ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Cardiovascular disease is the leading cause of death worldwide with almost one third of all cardiovascular deaths ascribed to stroke. In contrast to coronary heart disease, most of the strokes occur in developing countries; China alone has about 1 million deaths from stroke each year. From a global perspective the stroke situation is changing rapidly, and considerable progress has been made in documenting the changes in stroke mortality. Despite the favorable trends in stroke mortality in many countries, stroke will become an increasingly important health problem as the world's population continues to age.

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The termischemic penumbra, originally applied to brain tissue perfused at values between the functional and morphologic thresholds, has recently been extended to characterize ischemically affected but still viable tissue with uncertain chances for infarction or recovery. Results have accumulated supporting the concept of the ischemic penumbra as a dynamic process of impaired perfusion and metabolism eventually propagating with time from the center of ischemia to the neighboring tissue. As mediators and modulators of this process, waves of depolarization, extracellular increases in excitatory amino acids, activation of Ca++channels, induction of immediate early genes and expression of heat-shock proteins, among others, have been discussed. The contribution of the various electrophysiologic and biochemical/molecular events to the complex cascade, eventually leading to neuronal damage, is still controversial. The demonstration of viable (penumbra) tissue by positron emission tomography up to several hours after ischemic stroke renders the rationale for therapeutic interventions. A short therapeutic window of a few hours is relevant for re-establishment of perfusion; the time-dependent propagation of the ischemic penumbra suggests an extended period for effective intervention with biochemical/molecular processes.

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The electrocardiogram changes and cardiac arrhythmias frequently encountered after stroke are not solely explicable by concomitant ischemic cardiac disease. Excessive sympathoadrenal tone is contributory. Specifically, it is now believed that augmentation of intra-cardiac sympathetic nerve activity occurs, producing cardiac myocyte damage and depolarizing ionic shifts, resulting in electrocardiogram repolarization changes and arrhythmogenesis. Experimental and clinical evidence now implicates the insular cortex and its subcortical connections in the generation of cardiac arrhythmias under stress and following hemispheric stroke. Lateralization studies indicate that destruction of areas adjacent to the right insular cortex, or involving noncardioactive zones within this region have especially marked cardiac effects. This very likely contributes to the cardiac mortality which is the principle long-term cause of death in stroke patients.

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The physiology of thrombi and the pharmacology of thrombolytic drugs are under active study and improved regimens for the dosing of thrombolytic agents have been developed. In the setting of myocardial infarction, recently reported differences among thrombolytic agents have been slight, including the frequency of thrombolysis-associated hemorrhagic stroke following tissue plasminogen activator or strepto-kinase. In the setting of ischemic stroke, recanalization rates following intravenous tissue plasminogen activator have been modest and at least partly dependent on clot size. Conclusions regarding clinical benefit will depend on the results of multicenter randomized trials that should available in 1995. Studies of locally administered intra-arterial thrombolytic therapy demonstrate high rates of clot lysis, but clinical benefits have yet to be established. The results of randomized trials will be important in clarifying any cause-effect relationships between thrombolytic therapy and symptomatic and asymptomatic intracranial hemorrhage. Thrombolytic therapy in the study of subarachnoid hemorrhage is under active investigation.

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Morbidity and mortality rates for stroke are higher in men than women with the exception of subarachnoid hemorrhage. Temporal trends are similar in the two sexes with a slowdown in the decline in mortality rates and a leveling or increase in morbidity rates. Women are more likely than men to have cervical bruits but less likely to have carotid stenosis on ultrasonography. Some factors associated with stroke are unique to women: pregnancy, use of oral contraceptives, postmenopausal hormonal replacement, and choriocarcinoma. Postmenopausal hormonal use is associated with a decreased risk of stroke in observational studies but clinical trials are needed. Control of hypertension and cessation of smoking to reduce the risk of stroke is equally effective in both sexes. Aspirin and ticlopidine are effective in secondary prevention of stroke in women, whereas women may be more sensitive to warfarin than men.

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The incidence of stroke increases dramatically with advancing age. Progressive carotid atherosclerosis, cardiac arrhythmia and emboli, and vascular changes all contribute to this increasing incidence of stroke in the elderly. Treatment of hypertension and other risk factors have resulted in a decline in stroke over the last 50 years. The decline has been most prominent in the elderly. In recent years, this decline has slowed down or may even be reversing. Early and effective control of risk factors together with comprehensive management of acute stroke in a specialized unit is needed to further improve prognosis. Such an approach is especially important in the elderly, who may suffer from multiple problems. Treatment of hypertension and other risk factors have resulted in a decrease in an overall decline in the incidence of stroke over the last 50 years. This decline has been most apparent in the elderly. In recent years, however, there has been a slowing or possibly a reversal of this trend. Early and effective management of risk factors, aggressive therapy of patients with transient ischemic attacks and comprehensive management of acute stroke patients in specialized units may be required to further improve prognosis.

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Aspirin is the most widely used antiplatelet agent, reducing nonfatal ischemic stroke by 22%. There is increasing evidence that the efficacy of aspirin may vary with the etiologic subtype of stroke. Although the cost and side effects have limited the use of ticlopidine, patients who are intolerant of aspirin and those experiencing transient ischemic attack or stroke during aspirin therapy should be given ticlopidine. Patients with atrial fibrillation have a five-fold increased risk of stroke and require prophylactic therapy with warfarin or aspirin. Aspirin is less effective than warfarin in preventing atrial fibrillation-associated stroke, but the higher risk of hemorrhagic complications and frequent monitoring associated with warfarin must be considered. Clinical and echocardiographic predictors of increased thromboembolic risk in atrial fibrillation patients have been identified and may direct the treatment choice.

ISSN:1350-7540    

出版商:OVID    

年代:1994

数据来源: OVID