ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Coronary artery disease and ischemic cerebrovascular disease are leading causes of morbidity and mortality in the United States. Coronary artery disease often coexists with asymptomatic carotid artery atherosclerosis, transient ischemic attacks, or ischemic stroke. Numerous studies have shown that mortality from all forms of ischemic cerebrovascular disease is primarily due to coronary artery disease. Thus, there is increasing interest in identifying coronary artery disease in patients with cerebrovascular disease, including those without clinical manifestations of heart disease. We review the use of current noninvasive techniques to detect coronary artery disease and present practical approaches to screen for ischemic heart disease. Current diagnostic imaging methods for potential cardioembolic sources of cerebral infarction are also discussed.

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Twenty-three patients with hypesthetic ataxic hemiparesis underwent computed tomography or magnetic resonance imaging. Twenty-two patients had infarcts of lacunar or slightly larger size in the contralateral posterior limb of the internal capsule. In 15 patients the infarct extended superiorly into the adjacent paraventricular region, and in seven it extended into the lateral thalmus. In eight patients the infarct was limited to the posterior limb of the internal capsule, and in only two patients was an ipsilateral to capsular pontine lacune found. Despite a location similar to that of pure motor and pure sensory lacunar stroke, hypesthetic ataxic hemiparesis correlates with larger infarcts, most often located in the posterior medial superior territory of the antierior choroidal artery. Some infarcts appeared to be localized immediately posterolateral to this region, in the posterior cerebral artery territory. The presence and extent of infarction is better detected by the addition of magnetic resonance imaging to computed tomography.

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

To determine if certain transient monocular visual loss patterns predict the associated vascular abnormalities, we prospectively evaluated 100 consecutive patients. Each patient had hematologic tests, a carotid artery study (arteriography in 74, duplex uitrasonography in the remaining 26), and an ophthalmologic examination. Patients with aititudinai or Iateraiized transient monocular visual loss were more likely to have carotid artery stenosis, carotid artery ulceration, cardiac sources of emboli, or visible retinal emboli than patients with other visual loss patterns. Our findings suggest that aititudinai or Iateraiized transient monocular visual loss is primarily caused by embolism but that other visual loss patterns are usually caused by nonembolic mechanisms.

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Many patients suffer a stroke early after a transient ischemic attack, but the reason why is often unclear. We studied 12 patients with < 75% stenosis of the internal carotid artery and a single hemispheric transient ischemic attack lasting < 1 hour who had a normal neurologic examination 3–13 hours later and a normal computed tomogram 24–36 hours later. Singlephoton emission computed tomography using technetium-99m HM-PAO ⩽50 hours after the attack showed no abnormality in eight patients, but in the other four there was an area with 30–50% reduction in perfusion ipsilateral to the transient ischemic attack. Three of these four patients developed an ipsilateral infarct 3–7 days later, but none of the eight patients with normal single-photon emission computed tomograms had a stroke during the following weeks. No difference in therapy, risk factors, severity of internal carotid artery disease, or timing of the technetium-99m study could explain these findings. We suggest that some transient ischemic attacks, though clinically identical to others, may be associated with persisting focal hypoperfusion, which predisposes to early stroke.

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

We studied whether hemostatic abnormalities contribute to the increased risk of stroke in patients with nonvalvular atrial fibrillation. Hemostatic function was studied in four agematched groups: 20 patients with nonvalvular atrial fibrillation and a previous ischemic stroke, 20 patients with nonvalvular atrial fibrillation without a previous stroke, 20 stroke patients with sinus rhythm, and 40 healthy controls. Both groups with nonvalvular atrial fibrillation had significantly higher concentrations of von Willebrand factor, factor VM:C, fibrinogen, D-dlmer (a fibrinolytic product), β-thromboglobulin, and platelet factor 4; a significantly higher fibrinogen/antithrombin ratio; and significantly higher spontaneous amidolytic activity than the healthy controls. Prekallikrein levels were significantly lower in both groups with nonvalvular atrial fibrillation. Stroke patients with sinus rhythm had normal hemostatic function, normal concentrations of platelet-related factors, and a slightly increased concentration of fibrinopeptide A compared with the healthy controls. Both groups with nonvalvular atrial fibrillation differed from the stroke patients with sinus rhythm as they did from the healthy controls. No difference in hemostatic function was seen between the nonvalvular atrial fibrillation patients with and without a previous ischemic stroke. Thus, alterations in hemostatic function may contribute to the increased risk of stroke in patients with nonvalvular atrial fibrillation.

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

We studied the effect of acetazolamide on cerebellar blood flow in 11 stroke patients with large, unilateral cerebral hemispheric infarcts and no evidence of cerebellar infarction, but with cerebrocerebellar diaschisis of cerebral blood flow. Blood flow was determined with xenon-133 inhalation and dynamic single-photon emission computed tomography at rest and 20 minutes after the intravenous injection of 1.0 g acetazolamide. After acetazolamide, the mean±SD increases in blood flow in the affected and contralateral cerebellar hemispheres were 11.1±3.7 and 12.0 ± 5 3 ml/100 g/min, respectively, the difference between hemispheres was not significant The absolute increase in cerebellar flow in these 11 patients was of the same magnitude as that in 12 healthy controls. We conclude that cerebellar vasoreactivity is intact in stroke patients with crossed cerebrocerebellar diaschisis of cerebral blood flow. Our results lend further support to the concept that reduced cerebellar blood flow is secondary to functional deactivation. Our patients were studied 2 weeks to 5 years after their stroke, indicating that this phenomenon may be persistent

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Magnetic resonance angiography was applied to the study of blood flow dynamics in the circle of Willis in nine patients with cerebrovascular disease and two normal volunteers. In conjunction with two-dimensional or three-dimensional gradient-echo acquisitions, selective presaturation of individual vessels was used to determine the direction of blood flow and the origin of the vascular supply. Presaturation causes signal loss within the territory supplied by the presaturated artery, without affecting vessels not crossing the presaturation slab. The results were correlated with those from transcranial Doppler sonography and conventional angiography. Magnetic resonance angiography was able to demonstrate the direction of blood flow, the presence or absence of collateral blood flow, and the blood supply to the pericallosal arteries, as well as the presence of a fetal posterior circulation. Magnetic resonance angiography is a noninvasive means for imaging the blood supply of the major intracranial arteries.

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Lupus anticoagulant and antiphospholipid antibodies are associated with thromboembolic phenomena in individuals both with and without systemic lupus erythematosus. A 32-year-old woman (the index case) with lupus anticoagulant, multiple cerebrovascular events, and a family history of premature stroke raised the possibility of a familial diathesis. Histories or interviews, examinations, and blood tests were obtained for 23 members of four generations of her family. Four individuals had suffered strokes and three more had suffered neurologic symptoms. Two living individuals who had suffered strokes, two individuals with neurologic symptoms, and five asymptomatic individuals had antiphospholipid activity in their blood. In addition, a cousin of the index case was found to have systemic lupus erythematosus and antiphospholipid activity. Elevated concentrations of von Willebrand factor antigen were found associated with some positive lupus anticoagulant assays, the highest concentrations in the two individuals with stroke. The characteristic presentation of the index case and her good response to treatment suggests that further studies of families in whom antiphospholipid antibodies may represent a risk factor for stroke is worthwhile.

ISSN:0039-2499    

出版商:OVID    

年代:1990

数据来源: OVID