ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposeThe accuracy of routine ultrasonography in detecting severe carotid artery stenosis was evaluated in comparison with cerebral angiography. The precision of ultrasonographic criteria in predicting the risk of stroke was also assessed.MethodsA total of 1011 symptomatic carotid bifurcations were studied in patients from the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Given that all patients were considered for entry into the trial, the chance of a verification bias affecting the analyses was minimized. The ultrasonographic data consisted of peak systolic velocities and frequency changes from both the internal and common carotid arteries. Angiographic stenosis was calculated as in NASCET. Receiver operating characteristic (ROC) curves were constructed from the ultrasonographic data for the detection of 70% or greater stenosis on the basis of an angiographic assessment. Kaplan-Meier stroke-free survival curves were used to predict the risk of stroke.ResultsThe areas under the ROC curves ranged from 0.74 to 0.75 (95% confidence interval [CI], 0.69 to 0.79). The sensitivities and specificities ranged from 0.65 to 0.71. The risk of stroke at 18 months declined sharply as the degree of angiographically defined stenosis declined from 99% to 70%. No pattern of decline was apparent on the basis of the ultrasonographic data.ConclusionsThe results indicate that the accuracy of ultrasonography is moderate when flow parameters are used to assess the degree of stenosis. Ultrasonography should be used as a screening tool to exclude patients with no carotid artery disease from further testing. Conventional angiography remains an essential investigation before assigning the risk of stroke and deciding appropriate treatment for extracranial carotid artery disease.(Stroke. 1995;26:1747-1752.)

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposeNoninvasive studies are used with increasing frequency to assess the carotid bifurcation before endarterectomy. Therefore, assessment of their diagnostic accuracies is essential for appropriate patient management. We prospectively evaluate two noninvasive tests, magnetic resonance angiography (MRA) and duplex ultrasonography (DU), as potential replacements for contrast arteriography (CA).MethodsA blinded comparison of three-dimensional time-of-flight (TOF) MRA, two-dimensional TOF MRA, and DU in 176 arteries was performed. CA was used as the standard of comparison.ResultsThree-dimensional TOF MRA had a sensitivity of 94%, a specificity of 85%, and an accuracy of 88% for the identification of 70% to 99% stenosis; two-dimensional TOF MRA had a sensitivity and specificity that were approximately 10% lower than those of three-dimensional TOF MRA. DU resulted in a sensitivity of 94%, a specificity of 83%, and an accuracy of 86%. Combining data from three-dimensional TOF MRA and DU, allowing for CA only for disparate results, yielded a sensitivity of 100%, a specificity of 91%, and an accuracy of 94% among concordant noninvasive tests, with CA required in 16% of arteries. MRA accurately differentiated 17 carotid occlusions from 16 high-grade (90% to 99%) stenoses, whereas with DU two patent arteries were identified as occluded and one occluded artery was identified as patent.ConclusionsThree-dimensional TOF MRA is the most accurate noninvasive test. Combined use of MRA and DU results in a marked increase in accuracy to a level that obviates the need for CA in a majority of patients.(Stroke. 1995;26:1753-1758.)

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposeIt has been suggested that a substantial proportion of the excess stroke mortality among black Americans may be attributable to relatively lower socioeconomic status (SES) in this group. In this report we provide the first quantitative estimates of the proportion of excess black stroke mortality attributable to SES for a large populationbased cohort.MethodsWe used data from the National Longitudinal Mortality Study for persons 45 years and older (73 400 white men, 87 528 white women, 6522 black men, and 8816 black women). Sex-specific proportional hazards model were used to estimate excess black stroke mortality with and without adjustment for education and income (measures of SES). The contribution of SES to the excess black stroke risk was estimated from the difference in regression coefficients for race in these models.ResultsIn men, low SES was associated with increased stroke mortality (P less than equals .0001) and accounted for 14% to 46% of the excess black stroke risk (P less than .05). However, we could find no association between SES and stroke mortality in women, and SES did not account for a significant proportion of the excess stroke mortality in black women.ConclusionsAlthough SES proved to account for a statistically significant proportion of excess male black stroke mortality, overall SES explained less than one quarter of the observed excess between ages 45 and 65. In women, SES did not significantly reduce the estimated excess black stroke mortality. Although SES may be playing a role in excess black stroke mortality, a substantial proportion of the excess appears attributable to other sources, including cerebrovascular risk factors that are unrelated to SES, unmeasured lifestyle influences, social resources, and genetic factors.(Stroke. 1995;26:1759-1763.)

