking Atahualpa Project, a population-based study designed to reduce the increasing burden of strokes and other neurological disorders in rural Ecuador and similar communities in Latin America. Many Atahualpa residents have enrolled in studies of risk factors for common diseases, especially neurological and cardiovascular diseases. More than 95% of Atahualpa’s population belongs to the native/Mestizo ethnic group, and the villagers have similar diets and lifestyles, making them suitable subjects for population studies.
SOURCE: Loyola University Health System