摘要:

Background and PurposeWe sought to examine risk factors for all strokes and for ischemic stroke and primary intracerebral hemorrhage separately.MethodsThis was a population-based case-control study. Each case subject meeting World Health Organization criteria for stroke (n=536) from a population-based register of acute cerebrovascular events compiled in Perth, Western Australia, in 1989 to 1990 was matched for age and sex with up to five control subjects drawn from the same geographical area. Objective confirmation of the type of stroke was available from computed tomography, magnetic resonance imaging, or necropsy for 86% of the case subjects. Data on medical history and lifestyle factors were collected from case and control subjects by interview of the subject or a proxy informant.ResultsCurrent smoking, consumption of meat more than four times weekly, and a history of hypertension or intermittent claudication were each associated with increased risk in multivariate models for all strokes and for all first-ever strokes. Consumption of 1 to 20 g/d alcohol in the preceding week was associated with a significant reduction in the risk of all strokes, all ischemic strokes, and of primary intracerebral hemorrhage, while eating fish more than two times per month appeared to protect against first-ever stroke and against primary intracerebral hemorrhage. Diabetes mellitus was associated with a significantly increased risk of ischemic stroke but a decreased risk of hemorrhagic stroke.ConclusionsRisk factors for ischemic and hemorrhagic stroke are not exactly the same. Changes in lifestyle relating to tobacco and diet might make important contributions to further reductions in the incidence of stroke.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeThis report examines the hypothesis that the higher risk of stroke among Japanese men in Japan compared with those in Hawaii is related to pathology in small intracerebral arteries by comparing the prevalence of such lesions in autopsied participants from two cohorts of Japanese men in Japan and Hawaii.MethodsExisting histological sections from the left basal ganglia from 232 men from Japan and 175 men of Japanese ancestry in Hawaii were examined for selected abnormalities in arteries between 100 and 300 μm in diameter by three pathologists. The presence of lacunar infarcts was also noted, and information about cerebral infarcts, cerebral hemorrhages, and atherosclerosis in the circle of Willis was available for the Hawaii group.ResultsLacunar infarcts and all small intracerebral artery lesions except medial fibrosis were more common at every age in Japan than in Hawaii. By cause of death, all lesions were three or more times more prevalent among men who died of stroke than of noncardiovascular causes in both areas. In the Hawaii group, the small intracerebral artery lesions were significantly associated with autopsy evidence of cerebral and lacunar infarcts, and with atherosclerosis in the large arteries of the circle of Willis. Among a large number of risk factors measured at the baseline examination in Hawaii, only high blood pressure and reported usual Asian diet were significantly associated with one or more measures of small intracerebral artery lesions.ConclusionsAn overview of the accumulated data indicated that small intracerebral artery pathology plays an important role in the high risk of stroke in Japanese men in Japan compared with those in Hawaii. These studies support the idea that hypertension is a necessary factor in the causal pathway, but also indicate that some other factors are involved. Some aspect of an Asian diet continues to be of importance for future research.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeWe tested the hypothesis that body mass, waist-to-hip circumference ratio, physical inactivity, diabetes, hyperglycemia, and fasting insulin are each positively associated with asymptomatic carotid artery wall thickness.MethodsAverage intimal-medial carotid wall thickness (an indicator of atherosclerosis) was measured noninvasively by B-mode ultrasonography in cross-sectional samples of 45- to 64-year-old adults, both blacks and whites, free of symptomatic cardiovascular disease, in four US communities.ResultsSample mean carotid wall thickness was approximately 0.7 mm in women (n=7956) and 0.8 mm in men (n=6474). Body mass, waist-to-hip ratio, work physical activity, diabetes, and fasting insulin were associated (P< .05) with carotid wall thickness in the hypothesized direction. Adjusted for age, race, smoking, body mass index, artery depth, and Atherosclerosis Risk in Communities field center, mean wall thickness was greater by 0.02 mm in women and 0.03 mm in men for a 0.07-unit (one SD) larger waist-to-hip ratio. Adjusted mean wall thickness was about 0.07 mm thicker in participants with diabetes mellitus and 0.02 mm thicker in participants with hyperglycemia (fasting glucose 6.4 to 7.7 mmol/L) than in subjects with fasting glucose <6.4 mmol/L. Adjusted mean wall thickness increased by about 0.02 mm with an increase of 100 mmol/L in fasting serum insulin.ConclusionsAbdominal adiposity, physical inactivity, and abnormal glucose metabolism are associated positively with carotid intimal-medial wall thickness, suggesting these factors contribute to atherogenesis.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeSerum lipoprotein(a) level is genetically determined and remains almost constant throughout life. Based on this property, we investigated the serum lipoprotein(a) levels of ischemic stroke patients in the chronic stage (mean period after stroke, 27 months) and its relation to the types of ischemic stroke.MethodsWe measured serum lipoprotein(a) levels in 101 patients with chronic ischemic stroke and 37 normal control subjects, taking the clinical profiles into consideration.ResultsLipoprotein(a) levels in patients with atherothrombotic stroke were 28.0±19.6 mg/dL (mean±SD), which were significantly (P< .01) higher than those in patients with lacunar stroke and in normal control subjects (16.4±13.5 and 11.7±10.5 mg/dL, respectively). The lipoprotein(a) levels in patients with atherothrombotic stroke were significantly higher in the subgroup who were a younger age at onset: onset before age 50 years, 35.3±20.5; onset at age 50 to 59, 35.4±21.7; onset at age 60 to 69, 17.0±12.8; and onset at age 70 or older, 16.3±6.8 mg/dL (P< .01 for onset before age 50 versus 60 to 69 years or 70 years or older;P< .01 for onset at 50 to 59 years versus 60 to 69 years or 70 years or older). Serum lipoprotein(a) was significantly increased (40.2 ±20.1 mg/dL) in young adults with atherothrombotic stroke (onset at younger than age 45 years) compared with that in patients older than 45 years (P< .01).ConclusionsWe conclude that lipoprotein(a) is a genetic, independent, and critical risk factor for ischemic stroke, especially in young adults.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeWe used99mTc-hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) to study cerebral perfusion in patients treated with streptokinase for acute ischemic stroke in an open and prospective study. Our primary aims were (1) to compare the extent of reperfusion between patients who had received thrombolytic therapy and a control group studied during the same period who were ineligible to receive such therapy and (2) to determine if, among all patients, reperfusion led to improved outcome.MethodsFifty-seven patients (22 treated with streptokinase) had two SPECT studies performed, the first before streptokinase administration and the second 24 hours later.ResultsOn the first SPECT study hypoperfusion was present in the middle cerebral artery or anterior cerebral artery territories in 40 patients (17 treated with streptokinase). Patients in the treatment and control groups with initial hypoperfusion on SPECT were well matched for the volume of the perfusion defect and the severity of neurological deficit. A greater number of patients who received streptokinase developed at least partial reperfusion (streptokinase, 65%; control, 52%) on the second study but not significantly so (P=.43). Similarly, the proportion of each hypoperfused region that reperfused (P=.74) and the reduction in the size of the perfusion defect (P=.06) were higher in the streptokinase group but did not reach statistical significance. When all patients were considered, those who did not reperfuse had higher mortality rates (P=.008), less neurological improvement (P=.016), and more functional disability (P< .001) than patients who had reperfusion or normal perfusion initially.ConclusionsThese findings suggest that at least some reperfusion during the first 48 hours of ischemic stroke is a common natural occurrence and is of prognostic significance. The observed trend toward better reperfusion indexes among patients treated with streptokinase is encouraging, but larger controlled trials are required to answer this definitively.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeOur goal was to identify factors that play a role in false clinical diagnosis of small deep infarcts.MethodsIn 350 prospectively registered patients with a first supratentorial ischemic stroke, we clinically differentiated between lacunar and nonlacunar syndromes. Using computed tomography (CT), we distinguished small deep and territorial infarcts and also recorded leukoaraiosis and asymptomatic infarcts. Degree of initial handicap, potential source of cardioembolic stroke, and hypertension were also noted.ResultsOne hundred forty-seven patients had a lacunar and 203 a nonlacunar syndrome. Forty-two (12%) had a lesion visualized by CT that was compatible with a recent infarct but was considered inappropriate for the clinical syndrome: nineteen had a nonlacunar syndrome but a small deep infarct, and 23 had a lacunar syndrome but a territorial infarct. Patients with a nonlacunar syndrome but a small deep infarct were more severely disabled (a modified Rankin scale rating of 