摘要:

One hundred seventeen patients with clinical signs and symptoms of transient ischemic attacks (TIAs) were evaluated. All underwent clinical evaluation for bruit, ophthalmodynamometry, rapid sequence scintiphotography with rectilinear scanning and fourvessel cerebral angiography. The results of these tests were compared for reliability in predicting location of lesions causing transient ischemic attacks. Angiography remains the most accurate procedure in evaluating extracranial vascular lesions. When determination of bruits, ophthalmodynamometry and brain scanning are done together, accuracy is greater than when any one of the procedures is done alone.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

When the origin of the internal carotid artery is occluded, the transmission of cardiac sounds along the carotid stops at the site of occlusion. This is a new neurovascular sign which is being reported.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The autoregulatory capacity of areas of the cerebral circulation subjected to ischemia by acute middle cerebral occlusion has been assessed in experimental primates. Autoregulation was tested to a risein blood pressure induced by aramine, and to a fall in blood pressure induced by exsanguination. Whole hemisphere autoregulation was substantially disturbed due to both increased blood pressure and lowered blood pressure, but fractionation of this response indicated that autoregulation to increased blood pressure was preserved in the parasagittal and intermediate zones of the hemisphere, and totally lost in the region of the sylvian opercula where middle cerebral occlusion had produced the most dense ischemia. In relation to reduced perfusion pressure, autoregulation was again widely impaired and assessment of the degree of impairment by areas indicated no significant difference between the areas of the sylvian opercula and the remainderof the lateral aspect of the hemisphere studied. Where the degree of ischemia in each individual electrode was assessed, however, it appeared that the degree of autoregulatory loss to decreased perfusion pressure was dependent upon the intensity of ischemia, and autoregulation was partially preserved in electrodes whose immediate post-occlusion flow values were greater than 40% of basal Row, but absent in electrodes whose flow values were less than 20% of basal flow. Retransfusion following exsanguination in animals with acute middle cerebral occlusion indicated that there was a linear relationship betweenthe degree of reperfusion achieved by retransfusion and the intensity of ischemia induced by exsanguination following middle cerebral occlusion. Thus there was some support for the no-reflow phenomenon in intensely ischemic areas.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Some patients who have transient ischemic attacks are denied operation because severe occlusive lesions in other extracranial arteries may be inappropriately interpreted as constituting an unacceptablesurgical risk, or because the lesion is so distal as to make its removal hazardous. Failure of endarterectomy is usually due to incomplete removal of the lesion or to thrombosis upon the frayed intima. Such lesions require excellent visualization and meticulous surgical technique - not always possible with a shunt. Among 130 consecutive carotid endarterectomies performed under general anesthesia, EEG changes consistent with cerebral ischemia appeared in only nine (7%). These patients required a shunt. In 11 patients normal EEC tracings were obtained during endarterectomy despite contralateral carotid occlusion. None of these patients had a neurological deficit. Continuous EEG monitoring is a reliable method of detecting changes in cerebral perfusion, permits a more meticulous endarterectomy in high-lyinglesions without a shunt, and extends operability in high risk patients. Angiographical findings may be an unreliable predictor concerning risk of endarterectomy.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The local tissue Po2 in the brain cortex and in the spinal cord of rats was examined with ultramicroelectrodes. In the spinal cord the Po2 was highest in white matter, intermediate in dorsal horn gray matter, and lowest in the ventral horn gray matter. In the gray matter of the cord, as well as in the brain, the Po2 at a fixed locus was found normally to oscillate. CO2 responses were more brisk in the cord than in the brain while the responses to hypoxia were similar. Therefore, it appears that the physiological regulation of blood flow in the spinal cord is qualitatively similar to that of the brain.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Retinal artery pressure was measured by ophthalmodynamometry in IS patients with occlusion of the internal carotid artery in its extracranial part. Nine of the patients had severe neurological deficit whereas the remaining six had slight or intermittent symptoms. Retinal artery pressure was reduced on the side of the internal carotid artery occlusion in all patients studied. Near-zero low diastolic retinal artery pressure on the affected side was a common finding amongpatients with severe deficit and was also seen in some patients with slight deficit. Its presence strongly suggests occlusion of the ipsilateral internal carotid artery.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The effect of prostaglandin E, on regional cerebral blood flow (rCBF) was studied with the intra-arterial “*Xe method in ten awake patients under local anesthesia. Measurements were taken from 16 areas of a hemisphere in seven patients, from 35 areas of a hemisphere in two patients and from 256 areas of a hemisphere in one patient. The prostaglandin was dissolved from the crystalline state without the aid of alcohol. It was given intracarotidly as a constant infusion at a rate of 5 ng per kilogram per minute for five minutes before the measurement, and continued during the measurement. In every patient a mild increase in blood flow during the prostaglandin infusion was seen. The flow increase took place in all parts of the hemisphere. It averaged 11.2% (p < 0.01). During the infusion, the skin supplied by the internal carotid artery and the conjunctiva on the infused side became red and sometimes swollen. A slight pressure was noted by most patients, but none had pain. No side effects of the infusion were noted.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

By grouping patients who had carotid angiograms under unusually carefully monitored conditions it has been shown that hypocapnia is associated with vasodilatation at low blood pressure but not at high blood pressure. The mechanism is discussed in general terms and it is suggested that the hypocapnic vasodilatation may be a response to cerebral hypoxia and may be transmitted via an intracerebral autonomic pathway. Clinical and angiographical diagnoses are given for SO patients.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Two hundred eighty patients were admitted to an intensive care stroke unit over a one-year period. Subsequent investigation indicated that only 199 of these patients actually had cerebral ischemic or hemorrhagic lesions, 10 had other cerebrovascular lesions, and the remaining 71 patients had unrelated diseases, predominantly seizures. Detailed analysis of 103 stroke ptients revealed an overall incidence of 59% hypertension, and 72% had hypertensive, ischemic or valvular heart disease. Fifty percent of the patients had various cardiac arrhythmias, some of which were responsible for the acute cerebrovascular lesion.Fourteen patients died during the acute phase, 11 from apparently irreversible cerebral swelling, mainly due to cerebral hemorrhage. Secondary complications such as pneumonia, pulmonary embolism, pressure sores and urinary infection were almost nonexistent, but beneficial effects on the primary cerebral lesions were more difficult to demonstrate.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Twenty rhesus monkeys were used to evaluate the effects of dexamethasone and dimethyl sulfoxide (DMSO) following experimental occlusion of the middle cerebral artery (MCA) for 17 hours.Animals were initially treated after four hours while the MCA remained occluded and a series of tests was used to evaluate the neurological and cerebral status of each monkey for seven days. The results show that the gross, microscopic and angiographical picture of dexamethasone and no-treatment controls was practically identical. In contrast, DMSO-treated monkeys showed significant protection from the severe neurological deficits seen in the other groups. It is concluded that DMSO has a positive effect in reducing the neurological deficits seen in this model and may be potentially useful in clinical embolic stroke.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID