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At least 1,531 records · Page 85Linked to original sources
PubMed2001

Severe hemodynamic impairment and border zone--region infarction.

PURPOSE: To investigate the relationship between the patterns of cerebral infarction that have been associated with hemodynamic impairment and the presence of severe chronic hemodynamic compromise (increased oxygen extraction fraction) in a large prospectively enrolled group of patients with carotid artery occlusion. MATERIALS AND METHODS: At enrollment in a prospective study of cerebral hemodynamics, 110 patients with carotid occlusion underwent (a) positron emission tomography for the measurement of cerebral oxygen extraction fraction and (b) computed tomographic (CT) or magnetic resonance (MR) examinations of the brain. Infarcts were categorized retrospectively by vascular territory, location, and pattern. The association of these findings with hemodynamic impairment (increased oxygen extraction fraction) was investigated. RESULTS: No border zone-region infarctions were found in 35 asymptomatic patients. In 75 symptomatic patients, cortical border zone-region infarction was found in seven of 36 patients with increased oxygen extraction fraction, and in two of 39 with normal oxygen extraction fraction (P =.08, difference not significant). The pattern of multiple white matter lesions arranged parallel to the lateral ventricle was observed only in symptomatic patients with increased oxygen extraction fraction (eight of 36 patients; P =.002; sensitivity, 22%; specificity, 100%). This finding was more frequent with MR imaging (seven of 14 patients) than with CT (one of 22 patients). CONCLUSION: Multiple white matter infarctions, arranged parallel to the lateral ventricle, are associated with severe hemodynamic impairment. This pattern of infarction is likely due to a hemodynamic mechanism.

Adult↗
PubMedDate not supplied

Fatal cerebral embolism following aorto-coronary bypass graft surgery.

In a case of fatal cerebral embolic infarction following aorto-coronary bypass graft (ACBG) surgery, postmortem examination revealed thrombosis of the vein grafts to the left circumflex and left anterior descending coronary arteries. Continguous with the thrombus in the graft to the circumflex artery was thrombotic material adherent to the aortic sutures and extending several millimeters into the lumen of the aorta. A nonadherent thrombus of similar histologic character was found in the right middle cerebral artery, associated with localized brain infarction. In addition to the risks of cerebral complication associated with other types of open-heart surgery, the location of the vein grafts in patients undergoing ACBG operations seems to offer a unique mechansim for the occurrence of systemic and cerebral embolism, which may be operational in other cases.

Coronary Artery Bypass↗
PubMed2003

Neuroprotective action of tacrolimus (FK506) in focal and global cerebral ischemia in rodents: dose dependency, therapeutic time window and long-term efficacy.

Tacrolimus (FK506), a potent immunosuppressive drug, is effective in attenuating brain infarction after cerebral ischemia. However, there has been no report characterizing the neuroprotective action and therapeutic time window of tacrolimus systematically using different types of stroke models and extended observation periods. Therefore, we evaluated the neuroprotective effect of tacrolimus in three different animal models of cerebral ischemia: transient and permanent focal ischemia in rats and transient global ischemia in gerbils. Tacrolimus at doses higher than 0.1 mg/kg (i.v.) produced a statistically significant reduction in ischemic brain damage following permanent and transient focal ischemia in rats when administered immediately after the onset of ischemia. Tacrolimus (1 mg/kg, i.v.) demonstrated similar neuroprotective activity even after delayed administration (2 h after permanent or 1 h after transient focal ischemia). The neuroprotective effect of tacrolimus was still present 2 weeks after transient focal ischemia and 1 week after permanent focal ischemia. After transient global ischemia in gerbils, tacrolimus (1 mg/kg, i.v.) given immediately after reperfusion also produced long-lasting neuroprotective effects with a protective time-window of 1-2 h. Taken together, the results clearly indicate that tacrolimus exerts potent, long-term neuroprotective effects with a favorable therapeutic time-window, regardless of the model of cerebral ischemia. These results strengthen the notion that tacrolimus might be of clinical value for the treatment of acute stroke.

Animals↗
PubMedDate not supplied

Risk factors for dementia in the cardiovascular health cognition study.

