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

During percutaneous transvenous endomyocardial biopsy, two cardiac transplant recipients developed symptoms of focal cerebral ischemia. Cerebrovascular injury has not been previously associated with endomyocardial biopsy. This procedure should be recognized as one of the causes of stroke following heart transplantation.
Cathet Cardiovasc Diagn 1991 May
PMID:Cerebral ischemia: a complication of right ventricular endomyocardial biopsy. 186 59

In order to investigate the relationship between carotid plaque morphology and symptoms of cerebral ischemia, a prospective clinicopathological study was performed. Ninety consecutive intact carotid plaques obtained from surgery and 43 carotid plaques from cadavers without symptoms of cerebral ischemia were evaluated. Ulceration and mural thrombus were the only morphologic findings statistically correlated to the presence of hemispheric symptoms (p less than 0.02). Intramural hemorrhage was more common in patients with hemispheric symptoms but this difference was not statistically significant (p = 0.31). Plaque causing high degree stenosis had a higher incidence of intramural hemorrhage (p = 0.04) and ulceration (p less than 0.02). Ulceration of plaque plays a major role in the onset of hemispheric symptoms. The results of our study support the hypothesis that in the majority of the cases, hemispheric symptoms are embolic in nature.
J Cardiovasc Surg (Torino)
PMID:Importance of ulceration of carotid plaque in determining symptoms of cerebral ischemia. 201 15

One of the problems in carotid surgery is the intraoperative detection of brain ischemia. None of the methods (EEG; stump pressure) applied so far have been successful. Branston et al. (1974) found a threshold relationship between cortical cerebral blood flow and cortical somatosensory evoked potential (SEP). As the local blood flow fell below about 16 ml/100 g/min a progressive reduction occurred in the amplitude of the cortical evoked potential (N20/P25), implying a fundamental failure of neuronal function in the somatosensory cortex. We have monitored cortical SEP (somatosensory evoked potential) during 734 CEA's (carotid endarterectomies) in order to find an index of risk of incipient cerebral ischemia during carotid cross-clamping, to determine the need for shunting and the causes of early irreversible neurologic deficits. In 59 cases evaluation of SEP was not possible because of technical difficulties. During 586 CEA's no alteration of SEP occurred. However, 4 patients had an immediate postoperative neurologic deficit, while the SEP remained normal. Abnormal SEP occurred in 89 cases and in 6 of these an irreversible loss of SEP was seen. These patients awoke with a new neurologic deficit. We found a reversible abnormal SEP in 83 cases. Reversible changes of SEP occurred mainly during carotid clamping. The diagnostic sensitivity of intraoperative SEP monitoring in predicting neurologic outcome was 60% with a specificity of 100%.
J Cardiovasc Surg (Torino)
PMID:Intraoperative assessment of cerebral ischemia during carotid surgery. 222 58

Somatosensory evoked cervical and cortical potentials (SEP) were analyzed under general anesthesia in 106 patients undergoing carotid endarterectomy. Cortical electrical silence occurred in 5 patients without an inlying shunt; all developed a new neurologic deficit postoperatively. Analysis of the SEP in these patients revealed progredient cerebral ischemia as indicated by an increase in central conduction time (CCT) and a decrease in amplitude of the primary cortical response N20P25 resulting in a complete loss of cortical SEP later on during the clamping period. In 6 patients the insertion of a shunt restored the deteriorated SEP, these patients and those with unchanged SEP after carotid clamping showed an uneventful postoperative recovery. Taking the presence or absence of N20P25 as the sole parameter, the sensitivity of this technique was 83%, specificity 99% and predictability 83%. A normal range for CCT and amplitude of N20P25 during anesthesia and criteria for shunt insertion were developed. The presented monitoring regimen appears to be rational and is based on current concepts of cerebrovascular physiology and pathophysiology.
Thorac Cardiovasc Surg 1985 Dec
PMID:Intraoperative somatosensory evoked potentials as a prognostic factor of neurologic state after carotid endarterectomy. 241 82

We addressed the questions of whether or not phenytoin is a direct vasodilator and if it is selective for brain blood vessels, by studying the relaxant effects of phenytoin on isolated segments of canine basilar, femoral, and brachial arteries. Two dihydropyridine calcium channel blockers, nifedipine and PY 108-068, were also studied for comparison with phenytoin and to test for cerebral selectivity. Blood vessels were contracted with K+, prostaglandin F2 alpha, or serotonin. Phenytoin relaxed the basilar artery with low potency (pD2, 4.71 +/- 0.14) and moderate selectivity. Phenytoin also antagonized Bay K 8644 contractions of basilar artery in a noncompetitive manner. Basilar arteries contracted with 60 mM K+ were the most sensitive to nifedipine (pD2, 8.72 +/- 0.18), followed by the mesenteric (pD2, 8.24 +/- 0.07), femoral (pD2, 8.04 +/- 0.18), and brachial (pD2, 7.66 +/- 0.23) arteries. A similar pattern was observed in potassium-depolarized arteries relaxed by PY 108-068. The calcium dependence of contraction was studied using intact muscles depolarized in 60 mM K+ as well as chemically skinned basilar artery. Mean pD2 values for Ca2+-induced contractions of intact, depolarized arteries were not different (basilar, 4.15 +/- 0.13; mesenteric, 4.04 +/- 0.07; femoral, 4.24 +/- 0.11). The mean Ca2+ EC50 of chemically skinned basilar arteries was 8.7 X 10(-7) M, which is similar to the Ca2+ sensitivity of other skinned smooth muscles. The beneficial effect of phenytoin in treating cerebral ischemia may be due in part to relaxation of vascular smooth muscle. The dihydropyridines were potent smooth muscle relaxants with selectivity for the basilar artery.(ABSTRACT TRUNCATED AT 250 WORDS)
J Cardiovasc Pharmacol 1987 Jul
PMID:Selectivity of phenytoin and dihydropyridine calcium channel blockers for relaxation of the basilar artery. 244 Nov 59

Diagnostic procedures for cerebral ischemia make clear strategies mandatory. Careful recording of case history, internal and neurological investigation either substantiate or make unlikely TIA and stroke. CT scan not only differentiates bleedings, tumors etc from ischemia but also can give very valuable information about the underlying vascular pathology. Multiple lacunes are characteristic of cerebral microangiopathy. Territorial and branch occlusion infarcts mostly indicate embolic occlusion of pial vessels from either cardiac or arterial sources. Endzone and borderline infarctions are seen with high grade stenosis or occlusion of the internal carotid artery. The identification of embolic sources necessitates cardiological (including echocardiography) and angiological (Doppler sonography and in selected cases angiography) investigations. Therapeutic and prophylactic measures depend on the etiology of TIA and stroke and are briefly dealt with.
Thorac Cardiovasc Surg 1989 Aug
PMID:The value of diagnostic procedures in treating ischemic attacks and stroke. 267 95

Cerebral function during carotid endarterectomy can reliably be monitored using somatosensory evoked potentials (SEP). Transcranial Doppler sonography (TCD) is a noninvasive method providing on-line data about cerebral hemodynamics. The combination of both techniques during carotid surgery is helpful in evaluating the hemodynamic ("input") and the functional ("output") consequences of carotid clamping within a short time. In the present report, combined TCD and SEP monitoring early detected left hemispheric ischemia in a 68-year-old woman subjected to left carotid endarterectomy. The impairment of cerebral perfusion occurred before carotid clamping due to an intraoperative thrombosis of the left internal carotid artery as could be revealed after declamping. A temporary shunt was not inserted. Postoperatively, the patient had a new transient neurological deficit. In this case, TCD correctly indicated cerebral ischemia as confirmed by SEP recording. For carotid artery surgery, combined TCD and SEP may be helpful in detecting those patients who will profit from temporary shunting if this is not done routinely.
Thorac Cardiovasc Surg 1989 Apr
PMID:Early detection of cerebral ischemia during carotid endarterectomy using transcranial Doppler sonography and somatosensory evoked potentials. 272 82

Over the past four years, 21 patients have been operated for aneurysms of the thoracic aorta requiring aortic arch reconstruction. The causes of the aneurysms were dissecting aneurysms of the aorta (type A) in 16 patients and atherosclerosis in 5 patients. To prevent cerebral ischemia during operation, selective cerebral perfusion (SCP) (600 ml/min at 25 degrees C) was employed in 11 patients and hypothermic circulatory arrest (HCA) at 15 degrees C in 10 patients. There were three early deaths (14.3%) in the series. There were no serious neurologic complications in either group. The present data suggests that both selective cerebral perfusion SCP and HCA are useful methods for cerebral protection during resection of aortic arch aneurysms, although the latter method has the limitation of restricted cerebral arrest time.
J Cardiovasc Surg (Torino)
PMID:Surgical treatment of aneurysms of the transverse aortic arch. 274 27

Atherosclerotic lesions obstructing the external carotid artery are generally disregarded in the evaluation of patients with symptoms of cerebral ischemia; nevertheless, in the presence of occlusion of the ipsilateral or of both the internal carotid arteries, external carotid artery endarterectomy may be indicated, in order to increase the flow to the brain through collaterals. A lesion of the external carotid artery may be the source of retinal emboli; patients may benefit from surgical treatment of the lesion. The Authors of the present paper operated on 6 such patients, from a total of 230 carotid bifurcation endarterectomies performed in the period between January 1982 and March 1988. Morbidity and mortality were nil and 5 of the 6 patients are free of symptoms after a mean follow-up period of 23 months. One patient died 2 months after surgery due to a myocardial infarction. On the basis of this experience, the Authors discuss indications, surgical techniques and results of the surgical treatment of lesions obstructing the external carotid artery.
J Cardiovasc Surg (Torino)
PMID:Surgical treatment of lesions obstructing the external carotid artery. 274 28

We report on the results of combined carotid endarterectomy and coronary artery bypass grafting in 82 patients. Vascular pathology was severe in these cases: 94% of patients had extensive multivessel coronary artery disease, 29% had unstable angina, 30% had severe left main stem stenosis and all patients had hemodynamically significant stenosis of at least one carotid artery, 13% had an additional occlusion of the contralateral internal or common carotid artery and 26% had severe bilateral carotid artery stenosis. The carotid lesion was asymptomatic in 64% of cases, 24% of the patients experienced previous transient cerebral ischemia and 12% of the patients had a history of completed stroke. Hospital mortality was 7.3%. Neurological deficit occurred in 7.3% but functional impairment was not permanent. Late results have been obtained for 76 survivors at a mean postoperative interval of 29 months. Five year life table survival rate was 86%. Follow-up showed that 3 patients (4%) have died and that 3 patients (4%) experienced a late neurologic event (one TIA; two strokes) but none of these events involved the cerebral cortex on the side of the carotid endarterectomy. The cumulative 5 year stroke free survival rate is 91%. We conclude that combined carotid endarterectomy and coronary artery bypass grafting can be done with an acceptable mortality rate in these critically ill patients and that the postoperative incidence of neurological events is low.
J Cardiovasc Surg (Torino)
PMID:Combined myocardial and cerebral revascularization. A ten year experience. 280 89


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