5) (odds ratio [OR], 4.31; 95% confidence interval [CI], 1.25 to 14.88) and had a cardioembolic source (OR, 4.07; 95% CI, 1.04 to 15.95), leukoaraiosis (OR, 3.79; 95% CI, 1.32 to 10.05), or asymptomatic infarcts visualized by CT (OR, 4.13; 95% CI, 1.45 to 11.71) compared with 124 patients with a correctly diagnosed small deep infarct. Twelve of 19 patients with a nonlacunar syndrome but a small deep infarct had a lesion in the left hemisphere, and 9 of these 12 had “aphasia.” Patients with a lacunar syndrome but a territorial infarct more often had a cardioembolic source (OR, 4.02; 95% CI, 1.15 to 14.03) and a pure motor syndrome (OR, 4.52; 95% CI, 1.55 to 13.18) than those with lacunar syndrome but a small deep infarct, although 21 (91%) were in the right hemisphere. Of the first 103 patients with lacunar stroke diagnosed by two of the study neurologists, 5 had an inappropriate lesion compared with 14 of the later 40 diagnosed by colleagues without a specific interest in cerebrovascular diseases (OR, 0.09; 95% CI, 0.03 to 0.26).Conclusions(1) Diagnosis of lacunar syndromes should not be influenced by deficit severity or the presence of a potential cardiac source of embolism. (2) Speech disorders should carefully be classified. (3) Routine tests of nondominant higher functions may be inadequate. (4) Doctors interested in cerebrovascular neurology have a lower failure rate in differentiating small deep infarcts from territorial infarcts than those less well-trained or interested in neurology. (5) Among the lacunar syndromes, pure motor syndrome may be the least specific predictor of a small deep infarct.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeClinical differentiation of lacunar from nonlacunar strokes in the very early phase could help to exclude patients with lacunar stroke from pharmacologic trials designed for nonlacunar strokes, namely, those with thrombolytic agents. In a continuous series of acute ischemic stroke patients, we evaluated how accurately a clinical diagnosis of pure motor hemiparesis or sensorimotor stroke formulated in the first hours from onset predicts a lacunar stroke documented by cerebral computed tomography or by autopsy.MethodsWe examined 517 patients (299 men, 218 women; mean±SD age, 67±10 years) within 12 hours (mean±SD, 6.1 ±3.2 hours) of the event. At hospital admission, we observed 151 (29%) patients with pure motor hemiparesis and 68 (13%) patients with sensorimotor stroke.ResultsComputed tomography or autopsy was compatible with a lacunar stroke (ie, detection of a lacune or permanently negative computed tomography) in 170 (33%) patients, of whom 123 (72%) had pure motor hemiparesis and 47 (28%) had sensorimotor stroke. This led to a sensitivity of 72%, a specificity of 72%, a positive predictive value of 56%, and a negative predictive value of 84%. Overall positive predictive value of pure motor hemiparesis was 58% (60% for two areas and 58% for three areas involved), and that of sensorimotor stroke was 51% (87% for two areas and 40% for three areas involved). By separately evaluating the sides of lesions, we found a positive predictive value of 46% for right-side infarcts and of 72% for left-side infarcts. Right-side lesions constituted 51% of lesions in lacunar syndrome patients with lacunar stroke, 76% in those with nonlacunar stroke, 19% in nonlacunar syndrome patients with lacunar stroke, and 31% in those with nonlacunar stroke (P< .0001). During the first days of hospital stay we observed a deterioration of 21% of lacunar syndrome patients with nonlacunar stroke and an improvement of 49% of nonlacunar syndrome patients with lacunar stroke, with appearance and disappearance of symptoms of cortical involvement, respectively. The examination of these patients after the occurrence of these clinical changes would have led to a daily increase of the positive predictive value up to a maximum of 66% at day 7.ConclusionsPure motor hemiparesis and sensorimotor stroke diagnosed within 12 hours of the event are poorly predictive of lacunar strokes. Hence, the very early identification of these syndromes cannot be used for patient selection in therapeutic trials.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeOur objective was to study age-specific prevalence, computed tomographic (CT) characteristics, risk factors, and the prognostic influence on stroke outcome of silent infarction in acute stroke patients.MethodsThe study was prospective and community-based and included 801 acute stroke patients, of whom 587 had first-ever stroke. A CT scan was performed in 500 (85%) of the 587 patients with first-ever stroke. CT was reviewed blindly, and infarcts were classified according to patient history as silent or symptomatic. Patients were evaluated initially with the Mini-Mental State Examination (MMSE) and weekly with both the Scandinavian Stroke Scale (SSS) and the Barthel Index (BI) from the onset of stroke to completion of rehabilitation. CT characteristics, risk factors, and stroke outcome were compared in stroke patients with and without silent infarction.ResultsThe prevalence of silent infarction in patients with first-ever stroke and recurrent strokes was similar, at 29% (group aged 0 to 54 years, 16%; 55 to 64 years, 22%; 65 to 74 years, 30%; 75 years or older, 33%). Silent infarcts were small and subcortical. Independent risk factors were increasing age (odds ratio [OR], 1.95 per 25 years; confidence interval [CI], 1.19 to 3.15), hypertension (OR, 1.75; CI, 1.13 to 2.70), claudication (OR, 1.74; CI, 1.01 to 3.00), and male sex (OR, 1.72; CI, 1.12 to 2.64); other stroke risk factors such as atrial fibrillation and former transient ischemic attack were not independent risk factors. Patients with and without silent infarction did not differ in frequency of prestroke home care (P=.2), MMSE (P=.56), initial BI (P=.62) and SSS score (P=.08), BI (P=.85) and SSS score (P=.75) after completion of rehabilitation, or in the speed of recovery (P=.85). Length of hospital stay, mortality rate, and discharge rate to nursing home also did not differ between the two groups.ConclusionsThis community-based study shows that silent infarction in stroke patients is more related to certain stroke risk factors than others and that silent infarction does not seem to influence the prognosis of stroke.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeTerritorial cerebellar infarcts have mainly a thromboembolic mechanism. Cerebellar infarcts less than 2 cm in diameter have recently been reported as nonterritorial infarcts, but it is not clear whether they are low-flow or embolic infarcts. The aim of the present study was to compare the characteristics and causes of territorial and nonterritorial infarcts in a prospective series of 115 patients.MethodsWe collected data from 115 consecutive patients with cerebellar infarcts (79 territorial and 36 nonterritorial [ie, less than 2 cm]), using magnetic resonance imaging (88 patients) and computed tomography.ResultsPatients with territorial infarcts and those with nonterritorial infarcts had similar vascular risk factors and clinical presentations and an equal frequency of cardiac source of embolism (32% versus 42%;P=NS) and of large artery occlusive disease (23% versus 19%;P=NS). Occlusive lesions of large arteries at angiography occurred at the level of one cerebellar artery (5% versus 0%;P=NS) and proximal to the ostia of the cerebellar arteries (18% versus 19%;P=NS). Infarcts distal to occlusive lesions were subdivided into unilateral vertebral artery occlusive disease (presumed artery-to-artery embolic mechanism; 18% versus 5%;P=NS) and low-flow state distal to bilateral vertebral or basilar artery occlusion (presumed hemodynamic mechanism; 0% versus 14%;P=.004). Patients with nonterritorial infarcts had more frequent hypercoagulable state (17% versus 1.25%; odds ratio, 15.6 [95% confidence interval, 1.8 to 135]). For the remaining patients, the mechanism of the infarct was unknown (34% versus 22%;P=NS).ConclusionsCerebellar infarcts less than 2 cm in diameter (ie, nonterritorial) have the same high rate of embolic mechanism as territorial infarcts (47% versus 49%;P=NS), have more frequent hypercoagulable state, and sometimes have a hemodynamic mechanism.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background and PurposeRecently, supraventricular tachycardia has been reported following right hemisphere stroke, suggesting a reduction in parasympathetic cardiac innervation after stroke of the right hemisphere. We performed power spectrum analysis of fluctuations in RR interval duration in the electrocardiogram in an attempt to determine how ischemic stroke influences autonomic cardiac innervation.MethodsPower spectrum analysis of the variation in 256 consecutive electrocardiographic RR intervals was performed using the fast-Fourier transformation. The area under the spectral curve from 0 to 0.5 Hz and the area under that portion of the curve produced by parasympathetically mediated respiratory variations were determined in 20 patients with right-hemisphere and 20 patients with left-hemisphere ischemic stroke confirmed by computerized tomography. Data were compared with 40 age- and sex-matched healthy controls.ResultsTotal cardiac autonomic innervation was reduced after a stroke of either hemisphere without regard to laterality. Cardiac parasympathetic innervation was reduced after stroke of either hemisphere with a significantly greater reduction after stroke on the right (P=2.9×10−5).ConclusionsPower spectral analysis of heart rate variability can detect autonomic consequences of stroke. The spectral data predict that, to the degree that cardiac arrhythmia is produced by unbalanced cardiac autonomic activity favoring the sympathetic system, such arrhythmias could be seen after stroke of either hemisphere and would be more common after cerebral infarction on the right. This is consistent with evidence from the recent literature.

ISSN:0039-2499    

出版商:OVID    

年代:1994

数据来源: OVID