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Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sixty-eight patients (7.1% of all cases) underwent bilateral carotid thrombo-endarterectomy, with one peroperative death due to permanent vascular cerebral ischemia. Two patients were re-operated (saphenous vein) for a thrombosis which had given rise to a totally regressive transient ischemia. The usual surgical technique was not modified for bilateral lesions, and the follow-up was similar. The evolutive risk of bilateral lesions was higher than that for isolated lesions as the risk of an accident after unilateral surgery in bilateral cases remained higher. As regards the surgical technique, we did not observe significant differences between the stump pressures according to the side operated. A one-week interval between the two surgical stages seems necessary and sufficient. Operative indications are studied except in cases of bilateral lesions which are asymptomatic or with former TIA, where surgery is considered mandatory.
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PMID:Surgical treatment of bilateral carotid artery lesions. 652 9

The authors discuss the indications for emergency carotid endarterectomy, based on their experience between 1956 and 1975 when 15 patients with completed stroke and internal carotid occlusion (Group I) underwent this operation, and after 1975 when emergency revascularization was performed in 22 patients with unstable neurological deficit (Group II) and 21 patients with TIA's associated with preocclusive internal carotid stenosis (Group III). The good early and late results show that surgery was indicated in these cases. An attempt to identify the patients at high risk of acute ischemia on the basis of clinical or anatomical findings is made to ascertain the physiopathologic patterns of cerebral ischemia.
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PMID:Emergency carotid surgery. 652 8

Repeated CBF-measurements can be performed after inhalation or intravenous injection of 133Xe. After the development of a bicompartmental model by Obrist et al. in 1975 atraumatic CBF-measurements became widely used but there were still some difficulties concerning the sensitivity of different flow-indices towards CBF changes in normals under test conditions or ischemia in stroke patients. Due to the "slippage phenomenon" mostly noncompartmental flow-indices are used for the detection of ischemic brain areas. In this study a scintillation camera, that is usually available in every nuclear medicine department, was used for atraumatic CBF-studies. A collimator consisting of hexagonal lead tubes (septa 0.2 mm thick; FWHM 1.7 cm in 10 cm) was constructed for this purpose. The obtained counting rate varied between 2432 and 9081 cps over the whole hemisphere and 116-1094 cps in regions of approximately 2.5 X 2.5 cm. In 31 patients with CVD CBF was measured with the intracarotid (i.c.) technique and 1 hour later after i.v. 133Xe-injection. Intravenous flow values were comparable to those obtained after i.c. 133Xe injection (fB X MFr = 0.904; p less than 0.001). In 12 of the used 13 regions also significant correlation coefficients were found. In order to estimate the reproducibility of the intravenous injection method CBF-measurements were performed in both hemispheres of 10 patients on two consecutive days. Highly significant correlation coefficients were found for hemispheric blood flow (r = 0.933; p less than 0.001) and temporal, frontotemporal, temporoparietal and praecentral regions, while in the high parietal, frontal and occipital region lower reporducibility was found. Normal CBF-values were obtained from 12 healthy volunteers (MF right hemisphere: 50.7 +/- 4.6 ml/100 g/min; MF left hemisphere: 50.6 +/- 4.6 ml/100 g/min). MF did not show any hyperfrontality, while F1 and the ISI gave highest flow values in frontal regions. The clinical status of 76 patients suffering from cerebral ischemia (68 with flow disturbances in one hemisphere, 8 with vertebrobasilar insufficiency) was estimated by a semiquantitative scorescale at time of admission and after an observation period lasting from 6 to 35 months. In each case CBF was measured twice: once in the subacute stage after onset of symptoms and once after the observation period. The duration of neurologic symptoms (TIA, RIND, CS) was compared to the obtained flow values. A significant relationship was found between the duration of symptoms and impairment of CBF, thus showing the prognostic value of intravenous CBF measurements.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Noninvasive measurement of cerebrovascular circulation with the scintillation camera. A neurologic nuclear medicine study]. 659 71

Repeated cerebral blood flow (CBF) measurements with xenon-133 inhalation and single photon emission tomography were performed in a patient suffering a minor stroke with subsequent orthostatic-provoked transient ischemic attacks (TIA's). Angiography revealed a thread-like internal carotid artery and an occluded external carotid artery on the side of the ischemic neurological symptoms. Computerized tomography and technetium-99m-pertechnetate brain scintigraphy 2 weeks after stroke were both normal. Before reconstructive vascular surgery, resting CBF showed a hypoperfused area corresponding to the clinical symptoms. Diamox (acetazolamide, 1 gm) increased CBF by 24% in the unaffected hemisphere, whereas even a slight decrease in flow ("steal") was seen in the maximally affected region. In contrast, theophylline (220 mg) reduced CBF in the unaffected hemisphere and caused a slight increase in the previously maximally hypoperfused area ("inverse steal"). After surgery, the flow pattern practically normalized and the TIA's disappeared. The CBF measurements before surgery and also after the injection of the vasoactive drugs indicated that focal hemodynamic insufficiency elicited the TIA's, and pointed at a low mean arterial blood pressure of about 35 mm Hg in the affected hemisphere. The perioperative finding of a mean blood pressure in the internal carotid artery of 31 mm Hg on the symptomatic side confirmed that the brain tissue had a severely reduced perfusion pressure. On clamping the artery, a stump pressure of 22 mm Hg and electroencephalogram flattening was noted, so a temporary internal shunt was inserted. The findings demonstrate that preoperative CBF measurements, including studies of the regional vasoreactivity, may identify patients with hemodynamic TIA's. These patients are at particular risk of developing cerebral ischemia during carotid endarterectomy, as any further compromise of the inflow may precipitate frank ischemia.
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PMID:Hemodynamically significant stenosis of the internal carotid artery treated with endarterectomy. Case report. 660 27