BACKGROUND: The Cardiovascular Health Cognition Study has evaluated the determinants of dementia among 3,608 participants that had a magnetic resonance imaging (MRI) of the brain in 1991 and were followed to 1998-1999. METHODS: There were 480 incident dementia cases, 330 (69%) were classified as Alzheimer's disease (AD). RESULTS: In univariate analysis, low scores on the Modified Mini-Mental State Examination (3MSE) and on the Digit Symbol Substitution Test as well as declines in scores over time prior to the development of dementia were significant predictors of dementia. A high ventricular grade on the MRI (atrophy) as well as high white matter grade, a number of brain infarcts on the MRI were all determinants of dementia. Apolipoprotein E epsilon4 (Apo(E-4)) was also a powerful predictor of dementia. In a multivariate Cox proportional hazards model controlling for race, gender and grade, the hazard ratios for age (1.1), 3MSE score (0.9), ventricular size (1.4), white matter grade (1.8), presence of large infarcts >3 mm (1.3) and Apo(E-4) (2.1) were significant predictors of dementia. The combination of an Apo(E-4) genotype, 3MSE score <90, > or =5 ventricular grade, > or =3 white matter grade at the time of the MRI were associated with a 17-fold increased risk (95% CI: 8.6-34.9) of dementia as compared to individuals with none of the above attributes. CONCLUSIONS: Measures of cognition, Apo(E-4) and MRI of the brain are strong predictors of both dementia and of AD.

Aged↗
PubMedDate not supplied

Cranial computerized tomography in systemic lupus erythematosus.

Twelve patients with active central nervous system systemic lupus erythematosus (CNS SLE) and 11 patients without CNS involvement, all taking corticosteroids, were studied by computerized tomography (CT). Thirty CT scans on 23 individuals were performed and read blindly and independently by 2 neuroradiologists with an 86% correlation. Minimal to moderate atrophy was the most frequent finding, both in CNS SLE and controls, severe atrophy seen in 1 patient only, and no atrophy in 3 patients and a single control. Of the 6 patients who had repeated scans, 4 showed no change in the degree of atrophy, 1 had more and 1 less atrophy. Three patients had evidence of multiple brain infarcts on scan with or without associated cerebral atrophy. Sequential scans in 1 of these patients showed total resolution of the infarcts after 30 months. Thus, there was no correlation between the presence of cerebral atrophy on CT scan and CNS SLE. Rather our findings suggest that steroids may be the cause of atrophy.

Adolescent↗
PubMed1993

[A case of perinatal cytomegalovirus infection with severe progressive brain atrophy].

A 2-month-old girl had focal tonic convulsions. Brain CT showed no abnormalities on admission. Three weeks later she got a severe epileptic status. T 1-weighted MRI demonstrated low intensity areas in the right occipital and left frontal regions, and enhanced CT demonstrated low density areas in the same region. An increase of CMV antibody titer in serum suspected CMV infection associated with brain infarction. Then gamma-globulin was given in addition to PB, CBZ, and VPA, resulting in suppression of seizures. At 9 months of age, she had right tonic hemiconvulsions. An increase of CMV IgM antibody titer showed reactivation of CMV infection. Acyclovir and gamma-globulin were given, and her seizures were controlled. However, she showed progressive motor disability with spastic muscle tonus. CT and MRI showed a severe progressive atrophy of the cerebrum and brain stem.

Atrophy↗
PubMed1996

[The prognostic value and evolution of blood pressure during an acute phase of stroke].

We studied the prognostic influence and evolution of blood pressure during the acute phase of stroke in 89 patients (50 men and 39 women) with an average age of 69.4 +/- 10.8 years. Seventy-two were diagnosed as having ischaemic infarct and 17 as having spontaneous intracerebral haemorrhage. Blood pressure was taken every four hours for twelve days. Clinical situation was evaluated using the Rankin scale. Systolic and diastolic blood pressure progressively decreased without needing any medication in the first two weeks of evolution. The decrease was greatest in hypertense patients and in those with left ventricle hypertrophy. We found the initial figures for systolic and diastolic blood pressure significantly higher in those patients with brain infarct who had not died and in those in a better functional position the second week of evolution. Blood pressure did not influence the prognosis of intracerebral haemorrhage patients.

Acute Disease↗
PubMed1996

Clinical impact of insulin resistance syndrome in cardiovascular diseases and its therapeutic approach.

