Hypertension confers increased risk for cognitive decline, dementia, and cerebrovascular disease. These associations have been attributed, in part, to cerebral hypoperfusion. Here we posit that relations of higher blood pressure to lower levels of cerebral perfusion may be potentiated by a prior head injury. Participants were 87 community-dwelling older adults - 69% men, 90% white, mean age=66.9years, 27.6% with a history of mild traumatic brain injury (mTBI) defined as a loss of consciousness ≤30min resulting from an injury to the head, and free of major medical (other than hypertension), neurological or psychiatric comorbidities. All engaged in clinical assessment of systolic and diastolic blood pressure (SBP, DBP) and single photon emission computed tomography (SPECT). Computerized coding of the SPECT images yielded relative ratios of blood flow in left and right cortical and select subcortical regions. Cerebellum served as the denominator. Sex-stratified multiple regression analyses, adjusted for age, education, race, alcohol consumption, smoking status, and depressive symptomatology, revealed significant interactions of blood pressure and head injury to cerebral blood flow in men only. Specifically, among men with a history of head injury, higher systolic blood pressure was associated with lower levels of perfusion in the left orbital (β=-3.21, p=0.024) and left dorsolateral (β=-2.61, p=0.042) prefrontal cortex, and left temporal cortex (β=-3.36, p=0.014); higher diastolic blood pressure was marginally associated with lower levels of perfusion in the left dorsolateral prefrontal cortex (β=-2.79, p=0.051). Results indicate that men with a history of head injury may be particularly vulnerable to the impact of higher blood pressure on cerebral perfusion in left anterior cortical regions, thus potentially enhancing risk for adverse brain and neurocognitive outcomes.

Objectives: To determine whether vascular and demographic factors predict worsening disability up to 8 years after lacunar stroke. Methods: SPS3 (Secondary Prevention of Small Subcortical Strokes) was a clinical trial in lacunar stroke patients with annual assessment of disability using the Older Americans Resources and Survey instrumental activities of daily living (IADL) scale (range 0–14). Generalized estimating equations modeled the likelihood of disability (IADL <14) over time, adjusting for demographics, medical risk factors, cognition, mood, stroke location, and geographic region in univariate and multivariable models. IADL assessments after recurrent stroke were censored. We stratified by study region and age quartile. Results: Among 2,820 participants, mean age was 63.4 years (SD 10.8), 63% were male, 36% had diabetes, 90% hypertension, and 10% prior stroke. Mean follow-up was 3.7 years. In multivariable models, female sex, education, diabetes, nonregular alcohol use, prior stroke, Cognitive Abilities Screening Instrument score, depression, mild cognitive impairment, and stroke location were associated with disability. The youngest age quartile had decreased odds of disability over time (odds ratio 0.90 per year, 95% confidence interval 0.85–0.95), whereas the oldest age quartile had increased odds (2.20, 95% confidence interval 1.75–2.75). Americans and Latin Americans had >2-fold greater odds of disability per year compared with Spaniards (p < 0.0001). Conclusions: In lacunar stroke patients, older age was associated with worsening long-term disability, even without recurrence. Worse long-term function was associated with diabetes, cognitive status, and prior stroke, and regional differences may be attributable to variations in health care delivery or scale interpretation.

Background and Purpose— Little is known about the acute precipitants of ischemic stroke, although evidence suggests infections contribute to risk. We hypothesized that acute hospitalization for infection is associated with the short-term risk of stroke. Methods— The case-crossover design was used to compare hospitalization for infection during case periods (90, 30, or 14 days before an incident ischemic stroke) and control periods (equivalent time periods exactly 1 or 2 years before stroke) in the Cardiovascular Health Study, a population-based cohort of 5888 elderly participants from 4 US sites. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by conditional logistic regression. Confirmatory analyses assessed hazard ratios of stroke from Cox regression models, with hospitalization for infection as a time-varying exposure. Results— During a median follow-up of 12.2 years, 669 incident ischemic strokes were observed in participants without a baseline history of stroke. Hospitalization for infection was more likely during case than control time periods; for 90 days before stroke, OR=3.4 (95% CI, 1.8 to 6.5). The point estimates of risks were higher when we examined shorter intervals: for 30 days, OR=7.3 (95% CI, 1.9 to 40.9), and for 14 days, OR=8.0 (95% CI, 1.7 to 77.3). In survival analyses, risk of stroke was associated with hospitalization for infection in the preceding 90 days, adjusted hazard ratio=2.4 (95% CI, 1.6 to 3.4). Conclusions— Hospitalization for infection is associated with a short-term increased risk of stroke, with higher risks observed for shorter intervals preceding stroke.

