ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and PurposeWe studied the frequency and grade of atherosclerotic changes in the thoracic aorta and their significance as embologenic lesions in patients with stroke.MethodsUsing transesophageal echocardiography, we evaluated complicated lesions in the thoracic aortas of 62 patients who met our clinical criteria for embolic stroke. A complicated lesion was defined as a raised lesion with an irregular surface or acoustic shadow based on a comparative study of echocardiographic and histopathologic findings. The results were compared with plain radiographic findings and in some cases with computed tomographic or aortographic findings.ResultsTwenty-six patients (42%) showed complicated aortic arch lesions on echocardiogram. Transesophageal echocardiography brought us more abundant information than other techniques. Aortic knob calcification by plain radiography correlated well with the presence of echocardiographically complicated lesions, suggesting its utility for rough screening of atherosclerotic changes. Fifty-two patients had other potential embolic sources in the heart or cervical arteries. Among the remaining 10 patients without extra-aortic embolic sources, three showed complicated lesions and were diagnosed as having aortogenic embolic stroke.ConclusionsAortic atherosclerosis should be recognized as an embolic source of stroke and the advantage of transesophageal echocardiography recognized in its evaluation.

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and PurposeTo determine the effect of a lipid-lowering agent and/or a low-dose antithrombotic agent on the progression of early-stage carotid atherosclerosis, noninvasive B-mode ultrasound was used to measure intimal-medial thickness in asymptomatic individuals with moderately elevated lipids as part of the ongoing multicenter Asymptomatic Carotid Artery Plaque Study.MethodsUniform ultrasonic scanning and reading protocols were implemented to obtain maximum intimal-medial thickness measurements in 12 standard segments in patients having a small to moderate wall thickness (1.5-3.5 mm) in at least one of the carotid arteries. Paired B-mode image recordings on 858 patients, performed 1 month apart and read at a core laboratory (each pair by the same reader), determined both within-sonographer (W,n=405) and between-sonographer (B,n=453) reproducibility.ResultsThe primary end point (mean±SD), denned in each individual as the mean value of the 12 maximum intimal-medial thickness measurements, was 1.31±0.21 mm (W) and 1.32±0.22 (B) at the time of the second examination. The mean difference in the primary end point (exam 2-exam 1) was −0.01±0.13 mm (W) and 0.00±0.15 mm (B). The Pearson correlation coefficients were 0.79 (W) and 0.75 (B). In 90% of the patients, the absolute difference in the primary end point was <0.22 mm (W) and <0.24 mm (B). Variability of the secondary end point, denned as the single largest intimal-medial thickness measurement in a patient, was between three and four times larger than the variability for the primary end point. Differences in sonographer performance between clinical centers were very small.ConclusionsThe results demonstrate that standardized noninvasive ultrasonic techniques yield highly reproducible measures of carotid intimal-medial thickness, which can serve as a measure of carotid atherosclerosis in clinical trials that monitor small rates of lesion progression.

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and PurposeThe clinical course of stroke due to occlusion of the internal carotid artery is influenced by amount of collateral flow. We measured mean frequency shifts in the middle cerebral artery by transcranial Doppler ultrasonography to determine its prognostic value.MethodsPatients with proven extracranial occlusion of the internal carotid artery and ipsilateral hemispheral stroke were enrolled in our study. We performed transcranial Doppler ultrasonography on 31 patients within 48 hours after the stroke onset and followed up 25 patients in 28 days. At the same time, neurological examination with quantification of neurological deficit was done. We correlated values of flow frequency shifts on the side of stroke with degree of neurological deficit at the onset and at 28 days as well as the degree of clinical improvement and the value of frequency shifts.ResultsWe found a negative correlation between blood flow frequency shifts in the middle cerebral artery and degree of neurological deficit at the onset (Spearman rank correlation coefficient, −0.567;p<0.001). We also found a positive correlation between the change of the neurological deficit during follow-up and frequency shifts at the onset (Spearman rank coefficient, 0.548;p<0.05).ConclusionsDiminished blood flow velocity (mean frequency shift) in the area of stroke is a negative prognostic factor for the degree of neurological deficit at the onset and a negative prognostic factor for possible improvement. Knowledge of hemodynamic conditions in the stroke area may help to improve therapeutic decisions.

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and PurposeCerebral infarction in sickle cell disease is associated with arterial narrowing or occlusions of intracranial arteries. Primary stroke prevention would be feasible if a noninvasive screening test could be developed to detect intracranial disease in patients before symptoms develop.MethodsTo determine the sensitivity and specificity of transcranial Doppler in detecting significant (≥50% lumen diameter reduction) intracranial arterial lesions, we compared transcranial Doppler and cerebral angiography in a primarily young, symptomatic group of 33 patients (18 males and 15 females) with sickle cell disease.ResultsFrom a total of 34 examinations, transcranial Doppler detected significant abnormalities in 26 of 29 (sensitivity 90%, specificity 100%). Five were normal by both techniques. The transorbital examination detected abnormalities in two patients whose studies were otherwise unremarkable.ConclusionsTranscranial Doppler is sensitive and specific for the detection of arterial vasculopathy of sickle cell disease. Screening should include a transorbital examination of the distal internal carotid artery as well as examination using the transtemporal approach.

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and PurposeIn this study we sought to evaluate the clinical significance of serum autoantibodies to dementing processes.MethodsWe assessed 40 age-matched subjects: 10 patients with probable Alzheimer's disease, 10 with possible Alzheimer's disease with cerebrovascular disease, 10 with vascular dementia, and 10 nondemented control subjects. Serum from each subject was tested for the presence of antithyroglobulin antibody, thyroid antimicrosomal antibody, gastric anti-parietal cell antibody, anti-smooth muscle antibody, antinuclear antibody, rheumatoid factor, antineuronal antibody, and anticardiolipin antibody. In addition, we investigated the sera of these patients for the presence of an antivascular antibody directed against the vascular basement membrane proteoglycan antigen and for circulating immune complexes.ResultsAutoantibodies were present in 100% of the patients with possible Alzheimer's disease with cerebrovascular disease, 80% of those with vascular dementia, 40% of those with probable Alzheimer's disease, and 30% of the nondemented control subjects. The highest number of autoantibodies was observed in patients with vascular dementia and possible Alzheimer's disease with cerebrovascular disease. Antinuclear antibody was present in 60% of vascular dementia patients and antineuronal antibody in 50% of these patients. However, no individual autoantibody could differentiate Alzheimer's disease from cerebrovascular disorders. Immune complexes were detected in the serum of 20-30% of each patient group. Neither the patient nor the control sera was found to contain antiendothelial antibody.ConclusionsDespite the relatively small number of individuals examined in each category, the elevated number of autoantibodies associated with possible Alzheimer's disease with cerebrovascular disease and vascular dementia indicates a possible link between the presence of autoantibodies and cerebrovascular disorders in dementia.

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and PurposeThe purpose of this study was to analyze recovery of motor function in a cohort of patients presenting with an acute occlusion in the carotid distribution. Analysis of recovery patterns is important for estimating patient care needs, establishing therapeutic plans, and estimating sample sizes for clinical intervention trials.MethodsWe prospectively measured the motor deficits of 104 stroke patients over a 6-month period to identify earliest measures that would predict subsequent motor recovery. Motor function was measured with the Fugl-Meyer Assessment. Fifty-four patients were randomly assigned to a training set for model development; 50 patients were assigned to a test set for model validation. In a second analysis, patients were stratified on basis of time and stroke severity. The sample size required to detect a 50% improvement in residual motor function was calculated for each level of impairment and at three points in time.ResultsAt baseline the initial Fugl-Meyer motor scores accounted for only half the variance in 6-month motor function (r2=0.53,p<0.001). After 5 days, both the 5-day motor and sensory scores explained 74% of the variance (p<0.001). After 30 days, the 30-day motor score explained 86% of the variance (p<0.001). Application of these best models to the test set confirmed the results obtained with the training set. Sample-size calculations revealed that as severity and time since stroke increased, sample sizes required to detect a 50% improvement in residual motor deficits decreased.ConclusionsMost of the variability in motor recovery can be explained by 30 days after stroke. These findings have important implications for clinical practice and research.

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and PurposePlatelet-activating factor is a potent bioactive phospholipid and may play an important role in occlusive vascular diseases. To assess the inactivation of this autacoid in plasma, we measured platelet-activating factor acetylhydrolase activity in plasma low density and high density lipoproteins from patients with ischemic stroke.MethodsLow density and high density lipoproteins were separated by ultracentrifugation from plasma of 33 patients with cerebral thrombosis and 31 age-matched healthy control subjects, and plateletactivating factor acetylhydrolase activity in each fraction was assayed.ResultsThe average values of platelet-activating factor acetylhydrolase activity in low density lipoprotein from patients and control subjects were 41±18 and 29±17 nmol/ml per minute, respectively, and the difference was statistically significant (p<0.01,Utest). There was no difference in activity in high density lipoprotein between the two groups (16±11 versus 14±9 nmol/ml per minute, respectively).ConclusionsThe increased plasma platelet-activating factor acetylhydrolase activity in stroke patients is primarily attributable to the increased binding to low density lipoprotein, and this increase may be an adaptation to the augmented generation of platelet-activating factor in ischemic stroke.

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID