@article {1524, title = {Prevalence and associations of MRI-demonstrated brain infarcts in elderly subjects with a history of transient ischemic attack. The Cardiovascular Health Study.}, journal = {Stroke}, volume = {30}, year = {1999}, month = {1999 Feb}, pages = {383-8}, abstract = {

BACKGROUND AND PURPOSE: MRI is more sensitive than CT, but the significance of brain abnormalities seen on MR images obtained in older subjects with transient ischemic attack (TIA) is not clear. We studied the prevalence and risk factors associated with MRI-demonstrated infarcts in elderly subjects with a history of TIA.

METHODS: Participants of the Cardiovascular Health Study, aged 65 years or more and without prior stroke, were studied with brain MRI (n=3456). The prevalence of brain infarcts (>/=3 mm) on MRI was determined in subjects with and without TIA. The cardiovascular risk factors and clinical and subclinical cardiovascular disease associated with MRI infarcts were studied in subjects with TIA.

RESULTS: Subjects with TIA (n=100) had a higher prevalence of MRI infarcts than subjects without TIA (46\% versus 28\%; P<0.001). The unadjusted odds ratio for having MRI infarcts in subjects with TIA was 2.20 (95\% CI, 1.47 to 3.30) and remained significantly elevated after adjustments for risk factors and cerebrovascular disease (odds ratio, 1.86; 95\% CI, 1.23 to 2.83). In subjects with TIA, diastolic blood pressure (P=0.01) and internal carotid artery intima-media thickness (P=0.01) were the only factors predictive of the presence of MRI infarcts by stepwise logistic regression analysis.

CONCLUSIONS: MRI infarcts are imaging manifestations of clinically important cerebrovascular disease in subjects with a history of TIA, given their increased prevalence and positive association with increased diastolic blood pressure and internal carotid artery intima-media thickness.

}, keywords = {Aged, Brain, Cardiovascular Diseases, Cerebral Infarction, Cross-Sectional Studies, Female, Humans, Ischemic Attack, Transient, Magnetic Resonance Imaging, Male, Odds Ratio, Population Surveillance, Predictive Value of Tests, Prevalence, Prospective Studies, Risk Factors, United States}, issn = {0039-2499}, author = {Bhadelia, R A and Anderson, M and Polak, J F and Manolio, T A and Beauchamp, N and Knepper, L and O{\textquoteright}Leary, D H} } @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} }