@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 {1525, title = {Relationships of cerebral MRI findings to ultrasonographic carotid atherosclerosis in older adults : the Cardiovascular Health Study. CHS Collaborative Research Group.}, journal = {Arterioscler Thromb Vasc Biol}, volume = {19}, year = {1999}, month = {1999 Feb}, pages = {356-65}, abstract = {

Cerebral magnetic resonance imaging (MRI) has demonstrated a high prevalence of infarct-like lesions, white matter hyperintensities, and evidence of cerebral atrophy in older adults. While these findings are generally believed to be related to ischemia and atherosclerosis, their relationship to atherosclerosis in the carotid arteries remains to be explored. Study subjects were part of the multicenter Cardiovascular Health Study, a cross-sectional study of 3502 women and men >/=65 years of age undergoing cranial MRI and carotid ultrasonography. MRI infarcts were detected in 1068 participants (29.3\%) and measurable carotid plaque in 2745 (75.3\%). MRI infarcts, ventricular and sulcal widening, and white matter score were strongly associated with carotid intimal-medial thickness (IMT) and stenosis degree after adjustment for age and sex (all P<0. 01). Associations with plaque characteristics were less strong and less consistent; MRI infarcts were weakly associated only with surface irregularity, and ventricular size was weakly associated only with lesion density (both P<0.04). In contrast, sulcal widening was strongly related to plaque characteristics, with scores being higher in those with heterogeneous and irregular plaque (both P<0. 009). Adjustment for other risk factors, and for carotid IMT/stenosis, removed associations of MRI findings with plaque characteristics except for weak relationships remaining between MRI infarcts and surface irregularity and between sulcal score and heterogeneous plaque (both P<0.03). MRI abnormalities show strong and consistent relationships with increasing carotid IMT and stenosis degree but less strong associations with plaque characteristics, especially after adjusting for IMT and stenosis.

}, keywords = {Aged, Arteriosclerosis, Brain, Cardiovascular System, Carotid Artery Diseases, Cerebral Infarction, Cohort Studies, Cross-Sectional Studies, Echoencephalography, Female, Health Status, Humans, Magnetic Resonance Imaging, Male, Prevalence}, issn = {1079-5642}, author = {Manolio, T A and Burke, G L and O{\textquoteright}Leary, D H and Evans, G and Beauchamp, N and Knepper, L and Ward, B} } @article {663, title = {Silent MRI infarcts and the risk of future stroke: the cardiovascular health study.}, journal = {Neurology}, volume = {57}, year = {2001}, month = {2001 Oct 09}, pages = {1222-9}, abstract = {

BACKGROUND: Silent infarcts are commonly discovered on cranial MRI in the elderly.

OBJECTIVE: To examine the association between risk of stroke and presence of silent infarcts, alone and in combination with other stroke risk factors.

METHODS: Participants (3,324) in the Cardiovascular Health Study (CHS) without a history of stroke underwent cranial MRI scans between 1992 and 1994. Silent infarcts were defined as focal lesions greater than 3 mm that were hyperintense on T2 images and, if subcortical, hypointense on T1 images. Incident strokes were identified and classified over an average follow-up of 4 years. The authors evaluated the risk of subsequent symptomatic stroke and how it was modified by other potential stroke risk factors among those with silent infarcts.

RESULTS: Approximately 28\% of CHS participants had evidence of silent infarcts (n = 923). The incidence of stroke was 18.7 per 1,000 person-years in those with silent infarcts (n = 67) compared with 9.5 per 1,000 person-years in the absence of silent infarcts. The adjusted relative risk of incident stroke increased with multiple (more than one) silent infarcts (hazard ratio 1.9 [1.2 to 2.8]). Higher values of diastolic and systolic blood pressure, common and internal carotid wall thickness, and the presence of atrial fibrillation were associated with an increased risk of strokes in those with silent infarcts (n = 53 strokes).

CONCLUSION: The presence of silent cerebral infarcts on MRI is an independent predictor of the risk of symptomatic stroke over a 4-year follow- up in older individuals without a clinical history of stroke.

}, keywords = {Aged, Cerebral Infarction, Cohort Studies, Female, Follow-Up Studies, Humans, Incidence, Magnetic Resonance Imaging, Male, Predictive Value of Tests, Risk Factors, Stroke}, issn = {0028-3878}, doi = {10.1212/wnl.57.7.1222}, author = {Bernick, C and Kuller, L and Dulberg, C and Longstreth, W T and Manolio, T and Beauchamp, N and Price, T} } @article {954, title = {Physical activity and white matter lesion progression: assessment using MRI.}, journal = {Neurology}, volume = {68}, year = {2007}, month = {2007 Apr 10}, pages = {1223-6}, abstract = {

We evaluated the association between physical activity and changes in white matter lesions (WMLs) on MRI in a sample of 179 older adults comprising 59 incident cases of Alzheimer disease, 60 persons with mild cognitive impairment, and 60 persons who remained cognitively stable over a median 5-year follow-up. Physical activity was not significantly associated with a decreased rate of periventricular or deep WML progression.

}, keywords = {Activities of Daily Living, Aged, Alzheimer Disease, Cognition Disorders, Cohort Studies, Demyelinating Diseases, Disease Progression, Female, Humans, Magnetic Resonance Imaging, Male, Motor Activity, United States}, issn = {1526-632X}, doi = {10.1212/01.wnl.0000259063.50219.3e}, author = {Podewils, L J and Guallar, E and Beauchamp, N and Lyketsos, C G and Kuller, L H and Scheltens, P} }