In subjects with coronary artery diseases (obstructive and vasospastic angina pectoris (AP)) who have no diabetes, hypertension, obesity and physical inactivity, insulin sensitivity was significantly reduced with compensated hyperinsulinemia on OGTT. Insulin resistance significantly correlated with coronary atherosclerosis score. In vasospastic AP (VAP), those who fulfilled more than 3 risk factors out of 5 (hyperinsulinemia, obesity, glucose intolerance, hypertension, dyslipidemia) consist of 70 and 40% for smokers and nonsmokers respectively. Insulin resistance syndrome who fulfilled all the criteria was 9-10% for VAP. In atherothrombotic brain infarction (ATTI) with the same exclusion criteria, the similar insulin resistance and hyperinsulinemia have been observed, but not in embolic (cardiac origin) or lacunar infarction. In ATTI, high TG and apo B with low HDL-chol were noted in blood. In essential hypertension without diabetes and obesity, hyperinsulinemia was noted in 25-35% and insulin resistance in 56-88%. Reduction of blood pressure with alpha blocker (bunazosin), ACE inhibitor (cilazapril), long-acting Ca++ blocker (amlodipine) significantly improved lowered insulin sensitivity. Insulin resistance rather than hyperinsulinemia is more closely associated with blood pressure. Cardiovascular diseases (vasospastic and obstructive AP, brain cortical artery diseases) are prone to develop diabetes because of insulin resistance and also promote the generation of cumulative risk factors resulting in a vicious cycle. Efforts to alleviate insulin resistance is crucial for the primary and secondary prevention of cardiovascular diseases.

Adrenergic alpha-Antagonists↗
PubMedDate not supplied

[Atherosclerosis and brain circulation].

INTRODUCTION: Atherosclerosis affects the vascular system in a diffuse way and its is clearly implicated in some of the most prevalent diseases in western countries such as cerebrovascular and cardiovascular diseases. Knowing more about the underlying pathogenic mechanisms may contribute to a better understanding of this entities and the development of therapies for both its treatment and prevention. DEVELOPMENT: We review herein the concepts included in the term atherosclerosis, the growth of the atheromatous plaque and its complications and the cellular mechanisms which intervene in its development. We analyze how it influences brain hemodynamics and its implication in cerebrovascular ischemic disease paying attention to the dissimilarities with other vascular territories and the clinical syndromes which derive from its development on different vascular structures. CONCLUSIONS: Under the concept of ischemic cerebrovascular disease we can find a group of heterogeneous clinical syndromes, usually associated to different etiopathogenic mechanisms: cardioembolic, atherothrombotic or hemodynamic. Although their risk factors may be common, these processes are clearly different form each other. Therefore including ischemic brain infarctions all together without attending to their etiology may produce important methodological biases when interpreting the results in clinical trials or other studies, and may also be a suitable explanation for differences between authors.

Arteriosclerosis↗
PubMed2004

[The dynamics of recovery processes in ischemic stroke as shown by comparison of clinical and tomographic indices].

The aim of this study was to assess the relation between MRI-changes of the brain infarction (BI) and neurological status in patients with hemispheric ischemic stroke. Clinical and MRI examinations were performed in 70 patients (aged from 46 to 89 years, 37 females, 33 males) 1, 3, 7-10, 14 and 21-30 days (in all cases) and 2, 6 and 12 months (n=29) after stroke onset. On FLAIR-images the criteria of assessment of cystic and gliosis transformation were determined. The tissue contrast of BI is assigned mainly to brain edema and hemorrhagic transformation, the cystic and gliosis transformation visualized in 1-2 months after stroke onset. The ratio between cystic and gliosis transformation correlated with clinical dynamics and the size of BI.

Aged↗
PubMed1996

Agreement on disease-specific criteria for do-not-resuscitate orders in acute stroke. Members of the Canadian and Western New York Stroke Consortiums.

BACKGROUND AND PURPOSE: The do-not-resuscitate (DNR) order is a mechanism of withholding cardiopulmonary resuscitation (CPR). The lack of DNR guidelines specific for acute stroke may result in many stroke patients receiving unnecessary and futile resuscitation and ventilator-assisted breathing. METHODS: A prospective multicenter evaluation of disease-specific criteria for DNR orders in acute stroke was initiated using a modified Delphi process. The participants were the Canadian and Western New York Stroke Consortium members who are closely involved in caring for acute stroke patients and conducting clinical trials at the academic centers. Previously published provisional criteria were reviewed by the participants. Modifications were made to the criteria until statistically significant agreement (P < .05, z score, or 67% similar answers) was achieved. RESULTS: Disease-specific criteria for DNR orders in acute stroke were discussed by 26 physicians in three rounds of the opinion survey. An agreement was reached that a "no resuscitation" decision is appropriate when any two of the following three clinical criteria are present (the degree of agreement is given in parentheses): severe stroke (88%, P = .00007), life-threatening brain damage (73%, P < .01), and significant comorbidities (92%, P = .00003). The poor prognosis implied by these criteria should be discussed whenever possible among physician(s), the patient, and family members before the decision to withhold CPR is made. Eighty-one percent of the participants agreed that these disease-specific criteria are appropriate for clinical use (P = .0008). CONCLUSIONS: Disease-specific criteria for DNR orders were developed to supplement general DNR policies for patients with hemispheric brain infarction and intracerebral hemorrhage during the first 2 weeks of stroke. A significant agreement was reached by a panel of physicians that patients with acute stroke should not be resuscitated if these disease-specific criteria are met.

Acute Disease↗
PubMed2001

Cooling for acute ischemic brain damage (cool aid): an open pilot study of induced hypothermia in acute ischemic stroke.

BACKGROUND AND PURPOSE: Hypothermia is effective in improving outcome in experimental models of brain infarction. We studied the feasibility and safety of hypothermia in patients with acute ischemic stroke treated with thrombolysis. METHODS: An open study design was used. All patients presented with major ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score >15) within 6 hours of onset. After informed consent, patients with a persistent NIHSS score of >8 were treated with hypothermia to 32+/-1 degrees C for 12 to 72 hours depending on vessel patency. All patients were monitored in the neurocritical care unit for complications. A modified Rankin Scale was measured at 90 days and compared with concurrent controls. RESULTS: Ten patients with a mean age of 71.1+/-14.3 years and an NIHSS score of 19.8+/-3.3 were treated with hypothermia. Nine patients served as concurrent controls. The mean time from symptom onset to thrombolysis was 3.1+/-1.4 hours and from symptom onset to initiation of hypothermia was 6.2+/-1.3 hours. The mean duration of hypothermia was 47.4+/-20.4 hours. Target temperature was achieved in 3.5+/-1.5 hours. Noncritical complications in hypothermia patients included bradycardia (n=5), ventricular ectopy (n=3), hypotension (n=3), melena (n=2), fever after rewarming (n=3), and infections (n=4). Four patients with chronic atrial fibrillation developed rapid ventricular rate, which was noncritical in 2 and critical in 2 patients. Three patients had myocardial infarctions without sequelae. There were 3 deaths in patients undergoing hypothermia. The mean modified Rankin Scale score at 3 months in hypothermia patients was 3.1+/-2.3. CONCLUSION: Induced hypothermia appears feasible and safe in patients with acute ischemic stroke even after thrombolysis. Refinements of the cooling process, optimal target temperature, duration of therapy, and, most important, clinical efficacy, require further study.

Acute Disease↗
PubMed2001

Cerebral vasculitis and ischaemic stroke in Behçet's disease: report of one case and review of the literature.

INTRODUCTION: Behçet's disease (BD) is a multisystemic, recurrent, inflammatory disorder. Neurological involvement is well-known but cerebral vasculitis and ischaemic stroke are unusual. CASE DESCRIPTION: A 43-year-old male patient presented with acute left hemiparesis, he had recurrent oral aphthae and scrotal ulcerations. Two episodes of transient brainstem ischaemia and an episode of right hemiparesis were reported in the past 2 years. Cranial magnetic resonance (MR) imaging showed a right striatocapsular infarction and multiple segmental stenosis, fusiform enlargement and beading of the arteries of the polygone of Willis were seen on angiography. Cerebro-spinal fluid (CSF) examination disclosed lymphocytic pleocytosis. Skin pathergy test was positive. A diagnosis of BD with cerebral vasculitis was made and immunosuppressive therapy was started. Some improvement of the arterial lesions on MR angiography and normalization of CSF were observed after 1 year of treatment. DISCUSSION: Low grade chronic meningo-encephalitis is the core neuropathological process in neuro-Behçet's disease. Nevertheless BD is a systemic disease known to cause vasculitis and can exceptionally lead to cerebral vasculitis and brain infarction. While BD is usually not part of the differential diagnosis of cerebral vasculitis, it should be borne in mind especially in endemic areas of the disease and in patients from these areas.

Adult↗
PubMed1997

[Familial hypercholesterolemia: involvement of cerebral major arteries (communication 1)].

Ultrasound dopplerography, MR tomography were performed to assess the brain, major cerebral arteries and audiometry was conducted to study cochleovestibular system in 38 patients aged 16-63 years with heterozygous family hypercholesterolemia. Vascular disorders and defects in the white brain matter (in patients with transitory hypertension) were registered. Complications of cerebral atherosclerosis (brain infarction, perception cochleovestibular alterations) contributed to aggravation of ischemic heart disease. Patients with heterozygous family hypercholesterolemia should be observed and treated by cardiologist, neuropathologist and psychoneurologist to prevent cardiocerebral complications.

Adolescent↗
PubMed1997

Cerebellar atrophy with basilar artery occlusion.