Background and Purpose— To determine whether progression of MRI-defined vascular disease predicts subsequent vascular events in the elderly. Methods— The Cardiovascular Health Study, a longitudinal cohort study of vascular disease in the elderly, allows us to address this question because its participants had 2 MRI scans ≈5 years apart and have been followed for ≈9 years since the follow-up scan for incident vascular events. Results— Both MRI-defined incident infarcts and worsened white matter grade were significantly associated with heart failure, stroke, and death, but not transient ischemic attacks, angina, or myocardial infarction. Strongest associations occurred when both incident infarcts and worsened white matter grade were present for heart failure (hazard ratio, 1.79; 95% confidence interval, 1.18–2.73), stroke (hazard ratio, 2.58; 95% confidence interval, 1.53–4.36), death (hazard ratio, 1.69; 95% confidence interval, 1.28–2.24), and cardiovascular death (hazard ratio, 1.97; 95% confidence interval, 1.24–3.14). Conclusions— Progression of MRI-defined vascular disease identifies elderly people at increased risk for subsequent heart failure, stroke, and death. Whether aggressive risk factor management would reduce risk is unknown.

Background and Purpose— Little is known about the acute precipitants of ischemic stroke, although evidence suggests infections contribute to risk. We hypothesized that acute hospitalization for infection is associated with the short-term risk of stroke. Methods— The case-crossover design was used to compare hospitalization for infection during case periods (90, 30, or 14 days before an incident ischemic stroke) and control periods (equivalent time periods exactly 1 or 2 years before stroke) in the Cardiovascular Health Study, a population-based cohort of 5888 elderly participants from 4 US sites. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by conditional logistic regression. Confirmatory analyses assessed hazard ratios of stroke from Cox regression models, with hospitalization for infection as a time-varying exposure. Results— During a median follow-up of 12.2 years, 669 incident ischemic strokes were observed in participants without a baseline history of stroke. Hospitalization for infection was more likely during case than control time periods; for 90 days before stroke, OR=3.4 (95% CI, 1.8 to 6.5). The point estimates of risks were higher when we examined shorter intervals: for 30 days, OR=7.3 (95% CI, 1.9 to 40.9), and for 14 days, OR=8.0 (95% CI, 1.7 to 77.3). In survival analyses, risk of stroke was associated with hospitalization for infection in the preceding 90 days, adjusted hazard ratio=2.4 (95% CI, 1.6 to 3.4). Conclusions— Hospitalization for infection is associated with a short-term increased risk of stroke, with higher risks observed for shorter intervals preceding stroke.

Ipsilateral transient ischemic attack (TIA) and cerebral infarction (CI) are primary end points of the Asymptomatic Carotid Atherosclerosis Study (ACAS), an ongoing multicenter, prospective, randomized trial designed to assess the effectiveness of carotid endarterectomy for patients with asymptomatic, hemodynamically significant stenosis of the internal or common carotid artery. The evanescent nature and absence of residual physical findings in TIAs pose special difficulties that contribute to interobserver disagreement. A standardized definition was established to be applied accurately and uniformly at the participating centers, including a questionnaire on six cardinal neurological symptoms, a computerized algorithm for characterization of events, and a verification system involving the independent evaluations of three reviewers. Modifications to the end point verification protocol after pilot testing in 115 patients with one or more symptoms enabled the algorithm to distinguish vascular from nonvascular events with a sensitivity of 83%, a specificity of 69%, positive predictive value of 71%, and negative predictive value of 82%. ACAS has developed a system for detecting and diagnosing end points. Using the algorithm as a guideline, consensus between two institutional physicians and a blinded independent reviewer must be made for an end point to be declared. If no consensus can be reached, a panel of two blinded external reviewers confers to arrive at an adjudication of the case. All potential end points are reviewed retrospectively by an end points committee for final adjudication.

The establishment of 60% or greater diameter stenosis by Doppler ultrasound is an eligibility requirement of the Asymptomatic Carotid Atherosclerosis Study (ACAS). We used a uniform statistical approach for each of 30 Doppler devices to establish a cutpoint for the peak systolic flow to insure a positive predictive value of 90% in predicting a 60%+ stenosis by angiography. Data were analyzed by device; however, performance relates to the device-sonographer-reader system. For those devices reporting in peak systolic velocity, cutpoints ranged from 151 to 390 cm/s, and for those reporting a peak systolic frequency from 5,400 to 11,250 Hz. Eighteen devices had a sensitivity above 60%, and nine devices had a sensitivity above 80%. However, for six instruments, the relationship between Doppler and angiography was too weak to establish any cutpoint. In addition, for one instrument a value could be established, but the associated sensitivity was only 18%. This remarkable variability in the performance is at odds with the high sensitivity uniformly published in the literature, suggesting (a) that the high reported sensitivity for Doppler may represent an overestimate of average performance, perhaps due to publication bias, (b) the paramount need for documented quality control measures within local laboratories to insure that Doppler examinations are performed reliably, and (c) the need for caution in the generalization of results among laboratories.

