摘要:

In lightly anesthetized cats, the left middle cerebral artery was occluded using a transorbital approach. Pial arterial pressure was measured with a feedback-controlled micropressure recording system in the territory of the occluded artery, and compared with changes of cortical blood flow, cortical steady potential and cortical EEG activity. After middle cerebral artery occlusion pial artery pressure fell from 56.2 +/− 1.6 to 7.8 +/− 0.4 mm Hg; during the following two hours it again slowly rose to about 15 mm Hg. Cortical heat conductance, as a measure of blood flow, decreased from 15.1 +/− 0.2 to 11.9 +/− 0.2 × 10(−4) cal × cm-1 × sec-1 × degrees C-1, and remained at this level throughout the observation period. Cortical steady potential shifted by 9.1 +/− 0.7 mV towards negativity, and EEG amplitude was reduced by about 50%. Pial arterial pressure correlated with blood flow, cortical steady potential and EEG amplitude, but not with EEG frequency. Autoregulation and CO2 reactivity of blood flow were disturbed after middle cerebral artery occlusion. Calculation of extra- and intracortical vascular resistances revealed that this disturbance was entirely due to intracortical vasoparalysis whereas the collateral vessels supplying the ischemic territory continued to react to both pressure and CO2 changes. Maintained vascular reactivity of collateral vessels, therefore, is a decisive factor for the efficiency of therapeutic blood flow improvement after acute middle cerebral artery occlusion.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The chronic effects of smoking on regional cerebral blood flow (CBF), and on serum lipids and lipoprotein levels in neurologically normal subjects, were studied. CBF was studied by the 133-Xenon inhalation method and gray matter flow was calculated following the method of Obrist et al. One hundred and eleven subjects, who had no abnormalities in neurological examinations nor in CT scans, were divided into two groups: smokers (37) and non-smokers (74). Those who had a smoking index (Number of cigarettes/day) × (years of smoking history) greater than 200 were designated as smokers. The mean smoking index of smokers was 760. Sixty-two of the 74 subjects in the non-smoking group had never smoked, and the mean smoking index of non-smokers was 17. In the male, CBF was significantly lower in smokers than in non-smokers (mean CBF, 12.5% lower in smokers, p less than 0.001). Increased reduction of CBF with advancing age was also observed. Compared to non-smokers, CBF in smokers was found to be significantly lower than the expected age matched value. Serum high density lipoprotein cholesterol values in smokers were significantly lower, and total cholesterol levels significantly higher than in non-smokers. We concluded that smoking chronically reduces CBF. Decrease of CBF in smokers was probably due to advanced atherosclerosis which produces vascular narrowing and raised resistance in cerebral blood vessels.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

In normothermic cats under light barbiturate anesthesia, cerebral blood flow was arrested for one hour by intrathoracal occlusion of the innominate, the left subclavian, and both mammary arteries. Recirculation of the brain after ischemia resulted in reactive hyperemia, followed by a decrease of blood flow to about 70% of control (post-ischemic hypoperfusion). During postischemic hypoperfusion, CO2-reactivity was completely abolished. Intravenous infusion of prostacyclin 2 hours after ischemia (1.8 micrograms/kg/min) decreased systemic arterial blood pressure and reduced platelet aggregability but did not improve cerebral blood flow, did not restore CO2-reactivity, and did not influence postischemic changes of blood coagulation. It is concluded that prostacyclin deficiency is not or not the only reason for the development of post-ischemic hypoperfusion and the associated disturbance of flow regulation.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Eighty-one young Japanese patients with occlusive thromboaortopathy (Takayasu's disease) were classed into three groups according to the degree and extent of diameter stenosis in the 4 cervical arterial systems, as determined by serial aortography. Class I was made up of 63 patients with 70% or greater stenosis in less than 3 systems, including 33 patients without systemic hypertension (Class Ia). Class II was made up of 6 patients with 70% or greater stenosis in 3 systems and less than 50% stenosis in the remaining 1, including 5 patients without systemic hypertension (Class IIa). Class III was up of 12 patients with 70% or greater stenosis in 3 systems and 50% or greater stenosis in 1 system. Ophthalmodynamometric systolic pressure in patients in Class III was significantly lower than that in patients in Class IIa (p less than 0.001), but there was no significant difference between patients in Classes Ia and IIa. Microaneurysms and/or arteriovenous anastomoses in the retinal vessels were found in all but one patient in Class III and in only one patient in combined Classes I and II. These results indicate that each of the ophthalmodynamometric values and fundoscopic findings are very helpful in identifying the markedly severe occlusive lesions (Class III) of the 4 cervical arterial systems. In this chronic disease, however, angiography is most useful for evaluation of these severe lesions, to monitor progression from Classes I and II to Class III, in which the prognosis is rather poor.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

