[Surgical indication, surgical technic and hemodynamics of supra-aortic arterial diseases].
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Carotid Arteries↗
Biomedical subjects
M Hennerici
Publications and source records attributed to M Hennerici.
Reversal of surround- into centre-type responses of cat retinal ganglion cells by local darkening of the receptive field centre.
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Animals↗
The comparison of small-size rectangle and checkerboard stimulation for the evaluation of delayed visual evoked responses in patients suspected of multiple sclerosis.
The use of foveal small-size rectangle stimulation to elicit visual evoked responses was compared with VERs elicited by the standard checkerboard pattern. Foveal stimulation achieved a significantly better discrimination of optic nerve lesions in the early diagnosis of multiple sclerosis. Sources of misdiagnosis due to different neurological disorders are discussed.
Adolescent↗
[The diagnosis of stenoses and occlusions of the carotid arteries by means of directional Dopplersonography (author's transl)].
The Doppler examination of the carotid arteries in the neck was compared with the results of the examination of the supratrochlear artery and of the angiographic controls in 76 patients. The results of this study indicate that the insonation of the carotid arteries considerably improves the diagnostic possibilities offered by the examination of the supratrochlear artery alone. There are three main advantages: 1. The reliability of the Doppler examination is improved. The insonation of the carotid arteries of the 76 angiographically controlled patients including stenoses from 50% onward gave only one false-positive and one false-negative result. The percentage of correct diagnoses thereby attained was 97%. 2. The insonation of the carotid arteries permits reliable differentiation between stenoses and occlusions. This is not possible by the insonation of the supratrochlear artery alone. There was only one case in which the distinction was wrong. 3. The localization of the pathologic process was possible in all cases. These conclusions are only valid for the detection of occlusions and stenoses of more than 50%. Low degree stenoses cannot be detected by this method.
Arterial Occlusive Diseases↗
[Diagnosis of internal carotid artery obstructions (author's transl)].
The diagnostic value of directional ultrasound Doppler-sonography (UDS) of the supratrochlear (medial frontal) artery was evaluated by examination of 191 angiographically controlled cases in whom a carotid obstruction was suspected. A systematic compression of the facial and temporal arteries of both sides was performed. In 108 cases the UDS findings were normal, 6% of these were false negative and actually had a stenosis (n = 6) or occlusion (n = 2) of the internal carotid artery. In 88% of the pathological findings a stenosis (n = 39) or occlusion (n = 34) of the internal carotid artery was revealed by angiography. 79% of the stenoses were of severe degree (more than 50%). These results show that UDS is a useful diagnostic tool for the detection of severe stenoses or occlusions of the internal carotid artery. A distinction between stenosis and occlusion by UDS of the supratrochlear artery is, however, not possible, unless additional examination of the carotid arteries is performed. The method is not suitable for the detection of low grade stenoses.
Arterial Occlusive Diseases↗
Efficacy of CW-Doppler and duplex system examinations for the evaluation of extracranial carotid disease.
The efficacy of different ultrasound methods for the detection of extracranial arterial disease (EAD) was evaluated on the basis of the comparison with angiography. High-resolution B-scan imaging combined with a multigated pulsed Doppler flow pattern analysis (Duplex system) achieved the best results for the detection of morphological and hemodynamic changes of nonstenotic lesions and low grade stenosis. However, a technically unsatisfactory examination rate of 19%, the failure to differentiate between total and subtotal carotid occlusions, underestimation of significant stenosis and impracticable vertebral flow studies were disadvantages of the Duplex technique. CW-Doppler examinations proved to be more precise and more reliable for the detection of significant stenosis and occlusions. Since vertebral blood flow studies were impractical with the Duplex system, CW-Doppler provides more comprehensive information about the hemodynamics of cerebral blood supply.
Arterial Occlusive Diseases↗
Free intracellular calcium in peripheral cells in Alzheimer's disease.
The goal of the present study was to evaluate several parameters of free intracellular Ca2+ regulation ([Ca2+]i) in Alzheimer's disease (AD) in a very large group of patients (n = 50) and nondemented controls (n = 41), using blood lymphocytes and neutrophils as two different peripheral model systems. We found no major difference, because neither the basal [Ca2+]i, nor the activation-induced Ca2+ responses differed among neutrophils or lymphocytes from aged controls and AD patients. However, we observed a delayed Ca2+ response of AD lymphocytes after phytohemagglutinin (PHA) stimulation, indicating an impaired function of Ca2+ influx-controlling mechanisms, because Ca2+ release from intracellular stores appears to be unchanged. Because the PHA-induced Ca2+ response in lymphocytes is accelerated by beta-amyloid (Beta A) similarly to its effects on central neurons, we also investigated the effect of beta A on Ca2+ signalling with regard to AD-related alterations. In contrast to lymphocytes from aged controls, the amplifying effect on Ca2+ signalling was significantly reduced in lymphocytes from a high percentage of AD patients. The results are discussed with respect to their diagnostic potential and to a possible involvement of altered beta A sensitivity of lymphocytes in the pathophysiology of AD.
Aged↗
Vascular cell adhesion molecule--a new approach to detect endothelial cell activation in MS and encephalitis in vivo.
INTRODUCTION: Leukocyte migration into inflammatory lesions is controlled by adhesion molecules on activated vascular endothelium. Pivotal among these are E-selectin and the vascular cell adhesion molecule-1 (VCAM-1), which are found on very few cell types other than activated endothelium. METHODS: We determined the presence of the soluble form of these adhesion molecules (sE-selectin and sVCAM-1) in serum and CSF of patients with multiple sclerosis (MS), viral encephalitis, and controls, using enzyme-linked immunosorbent assays. RESULTS: MS patients with active, Gadolinium-DTPA-enhancing lesions on magnetic resonance imaging had significantly higher sVCAM-1 serum levels than normal controls. Patients with viral encephalitis had significantly higher levels of sVCAM-1 in serum and cerebrospinal fluid than controls. sE-selectin levels showed no significant variations. CONCLUSION: Activated vascular endothelium controlling leukocyte migration may be demonstrated in MS patients in vivo by determining sVCAM-1 in serum. Furthermore, sVCAM-1 may be useful for monitoring inflammatory activity in central nervous system inflammatory disease.
Adult↗
Cardiovascular safety of lubeluzole (Prosynap(R)) in patients with ischemic stroke.
The cardiovascular safety of lubeluzole was evaluated in patients with ischemic stroke in a double-blind, placebo-controlled trial. Forty-six patients were randomized to receive a continuous daily infusion of lubeluzole 5 mg (loading dose 3.75 mg over 1 h), lubeluzole 10 mg (loading dose 7.5 mg over 1 h), or placebo for 5 days within 24 h of stroke onset. The primary measure of cardiovascular safety was the QTc interval, derived from the continuous electrocardiogram (ECG) and measured during treatment and a 2-day follow-up. Compared with placebo. Neither dosage of lubeluzole had any statistically or clinically relevant effects on the QTc. Neither were there any significant differences among the three treatment groups in the area under the curve for heart rate, QT interval, QT dispersion, or QTlc. Lubeluzole did not increase the frequency of ECG abnormalities. No ventricular fibrillation, ventricular tachycardia, or torsades de pointes were observed in any of the treatment groups. During this trial, 3 patients in the placebo group and 2 patients in the lubeluzole 5-mg group died. There were no deaths in the lubeluzole 10-mg group. Adverse experiences were similar in all three treatment groups except that superficial thrombophlebitis was more frequent in the lubeluzole 10-mg group. In doses to 10 mg/day, lubeluzole has a favorable cardiovascular safety profile, as demonstrated by the lack of clinically relevant effects on heart rate, QT, QTc, and QTlc, and it was well tolerated by patients with ischemic stroke.
Acute Disease↗
Stroke vignette. Epidural hematoma and hemorrhagic infarction mimicking a left temporal meningioma.
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Aged↗
Stroke vignette. Duplex ultrasound diagnosis of carotid/vertebral dissection without hemodynamically relevant stenosis.
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Adult↗
Elevated levels of fragmented DNA nucleosomes in native and activated lymphocytes indicate an enhanced sensitivity to apoptosis in sporadic Alzheimer's disease. Specific differences to vascular dementia.
Apoptotic cell death is thought to be the most likely mechanism of cell death contributing to neurodegeneration in Alzheimer's disease (AD). Here, we provide evidence that in sporadic AD cases the vulnerability of peripheral cells to undergo apoptosis is increased compared to non-demented elderly controls and, very importantly, to patients with subcortical vascular encephalopathy (SVE) as another, but demented control group. Quiescent 'native' and 'activated' lymphocytes from AD patients that were predisposed to commit apoptotic cell death by priming the cells with interleukin-2, are shown to accumulate apoptosing cells to a significantly higher extent in spontaneous and in oxidative stress-induced in vitro apoptosis. Our results demonstrate robust differences in cell death sensitivity between AD and vascular dementia. In none of the conditions investigated, lymphocytes from SVE patients were significantly different from non-demented controls. The comparable findings of a higher extent of apoptotic features in neurons and in peripheral blood cells of AD patients are remarkable and may suggest a rather general modulation of apoptotic mechanisms by the disease, which even can be picked up at the level of peripheral lymphocytes under specific in vitro conditions.
Aged↗
Incidence of asymptomatic extracranial arterial disease.
Investigations of the incidence and the extent of the asymptomatic early stages of extracranial arterial disease (EAD) have been restricted for methodical reasons. Direct Continuous Wave-Doppler examination has given highly accurate results in the location and correct estimation of the degree of EAD both for the carotid (97%) and the vertebral arteries (90%), as shown from a detailed comparison with carotid (n = 604) and vertebral (n = 426) angiograms. Compared with this degree of reliability, the validity of normal auscultation for the diagnosis of EAD is shown to be poor: if bruits are taken as the only signs of associated EAD in patients with systemic atherosclerosis, only 27.6% in a group of 123 patients would have been correctly diagnosed. This parallels the number of false-positives (22.6%) in patients with normal results. The frequency and degree of EAD was studied by the use of direct Doppler examination in 2009 neurologically asymptomatic patients admitted either with severe vascular (n = 375) or coronary atherosclerosis (n = 262) or with high-risk factors (n = 1370). The frequency was significantly higher (32.8%) in patients with peripheral vascular disease than in those with coronary artery disease (6.8%) and in risk-factor patients (5.9%). The combination and degree of vessel involvement are presented in detail and their possible prognostic significance discussed.
Aged↗
Cerebral ischemia in young patients: it is associated with mitral valve prolapse and abnormal platelet activity in vivo?
The etiology of cerebrovascular disease (CDV) in young patients is difficult to establish if the common causes of a focal neurological deficit are excluded by appropriate investigations. Since in some observations prolapse of the mitral-valve (MVP), alterations of platelet function, or both have been linked with cerebral ischemic events, we studied the in vivo platelet release reaction and the incidence of MVP in 47 patients (12 males, 35 females) under 45 years of age with TIA or stroke of unknown cause and in an age- and sex-matched control group. The mean plasma beta-thromboglobulin (beta-TG) level of the patients (mean = 54.9 +/- 31.4 ng/ml) was significantly higher than that of the controls (mean = 20.6 /- 6.9 ng/ml, p less than 0.001). MVP was demonstrated in 13 of 47 patients in contrast to 4 of the controls (p less than 0.01). However, the beta-T levels of patients with MVP (n = 13, 52.9 +/- 25.5 ng/ml) did not differ from those of patients without MVP (n = 34, 55.7 +/- 33.7 ng/ml) significantly (p less than 0.4). Our results confirm that the incidence of MVP is higher in young patients with cerebral ischemia of unknown cause than in asymptomatic controls. The significantly elevated plasma beta-TG concentrations in the patient's group indicate an increased platelet activity in vivo. Since there was no significant difference between beta-TG levels of patients with and without MVP, the mitral-valve abnormality can not be the cause for the altered platelet activity.
Blood Platelets↗
Spontaneous history of asymptomatic internal carotid occlusion.
Forty-nine patients with ICA occlusion, who presented without any neurological signs or symptoms, were prospectively followed for an average of 31.2 months. Eight patients (16%) suffered a stroke during follow-up, of which five were within the vascular territory of the occluded artery--5 patients (10%) developed TIAs 4 of which were ipsilateral to the occluded artery. Non-invasive vascular follow-up did not reveal a progression of extracranial arterial disease in the majority of later symptomatic patients. Twenty-three patients (46.9%) died during follow-up, coexisting coronary artery disease being the major cause of death.
Adult↗
Carotid artery disease assessed by color Doppler flow imaging: correlation with standard Doppler sonography and angiography.
Carotid artery disease was assessed in 180 patients by means of color Doppler flow imaging. Color Doppler findings in 360 carotid arteries were compared with the results of standard Doppler sonography, and color Doppler findings in 60 bifurcations were compared with the results of intraarterial angiography. The sensitivity of color Doppler for the detection of carotid disease was 100% when compared with angiography. The accuracy of color Doppler in classifying minor (40-60%), moderate (61-80%), and severe (81-90%) stenosis ranged from 91.3% to 97.8% vs standard Doppler sonography, and from 91.7% to 95.8% vs angiography. Whereas all occlusions were identified correctly by both color Doppler and angiography, four pseudoocclusions of the carotid artery were misdiagnosed as occluded. Characteristic features providing reliable criteria of the degree of stenosis are (1) intensity, extent, and duration of color fading; (2) postprocessed systolic peak frequency; (3) plaque extent on serial sonograms; and (4) poststenotic flow patterns. Display of hemodynamic disturbances induced by less pronounced plaques showed highly variable patterns that could not be anticipated from the plaque morphology alone. Thus, color Doppler preserves the advantages of standard Doppler and duplex sonography but provides additional information about otherwise anechoic necrotic and thrombotic material that often causes cerebral embolisms. With atherogenesis, repair mechanisms may be sustained or progression be stopped by reducing the risk factors and instituting medical treatment; thus, the application of this noninvasive technique is important.
Carotid Artery Diseases↗
The clinical significance of blood-flow measurements.
The validity of different non-invasive methods of detecting extracranial arterial disease is assessed in a large series of more than 20 000 patients studied using CW-Doppler (indirect and direct techniques) and more than 2000 patients studied by a newly developed ultrasound Duplex system. While CW-Doppler analysis still represents the method of choice for the evaluation of various degrees of carotid obstructions causing more than 50 per cent lumen narrowing (overall accuracy 99 per cent), the technically far more complex and expensive Duplex systems should be used for the diagnosis of normal arterial vessels versus minor plaques, and in particular for the detection of ulcerative lesions representing possible sources of cerebral embolism. Furthermore, simultaneous flow-volume and velocity-pattern analysis across the arterial lumen provides new insight into the cerebral blood flow, thus promising acquisition, for the first time, of rapid changing parameters in the cerebral circulation.
Carotid Artery Diseases↗
Failure to identify cerebral infarct mechanisms from topography of vascular territory lesions.
PURPOSE: Our purpose was to determine whether topographic patterns of ischemic damage seen on brain imaging studies are useful for evaluating different mechanisms of infarction and for distinguishing embolic from hemodynamic disorders. METHODS: Early CT scans were reviewed to identify brain infarctions in the middle cerebral artery territory in 800 patients with either significant obstructive lesions of the internal carotid artery (70% stenosis, n = 17; occlusion, n = 85) or nonvalvular atrial fibrillation (n = 186) as the only identified source of stroke. Ninety-nine CT studies were considered suitable for entry into the final analysis. The scans were digitized and superimposed on postmortem brain sections by matching algorithms to display the variability of the cerebrovascular territories. RESULTS: Cortical borderzone-type infarctions were rare and evenly distributed among patients with cardiac sources of embolism (3.2%) and severe carotid obstructions (3.6%). In contrast, subcortical borderzone infarcts occurred significantly more often in patients with carotid obstructive disease (36% versus 16%). However, on computerized segmentation analysis, the topography of infarction was the same in both groups. CONCLUSION: The current concept that stroke mechanisms can be inferred from interpretation of stroke patterns on brain scans is heavily confounded by the variability in intracranial arterial territory distributions. Since individual arterial territories cannot be identified in vivo, interpretation of stroke topography is invalidated. In particular, the cortical wedge-type of borderzone infarction, said to result from hemodynamic compromise in low-flow perfusion territories, is an ambiguous observation and may be seen in patients with cerebral embolism and hemodynamic compromise due to severe carotid disease.
Adult↗