ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Embolization from or decreased flow through cervical carotid and vertebral arteries causes ischemic stroke syndromes. Specific pathologic findings were studied in SO symptomatic patients who underwent 69 carotid endarterectomies. Detailed analyses of their carotid plaques included correlations between photographs of gross specimens, microscopic findings, angiograms, preoperative symptoms and long-term postoperative follow up. Carotid plaques were primarily fibrous with significant (> 70%) stenoses encountered in 70% of the arteries. Stenoses were due to simple fibrous thickening in only 20%; the remainder due to intraplaque hemorrhage, atheromatous debris and, least often, luminal thrombus with or without ulceration. Intramural hemorrhage was frequent in plaques associated with focal neurologic symptoms and may have preceded localized collections of atheromatous debris. Ulceration occurred in 1/3 of all plaques, symptomatic or not. It is concluded that the carotid plaques start as fibrointimal thickening evolving to symptomatic stages by the occurrence of one or more of a number of pathologic changes, intraplaque hemorrhage being prominent. A single rational therapeutic regimen seems impossible until patients can be classified according to their pathologic changes diagnosed non-invasively.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Endothelial cells of the cerebral arterial system in spontaneously hypertensive rats were investigated by scanning electronmicroscopy and found to show progressive changes such as increased microvilli, numerous plasmalemmal pits, enlargement of the cells and well-developed marginal folds. Regressive changes, such as balloon-like protrusions and crater-like cave-ins, were also observed. Platelet adhesion to the injured endothelial surface of cerebral arteries was frequent. The significance of these changes in the development of hypertensive cerebrovascular lesions is discussed.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The author reviewed electrocardiograph records of ISO patients with acute stroke and 150 age- and sex-matched controls, to assess the relative frequencies of ECG abnormalities among the pathophysiologic categories of stroke, and to distinguish new abnormalities at the time of the stroke from those noted on prior tracings. Of the 150 patients with stroke, 138 (92%) showed ECG abnormalities. The most common abnormalities were also changes from prior tracings: QT prolongation (68 patients, 45%), ischemic changes (59, 35%), U waves (42, 28%), tachycardia (42, 28%), and arrhythmias (41, 27%). Patients with cerebral embolus had a significantly increased frequency of atrial fibrillation (9 patients, 47%); and with subarachnoid hemorrhage an increased frequency of QT prolongation (20, 71%) and sinus arrhythmia (5, 18%). The frequencies of QT prolongation and ischemic changes related strongly to admission systolic pressure but not to mortality. Stroke patients had an increased frequency of pathologic Q waves (30 patients, 20%) and left ventricular hypertrophy (39, 26%), but these were not new findings at the time of the stroke. The results are consistent with an interaction of underlying hypertensive or atherosclerotic cardiovascular disease, sympathetic hyperactivity, and possibly myocardial necrosis, in producing ECG changes.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Transient ischemic attacks (TIA) are episodes of abrupt beginning, consisting of subjective or & objective neurological dysfunction of short duration, with complete recovery of neurological function in the & course of 24 hours. With this definition, the authors carried out a retrospective study of ISO patients suffering & from ischemic infarct in the brain in the territory of the middle cerebral artery. Thirty-eight percent of the & patients had had TIAs before their cerebral infarct. The symptoms, in order of frequency, were motor, sensory & deficits, alterations of speech and vision. Most of the patients had a definite cerebral infarct, occurring one & month after the last TIA; the symptoms of both processes were remarkably similar.The authors studied the angiographic characteristics, pharmacological and toxic antecedents, and & associated diseases in these patients. The study indicates that TIA may be the first manifestation of cerebral & vascular disease.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Hypertension was produced in 8 cats by nephrectomy and wrapping the opposite kidney. Subsequent occlusion of one middle cerebral artery caused ischemic infarcts that were larger than those of 8 normotensive cats. The larger infarcts may have been caused by increases of ischemic cerebral edema resulting from changes in the cerebral endothelial barrier induced by hypertension. In addition to increasing the likelihood of strokes, hypertension in humans may predispose toward larger cerebral infarcts.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

A new model of transient, bilateral hemispheric ischemia in the unanesthetized rat is described. During ether anesthesia the rat's vertebral arteries were electrocauterized through the alar foramina of the first cervical vertebra and reversible clasps placed loosely around the common carotid arteries. Twenty-four hr later, the awake rats were restrained and the carotid clasps tightened to produce 4-vessel occlusion. The carotid clasps were removed after 10,20 or 30 min of 4-vessel occlusion and the animals killed by perfusion fixation 72 hr later. Rats which convulsed during the ischemic or post-ischemic period were excluded from further study. All rats subjected to 20 or 30 min of 4-vessel occlusion demonstrated ischemic neuronal damage. The HI and paramedian hippocampus, striatum and layers 3, 5 and 6 of the posterior neocortex were the regions most frequently damaged. The advantages of this model are the ease of preparation of large numbers of animals, a high rate of predictable ischemic neuronal damage, a low incidence of seizures and the absence of anesthesia.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Cerebral ischemia was produced by a combination of vascular occlusion and mild systemic hypotension in 2 groups of rabbits. Arterial blood pressure, arterial pH, arterial blood gases, blood glucose and PCV were monitored and recorded before, during and for 3 hours after reperfusion. Return of EEC activity, vasomotor control, spontaneous ventilation and corneal reflex were also recorded. At 4, 8, 12, 24 and 48 hours after reperfusion, the rabbits' neurologic status was assessed according to an arbitrary scale based on motor function. The 2 groups differed in return of reflexes and motor function. Eighty percent of the rabbits ischemic for 20 minutes and 75% of the rabbits ischemic for 30 minutes survived. The graduated response of motor function to cerebral ischemia is attributed to the ventilatory and circulatory support given the rabbits for the first 3 hours after reperfusion. The graduated response of motor function to ischemia supports the suggestion that motor function can be used as an index of neurologic damage.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Ten patients with angiographically verified occlusion of the basilar or vertebral artery have been followed for an average of 2.75 years. None has developed further ischemia after the initial stroke, and 4 patients survived without any clinical deficit. In occlusive disease of the posterior circulation, the critical period for deficit acquisition is at the time of occlusion. Extent of the deficit depends on the rapidity of development of adequate collateral circulation, and the presence of distal embolization at the time of occlusion. Some patients survive basilar occlusion without permanent deficit.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Brain hemorrhage from an intracranial tumor was encountered in 7 males and 6 females during a 4-year period. In 5 patients, hemorrhage was responsible for the first signs of a previously unsuspected neoplasm. The intracranial lesion was demonstrated by computed tomography (CT scanning) in each patient. Characteristic CT scan findings included: a neoplastic core (high or low density); small, multifocal clots usually at the margin of the tumor; and, surrounding, often extensive, edema. Enhancement of the tumor tissue with intravenous injection of 60% Hypaque was observed in the 8 patients so studied. The regions which were enhanced had a peripheral distribution corresponding to the site of hemorrhage. Microscopic examination demonstrated 7 glioblastoma multiforme, 1 oligodendroglioma, 4 metastatic carcinomas (including 1 each of bronchogenic carcinoma, melanoma, hypernephroma, and adrenal carcinoma), and 1 hemangiopericytoma. High-grade malignancy and extensive, abnormal vascularity appeared to be predisposing factors.

ISSN:0039-2499    

出版商:OVID    

年代:1979

数据来源: OVID