The pathogenesis and clinical manifestations of complete and focal cerebral ischemia are described. Special attention is paid to the recognition of TIA's, the non-invasive diagnostic possibilities (Doppler ultrasonic imaging, digital subtraction angiography, cranial computerized tomography), the medicamentous and surgical prevention of stroke. Cranial computerized tomography is important for the differential diagnosis of cerebral ischemia/cerebral hemorrhage. The pray and rehabilitation of patients with stroke are discussed. The possibilities of pharmacotherapy are critically reviewed.
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PMID:[Diagnosis and therapy of cerebrovascular ischemia]. 663 41

Transient cerebral ischemia and stroke may occur despite previous occlusion of the artery supplying the appropriate part of the brain. After occlusion of the internal carotid artery, emboli may pass from the "stump" of the occluded artery to later produce transient cerebral ischemia or a stroke. Transient cerebral ischemia and stroke are due to a variety of conditions, some of which are strongly correlated with platelet thromboembolism, while others have little primary relation to thrombosis. The impact of this on therapeutic considerations is obvious. Thromboembolism related to myxomatous degeneration of the mitral valve (mitral valve prolapse) is a factor to consider in determining the cause of a stroke in a younger person. The prognosis for the different varieties of threatened stroke is incompletely known. When due to arteriosclerosis of the large cerebral arteries, transient cerebral ischemia and minor strokes pose a cumulative threat for a major stroke or death of 13% in the first year, 22% in the second year and 30% in the third year.
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PMID:Randomized trial of therapy with platelet antiaggregants for threatened stroke. 2: Observations on the pathogenesis and natural history of threatened stroke. 698 64

Seventy-three patients with an angiographically identified asymptomatic stenosis (greater than 50%) and/or ulceration of the common carotid bifurcation have been followed from 6 months to 10 years (average 4 years). All patients had previously undergone contralateral carotid endarterectomy for a transient ischemic attack (TIA) or minor stroke in that carotid territory. During follow-up, 22 patients (30%) developed new symptoms of cerebral ischemia. Twelve developed ischemia referable to the previously asymptomatic side (10 TIA's, 2 strokes). Six developed recurrent ischemic symptoms in the territory of the previously symptomatic and operated carotid artery (2 TIA's, 4 strokes). Five developed ischemia in the vertebro-basilar territory (2 TIA's, 3 strokes). Thirteen patients (17%) died during follow-up, including 6 from cardiovascular disease and 3 from stroke. In our series the incidence of stroke in the territory of a significant asymptomatic carotid plaque was low (3%). Patients were as likely to develop stroke in the territory of a previously operated carotid artery (5%) with asymptomatic carotid lesions is to keep them under review and to consider endarterectomy only if appropriate ischemic symptoms (which are most likely to be TIA's) develop.
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PMID:The natural history of asymptomatic carotid bifurcation plaques. 710 45

Platelet scintigraphic examination using indium-111 was performed on 12 patients with cerebral ischemia. Of these patients 5 had a history of TIA, 3 had a prolonged reversible neurologic deficit (PRIND), 3 cases were presented with a completed stroke and 1 patient suffered from a suspected venous thrombosis of the sinus sagittalis superior. In total 8 cases showed pathological platelet accumulations in the vessel clinically affected, 5 extracranially and 3 intracranially. In the other 4 cases the platelet scintigraphy was normal. The cases with TIA showed pathological platelet accumulations in the appropriate vessel, even if the angiogram was normal. On the other hand platelet scintigraphy did not show any abnormality in 2 patients with an occlusion of the carotid artery. So platelet scintigraphy might be useful in the detection of small arterial lesions producing small strokes, and which remain undetected by other diagnostic methods.
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PMID:[Platelet scintigraphy using indium-111]. 712 82

In a group of 132 patients with transient ischemic attacks ((TIAs) 7 patients (4 men, 3 women, ages 64 to 81) had TIAs preceded by hypotension. The average fall of mean blood pressure during an attack was 26.4 +/- 5.5 mm Hg (SD). Only one of these patients had a TIA which was not preceded by hypotension. This episode occurred during a paroxysm of coughing. All 7 of these patients had hypertension, and cerebral arteriography performed in 4 of the 7 revealed hemodynamically significant carotid artery stenosis. Each of the 4 patients developed hypotension and a TIA after the procedure. Twenty of the other patients had hypotensive episodes but did not develop focal neurological deficits. None of these patients had carotid artery stenosis. This study suggests that hypertensive patients with carotid artery stenosis may be at risk to develop focal cerebral ischemia during acute hypotensive episodes.
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PMID:Transient ischemic attacks associated with hypotension in hypertensive patients with carotid artery stenosis. 724 1

Transient cerebral ischemia was the initial manifestation of a ruptured intracranial dermoid cyst in a young adult male. The ischemia could have resulted from vasospasm caused by release of the contents of the dermoid cyst into the subarachnoid space or from other local effects of the tumor. The role of computed tomography in the evaluation of patients with transient cerebral ischemia is discussed.
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PMID:Case report. Transient cerebral ischemia as a manifestation of ruptured intracranial dermoid cyst. 732 Feb 99


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