@article {801, title = {Stroke risk factors and loss of high cognitive function.}, journal = {Neurology}, volume = {63}, year = {2004}, month = {2004 Sep 14}, pages = {793-9}, abstract = {

BACKGROUND: Modifiable stroke risk factors may contribute to age-associated declines in cognitive function. Individuals with high levels of cognitive function after midlife may have less exposure to these stroke risk factors or may be less susceptible to their effects on cognition.

METHODS: The Cardiovascular Health Study (CHS)* is a population-based, longitudinal cohort study of 5,888 people age 65 years and older. Participants (n = 4,129) who were free of dementia, stroke, or TIA at the time of baseline cranial MRI were selected for analysis. High cognitive function at baseline was defined by performance at or above midlife norms on the Modified Mini-Mental State Examination (3MS).

RESULTS: The odds of having high cognitive function at baseline decreased by quartile of stroke risk (highest vs lowest risk quartile, adjusted odds ratio [OR] 0.68; 95\% CI 0.52 to 0.88; p for trend = 0.005). Stroke risk was a predictor of decline on the 3MS in those with typical levels of cognitive function at baseline, even in the absence of incident stroke or TIA (highest vs lowest risk quartile for 3MS decline, adjusted OR 2.11; 95\% CI 1.42 to 3.13; p for trend < 0.001). In contrast, stroke risk was not associated with decline on the 3MS in those with high cognitive function at baseline (p = 0.03 for interaction).

CONCLUSIONS: In a cohort of older adults without stroke, TIA, or dementia, cognitive function and incident cognitive decline were associated with risk for stroke. Additional studies are needed to determine whether modification of stroke risk factors can reduce the cognitive decline that is often attributed to normal aging.

}, keywords = {Aged, Aged, 80 and over, Aging, Cognition Disorders, Cohort Studies, Comorbidity, Female, Follow-Up Studies, Higher Nervous Activity, Humans, Incidence, Male, Risk Assessment, Risk Factors, Sampling Studies, Sensitivity and Specificity, Severity of Illness Index, Stroke, United States}, issn = {1526-632X}, doi = {10.1212/01.wnl.0000137014.36689.7f}, author = {Elkins, J S and O{\textquoteright}Meara, E S and Longstreth, W T and Carlson, M C and Manolio, T A and Johnston, S C} } @article {911, title = {Education and the cognitive decline associated with MRI-defined brain infarct.}, journal = {Neurology}, volume = {67}, year = {2006}, month = {2006 Aug 08}, pages = {435-40}, abstract = {

OBJECTIVE: To assess whether educational attainment, a correlate of cognitive reserve, predicts the amount of cognitive decline associated with a new brain infarct.

METHODS: The Cardiovascular Health Study is a population-based, longitudinal study of people aged 65 years and older. Cognitive function was measured annually using the Modified Mini-Mental State Examination (3MS) and the Digit-Symbol Substitution Test (DSST). The authors tested whether education level modified 1) the cross-sectional association between cognitive performance and MRI-defined infarct and 2) the change in cognitive function associated with an incident infarct at a follow-up MRI.

RESULTS: In cross-sectional analysis (n = 3,660), MRI-defined infarct was associated with a greater impact on 3MS performance in the lowest education quartile when compared with others (p for heterogeneity = 0.012). Among those with a follow-up MRI who had no infarct on initial MRI (n = 1,433), education level was not associated with the incidence, size, or location of new brain infarct. However, a new MRI-defined infarct predicted substantially greater decline in 3MS scores in the lowest education group compared with the others (6.3, 95\% CI 4.4- to 8.2-point decline vs 1.7, 95\% CI 0.7- to 2.7-point decline; p for heterogeneity < 0.001). Higher education was not associated with smaller declines in DSST performance in the setting of MRI-defined infarct.

CONCLUSIONS: Education seems to modify an individual{\textquoteright}s decline on a test of general cognitive function when there is incident brain infarct. These findings are consistent with the hypothesis that cognitive reserve influences the impact of vascular injury in the brain.

}, keywords = {Cerebral Infarction, Cognition Disorders, Cross-Sectional Studies, Educational Status, Humans, Longitudinal Studies, Magnetic Resonance Imaging, Neuropsychological Tests}, issn = {1526-632X}, doi = {10.1212/01.wnl.0000228246.89109.98}, author = {Elkins, J S and Longstreth, W T and Manolio, T A and Newman, A B and Bhadelia, R A and Johnston, S C} }