摘要:

Abstract not available.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

604 Patients with atherothrombotic cerebral ischemic events (transient, 16%: or completed, 84%) referrable either to the carotid or to the vertebral-basilar circulation were entered into a double blind randomized clinical trial (AICLA) to determine whether aspirin (A) (1 g/day) or aspirin (1 g/day) + Dipyridamole (225 mg/day) (AD) would produce a significant reduction in the subsequent (3 years) occurrence of fatal and nonfatal cerebral infarction. Randomization produced remarkably comparable treatment groups and this good comparability was maintained throughout the study. Adherence to the protocol and drug compliance were excellent. Side effects, particularly symptoms of peptic ulcer and hemorrhagic events were significantly (p less than 0.03) more frequent in the two treatment groups containing aspirin. With the exception of patients who withdrew from the study, each patient was followed for 3 years. At the end of the study, the number of fatal and nonfatal cerebral infarctions was 31 in the placebo (P) group, 17 in the A group and 18 in the AD group. Taking into account the duration of follow-up for each patient, these figures correspond to cumulative rates of 18% in the P group and 10.5% in each of the 2 active treatment groups. Analysis with the Mantel Method showed: 1)–A difference at the 6% level between the 3 groups and between P and AD; 2)–A difference at the 5% level between P and A; 3)–No difference between (A and AD; 4)–A difference at the 2% level between the P group and the two treated groups taken together (A + AD). Among other diseases occurring during the trial, the only significant difference concerned myocardial infarction, which was less frequent in the 2 treated groups (P less than 0.05). Subgroup analysis failed to show a significant sex difference in the efficacy of aspirin. It is concluded that, in patients comparable to those defined in the protocol, Aspirin (1 g) has a significantly beneficial effect in the secondary prevention of atherothrombotic cerebral infarction.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Two hundred and three patients, 148 males and 55 females, who during the last month before admission had experienced at least one reversible cerebral ischemic attack of less than 72 hours duration, were randomly assigned to treatment with either acetylsalicylic acid (ASA) 1000 mg daily (101 patients) or placebo (102 patients). The average follow-up period was 25 months. The two treatment groups were comparable with respect to age, sex, associated diseases, risk factors, number and duration of cerebral ischemic attacks. No statistically significant differences were found between the treatment groups as to the primary end point: stroke or death (ASA group 20.8%, placebo group 16.7%). Occurrence of transient ischemic attacks during the treatment period was not reduced by ASA treatment, whereas there was a trend suggesting fewer myocardial infarctions in the ASA group (5.9%) than in the placebo group (13.7%). The difference, however, was not statistically significant (p = 0.10). We were thus unable to demonstrate any favorable influence of ASA 1000 mg daily in patients with reversible ischemic attacks. This study does not, of course, prove that ASA treatment is ineffective in stroke prevention.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

In 6 cats, cerebral infarction was produced by transorbital occlusion of the left middle cerebral artery (MCA). Five animals developed typical cortical infarcts. Eight weeks later, cerebral blood flow (CBF) was determined by 14C-iodoantipyrine autoradiography and the number of intact neurons was counted histologically. Two non-operated cats served as controls. Cortical blood flow in the infarcted hemisphere was reduced by 24.6-74.4% when compared to the flow in the contralateral cortex and in controls. Averaged white matter flow was decreased by 39.1%. Regional cortical flow was gradually reduced from parasagittal regions towards the infarct. In the surrounding of the infarct, cortical perfusion was decreased to 24.8 +/− 9.7 ml/100 g/min, i.e. 19.7% of contralateral flow. Although the infarcts were sharply demarcated macroscopically, the number of cortical neurons decreased gradually from the midline to the peri-infarct zone. A significant linear correlation was found between absolute CBF-values and the number of neurons in areas of the infarcted hemisphere. The homolateral gyrus lateralis had normal neuronal density but flow was reduced by 20%. These findings suggest that the blood flow reduction in tissue surrounding chronic infarcts is due to neuronal cell loss and to functional inactivation caused by damage of afferent fibers.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Eleven freshly removed brains and 20 lenticulostriate arteries (collected at emergency surgery for intracerebral hemorrhage) were examined by electron microscopy in a search for the mechanism of arterial rupture in hypertensive intracerebral hemorrhage. Forty-six of 48 ruptured arteries examined showed severe arteriosclerosis including degenerative changes of the media at or near bifurcations. Atrophy and fragmentation of smooth muscle cells gave them a moth-eaten appearance. Material resembling basement membrane and cell debris was also present in the arterial walls. The above findings were restricted to the middle and distal portions of the perforating arteries. Rupture from a miliary aneurysm was observed in only 2 of the 48 specimens examined. These resembled saccular aneurysms, ultrastructurally. They seemingly formed at a cavity which we strongly felt may have been formed by complete or incomplete subclinical hemorrhages; reabsorption of the hemorrhage from the dissection resulted in the aneurysms seen. Degeneration of smooth muscle cells may be the result of prolonged tension or spasm of the arterial wall as a result of longstanding hypertension.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

This paper describes a method of detecting intracranial aneurysm and arteriovenous malformation (AVM) by analysing weak sounds produced by the blood circulation at the affected part. There is thought to be no turbulence in the normal cerebrovascular system, whereas abnormalities such as aneurysm and AVM sometimes cause turbulence in the blood flow. Thus, a small fraction of the flow energy might be converted into an acoustically detectable noise. For the detection of the sound, sensitive detectors must be applied close to the head since the sound is very weak, and, as in cerebrovascular diseases, the origin of the sound is usually concealed deep inside the hard shelter of the skull. The detection system we used had a gain of 40 to 50 dB greater than that of an ordinary stethoscope. The detection points were the teeth or forehead. Usually the sound started about 160 msec after the ventricular contraction and lasted for 100 to 400 msec. Its frequency component mostly ranged from 400 to 2000 Hz, but the spectrum profile changed according to the position and degree of abnormalities. The uttered sound was very random, which facilitated detection of the position of the sound origin by means of cross correlation methods using a pair of detectors. This method is completely noninvasive, causes no pain to the patient, and might be used even in mass examinations.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

We evaluated immediate anticoagulation of embolic stroke. Of 39 patients suffering a focal cerebral ischemia caused by a cardiac embolus, 38 were submitted to CT within 24 hours after onset. Twenty-one patients received direct full anticoagulation and, in 10 patients, treatment was delayed because of hemorrhagic infarction on initial CT (3 cases), cardiac cause 24 hours or more after stroke onset, or treatment delay without specific reason (6 cases). Eight patients with severe deficit were not anticoagulated because of hemorrhagic signs on initial CT, impaired consciousness, or general contra-indications to such treatment. Twenty-one follow-up CT-scans were performed under full anti-coagulation, and in only 2 cases hemorrhagic infarction was noticed without clinical deterioration. No clinical worsening attributable to anticoagulant treatment was observed during the three week observation period. It is concluded that direct anticoagulation therapy does neither induce hemorrhagic infarction nor cerebral hemorrhage in patients with embolic stroke nor does it cause clinical deterioration.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Using the canine thalamic infarction model, we have investigated the effects of 10 ml/kg of 20% mannitol on the hemodynamics of the ischemic brain. Mannitol was found to cause an increase in rCBF, but it is not marked in animals with severe ischemic foci. Increases were statistically significant in the animals with moderate ischemia. Increases in rCBF due to mannitol administration lasted for about 1 hour, as did the rise in serum osmolarity. The actual relationship between these two parameters, remains unclear.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

There is an unusual vascular network at the base of the brain in patients with moyamoya disease. We detected various histologic lesions in the perforating arteries of 22 patients. Vessels showing rupture ranged from 50 to 530 microns in diameter; they were dilated, some had fibrin deposits in the wall, fragmented elastic laminae and attenuated media. Non-ruptured perforating arteries (diameter 200 to 550 microns) revealed microaneurysm formation, focal fibrin deposits and marked attenuation of the wall thickness with diminution of the elastic lamina. These changes seem to predispose to rupture of perforating arteries. Stenotic changes such as fibrous intimal thickening, collapse of the lumen and thrombosis were detected in 14 out of 22 cases. Morphometric analysis of perforating arteries indicated that arteries showing extreme degrees of stenosis or dilatation were more frequent in the patients with moyamoya disease than in the control cases. Dilative arteries were more frequent in the young patients and stenotic vessels were, in contrast, less frequent in the young patients.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

We studied 4 patients with bilateral carotid artery occlusion who suffered delayed TIAs in one of the occluded internal carotid or common carotid areas. Hemodynamic mechanisms were prominent in two patients, in head turning and orthostatic hypotension. In the other two cases, embolic phenomena through the homolateral external carotid collateral pathways were probable, because this artery (or the common carotid artery) showed atheromatous stenosis and major collateral supply to the brain and retina. Different mechanisms may be responsible for further ischemia after bilateral occlusion of carotid arteries.

ISSN:0039-2499    

出版商:OVID    

年代:1983

数据来源: OVID