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1.
Article in English | MEDLINE | ID: mdl-23808108

ABSTRACT

BACKGROUND: Healthy diet and physical activity improve risk factors for cerebrovascular disease. It is unclear whether patients with carotid artery disease from Luxemburg meet common guideline criteria and whether systematic counseling has a sustained effect. METHODS: We assessed anthropometric data, eating habits and physical activity habits in 53 patients with carotid atherosclerosis at baseline, after 4 and 20 weeks, and advised them five times for 30 min to follow a modified Mediterranean diet and to perform moderate physical exercise at least during 30 min/day. RESULTS: The patients had a mildly increased BMI (mean 27.6, recommended below 25), they already ate enough vegetables and fruits (mean 485 g daily, recommended at least 400 g), they ate too much sugar (mean 74 g daily) and sodium (mean 2710 mg daily, recommended less than 1500), they consumed 13% of calories from saturated fatty acids (recommended less than 10%), and they already moved sufficiently (62 min daily of moderate and intense physical activity, recommended at least 30 min of moderate physical activity). Lifestyle counseling had a sustained effect on weight, reduction of global caloric intake, carbohydrate and cholesterol intake and on an increase in consumption of poly-unsaturated fatty acids, vegetables and fibres. There was no sustained effect on the consumption of sugar, sodium, and saturated fat. CONCLUSIONS: The reduction of sugar, sodium and saturated fat consumption should be stressed more in counselling of this patient group.


Subject(s)
Carotid Artery Diseases/diet therapy , Counseling , Diet, Carbohydrate-Restricted , Diet, Fat-Restricted , Diet, Sodium-Restricted , Life Style , Adult , Aged , Aged, 80 and over , Body Mass Index , Diet , Energy Intake , Exercise , Female , Fruit , Humans , Luxembourg , Male , Middle Aged , Patient Education as Topic , Vegetables , Weight Loss
2.
Article in German | MEDLINE | ID: mdl-24437075

ABSTRACT

There is no doubt that a healthy diet and regular physical activity improve risk factors for cerebro-cardio-vascular disease and death. However, there is less evidence from prospective randomised controlled trials that they also reduce the actual risk of stroke, myocardial infarction and death. The only evidence from randomised controlled trials is, that a mediterranean diet with nuts and/or native olive oil considerably reduces stroke risk by 47% respectively 31%, however not the risk of myocardial infarction and death. A low-fat diet, a low-salt diet, and the addition of omega-3 fatty acids have no influence. In case of severe obesity with a BMI of > 34-38 kg/m2, weight reduction is the priority, if necessary by means of bariatric surgery. In longitudinal studies mortality (-29%), stroke (-34%), and myocardial infarction (-29%) could thus be reduced. Regular physical activity, whether endurance or more intense activity, leads to weight loss and improved vascular risk factors. An independent impact on stroke, myocardial infarction and mortality has not yet been demonstrated in prospective studies (double-blinding being impossible). Nevertheless, several epidemiological meta-analyses with observation durations of 4 to 28 years using data of up to 880 000 persons, indicate that there is a 2-3 fold risk reduction of cerebro-cardio-vascular death and global mortality in people with regular physical activity versus sedentary behaviour.


Subject(s)
Diet, Mediterranean , Motor Activity , Myocardial Infarction/mortality , Myocardial Infarction/prevention & control , Stroke/mortality , Stroke/prevention & control , Body Mass Index , Diet, Fat-Restricted , Diet, Sodium-Restricted , Evidence-Based Medicine , Global Health , Humans , Obesity/complications , Obesity/etiology , Obesity/therapy , Risk Assessment , Risk Factors , Sedentary Behavior , Treatment Outcome , Weight Loss
3.
Acta Neurol Scand ; 124(3): 218-20, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21595634

ABSTRACT

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) affects predominantly the parietal and occipital lobes. Frequent clinical features are epileptic seizure, altered mental status and visual disturbances. CLINICAL PRESENTATION: We present the first case of a patient with pericarditis and mitral valve insufficiency, who developed PRES after application of a glycerolnitrate patch day three post-operatively and whose neurological deficits improved within 2 days after withdrawal of patch therapy. CONCLUSION: The precise pathomechanism of PRES is unknown. The lower sympathetic innervation of the posterior circulation may be one explanation for its particular vulnerability to vasodilatation caused by glycerolnitrate.


Subject(s)
Blindness, Cortical/chemically induced , Brain Infarction/chemically induced , Nitroglycerin/adverse effects , Posterior Leukoencephalopathy Syndrome/chemically induced , Blindness, Cortical/diagnostic imaging , Blindness, Cortical/physiopathology , Brain Infarction/diagnostic imaging , Brain Infarction/physiopathology , Humans , Male , Middle Aged , Nitroglycerin/administration & dosage , Posterior Leukoencephalopathy Syndrome/diagnostic imaging , Posterior Leukoencephalopathy Syndrome/physiopathology , Postoperative Care/adverse effects , Radiography
4.
Article in German | MEDLINE | ID: mdl-22272443

ABSTRACT

Stroke is a neurological emergency condition that warrants immediate hospitalisation on a stroke unit, where a dedicated team offers state-of-the-art diagnostic and therapeutic measures. Stroke units have shown to reduce mortality and handicap especially if thrombolysis is possible. A critical mass of stroke patients with standardised, simplified and automated processes is required to achieve good results. Stroke teams are no alternative to a stroke unit as a geographic unit. A turnover of less than 200-250 strokes per year is associated with a worse patient outcome and the treatment effect of a stroke unit may be abolished. The situation in Luxembourg offers the possibility to create units of this size and performance if all the concerned physicians and hospitals, health insurance and health administration join their efforts.


Subject(s)
Hospital Units , Stroke/epidemiology , Stroke/therapy , Humans , Luxembourg/epidemiology
5.
Article in English | MEDLINE | ID: mdl-18084908

ABSTRACT

Sporadic Creutzfeldt-Jakob disease (sCJD) does not always present with typical clinical signs, such as myoclonus in association with periodic sharp-wave complexes. We present a 67-year old female patient with initial falls and vertical gaze palsy, suggesting the diagnosis of Progressive Supranuclear Palsy (PSP). EEG and MRI were not contributory. Typical clinical and paraclinical CJD signs were only seen after 17 months. The diagnosis was confirmed by autopsy. - CJD can be a neurodegenerative chameleon. The present case adds to the scare literature of slowly evolving CJD mimicking Parkinsonism related to tauopathies.


Subject(s)
Creutzfeldt-Jakob Syndrome/diagnosis , Supranuclear Palsy, Progressive/diagnosis , Aged , Atrophy , Brain/pathology , Creutzfeldt-Jakob Syndrome/physiopathology , Diagnosis, Differential , Disease Progression , Female , Humans , Magnetic Resonance Imaging
6.
Neurology ; 64(7): 1233-7, 2005 Apr 12.
Article in English | MEDLINE | ID: mdl-15824353

ABSTRACT

OBJECTIVE: To assess the interaction of cerebral amyloid angiopathy (CAA) and arterial hypertension as cofactors for intracerebral hemorrhage (ICH). METHODS: The authors investigated 129 postmortem brains of hypertensive patients with and without ICH. Sixty-four patients had had deep (n = 40) or lobar (n = 24) ICH. Sixty-five patients without ICH served as controls. Established risk factors for ICH (age, gender, severity of hypertension, bleeding disorders, intake of anticoagulants, and chronic alcoholism) were identified from medical records. Four specimens per brain were stained with hematoxylin-eosin and Congo red. The entire ICH cohort and subgroups were compared with controls using single-factor and multiple logistic regression analyses. RESULTS: CAA was found in 15 of 64 subjects (23%) with ICH and in five of 65 controls (8%; p = 0.026). In single-factor analysis, CAA was more prevalent in lobar ICH compared with controls (p = 0.007) but not in deep ICH. Poor control of hypertension was more prevalent in the entire ICH group (p = 0.01) and in deep ICH (p = 0.016) but not in lobar ICH. ICH was predictive of the presence of CAA (odds ratio: 5.6, 95% CI: 1.8 to 19.5, p = 0.003), and CAA was more likely to be found in lobar ICH in multivariable-adjusted analysis. After adjustment for conventional risk factors, there was a weak association between CAA and deep ICH. CONCLUSION: Cerebral amyloid angiopathy plays a major role in the pathogenesis of intracerebral hemorrhage even in patients with more evident risk factors.


Subject(s)
Cerebral Amyloid Angiopathy/complications , Cerebral Amyloid Angiopathy/pathology , Hypertension/complications , Hypertension/pathology , Intracranial Hemorrhage, Hypertensive/etiology , Intracranial Hemorrhage, Hypertensive/pathology , Aged , Aged, 80 and over , Cerebral Amyloid Angiopathy/physiopathology , Cerebral Arteries/pathology , Cerebral Arteries/physiopathology , Cerebral Cortex/blood supply , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Disease Progression , Female , Humans , Hypertension/physiopathology , Intracranial Hemorrhage, Hypertensive/physiopathology , Male , Middle Aged , Plaque, Amyloid/pathology , Predictive Value of Tests , Risk Factors
7.
Acta Neurol Scand ; 107(4): 241-51, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12675696

ABSTRACT

OBJECTIVES: Arterial hypertension is, besides age, the number one risk factor for ischaemic stroke. Patients with arterial hypertension frequently present with additional coexisting vascular risk factors interacting in a complex way. MATERIAL AND METHODS: This paper reviews the benefit of antihypertensive treatment, as well as different treatment options of arterial hypertension and their side-effects. RESULTS: Patients with definite arterial hypertension, but also patients with so-called normal or high-normal blood pressure are at increased risk to develop stroke and other cardiovascular complications. Vascular remodelling of small and large vessels provoked by arterial hypertension is the initial step in the development of atherosclerosis and lipohyalinosis. Vascular remodelling can be improved or even normalized by antihypertensive treatment with angiotensin-converting-enzyme inhibitors and angiotensin-I-receptor antagonists showing the most convincing effects. Angiotensin-converting-enzyme inhibitors and angiotensin-I-receptor antagonists have the lowest rate of side-effects, however, economic restraints hinder their general application. Statins are needed to treat dyslipidaemia. They also lower blood pressure and have a synergistic effect with the above two antihypertensive components in lowering blood pressure. In hypertensive patients, risk of stroke and other cardiovascular complications is determined by the blood pressure level and the presence or absence of target organ damage and the interaction with other risk factors, such as cigarette smoking, dyslipidaemia, and diabetes. These high-risk patients should be treated even more aggressively than usual. CONCLUSIONS: In the vast majority of patients and healthy individuals, target blood pressure should be as high as or below 120/80 mmHg to minimize the occurrence of stroke and other cardiovascular complications.


Subject(s)
Antihypertensive Agents/therapeutic use , Brain Infarction/etiology , Brain Ischemia/complications , Hypertension/complications , Hypertension/drug therapy , Angiotensin Receptor Antagonists , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Antihypertensive Agents/adverse effects , Brain Infarction/prevention & control , Brain Ischemia/etiology , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Risk Factors
8.
Cerebrovasc Dis ; 14(2): 105-8, 2002.
Article in English | MEDLINE | ID: mdl-12187014

ABSTRACT

Proper assessment of intracranial arteries by transcranial Doppler sonography (TCD) in patients with intracranial stenoses is occasionally made difficult by an insufficient temporal bone window, an unfavourable insonation angle, or low flow velocity or volume. This condition is frequently found in Chinese. In these cases, echocontrast could be helpful. We investigated 48 temporal windows of 24 acute Chinese stroke patients with insufficient native transtemporal insonation conditions before and after the application of the echo enhancer Levovist (galactose/palmitic acid) by an injection pump. We classified the signal quality from four segments of the main intracranial arteries: anterior cerebral artery (A1), main stem of the middle cerebral artery (MCA, M1), intracranial segment of the carotid artery (C1), and posterior cerebral artery (P1). The signal quality was classified as follows: 0 = no signal, 1 = poor, envelope curve does not follow spectrum, 2 = adequate, envelope curve follows spectrum. As compared to the pre-contrast scans, echocontrast allowed for more segments to be evaluated by pulsed Doppler sonography. Before Levovist, only 12% of the segments could be detected, after Levovist 63%. For all arteries, signal quality was better after Levovist, p between 0.0180 and 0.0003. In 3 patients, MCA stenoses with peak systolic Doppler flow velocities above 160 cm/s were found only after Levovist. In patients with poor pre-contrast detection, echocontrast-enhanced TCD allows for more arterial segments to be insonated and for the detection of stenoses unnoted during the non-enhanced investigation.


Subject(s)
Asian People , Carotid Stenosis/ethnology , Contrast Media , Image Enhancement , Infarction, Middle Cerebral Artery/ethnology , Intracranial Arteriosclerosis/diagnosis , Intracranial Arteriosclerosis/ethnology , Polysaccharides , Ultrasonography, Doppler, Transcranial , Aged , Aged, 80 and over , Blood Flow Velocity/physiology , Carotid Stenosis/diagnosis , Female , Humans , Infarction, Middle Cerebral Artery/diagnosis , Injections, Intravenous , Male , Middle Aged , Signal Processing, Computer-Assisted
9.
Stroke ; 32(12): 2803-9, 2001 Dec 01.
Article in English | MEDLINE | ID: mdl-11739977

ABSTRACT

BACKGROUND AND PURPOSE: Transcranial Doppler (TCD) can detect high-intensity transient signals (HITS) in the cerebral circulation. HITS may correspond to artifacts or solid or gaseous emboli. The aim of this study was to develop an offline automated Doppler system allowing the classification of HITS. METHODS: We studied 600 HITS in vivo, including 200 artifacts from normal subjects, 200 solid emboli from patients with symptomatic internal carotid artery stenosis, and 200 gaseous emboli in stroke patients with patent foramen ovale. The study was 2-fold, each part involving 300 HITS (100 of each type). The first 300 HITS (learning set) were used to construct an automated classification algorithm. The remaining 300 HITS (validation set) were used to check the validity of this algorithm. To classify HITS, we combined dual-gate TCD with a wavelet representation and compared it with the current "gold standard," the human experts. RESULTS: A combination of the peak frequency of HITS and the time delay makes it possible to separate artifacts from emboli. On the validation set, we achieved a sensitivity of 97%, a specificity of 98%, a positive predictive value (PPV) of 99%, and a negative predictive value (NPV) of 94%. To distinguish between solid and gaseous emboli, where positive refers now to the solid emboli, we used the peak frequency, the relative power, and the envelope symmetry of HITS. On the validation set, we achieved a sensitivity of 89%, a specificity of 86%, a conditional PPV of 89%, and a conditional NPV of 89%. CONCLUSIONS: An automated wavelet representation combined with dual-gate TCD can reliably reject artifacts from emboli. From a clinical standpoint, however, this approach has only a fair accuracy in differentiating between solid and gaseous emboli.


Subject(s)
Intracranial Embolism/classification , Intracranial Embolism/diagnosis , Ultrasonography, Doppler, Transcranial/methods , Adult , Algorithms , Artifacts , Carotid Stenosis/complications , Heart Septal Defects, Atrial/complications , Humans , Intracranial Embolism/complications , Middle Aged , Middle Cerebral Artery/diagnostic imaging , Predictive Value of Tests , Reproducibility of Results , Sensitivity and Specificity , Signal Processing, Computer-Assisted
10.
Cerebrovasc Dis ; 12(3): 181-5, 2001.
Article in English | MEDLINE | ID: mdl-11641581

ABSTRACT

BACKGROUND AND PURPOSE: Carotid and vertebral artery dissections are frequently complicated by cerebral embolism. Detection of clinically silent circulating microemboli by transcranial Doppler sonography (TCD) is now widely investigated in patients with carotid artery disease in the hope to identify patients at increased risk for stroke. METHODS: In 20 patients with carotid (n = 17) or vertebral (n = 2) artery dissection, or both (n = 1), we performed a 1-hour microembolus detection downstream to the dissection in the middle or in the posterior cerebral artery, respectively. RESULTS: Five patients with a carotid artery stenosis of > or = 90% or with carotid artery occlusion showed microembolic signals at a rate of up to 15 events/h. In all these patients, the onset of the dissection was within the last 58 days. Patients with lower degrees of stenosis or onset of symptoms beyond 58 days did not show microembolic signals at all. Three patients who had presented with recurrent ischaemic events prior to TCD monitoring unexceptionally had microembolic signals. CONCLUSION: Microembolic signals occur in patients with high-grade stenosis or occlusion due to acute cervical artery dissection. Patients with microemboli seem to be at increased macroembolic risk, i.e. stroke recurrence, and may require close-meshed clinical follow-up and possibly stronger antithrombotic treatment.


Subject(s)
Aortic Dissection/complications , Carotid Artery Diseases/complications , Intracranial Aneurysm/complications , Intracranial Embolism/etiology , Vertebral Artery , Adult , Aged , Arterial Occlusive Diseases/complications , Carotid Stenosis/complications , Female , Humans , Intracranial Embolism/diagnostic imaging , Ischemic Attack, Transient/complications , Male , Middle Aged , Neck/blood supply , Ultrasonography, Doppler, Transcranial
11.
Stroke ; 32(7): 1520-4, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11441195

ABSTRACT

BACKGROUND AND PURPOSE: This study aimed to determine the correlation of in vivo ultrasound measurements of intima-media thickening (IMT), lumen diameter, and cross-sectional area of the common carotid artery (CCA) with corresponding measurements obtained by gross pathology and histology. METHODS: Sixty-six moribund neurological patients (mean age 71 years) underwent B-mode ultrasound of the CCA a few days before death. During autopsy, carotid specimens were removed in toto. Carotid arteries were ligated and cannulated for injection of a hydrophilic embedding material under standardized conditions. The carotid bifurcation was frozen and cut manually in 3-mm cross slices. Digital image analysis was carried out to determine the diameter and the cross-sectional area of the frozen slices of the CCA. IMT was assessed by light microscope. Ultrasonic and planimetric data were compared. RESULTS: Mean measurements of lumen diameter and cross-sectional area were 7.13+/-1.27 mm and 0.496+/-0.167 cm(2), respectively, by ultrasound, and 7.81+/-1.45 mm and 0.516+/-0.194 cm(2), respectively, by planimetric analysis of the unfixed redistended carotid arteries (R(2)=0.389 and 0.497). The mean IMT was 1.005+/-0.267 mm by ultrasound and 0.67+/-0.141 mm histologically, resulting in a mean difference of -31%. CONCLUSIONS: Transcutaneous B-mode ultrasound provides a reliable approach for in vivo measurements of the cross-sectional area and, less exactly, of the lumen diameter of the CCA. Compared with histological results, in vivo ultrasound measurements of the IMT are systematically larger.


Subject(s)
Arteriosclerosis/diagnostic imaging , Arteriosclerosis/pathology , Carotid Artery Diseases/diagnostic imaging , Carotid Artery Diseases/pathology , Carotid Artery, Common/diagnostic imaging , Ultrasonography/methods , Adult , Aged , Anatomy, Cross-Sectional , Carotid Artery, Common/pathology , Female , Humans , Male , Middle Aged , Tunica Intima/diagnostic imaging , Tunica Intima/pathology , Tunica Media/diagnostic imaging , Tunica Media/pathology
12.
Cerebrovasc Dis ; 11(2): 95-9, 2001.
Article in English | MEDLINE | ID: mdl-11223660

ABSTRACT

Electrical cardioversion (CV) of atrial fibrillation (AF) is associated with an increased risk of stroke, and its appropriate prevention is still a matter of debate. It is known that, besides dislodgement of pre-existing intra-atrial thrombi, the "stunned" atrium after CV is an important cause of thrombus formation and subsequent embolism. We investigated whether CV of AF is associated with occurrence of circulating microemboli (ME) representing a sensitive marker of the actual thromboembolic activity. Twenty-nine patients (22 men) aged 54 +/- 13 years suffering from valvular (n = 5) or nonvalvular (n = 24) AF were studied. All but 1 patient (with recent-onset AF) had been put on oral anticoagulation (INR >2.0) for at least 3 weeks before and 4 weeks after successful CV. In all patients, exclusion of internal carotid artery stenosis and atrial thrombus was performed prior to CV. Five unilateral 1-hour transcranial Doppler ME monitorings over the middle cerebral artery were performed (1) before CV, and (2) immediately, (3) 4-6 h, (4) 24 h, and (5) 2-4 weeks after CV. Total absence of circulating ME was found before CV as well as during a cumulative monitoring time of 115 h after successful CV. Electrical CV of AF after at least 3 weeks of effective anticoagulation is not associated with occurrence of cerebral circulating ME. This finding requires further investigation including high-risk patients with AF undergoing CV based on different treatment protocols.


Subject(s)
Atrial Fibrillation/therapy , Electric Countershock/adverse effects , Intracranial Embolism/diagnostic imaging , Intracranial Embolism/etiology , Aged , Female , Humans , Male , Middle Aged , Prospective Studies , Ultrasonography, Doppler, Transcranial
13.
Z Kardiol ; 90(1): 43-51, 2001 Jan.
Article in German | MEDLINE | ID: mdl-11220086

ABSTRACT

Thromboembolic events represent a major complication of cardiovascular diseases and interventions. Although general risk factors and predictors for thromboembolic events are well known from population-based studies, hardly any therapeutic consequences for the individual patient can be drawn, e.g. for a well-balanced therapy with anticoagulants. A new approach towards an optimised therapy adapted to the individual risk of each patient may be based on the detection of circulating microemboli by transcranial Doppler sonography. With this technique, gaseous or solid microparticles circulating in the blood can noninvasively be detected. Due to their small size, they do not induce thromboembolic events themselves. However, several studies demonstrate that they indicate an increased thromboembolic activity and correlate directly with manifest stroke or emboli. From a transcranial Doppler probe positioned on the temporal plane at the patient's skull, the middle cerebral artery's blood flow is recorded and is analysed acoustically and optically for circulating microemboli. This technique has already been used for risk stratification of high-risk patients and therapeutic decision-making in neurologic routine, e.g. for the indication to anticoagulate the patient or for carotis surgery. Data to evaluate its value in cardiology are limited and based on few clinical studies. In this review, the basic principles and the methodological and technical background for the detection of microemboli, as well as current limitations, are discussed. Furthermore, clinical studies and their results evaluating this technique in patients with cardiological diseases and during cardiovascular interventions are reviewed.


Subject(s)
Intracranial Embolism/diagnostic imaging , Middle Cerebral Artery/diagnostic imaging , Ultrasonography, Doppler, Transcranial , Angioplasty, Balloon, Coronary/adverse effects , Artifacts , Blood Vessel Prosthesis/adverse effects , Catheter Ablation/adverse effects , Cerebrovascular Circulation , Extracorporeal Circulation/adverse effects , Fourier Analysis , Humans , Primary Prevention , Risk Factors , Stroke/etiology , Stroke/prevention & control , Ventricular Dysfunction, Left/complications
14.
Cardiovasc Intervent Radiol ; 23(4): 312-4, 2000.
Article in English | MEDLINE | ID: mdl-10960549

ABSTRACT

Twenty carotid bifurcations were examined. During autopsy, carotid bifurcations were removed in toto. Unfixed carotids were ligated and cannulated for injection of an angiographic contrast medium followed by injection of a tissue-embedding medium at physiologic pressure and temperature. The carotid bifurcation was frozen and cut manually in 3-mm cross-sections. Photographs were then taken of every slice. Angiography, filling with tissue-embedding material, and sectioning were successful in all cases. In the macropathologic sections, the extent, configuration and location of atherosclerotic lesions could be identified.


Subject(s)
Angiography , Autopsy , Carotid Arteries/anatomy & histology , Carotid Arteries/diagnostic imaging , Aged , Angiography/methods , Arteriosclerosis/diagnostic imaging , Arteriosclerosis/pathology , Autopsy/methods , Carotid Artery Diseases/diagnostic imaging , Carotid Artery Diseases/pathology , Diagnosis, Differential , Female , Humans , Image Processing, Computer-Assisted , Male
15.
Acta Neurol Scand ; 102(1): 1-10, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10893056

ABSTRACT

OBJECTIVES: Ultrasound of the brain supplying arteries is a standard diagnostic procedure in patients with suspected and definite acute and chronic cerebrovascular occlusive disease. Anatomical and pathological limitations led to the development of echocontrast agents which are able to survive pulmonary and capillary transit and improve the echogenicity of the flowing blood. MATERIAL AND METHODS: This article reviews present and future applications of echocontrast agents in conjunction with personal experiences. RESULTS: Currently, echocontrast is used for the differentiation of internal carotid artery occlusion and pseudoocclusion, better delineation of the maximal narrowing in high-grade stenoses, and better visualization of the extracranial vertebral artery and its collaterals. Transcranial applications include the insufficient foraminal or temporal window, assessment of arteriovenous malformations, thrombosis of cerebral veins and sinuses, and intracranial aneurysms. The use of echocontrast can have direct diagnostic and therapeutic consequences. Harmonic imaging, perfusion imaging, stimulated acoustic emission, and drug delivery are possible future domains of the technique. DISCUSSION: Besides the support of conventional neurovascular ultrasound in poor examination conditions due to the patients' anatomy or pathology, echocontrast agents may allow for novel applications in the diagnosis and treatment of cerebrovascular patients.


Subject(s)
Cerebrovascular Disorders/diagnostic imaging , Ultrasonography, Doppler, Transcranial/methods , Carotid Artery Diseases/diagnostic imaging , Carotid Artery, Internal , Contrast Media , Diagnosis, Differential , Humans , Intracranial Arteriovenous Malformations/diagnostic imaging , Vertebrobasilar Insufficiency/diagnostic imaging
16.
Stroke ; 31(7): 1640-5, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10884466

ABSTRACT

BACKGROUND AND PURPOSE: Cardiac right-to-left shunts can be identified by transesophageal echocardiography (TEE) and by transcranial Doppler ultrasound (TCD) with the use of contrast agents and a Valsalva maneuver (VM) as provocation procedure. Currently, data on the appropriate timing of the VM, the use of a diagnostic time window, and a threshold in contrast agent microbubbles detected are insufficient. METHODS: Fifty-eight patients were investigated by both TEE and bilateral TCD of the middle cerebral artery. The following protocol with injections of 10 mL of the commercial galactose-based contrast agent Echovist was applied in a randomized way: (1) no VM, (2) VM for 5 seconds starting 2 seconds after the beginning of contrast injection, (3) VM for 5 seconds starting 5 seconds after the beginning of contrast injection, (4) VM for 5 seconds starting 8 seconds after the beginning of contrast injection, and (5) repetitive short VMs in between 2 and 13 seconds after the beginning of contrast injection. In addition to the single tests, we also tested the sensitivity and specificity of combined results of the tests with VM. RESULTS: In 21 patients, a right-to-left shunt was demonstrated by TEE and contrast TCD (shunt positive). Twenty-one patients were negative in both investigations, no patient was positive on TEE and negative on TCD, and 16 patients were only positive on at least 1 TCD investigation but negative during TEE. Test 3 was the most appropriate test when combined with the results of 1 of the other tests with VM. The highest sensitivities were achieved with a diagnostic time window of 40 seconds and when the presence of a single microbubble was sufficient for the diagnosis of a shunt. CONCLUSIONS: TCD performed twice with 2 provocation maneuvers with Echovist is a sensitive method to identify TEE-proven cardiac right-to-left shunts. The VM should be performed for 5 seconds starting at 5 seconds after the beginning of contrast injection.


Subject(s)
Heart Septal Defects, Atrial/diagnostic imaging , Intracranial Embolism/diagnostic imaging , Stroke/diagnostic imaging , Ultrasonography, Doppler, Transcranial/methods , Adolescent , Adult , Aged , Aged, 80 and over , Contrast Media , Echocardiography , Female , Humans , Male , Middle Aged , Sensitivity and Specificity , Time Factors , Ultrasonography, Doppler, Transcranial/standards , Valsalva Maneuver
17.
Cerebrovasc Dis ; 10(4): 272-7, 2000.
Article in English | MEDLINE | ID: mdl-10878431

ABSTRACT

The present study was designed to perform follow-up transcranial Doppler investigations for microembolic signals (MES) in acute stroke patients by means of a strict protocol. The number of MES was correlated with stroke etiology and the strength of antithrombotic treatment. Concurrently, we wanted to demonstrate that MES in acute stroke patients are solid in nature and not gaseous. Nineteen patients with middle cerebral artery ischemic events, 16 with completed stroke and 3 with transient ischemic attack (TIA) were investigated within 24 h following the onset of symptoms. Six 1-hour recordings on days 1, 2, 3, 4, 7 and 14 were performed from the affected middle cerebral artery. The four-gate technique and recently established criteria for the identification of MES were used. Eight of 19 patients showed MES in at least one recording. Variability was high and showed no uniform tendency with respect to time since onset of symptoms or treatment. All 3 patients with internal carotid artery dissection showed MES. In 3 patients with lacunar stroke, no MES were detected. Two patients with MES suffered recurrent TIAs during the observation period, whereas none of the patients without MES suffered a recurrent ischemic event. In the acute phase following stroke, ongoing, emerging and vanishing embolization in some patients may reflect individual active processes of remodelling, healing and disruption or disappearance of the embolic source.


Subject(s)
Intracranial Embolism/complications , Intracranial Embolism/diagnostic imaging , Stroke/etiology , Acute Disease , Adult , Aged , Female , Follow-Up Studies , Humans , Male , Middle Aged , Stroke/diagnostic imaging , Ultrasonography, Doppler, Transcranial
18.
Stroke ; 31(6): 1335-41, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10835453

ABSTRACT

BACKGROUND AND PURPOSE: The clinical application of Doppler detection of circulating cerebral emboli will depend on a reliable automated system of embolic signal detection; such a system is not currently available. Previous studies have shown that frequency filtering increases the ratio of embolic signal to background signal intensity and that the incorporation of such an approach into an offline automated detection system markedly improved performance. In this study, we evaluated an online version of the system. In a single-center study, we compared its performance with that of a human expert on data from 2 clinical situations, carotid stenosis and the period immediately after carotid endarterectomy. Because the human expert is currently the "gold standard" for embolic signal detection, we also compared the performance of the system with an international panel of human experts in a multicenter study. METHODS: In the single-center evaluation, the performance of the software was tested against that of a human expert on 20 hours of data from 21 patients with carotid stenosis and 18 hours of data from 9 patients that was recorded after carotid endarterectomy. For the multicenter evaluation, a separate 2-hour data set, recorded from 5 patients after carotid endarterectomy, was analyzed by 6 different human experts using the same equipment and by the software. Agreement was assessed by determining the probability of agreement. RESULTS: In the 20 hours of carotid stenosis data, there were 140 embolic signals with an intensity of > or =7 dB. With the software set at a confidence threshold of 60%, a sensitivity of 85.7% and a specificity of 88.9% for detection of embolic signals were obtained. At higher confidence thresholds, a specificity >95% could be obtained, but this was at the expense of a lower sensitivity. In the 18 hours of post-carotid endarterectomy data, there were 411 embolic signals of > or =7-dB intensity. When the same confidence threshold was used, a sensitivity of 95.4% and a specificity of 97.5% were obtained. In the multicenter evaluation, a total of 127 events were recorded as embolic signals by at least 1 center. The total number of embolic signals detected by the 6 different centers was 84, 93, 108, 92, 63, and 78. The software set at a confidence threshold of 60% detected 90 events as embolic signals. The mean probability of agreement, including all human experts and the software, was 0.83, and this was higher than that for 2 human experts and lower than that for 4 human experts. The mean values for the 6 human observers were averaged to give P=0.84, which was similar to that of the software. CONCLUSIONS: By using the frequency specificity of the intensity increase occurring with embolic signals, we have developed an automated detection system with a much improved sensitivity. Its performance was equal to that of some human experts and only slightly below the mean performance of a panel of human experts


Subject(s)
Algorithms , Carotid Stenosis/complications , Electronics , Endarterectomy, Carotid/adverse effects , Intracranial Embolism/diagnostic imaging , Middle Cerebral Artery/diagnostic imaging , Online Systems , Ultrasonography, Doppler, Transcranial , Automation , Carotid Stenosis/surgery , Equipment Design , Evaluation Studies as Topic , Expert Testimony , Fuzzy Logic , Humans , Intracranial Embolism/diagnosis , Intracranial Embolism/etiology , Observer Variation , Sensitivity and Specificity , Single-Blind Method , Software
20.
Neuroradiology ; 42(4): 233-9, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10872165

ABSTRACT

The frequency, predisposing factors and clinical consequences of haemorrhagic infarcts and damaged blood-brain barrier as shown by contrast enhancement (CE) in ischaemic cerebral infarcts are controversial. We prospectively compared the sensitivity of CT and MRI to haemorrhagic transformation (HT) and CE. We also wished to investigate the clinical significance of HT and factors possibly associated with it. We studied 36 patients with acute ischaemic infarcts in the middle cerebral artery territory during the first 2 weeks after the ictus. After CT and rating of the neurological deficit on admission, serial examinations with clinical neuromonitoring, contrast-enhanced CT and MRI were done on the same day. The occurrence and severity of HT were correlated with CE, stroke mechanism, infarct size, development of neurological deficits and antithrombotic treatment. The frequency of HT detected by MRI was 80%. CE usually preceded HT or was seen simultaneously. MRI had a higher sensitivity than CT to HT and CE. Severity of HT was positively correlated with infarct size (P < 0.01). HT had no influence on patient's neurological status. Neither the type of antithrombotic treatment nor the stroke mechanism was associated with the severity of HT. No parenchymal haemorrhage occurred.


Subject(s)
Brain Ischemia/diagnosis , Cerebral Hemorrhage/diagnosis , Cerebral Infarction/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Brain/pathology , Cerebral Hemorrhage/complications , Cerebral Infarction/complications , Child , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Prognosis , Prospective Studies , Severity of Illness Index , Tomography, X-Ray Computed
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