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposeBlack Americans with spontaneous intracerebral hemorrhage (SICH) may have unique clinical characteristics that affect outcome. The aim of this study was to determine the prognostic value of clinical characteristics and initial CT scan for outcome in black Americans with SICH.MethodsClinical and demographic data were extracted from the charts of 182 consecutive black Americans admitted for SICH diagnosed by clinical criteria and initial CT scan. Hemorrhage volumes were calculated from admission CT scans by a computerized method. Univariate and multiple logistic regression analyses were performed to determine independent predictors of early deterioration (defined as a decrease from an initial Glasgow Coma Scale score more than 12 by more than equals 4 points within 24 hours from presentation) and mortality.ResultsBoth hemorrhage volume and ventricular extension were significant, independent predictors of early deterioration (odds ratio [OR], 6.78; 95% confidence interval [CI], 1.89 to 24.35 and OR, 4.67; 95% CI, 1.30 to 16.72, respectively) and mortality (OR, 6.66; 95% CI, 2.85 to 15.58 and OR, 4.23; 95% CI, 1.82 to 9.82, respectively). A Glasgow Coma Scale score less than equals 12 also predicted mortality (OR, 3.23; 95% CI, 1.46 to 7.14). Initial mean arterial pressure was not an independent predictor of early deterioration or mortality.ConclusionsHemorrhage volume and ventricular extension are the best predictors of early deterioration and mortality in black Americans with SICH.(Stroke. 1995;26:1764-1767.)

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposeSince stroke is a principal cause of death in elderly people, we analyzed the association between alcohol and stroke mortality in a cohort of 15 077 middle-aged and older men and women.MethodsData on alcohol habits were obtained from a questionnaire in 1967. The subsequent 20 years yielded 769 deaths from stroke, of which 574 were ischemic. Relative mortality risks (RR) were estimated from logistic regression analyses with lifelong alcohol abstainers as a reference group. Adjustments were made for age and smoking.ResultsNo association was found between alcohol intake and hemorrhagic stroke. An elevated risk of ischemic stroke was found for men who drank infrequently, that is, a few times a year or less often (RR, 2.0; 95% confidence interval [CI], 1.3 to 3.2), for those who were intoxicated now and then (RR, 1.8; 95% CI, 1.1 to 2.8), and for those who reported ``binge'' drinking a few times in the year or less often (RR, 1.6; 95% CI, 1.1 to 2.5). Among women only ex-drinkers had an elevated risk of dying of ischemic stroke (RR, 3.3; 95% CI, 1.5 to 7.2). The risk was reduced for women who had an estimated average consumption of 0 to 5 g pure alcohol per day (RR, 0.6; 95% CI, 0.5 to 0.8); for those who did not drink every day (RR, 0.7; 95% CI, 0.5 to 0.9); and for those who never ``went on a binge'' (RR, 0.6; 95% CI, 0.5 to 0.8) or became intoxicated (RR, 0.7; 95% CI, 0.5 to 0.9).ConclusionsDrinking habits were associated only with deaths from ischemic stroke, and the risk patterns were different for men and women. In analyses, ex-drinkers should not be included with lifelong abstainers, since the former tend to run high health risks.(Stroke. 1995;26:1768-1773.)

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposeStroke mortality worldwide has decreased in men and women in most industrialized countries, except in eastern European countries. The purpose of this study was to compare the sex ratio of stroke mortality between populations and over time. This approach may help to determine the factors influencing this ratio.MethodsThe sex ratios (men to women) of stroke mortality between ages 55 to 64, 65 to 74, and 75 to 84 years from 27 populations between 1955 and the latest available year were analyzed using World Health Organization data. The relationship between log stroke mortality and age and the relationships between alcohol, animal fat, cigarette consumption, and urinary cation excretion and the sex ratio of stroke mortality were also analyzed.ResultsThe mean sex ratio of stroke mortality increased 50%, 34%, and 15% in the three age classes, respectively, over 35 years. Highly significant relationships of log stroke mortality with age exist, which vary between men and women and among countries. In general, stroke mortality changed in the same direction in both sexes but decreased earlier and more rapidly in women than in men. Alcohol consumption and urinary sodium excretion correlated positively and significantly with the sex ratio. The time trends of the sex ratio also correlated positively and significantly with the time trends of cigarette consumption. No relationship with animal fat consumption was found.ConclusionsThe sex ratio of stroke mortality is increasing with time and decreasing with age. Differences in lifestyle among countries and over the last three decades may contribute partially to these differences in sex ratio.