A consecutive series of 103 stroke patients capable of undergoing a psychiatric interview were evaluated for mood disorders. Nearly 50% of patients studied in the acute stroke period had clinically significant depressions and one fourth had symptom clusters found in major depressive disorders. We confirmed our previous findings that lesion location is most important in determining frequency and severity of depression. In addition, we have identified other variables including functional physical impairment, intellectual impairment, quality of social support, and age which contribute to or modify depression. Post-stroke depressive disorders are multifactorial in their determination and expression and include both neurophysiological-neurochemical mechanisms and psychological factors in their etiology.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Fifty-nine patients had arteriography because of episodes of amaurosis fugax. Only one third of them had atherosclerotic lesions potentially treatable by carotid endarterectomy. Another third had normal arteriograms, some of these had migraine, heart disease or platelet disorders presumed to be the cause of their symptoms. Patients with amaurosis fugax are a heterogeneous group, and their visual symptoms should not be considered a specific indicator of stenosis of the internal carotid artery.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Eleven patients with large cerebellar infarctions were admitted recently to our service. Eight of them showed evidence of hydrocephalus on the CT scan examination. Five were treated with controlled external ventricular drainage and six were managed conservatively. One death, most likely due to progressive brainstem infarction, occurred. The outcome was favorable in the other patients. It is suggested that prompt treatment of the acute obstructive hydrocephalus may obviate the need for posterior fossa decompression in patients with massive cerebellar infarction.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

We have evaluated carotid gamma imaging using 111Indium-labelled platelets in the diagnosis of carotid artery disease and measured the accumulation of labelled platelets on endarterectomy specimens. Autologous 111In labelled platelets were injected in 25 patients with TIA. Gamma images were then taken daily and independently interpreted by two observers. Carotid endarterectomy was performed in 11 patients allowing measurement of the radioactivity on the operative specimen. These results were compared to the findings on angiography and Doppler spectral analysis. All endarterectomy specimens accumulated platelets with the most active equivalent to platelets from 1.8 ml blood. Atheromatous ulcers were more active than stenoses with mean (+/− SEM) activities of 1.12 +/− 0.37 and 0.38 +/− 0.10 respectively. These radioactivity levels were at the threshold of gamma camera resolution in a theoretical model. Both observers agreed that 22 of the 50 carotid bifurcations showed platelet accumulation on gamma imaging. Of the 12 atheromatous ulcers demonstrated by angiography 11 were visualized, but only five of ten stenoses greater than 80% were detected. As Doppler identified all stenoses only one angiographically diseased carotid was not detected by combining ultrasound with platelet scanning. Atherosclerotic arteries accumulate 111In platelets and the more thrombogenic ulcerated plaques are identified more frequently than stenoses. Long-term follow-up is required to establish the clinical relevance of platelet deposition.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Eight cases of presumed acute occlusion of intracranial arteries, 7 middle cerebral and 1 posterior cerebral, demonstrated the occluded artery as an abnormal high density structure on non-enhanced computed tomography. Three cases underwent subsequent angiography which confirmed the diagnosis. CT scanning is therefore able to visualize acute thromboembolism in the intracranial arteries. In the appropriate clinical setting of acute stroke, an artery visualized on non-contrast CT scan as diffuse high density and higher in density than other visualized vessels should be suspected as acutely occluded by clot.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Two patients with small primary pontine hemorrhage developed a syndrome identical to ataxic hemiparesis, one of the lacunar syndromes of Fisher. The possible mechanisms of the homolateral cerebellar signs, pyramidal signs, and dysarthria are discussed. Lesions of the ipsilateral pontine nuclei may be responsible for the homolateral ataxia.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID