Demographic Factors Accelerate Decline in Global Cognition and Executive Function Following Stroke
The identification of risk factors for cognitive decline following stroke could help to identify individuals for intervention.
Incident stroke is associated with faster declines in global cognition and executive function among individuals aged ≥45 years, according to a study in Stroke. In addition, this association between incident stroke and cognitive function deterioration appears to increase with advancing age, lower education, and cardioembolic stroke incidence.
Investigators evaluated 22,875 patients from the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study, a prospective cohort study consisting of non-Hispanic black and white participants aged ≥45 years. Using these data, the investigators assessed the impact of incident stroke (n=694) and patient-specific baseline factors on cognitive function and impairment at a median follow-up of 8.2 years.
Tests for cognitive function included the Six-Item Screener (SIS) for global cognition (primary outcome) and a battery comprising 3 cognitive tests (Consortium to Establish a Registry for Alzheimer's Disease Word List Learning [new learning], Word List Delayed Recall [verbal memory], and Animal Fluency Test [executive function]).
As assessed by SIS coefficient, survivors of stroke who experienced acute declines in global cognition were more likely to be men (female vs male, 0.10 [95% CI, 0.00-0.20]; P =.04), black (black vs white, -0.11 [95% CI -0.22 to -0.01]; P =.04), and have large vessel stroke (-0.24 [95% CI, -0.38 to -0.09]; P =.001) or cardioembolic stroke (-0.22 [95% CI, -0.34 to −0.09]; P =.001). Individuals who did not graduate high school demonstrated significantly greater declines in executive function following stroke compared with college graduates (adjusted difference in intercept after stroke between survivors with college degree and survivors with less than a high school education, −2.08 points per year [95% CI, −0.45 to −3.72 points]; P <.01).
Older survivors of stroke also demonstrated faster declines in executive function (adjusted difference in slope after stroke between survivors aged 75 years and survivors aged 65 years, −0.6 points per year [95% CI, −0.9 to −0.2 points]; P <.01) and global cognition (adjusted difference in slope after incident stroke between survivors aged 75 years and survivors aged 65 years, −0.04 points per year [95% CI, −0.06 to −0.03 points]; P <.01) compared with younger survivors. Additionally, individuals residing outside the 9-state Stroke Belt had faster declines in global cognition (adjusted difference in slope after stroke between survivors residing within the Stroke Belt vs survivors residing outside the Stroke Belt, −0.04 points per year [95% CI, −0.07 to −0.01 points]; P =.005).
A limitation to this study is that findings may not be generalizable to individuals who are not community-stroke survivors. In addition, the investigators had little data on the features of strokes, further limiting the findings.
The effect of incident stroke on older adults may be partially driven by the patients' greater prevalence of “neurodegenerative disease, atrophy, cerebrovascular disease, and comorbidity (eg, atrial fibrillation and other vascular risk factors),” all of which “may amplify brain injury and cognitive deficits.”
Levine DA, Wadley VG, Langa KM, et al. Risk factors for poststroke cognitive decline: the REGARDS Study (Reasons for Geographic and Racial Differences in Stroke). Stroke. 2018;49(4):987-994.