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposeTo clarify the clinical significance of carotid atherosclerosis for ischemic stroke events, a follow-up study was performed in Japanese patients.MethodsTwo hundred fourteen patients were registered from nine hospitals in the Osaka community. All patients were checked for a prior history of stroke, and the risk factors for stroke and atherosclerosis were evaluated. Carotid atherosclerosis was assessed by 7.5-MHz duplex ultrasonography. We studied the relationship between the ischemic stroke event rate and the severity and appearance of the carotid atherosclerosis. We also studied the relationship between stroke events and various risk factors.ResultsThe average duration of follow-up was 16 months. Ten patients suffered new ischemic stroke episodes during this follow-up period. At the initial ultrasonographic study, 16 patients had high-grade stenosis and 21 had ulcerated plaque. Proportional hazard regression analysis showed that grade of stenosis and plaque ulceration were positively related to the event rate. Patients with ulcerated plaque had a sevenfold higher hazard ratio for stroke in comparison to those without (P less than .01). The ipsilateral stroke recurrence rate was 11 times higher in patients with ulcerated high-grade stenotic carotid lesions.ConclusionsThe present findings demonstrate that the severity of carotid atherosclerosis as evaluated by ultrasonography is a useful indicator of the risk of ischemic stroke in symptomatic patients.(Stroke. 1995;26:1781-1786.)

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposeWe sought to register the incidence rate, risk factors, and case-fatality rate of all the new cases of first-ever-in-a-lifetime stroke in the province of Belluno, Italy. This study aimed to provide an epidemiological survey of cerebrovascular disease that could supply investigative objectives and support information for regional healthcare facilities planning.MethodsWe undertook a prospective population-based study in the territory of the 1st, 2nd, 3rd, and 4th local health units in the province of Belluno, an area located in northeast Italy (population, 211 389).ResultsIn the first year of the study (June 1, 1992, to May 31, 1993), 474 cases of first-ever stroke were registered. The crude annual incidence rate was 2.24/1000 (2.01/1000 for men and 2.45/1000 for women). After adjustment to the European population, the incidence rate for first stroke was 1.70/1000 per year. The pathological diagnosis was confirmed by a CT scan in 89.5% of cases. Cerebral infarction accounted for 319 cases, while 93 patients suffered a primary intracerebral hemorrhage, 12 patients a subarachnoid hemorrhage, and 50 patients a stroke of unknown origin. The overall 30-day case-fatality rate was 33%, and the mortality within the first week from stroke onset was 23%. The recurrence rate after 1 month was 1.9%. After 1 month, 46% of our patients were functionally independent in activities of daily living.ConclusionsOur first-year results confirm the fairly high risk for stroke in central and northern Italy and support European findings regarding risk factors for stroke.(Stroke. 1995;26:1787-1793.)

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Background and PurposePresyncope, characterized by symptoms and signs indicative of imminent syncope, can be aborted in many situations before loss of consciousness occurs. The plasticity of cerebral autoregulation in healthy humans and its behavior during this syncopal prodrome are unclear, although systemic hemodynamic instability has been suggested as a key factor in the precipitation of syncope. Using lower body negative pressure (LBNP) to simulate central hypovolemia, we previously observed falling mean flow velocities (MFVs) with maintained mean arterial blood pressure (MABP). These findings, and recent reports suggesting increased vascular tone within the cerebral vasculature at presyncope, cannot be explained by the classic static cerebral autoregulation curve; neither can they be totally explained by a recent suggestion of a rightward shift in this curve.MethodsFour male and five female healthy volunteers were exposed to presyncopal LBNP to evaluate their cerebrovascular and cardiovascular responses by use of continuous acquisition of MFV from the right middle cerebral artery with transcranial Doppler sonography, MABP (Finapres), and heart rate (ECG).ResultsAt presyncope, MFV dropped on average by 27.3 plus minus 14% of its baseline value (P less than .05), while MABP remained at 2.0 plus minus 27% above its baseline level. Estimated cerebrovascular resistance increased during LBNP. The percentage change from baseline to presyncope in MFV and MABP revealed consistent decreases in MFV before MABP.ConclusionsIncreased estimated cerebrovascular resistance, falling MFV, and constant MABP are evidence of an increase in cerebral vascular tone with falling flow, suggesting a downward shift in the cerebral autoregulation curve. Cerebral vessels may have a differential sensitivity to sympathetic drive or more than one type of sympathetic innervation. Future work to induce dynamic changes in MABP during LBNP may help in assessing the plasticity of the cerebral autoregulation mechanism.

ISSN:0039-2499    

出版商:OVID    

年代:1995

数据来源: OVID