Associations between findings on cranial magnetic resonance imaging (MRI) and retinal photographs have been described mostly in middle-aged people. In the Cardiovascular Health Study, 1,717 elderly participants underwent MRI and retinal photography between 1991 and 1999. Associations were sought between MRI findings and four findings of retinal microvascular disease: retinopathy, focal arteriolar narrowing, arteriovenous nicking, and the arteriovenous ratio—the last based upon semiautomated measurements of arterioles and venules. After controlling for age and gender, the authors found associations between MRI findings and the smaller arteriovenous ratio (per standard deviation decrease): prevalent infarcts (odds ratio = 1.18, 95% confidence interval: 1.05, 1.34; p = 0.007), white matter grade (regression coefficient, 0.093; p = 0.011), incident infarct (odds ratio = 1.26, 95% confidence interval: 1.09, 1.46; p = 0.002), and worsening white matter grade (odds ratio = 1.12, 95% confidence interval: 0.98, 1.29; p = 0.09). Arteriovenous nicking was also associated with prevalent (odds ratio = 1.84, 95% confidence interval: 1.23, 2.76; p = 0.003) and incident (odds ratio = 1.84, 95% confidence interval: 1.15, 2.94; p = 0.011) infarcts. Adjustment for hypertension and diabetes had minimal effect. Evidence of small vessel disease in the retina increases the likelihood of finding it in the brain. Associations were less prominent in this elderly population than have been described in middle-aged people.

OBJECTIVES: To examine the association between blood pressure (BP) levels and long-term stroke outcomes in elderly stroke survivors.DESIGN: Observational study.SETTING: The Cardiovascular Health Study (CHS) of 5,888 community-dwelling adults.PARTICIPANTS: Two hundred fifty-four adults aged 65 and older (mean age 78.6) who sustained a nonfatal first ischemic stroke.MEASUREMENTS: BP levels assessed at prestroke and poststroke CHS visits were examined as predictors of stroke recurrence, coronary heart disease (CHD), combined vascular events (CVEs), and mortality.RESULTS: Higher poststroke BP level, assessed 261.6 days (mean) after stroke, was associated with higher risk of stroke recurrence over 5.4 years (mean) of follow-up. The multivariate-adjusted hazard ratio for stroke recurrence was 1.42 (95% confidence interval (CI)=1.03-1.99) per standard deviation (SD) of systolic BP (P=.04) and 1.39 (95% CI=1.01-1.91) per SD of diastolic BP (P=.04). Mortality was significantly greater in patients with low or high poststroke BP than in those with intermediate BP. Poststroke BP was not associated with risk of CHD or CVE, although further analyses suggested that high systolic BP predicted CHD and CVE in younger but not older subjects. Prestroke BP did not predict poststroke outcomes.CONCLUSION: In this observational study of adults aged 65 and older assessed approximately 8 months after stroke, low BP was associated with favorable risk of recurrent stroke, although high and low poststroke BP levels were associated with greater mortality. Long-term antihypertensive trials in older stroke survivors would increase knowledge about the benefits of lowering BP in this population.

Goal: To develop a practical severity scale (Wake Forest Stroke Severity Scale [WFSSS]) to predict acute hospital outcomes and resource use after acute ischemic stroke based on the admission neurologic exam. Background: A useful scheme enabling physicians and other health care providers to stratify stroke severity on admission to predict acute hospital outcomes and improve efficiency of inpatient care has not been described. Methods: The study subjects consisted of 271 consecutive acute stroke patients admitted to the neurology department from July 1995 to June 1996 who were prospectively examined and whose stroke severity was classified on the basis of admission neurologic exam (level of consciousness, strength, dysphasia, neglect, and gait) as mild, moderate, or severe, based on the WFSSS. National Institutes of Health stroke scale (NIHSS) was performed early in admission (70% within 24 hours). Discharge disposition (home, inpatient rehabilitation [rehab], skilled nursing facility [SNF], or death); length of stay (LOS); and hospital charges were associated with initial stroke severity ratings using chi-square and Kruskal-Wallis tests. Results: Fifty-percent (136) of strokes were classified as mild, 22% (60) as moderate, and 28% (75) as severe. Initial severity ratings were significantly related to discharge disposition, LOS, and hospital charges (all P values <.001). Conclusions: A practical clinical severity scale (WFSSS) for acute ischemic stroke patients based on admission neurologic examination predicts hospital disposition, LOS, and hospital charges, and may allow more accurate severity-adjusted comparisons among institutions. Copyright © 2001 by National Stroke Association