Small and large vessel occlusive disease leading to chronic cerebral ischemia and brain atrophy is a concept originating in the last century. The modern notion of acute brain infarct, however, appears to have eclipsed the idea of chronic hypoperfusion as an important factor in ischemic cerebral damage. We present a patient history featuring recurrent episodes of acute posterior circulation infratentorial ischemia in addition to a progressive cerebellar syndrome over a course of several years. Laboratory work-up including cerebral angiography, repeated CT and MR scanning revealed basilar artery occlusion, a pontine infarct and a subsequently developing cerebellar atrophy without signs of cerebellar infarction. Findings indicating causes of cerebellar atrophy other than ischemia could not be elicited. We offer the hypothesis that basilar artery occlusion, inducing subsequent chronic ischemia, is the most likely cause of the cerebellar atrophy observed in our case.

Adult↗
PubMed1992

Effect of cerebral blood flow and cerebrovascular autoregulation on the distribution, type and extent of cerebral injury.

Global cerebral blood flow (GCBF) is low in the human neonate compared to the adult. It is even lower in mechanically ventilated, preterm infants: 10-12 ml/100 g/minute, a level associated with brain infarction in adults. The reactivity, however, of global CBF to changes in cerebral metabolism, PaCO2, and arterial blood pressure is normal, except following severe birth asphyxia, or in mechanically ventilated preterm infants, who subsequently develop major germinal layer hemorrhage. The low level of cerebral blood flow (CBF) matches a low cerebral metabolism of glucose and a relatively small number of cortical synapses in the perinatal period. It has not been possible to define a threshold for GCBF below which electrical dysfunction or brain damage occurs (such as white matter and thalamic-basal ganglia necrosis). Three explanations for the lack of clear relation between GCBF and electrical brain activity of the preterm infant must be examined more closely: 1) low levels of CBF are adequate; 2) GCBF does not adequately reflect critically low perfusion of the white matter, and 3) acute white matter ischemia does not result in electrical silence. Two clinical patterns of brain damage following asphyxia may be explained by changes in the blood flow distribution induced by asphyxia: brainstem sparing and parasagittal cerebral injury. Hours to days after severe asphyxia, a state of marked global hyperperfusion may prevail. It is associated with poor neurological outcome and may be an entry point for trials of interventions aiming sat blocking the translation of asphyctic injury to cellular death and tissue damage.

Brain Ischemia↗
PubMed1996

Short echo time proton magnetic resonance spectroscopic imaging of macromolecule and metabolite signal intensities in the human brain.

A novel approach is presented for imaging macromolecule and metabolite signals in brain by proton magnetic resonance spectroscopic imaging. The method differentiates between metabolites and macromolecules by T1 weighting using an inversion pulse followed by a variable inversion recovery time before localization and spectroscopic imaging. In healthy subjects, the major macromolecule resonances at 2.05 and 0.9 ppm were mapped at a nominal spatial resolution of 1 x 1 x 1.5 cm3 and were demonstrated to be highly reproducible between subjects. In subacute stroke patients, a highly elevated macromolecule resonance at 1.3 ppm was mapped to infarcted brain regions, suggesting potential applications for studying pathological conditions.

Adult↗
PubMed1992

Usefulness of the resting electrocardiogram in the elderly.

The ECG is useful in diagnosing acute myocardial infarction and unrecognized Q-wave myocardial infarction in the elderly. Unrecognized myocardial infarction and myocardial infarction associated with clinical symptoms have a similar incidence of new coronary events. Ischemic ST-segment depression on the resting ECG is associated with an increased incidence of new coronary events. The ECG is useful in the diagnosis of LV hypertrophy but is less sensitive and less specific than echocardiography in diagnosing LV hypertrophy. ECG LV hypertrophy is associated with an increased incidence of cardiovascular events in the elderly. However, echocardiographic LV hypertrophy is more sensitive in predicting new coronary events, atherothrombotic brain infarction, and congestive heart failure than is ECG LV hypertrophy. The ECG is also useful in diagnosing conduction defects and arrhythmias in the elderly. In the elderly, left bundle branch block, intraventricular conduction defect, Type II second-degree atrioventricular block, and pacer rhythm are associated with an increased incidence of new cardiac events, whereas right bundle branch block, left anterior fascicular block, and first-degree atrioventricular block are not. In the elderly, atrial fibrillation is associated with an increased incidence of thromboembolic stroke and new cardiac events. Premature atrial complexes and paroxysmal supraventricular tachycardia are not associated with an increased cardiac risk. Complex ventricular arrhythmias on the resting ECG are associated with an increased incidence of cardiac events in elderly patients with heart disease but not in elderly patients without heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