摘要:

An association of blood lipids with the development of atherothrombotic brain infarction under age 60 is demonstrated. This is based on 18 years' surveillance of 5,209 men and women, of whom 52 men and 59 women developed brain infarction. The relationship under age 60 was statistically significant only for men.Triglyceride-rich pre-beta and cholesterol-rich beta lipoprotein were both related to the incidence of premature brain infarctions. Regardless of associated lipoprotein pattern, risk was proportional to serum cholesterol value, under age 60. On the other hand, pre-beta lipoprotein was unrelated to risk when associated cholesterol was taken into account.At any lipid value risk of brain infarction varied greatly depending on the number and intensity of other contributors. Blood lipids are best considered as an ingredient of a stroke profile, and in the absence of other contributors to risk the influence of lipid is feeble.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

There is a practical way to measure metabolism, flow, and function in a localized area of brain serially in the same animal. Our preliminary anatomical and angiographical studies have indicated that certain pairedcerebral veinsdrain only blood from cortex supplied by easily identified cerebral arteries. These veins have been cannulated bilaterally without altering flow in their territory of distribution. When compared to the arterial concentrations of the substances and the regional blood flow, one can calculate the regional metabolic rate of the tissue in this inflow-outflow system (vascular-metabolic unit). This system can be subjected toischemia, trauma, and pharmacological and neurophysiological alterations. In addition, it is accessible for measurement of electrical activity, surface fluorometry, and sampling for histological and cortical biochemical analysis.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Autoregulation was tested by regional blood flow (rCBF) and cardiohemodynamic measurements before and after induced systemic arterial hypertension in 16 patients with varying neurological disorders. Hypertension was induced by increasing the arterial blood pressure by an intravenous infusion of Aramine. Seven (Group 1) of the patients had a mean increase in mean arterial pressure (MAP) of 32 mm Hg and had preserved autoregulation while nine (Group 2) with a 56 mm Hg increase in MAP showed complete or mixed loss of autoregulation. Group 1 had a higher baseline mean CBF than did the group with loss of autoregulation. The group with loss of autoregulation also generally had more severe involvement on the cerebral angiogram than did the other. Baseline cardiac index and cardiac work were lower in the group with loss of autoregulation. During Aramine infusion the MAP was increased by 38% in Group 1 and 59% in Group 2. The mean CBF was essentially unchanged in Group 1 but increased 24% in Group 2. When autoregulation is lost, rCBF may increase homogeneously or heterogeneously with some areas increasing while others remained unchanged or even decreased. In four instances there was an intracerebral steal during induced hypertension with a fall in rCBF. Whether or not autoregulation is preserved could be related to: (1) the greater induced increase in MAP in Group 2 than Group 1, (2) greater angiographical involvement with a lower baseline in CBF in Group 2 than in Group 1 or (3) a direct or indirect influence of various cardiovascular factors.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

In brain death cases who showed nonfilling phenomena in the internal carotid angiograms, the blood flow velocity patterns of the common carotid arteries were characterized by involvement of a single systolic peak and a marked reverse flow component which had never been observed in healthy subjects.The individuality of each blood flow velocity pattern in the common, internal and external carotid arteries was made clear by placing the transducer in contact with the respective artery in a certain case. The Doppler signal from the internal carotid artery involving a signal from a reverse flow was slightly detectable, even if the blood pressure was elevated by norepinephrine infusion and the external carotid artery was temporarily compressed. The blood flow velocity pattern of the external carotid artery was similar to the pattern of the common carotid artery. The peculiar flow pattern indicates that a brain death case has a to-and-fro movement in the internal carotid blood flow and an external carotid escape of common carotid arterial blood.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Reversal of blood flow in an ophthalmic artery as determined by directional Doppler ultrasound (OSM) was present in nine (3%) of 310 patients over 50 years of age who did not have complaints, diagnoses or examination findings suggesting disease of the central nervous system, and was present in nine (12%) of 73 patients with neurological disease selected as technical controls. Twenty-two of the control patients had four-vessel angiography. Five with OSM evidence of reversal of flow had functional occlusion of the appropriate internal carotid artery, and 17 without reversal did not. This study presents evidence that occlusion of an internal carotid artery frequently occurs without producing recognizable clinical dysfunction.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

