摘要:

Although large gaps in our knowledge concerning the epidemiology of cerebrovascular disease are apparent, careful inspection of all existing data now makes it possible to see certain patterns emerging which suggest certain risk factors for stroke.While the problem of differential diagnosis of the various categories of cerebrovascular disease presents a major obstacle to obtaining an undistorted picture of the epidemiological features of stroke from death certificate mortality data, the addition of evidence from prospective studies, including those in Framingham, Massachusetts, reveals that various types of arterial occlusion with cerebral infarction are by far the most prevalent type of stroke. Any specific origin of atherosclerosis remains obscure, as possible etiological candidates including dietary alterations in salt, fat and refined carbohydrate, sedentary living, excessive calories promoting obesity, the cigarette habit and even the mineral content of water in addition to marital status have all been incriminated. However uncertain the final answer is, certain precursors for atherosclerosis, such as hypertension, diabetes, and hyperlipidemia, are important. Of these, hypertension is clearly the most important contributor to stroke incidence. Certain combinations of items carry more risk than do the same items singly. For example, the risk of a brain infarction in diabetics with hypertension is probably about six times that of normal subjects. In persons under 50 at the time of measurement risk of cerebral infarction is possibly ten times higher in those with hypertension and elevated lipids than in those without either elevated. This compounding of risk has pathogenetic, preventive and public health implications. For purposes of stroke screening alone the most efficient and practical method would be to determine casual blood pressure, although it must be stated that as yet there is uncertainty concerning the change in the risk if such blood pressure is treated.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Previous studies have shown that occlusion of the middle cerebral artery (MCA) of the squirrel monkey results in a consistent large infarct; that in the initial two hours after occlusion of the MCA, blood flow in the central area of ischemia continues at a reduced rate (20% to 50% of normal); and that restoration of normal flow within three hours results in a survival rate of 65% without infarction. In this study, cerebral adenosine triphosphate (ATP), lactate, and pyruvate concentrations were measured at various time intervals after occlusion of the MCA. ATP decreased slowly during a three-hour period to 30% of normal, and lactate, after an initial rapid accumulation, increased slowly to about eight times normal. This compares to the effects of circulatory arrest which, in the dog, results in a reduction of the ATP level to 25% of normal within four minutes and a reciprocal increase in the lactate level. Because the effects of total cerebral anoxia are potentially reversible prior to four minutes, and, therefore, at an ATP concentration above 25% of normal, the slow rate of ATP depletion observed in the ischemic monkey brain supports the view that a significant period exists after occlusion of a major intracranial vessel wherein the ischemic effects are potentially reversible. Using the methods of this study, future investigations should permit a meaningful evaluation of the relative merits of those measures recommended for the treatment of acute cerebral ischemia.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Pathophysiological and pathogenetic concepts, particularly in occlusive cerebrovascular disease, are reviewed and discussed with emphasis on the results of current research. Therapy is discussed in the context of these concepts.When focal ischemia, with or without cerebral infarction, is not associated with definable arterial occlusion, studies of regional cerebral blood flow strongly support the thromboembolic theory; the arterial defect is relatively transient and is caused by an embolus or thrombus which rapidly disappears (fragments or is lysed). The treatment of transient ischemic attacks by the administration of anticoagulant or surgical reconstruction of the appropriate artery is discussed.When cerebral infarction is caused by arterial occlusion there is vasomotor paralysis (loss of autoregulation and of reactivity to carbon dioxide). In some instances hypercapnia apparently causes only the vessels in nonaffected brain to dilate so that an increased amount of blood streams to these parts while blood pressure falls in collaterals leading to the focus and blood flow to the infarct is decreased (steal syndrome). If blood flow is decreased to nonaffected brain, by vasoconstriction caused by hyperventilation, increased amounts of blood may be shunted into the infarct (reverse steal) where autoregulation is lost. Vasoconstriction, as a treatment, might be beneficial. However, in patients with severe cerebral infarction no convincing favorable affect has been noted. The potential therapeutic action of hyperventilation in patients with mild cerebral infarction has not been studied.Extensive (global) changes in the cerebral blood flow in cerebral infarction, certain aspects of intracerebral hemorrhage, and the role of hypertension in cerebrovascular disease are also dealt with.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

While neurological symptoms are often mentioned in reports of families with hereditary hemorrhagic telangiectasia (HHT) and are frequently assumed to be due to vascular anomalies of the central nervous system, documentation of such anomalies is surprisingly rare. Two cases of surgically treated symptomatic cerebral vascular malformations in HHT have been published previously. In addition, there are three descriptions of vascular anomalies discovered at autopsy in the brains of neurologically asymptomatic patients with HHT available in the literature. A complete postmortem examination of a patient with a symptomatic cerebral vascular anomaly associated with HHT has not been recorded previously.The patient reported in this paper presented with seizures and underwent surgical resection of infarcted brain tissue associated with a venous angioma. He died six months later and, at autopsy, was found to have multiple “cryptic” venous angiomas of the brain. Hypoxic damage to brain tissue related to small venous angiomas is one mechanism whereby these lesions may become symptomatic. Hemorrhage may also occur. Neurological symptoms in patients with HHT cannot be assumed to be due to cerebral vascular anomalies, and consideration must be especially given to the complications of pulmonary arteriovenous fistula such as polycythemia, embolism, and abscess.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Combined results of selected studies of the natural history and therapeutic results in patients with TIA indicate that anticoagulation therapy is clearly worthwhile in the prevention of completed strokes during the first 40 months after onset. Surgery is somewhat less valuable, but preferable to nihilism, which is associated with new completed strokes in 19% of patients and death in 20% of patients followed for an average of 40 months from onset of TIAs. The incidence of death from all causes is remarkably similar in both treated and untreated patients during this follow-up period, suggesting that fears of increased mortality in patients treated with anticoagulants are either unfounded or compensated by decreased mortality from occlusive strokes.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

This report presents an analysis of autopsy material from 3,942 cases of age 20 and older in whom the circle of Willis was scored for the severity and the extent of atherosclerosis. Several criteria were used to assess the effect of socioeconomic factors on cerebral atherosclerosis; these consisted of the financial hospital status of the patient, the place of residence, and occupation and physical activity. In the female patients it appeared that the indigent cases had a slightly higher prevalence of cerebral atherosclerosis than the private cases. In the males a difference in prevalence was found between urban and rural cases, the urban males showing higher scores. A comparison between a group of patients with mostly sedentary occupations and a group with more physically active occupations revealed no difference in atherosclerosis scores.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

In 44 patients with acute unilateral cerebral infarction, there was reduction of hemispheric blood flow (HBF) and metabolism in the healthy hemisphere (phenomenon of diaschisis) as well as in the diseased hemisphere in patients in all age groups (30 to 70 years of age). In patients with symptoms present for three weeks or longer, the decrease in HBF in the healthy hemisphere was less than during the acute stage of infarction. The HBF in the healthy hemisphere of the younger patients approached normal values months or years after the stroke but remained reduced in older patients, probably reflecting diffuse as well as focal cerebrovascular disease. When the severity and outcome of the neurological deficit was correlated with the blood flow and metabolism of the diseased hemisphere, it was apparent that HBF in patients with transient ischemic attacks and more prolonged but reversible neurological deficit was greater than in those who had sustained severe, permanent neurological deficit.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The problems involved in measuring improvement as well as the conceptual difficulties in considering this phenomenon were considered in general terms.Data on 300 patients with nonembolic cerebral infarction followed from five to nine years are presented, indicating that improvement in function of a paralyzed extremity may occur in the early phase after stroke but was extremely unlikely to continue during long-term follow-up from three months to five years. It was concluded that improvement in function might be determined more by retraining of the nonaffected muscles and particularly of the unaffected side rather than by recovery of the area paralyzed.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

During a period of approximately two years (1965 through 1966), 717 intracranial cerebral arteries (males and females) were obtained from the medicolegal autopsy cases. Systematic grading of the macroscopic severity of cerebral atherosclerosis was performed and the results were reported. In general, cerebral atherosclerosis appeared as early as the second decade and increased in severity with age, particularly at the fifth decade in males and the sixth decade in females. The prevalence of localization of early and/or severe cerebral atherosclerosis was studied. The results in the present study were not the same as in the previous investigations on Caucasians. The common sites of the severe cerebral atherosclerosis causing marked lumen narrowing were the proximal portion of posterior cerebral arteries, peripheral portion of the middle cerebral arteries, and the vertebral arteries and their fusing site at the basilar artery; the internal carotid artery was the least commonly involved.In the present study, the influence of sex in the production of cerebral atherosclerosis was suggested, and the simple senescence theory of cerebral atherosclerosis was not supported. The macroscopic severity of cerebral atherosclerosis of Japanese in the present study appeared to be equal to or slightly greater than that in Americans and Norwegians reported by Baker et al.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

An intermandibular-transclival approach to the posterior cranial fossa has been developed which allows exposure of the basilar artery for attachment of a small electromagnetic blood flow transducer. The results of single intravenous injections of betahistine hydrochloride indicated a mean increase in basilar artery blood flow of 54% and a simultaneous decrease in systemic arterial blood pressure of a duration of action of approximately one minute. Histamine phosphate yielded results similar to betahistine hydrochloride, while nicotinic acid produced only slight increases in blood flow in the basilar artery.

ISSN:0039-2499    

出版商:OVID    

年代:1971

数据来源: OVID