The simultaneous measurement of regional cerebral blood flow (rCBF), mean transit time (MTT), vascular volume (CVV) and cerebral vascular resistance (CVR) was performed in patients with cerebrovascular diseases. The measurement was made by a gamma-ray scintillation camera assisted by a minicomputer. A diffusible indicator of133Xe for CBF determination and a nondiffusible indicator of 99m Tc for MIT determination were used.The relation between rCBF and MTT showed a negative correlation in the nonfocal areas. The rCBF value in patients with normal brain was constant at high and low blood pressures. In patients with cerebral infarction there was a positive correlation between rCBF and mean arterial blood pressure. MTT had a negative correlation with mean arterial blood pressure in both patients with normal brain and those with cerebral infarction. In patients with normal brain a good negative correlation between CVV and CVR was found. In the nonfocal areas of cerebral infarction a high level of CVR was maintained regardless of the level of CVV.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Dialysis and transplantation are now standard treatments for end-stage renal failure. Often, neurologists are consulted regarding the neurological complications of these therapeutic procedures. In addition to previously reported complications, neurovascular disease is being recognized as a cause of mortality and morbidity in these patients. We report two cases of apparent thromboembolic stroke in young patients with renal failure — one treated by dialysis and the other by renal transplantation. The risk factors of both dialysis and transplant are identified and data from the American College of Surgeons/National Institutes of Health Transplant Registry are reviewed.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

In a series of 75 patients undergoing cardiac operations with the assistance of cardiopulmonary bypass (CPB), 15 patients were subjected to relatively large hypotensive stresses during CPB as measured by the depth and duration of the fall in cerebral perfusion pressure. Of these 15 patients, eight manifested cerebral dysfunction postoperatively ranging from temporary exacerbation of pre-existing focal neurological deficits to irreversible coma. In each of these eight cases, EEG disturbances which first appeared at the time of hypotensive episodes during CPB persisted postoperatively and correlated with the nature and evolution of the clinical deficit. In two of the patients who did not regain consciousness postoperatively, neuropathological studies revealed bilateral laminar cortical necrosis, primarily involving cerebral cortex in one case and cerebellar cortex in the other, with accentuation in arterial border zones. Of seven other patients who suffered comparable exposures to hypotension during CPB, none evidenced cerebral dysfunction postoperatively. The most important determinants of this selective vulnerability to low extracorporeal perfusion pressure appeared to be the “reperfusion” pressure established after the hypotensive episode, postoperative blood pressure and cardiac output, and brain temperature at the time of the hypotension. Advanced age and history of cerebrovascular insufficiency were the greatest risk factors among patient variables.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Cerebral autoregulation was studied in the baboon by increasing and decreasing cerebral perfusion pressure (CPP) before and after intravenous administration (1.5 mg per kilogram) of a long-acting alpha adrenergic blocker, phenoxybenzamine (PBZ). Likewise, cerebral vasomotor reactivity to changes of arterial carbon dioxide tension (PaCO2) was examined before and after PBZ.In order to permit quantitative analysis, cerebral autoregulation (A.I.) and chemical vasomotor reactivity (C.I.) were expressed as indices whereA.I.=δCBF/δCPP and C.I.=δCBF/δPaCO2.Following the intravenous injection of PBZ, cerebral autoregulatory vasoconstriction was impaired as CPP was increased. Cerebral vasomotor reactivity to changes in PaCO2was altered both during hyperventilation hypocapnia (HV) and hypercarbia induced by inhalation of 5% carbon dioxide if alterations of CPP brought about by these procedures were taken into consideration. During hypocapnia C.I. was reduced 30% and during hypercarbia C.I. was increased 10%.It is concluded that PBZ reduces the vasoconstrictor tonus of cerebral vessels during hypocapnia and raised CPP. It also enhances the vasodilator response to CO2inhalation.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Evidence is presented which supports the theory that intracranial hemorrhage may secondarily cause myocardial damage and cardiac arrhythmias.Fatal intracranial hemorrhage occasionally is accompanied by ECG changes which are consistent with myocardial infarction; histological examination of the heart revealed a variable amount of myocardial damage. After intracranial hemorrhage in animals, myocardial damage was frequent. Similar myocardial damage was produced in animals by intravenous infusion of norepinephrine or acetylcholine and by electrical stimulation of the stellate ganglia, vagus nerve or mesencephalic reticular formation.Atrial and ventricular arrhythmias and various degrees of A-V block were reported in patients suffering from subarachnoid hemorrhage. Similar cardiac arrhythmias were found in animals after intracranial hemorrhage, and with electrical stimulation of the vagus nerve, stellate ganglia or CNS centers. Available data suggest that increased or altered autonomic activity may be the mechanism whereby intracranial hemorrhage produces myocardial damage and cardiac arrhythmias.The efficacy of autonomic blockade in preventing myocardial damage, which was secondary to experimental intracranial hemorrhage in animals, was demonstrated. It is suggested that the initiation of therapy with autonomic blocking drugs, as soon as possible after the onset of intracranial hemorrhage in patients, may be useful in preventing myocardial damage and cardiac arrhythmias.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID