Platelets in patients with acute ischemic stroke are exhausted and refractory to thrombin, due to cleavage of the seven-transmembrane thrombin receptor (PAR-1)

Platelet activation is involved in the pathogenesis of cerebrovascular ischemia, but the major agonist involved has yet to be identified. To investigate the role of thrombin in platelet activation in patients with acute ischemic stroke, and while thrombin is the most likely candidate for activation of the thrombin receptor PAR-1 in vivo, we assessed its cleavage and internalization using the antibodies SPAN12, binding to uncleaved PAR-1, and WEDE15, recognizing cleaved and uncleaved, but not internalized PAR-1. In contrast to healthy age-matched controls, platelets from stroke patients exhibited significant cleavage and internalization of PAR-1 (P<0.001) and failed to respond to thrombin in vitro. Enhanced surface expression of CD62P, CD63, TSP-1 and less mepacrine uptake showed platelet degranulation during stroke. Platelets from patients with acute cerebral ischemia are exhausted and desensitized to thrombin through cleavage of PAR-1, indicating that high concentrations of thrombin occur with acute cerebrovascular ischemic events in vivo.

Randomised controlled trial to evaluate the efficacy and usability of a computerised phone-based lifestyle coaching system for primary and secondary prevention of stroke

Background

One of the most effective current approaches to preventing stroke events is the reduction of lifestyle risk factors, such as unhealthy diet, physical inactivity and smoking. In this study, we assessed the efficacy and usability of the phone-based Computer-aided Prevention System (CAPSYS) in supporting the reduction of lifestyle-related risk factors.

Methods

A single-centre two-arm clinical trial was performed between January 2013 and February 2014, based on individual follow-up periods of six months with 94 patients at high risk of stroke, randomly assigned to an intervention group (IC: 48; advised to use the CAPSYS system) or a standard care group (SC: 46). Study parameters, such as blood pressure, blood values (HDL, LDL, HbA1c, glycaemia and triglycerides), weight, height, physical activity as well as nutrition and smoking habits were captured through questionnaires and medical records at baseline and post-intervention and analysed to detect significant changes. The usability of the intervention was assessed based on the standardised System Usability Scale (SUS) complemented by a more system-specific user satisfaction and feedback questionnaire.

Results

The statistical evaluation of primary measures revealed significant decreases of systolic blood pressure (mean of the differences = –9 mmHg; p = 0.03; 95 % CI = [–17.29, –0.71]), LDL (pseudo-median of the differences = –7.9 mg/dl; p = 0.04; 95 % CI = [–18.5, –0.5]) and triglyceride values (pseudo-median of the differences = –12.5 mg/dl; p = 0.04; 95 % CI = [–26, –0.5]) in the intervention group, while no such changes could be observed in the control group. Furthermore, we detected a statistically significant increase in self-reported fruit and vegetable consumption (pseudo-median of the differences = 5.4 servings/week; p = 0.04; 95 % CI = [0.5, 10.5]) and a decrease in sweets consumption (pseudo-median of the differences = –2 servings/week; p = 0.04; 95 % CI = [–4, –0.00001]) in the intervention group. The usability assessment showed that the CAPSYS system was, in general, highly accepted by the users (average SUS score: 80.1).

Conclusions

The study provided encouraging results indicating that a computerised phone-based lifestyle coaching system, such as CAPSYS, can support the usual treatment in reducing cerebro-cardiovascular risk factors and that such an approach is well applicable in practice.

Trial registration

ClinicalTrials.gov Identifier: NCT02444715

Stroke awareness in luxemburg: deficit concerning symptoms and risk factors

BACKGROUND

Awareness of stroke risk factors is important for stroke prevention. Knowledge of stroke symptoms and awareness regarding the necessity of seeking urgent stroke treatment are vital to provide rapid admission to a stroke unit. Data on this specific knowledge in Luxemburg are lacking.

METHODS

We investigated 420 patients from the Department of Neurology and their relatives using a questionnaire. There were 44% men and 56% women; 25% were immigrants and 75% Luxemburgish nationals; 13% already had had a stroke or transient ischemic attack (TIA); and the mean age was 55 years ranging from 18 to 87 years.

RESULTS

A total of 88% of participants knew that a stroke occurs in the head/brain. In all, 10% of participants did not know any symptom of a stroke. The most frequently quoted symptoms (>15%) were paralysis/weakness (36%), speech disorders (32%), cranial nerve deficit (16%), vertigo (15%), and visual disorders (15%). Sensory deficits were mentioned by only 4% of patients. Known risk factors (>15%) were smoking (40%), hypertension (32%), alcohol (32%), poor nutrition (28%), high cholesterol (26%), stress (23%), and lack of exercise (19%). Age (4%), diabetes (6%), carotid stenosis (2%), and heart disease (1%) were less frequently known. In all, 11% of participants did not know any risk factor of a stroke. A total of 89% of participants would correctly call the 112 (emergency phone number). The following groups were better informed: Luxemburgish nationals, younger people, and participants with higher education level. Stroke/TIA patients were better informed concerning stroke symptoms, but unfortunately not concerning how to react in the case of a stroke. There was no relevant gender difference.

DISCUSSION

Although most of the participants knew what to do in the case of a stroke, they did not know the relevant stroke symptoms and risk factors. Future campaigns should therefore focus on risk factors and symptoms, and should address immigrants, elderly persons, less-educated persons, and patients who had already suffered a stroke/TIA.

Advice on lifestyle changes (diet, red wine and physical activity) does not affect internal carotid and middle cerebral artery blood flow velocity in patients with carotid arteriosclerosis in a randomized controlled trial

BACKGROUND

A Mediterranean diet, with and without small daily amounts of red wine, and physical activity reduce the risk of cerebrovascular disease and improve cognition. An increase in cerebral blood flow may be the underlying mechanism. Under normal conditions, cerebral blood flow velocity changes in the internal carotid arteries and in large basal cerebral arteries correlate closely with cerebral blood flow changes, as the diameter of these vessels hardly changes and only the smaller vessels downstream change their diameter.

METHODS

A prospective randomized controlled trial was performed in 108 patients with carotid atherosclerosis (mean age 64 years, 67% men, 66% on statin therapy). Half of them were advised to follow a polyphenol-rich modified Mediterranean diet including 1-2 tomatoes, 3-5 walnuts and a bar of dark chocolate (25 g) a day and to perform moderate physical exercise for 30 min/day (lifestyle changes). Within these two groups, half of the patients were randomized either to avoid any alcohol or to drink 100 ml of red wine (women) or 200 ml of red wine (men) daily. Bilateral middle cerebral and internal carotid blood flow velocity (peak systolic, peak end-diastolic and mean) was measured at baseline and after 4 and 20 weeks using colour-coded duplex ultrasound. Insonation depth and insonation angle were used to identically place the sample volume during follow-up investigations. A general linear model with Tukey-Kramer adjustment for multiple comparisons was used to assess the primary end points. For the analysis we used the mean values of the right and left artery.

RESULTS

Neither lifestyle changes nor red wine had an effect on peak systolic, peak end-diastolic or mean cerebral blood flow velocity.

CONCLUSIONS

Advice on lifestyle changes, including a modified polyphenol-rich Mediterranean diet, a glass of red wine daily and physical exercise, did not affect middle cerebral and internal carotid blood flow velocity in our patient group with carotid atherosclerosis. An increase in cerebral blood flow is thus unlikely to be the cause of the reduced risk of cerebrovascular disease and improved cognitive functioning described in the literature. One possible explanation for the fact that blood flow velocity was not affected by red wine, diet and physical activity advice is that two thirds of our patients were already on statin therapy. Statins increase cerebral blood flow and vasomotor reactivity via nitric oxide.

A daily glass of red wine associated with lifestyle changes independently improves blood lipids in patients with carotid arteriosclerosis: results from a randomized controlled trial

BACKGROUND

Physical exercise and a Mediterranean diet improve serum lipid profile. The present work studied whether red wine has an effect on top of a lipid-lowering lifestyle in patients with carotid atherosclerosis.

METHODS

A prospective randomised unblinded trial was performed from 2009 to 2011 in 108 patients with carotid atherosclerosis, 65% of whom were already on statin therapy with a low mean LDL of 104.9 mg/dl. Half of them were advised to follow a modified Mediterranean diet and to perform moderate physical exercise during 30 min/day (lifestyle changes) for 20 weeks. Within these two groups half of the patients were randomised either to avoid any alcohol or to drink 100 ml of red wine (women) or 200 ml of red wine (men) daily.

RESULTS

LDL was significantly lowered by 7% in the lifestyle-changes group compared to the no-lifestyle-changes group (p = 0.0296) after 20 weeks. Lifestyle changes lowered the LDL/HDL ratio after 20 weeks by 8% (p = 0.0242) and red wine independently by 13% (p = 0.0049). The effect on LDL/HDL ratio after 20 weeks was, however, more pronounced in the non-LC group. Total cholesterol (-6%; p = 0.0238) and triglycerides (-13%; p = 0.0361) were lowered significantly by lifestyle changes after 20 weeks compared to the no-lifestyle-changes group. Lipoprotein (a) was not significantly affected by any intervention. The given results are per ITT analysis.

CONCLUSIONS

Lifestyle changes including a modified Mediterranean diet and physical exercise as well as a glass of red wine daily improve independently the LDL/HDL ratio in patients with carotid arteriosclerosis even though the vast majority of them was already on statin therapy.

A daily glass of red wine and lifestyle changes do not affect arterial blood pressure and heart rate in patients with carotid arteriosclerosis after 4 and 20 weeks

BACKGROUND

Regular consumption of small amounts of red wine improves blood lipids. However, there is concern whether this beneficial effect might be counterbalanced by an increase in blood pressure (BP) and heart rate (HR), which are risk factors for cerebro-cardiovascular disease. In particular, we studied whether regular consumption of red wine with and without lifestyle changes (LC; healthy diet and physical activity advice) results in an increase in BP and HR.

METHODS

A prospective, unblinded randomized trial was performed in 108 patients (67% men) with carotid atherosclerosis documented by ultrasound, a mean BP of 122/79 mm Hg and a mean HR of 71 bpm at inclusion in the study. Sixty-eight percent were known and treated hypertensives. The mean 24-hour BP at baseline was 122/79 mm Hg. Half of the study participants, the control group, was seen by a nurse at baseline, after 4 and after 20 weeks, and was instructed not to change their eating and physical activity habits. In the other half, a dietician performed five sessions of 30 min each (at baseline, after 1 week and after 2, 3 and 4 weeks) giving advice on healthy eating based on a Mediterranean diet and physical exercise. The recommendations given were the following: 5 portions of fruit/vegetables per day, a diet low in absolute fat, a preference of vegetable oil (olive or rapeseed oil), whole-grain products, poultry, low-fat dairy products, 1 fat and 1 lean fish meal per week, reduced consumption of red meat, and avoidance of pork, ready-made meals, sugar and excessive salt intake. In addition, regular consumption of 1 bar of dark chocolate (25 g, >70% of cacao), 1-2 tomatoes, and 3-5 walnuts as well as at least 30 min of moderate daily physical activity were recommended. Within these two groups, half of the patients were randomized either to avoid alcohol completely or to drink 100 ml (women) or 200 ml of red wine (men) daily.

RESULTS

Neither LC nor red wine had an effect on the mean systolic and diastolic 24-hour BP and HR after 4 and 20 weeks, as analyzed by general linear modeling. No difference was found for diurnal and nocturnal values.

CONCLUSIONS

The possible beneficial effect of regular consumption of small amounts of red wine is not counterbalanced in the long term by an increase in the mean BP or HR in mainly normotensive and well-treated hypertensive patients with carotid atherosclerosis, neither in the patients given healthy lifestyle advice nor in those with a standard lifestyle. Yet, we remain cautious about actively advice patients to drink alcohol regularly given the well-known risks.

Clinical utility of echocontrast agents in neurosonology

INTRODUCTION

Neurosonological investigations of the extracranial and intracranial brain supplying arteries are helpful in the assessment of stroke and stroke-prone patients.

METHODS

In this paper we review the indications, application and advantages of second-generation (gas-filled) microbubble contrast agents such as SonoVue.

RESULTS

Gas-filled microbubbles have a strong echo enhancing effect and produce enhancement for several minutes, enabling the sonographer to perform the investigation with a single injection or two or three repeated injections without the need for continuous administration. Echocontrast agents provide better delineation of normal blood flow, occlusions, pseudo-occlusions, stenoses, and collaterals in the extracranial and intracranial vascular beds. They are of particular value during transcranial color-coded transcranial duplex investigations via the temporal and occipital window.

CONCLUSIONS

Echocontrast agents give additional information on the patient's vascular situation that is often crucial to planning further diagnostic and therapeutic steps. The use of second-generation gas-filled microbubbles, such as SonoVue in transcranial neurosonology, may help to avoid unnecessary, expensive and potentially harmful additional investigations such as intra-arterial DSA. Future applications include the visualization of brain tissue perfusion.

Comparison of a 1-MHz and a 2-MHz probe for microembolus detection using transcranial Doppler ultrasound

OBJECTIVES

Clinically silent microembolic signals (MES) can be detected by transcranial Doppler sonography (TCD). There is theoretical evidence that lower ultrasound emission frequencies may lead to a higher signal intensity and thus sensitivity to detect MES. We compared a 1-MHz probe with a 2-MHz probe regarding sensitivity in the detection of MES. Moreover, embolus detection by transcranial Doppler ultrasound is very time consuming and semi-automated detection is mandatory. Therefore, we studied an on-line algorithm using the bi-gate technique and the two transmission frequencies.

METHODS

After defining detection thresholds of > or = 12 dB (1 MHz) and > or = 10 dB (2 MHz) with eight normal subjects as MES-negative controls, taking into account natural fluctuations of the Doppler spectrum, we studied 36 patients with ischaemic events and five asymptomatic patients with incidental embolic sources. All patients subsequently underwent a 1-hour unilateral embolus detection from the middle cerebral artery (MCA) or the posterior cerebral artery (PCA), respectively, using 1 and 2 MHz for 30 minutes each in a randomized order. The software algorithm was compared with a blinded off-line analysis by an experienced observer as a gold standard.

RESULTS

The investigator detected 198 MES (range 0-41 MES) in the recordings of 29 patients out of the 41 patients using the 1-MHz probe and 101 MES (range 0-32 MES) in the recordings of 14 patients using the 2-MHz probe (p = 0.0007). Sensitivity of the software to detect MES confirmed by the investigator was 31% using 1 MHz and 41% using 2 MHz. The positive predictive value was 6 and 30%, respectively.

DISCUSSION

The sensitivity and positive predictive values of the automated algorithm to detect MES were unacceptably low for clinical practice with both frequencies. The use of 1 MHz instead of 2 MHz may, however, be useful when evaluating the recordings off-line by an experienced blinded observer.

The identification of right-to-left shunts using contrast transcranial Doppler ultrasound: performance and interpretation modalities, and absence of a significant side difference of cardiac micro-emboli

Cardiac and extracardiac right-to-left shunts can be identified by transesophageal echocardiography (TEE) as well as by transcranial Doppler ultrasound (TCD) using contrast agents that do not pass the lungs. Currently, the appropriate performance of a Valsalva manoeuvre (VM) to provoke the shunt, the use of different contrast agents and the classification of the TCD results are still under debate. In this study, we looked also at possible side effects of provoked cardiac micro-emboli in the left and right hemisphere. Seventy-one patients were investigated by both TEE and bilateral TCD of the middle cerebral arteries. The following protocol was applied in a randomized way: (1) Echovist-300 without VM; (2) Echovist-300, VM for 5 seconds starting 5 seconds after the beginning of contrast injection; (3) repetitive short VMs in between 2 and 13 seconds after the beginning of Echovist-300 injection; and (4) repetitive short VMs in between 2 and 13 seconds after the beginning of agitated saline injection. Only if one of the tests (2-4) was negative, this particular negative test was repeated. Use of Echovist-300, but not of saline yielded 100% sensitivity in the detection of TEE-proven shunts. The repetitive VM was slightly superior to the conventional VM. Introduction of a threshold of two or even three microbubbles produced less falsely positive TCD results in comparison to the TEE. There was no difference in microbubbles. TCD using Echovist-300 is a sensitive method to identify TEE-proven cardiac right-to-left shunts. Repetitive VM is an alternative to conventional VM.

[The reduction of stroke risk, risk of myocardial infarction and death by healthy diet and physical activity]

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.

Lifestyle counseling in patients with carotid arteriosclerosis from Luxemburg should focus more on the reduction of sugar, sodium and saturated fat consumption

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.

First description of posterior reversible encephalopathy syndrome as a complication of glycerolnitrate patch following open cardiac surgery

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.

[Actual state and prospects of acute stroke treatment in the Grand-Duchy of Luxemburg]

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.

Activated monocytes capture platelets for heterotypic association in patients with severe carotid artery stenosis

Inflammation and thrombosis, two processes influencing each other, are involved in the pathogenesis of cerebrovascular disease. We showed that in patients with acute ischaemic stroke circulating platelets are activated and exhausted. To identify whether activated haemostasis might be cause or effect, we investigated the role of leukocyte and platelet activation in patients with severe asymptomatic and symptomatic carotid artery disease. Flow cytometry analysis demonstrated that monocytes from symptomatic (acute stroke aetiology) and asymptomatic patients were highly activated, shown by significantly enhanced presentation of inflammatory markers CD11b and thrombospondin-1 (TSP-1) on the surface. Both correlated positively with monocyte-platelet association rate. However, increased monocyte activation and elevated levels of monocyte-platelet associates in asymptomatic patients were restricted to patients with echo-lucent plaques, providing a close link between monocyte activation and plaque morphology. Circulating single as well as monocyte-bound platelets from symptomatic patients showed significantly enhanced surface expression of P-selectin and TSP-1, whereas platelets from asymptomatic patients were not significantly activated. These results indicate that monocytes activated by inflammation rather than platelets might be the candidates to initiate platelet-monocyte rosetting during the pathogenesis of atherothrombotic cerebral ischaemia and that haemostasis might be activated secondarily by the first occurring inflammation.

Microembolic signals on transcranial Doppler ultrasound are correlated with platelet activation markers, but not with platelet-leukocyte associates: a study in patients with acute stroke and in patients with asymptomatic carotid stenosis

BACKGROUND

The in vivo correlates of microembolic signals (MES) are still unknown. Platelet-associates (PA) with monocytes or granulocytes or platelet aggregates only may represent these correlates.

METHODS

Thirty patients with asymptomatic carotid stenosis >50% and 16 patients with acute (<4 days) atherothrombotic stroke were investigated. PA, P-selectin and thrombospondin expressions on platelets were assessed by flow cytometry. Soluble P-selectin (sPS) levels were assessed. MES detections were performed by transcranial Doppler sonography for 1 hour. PA, P-selectin and thrombospondin expressions on platelets and sPS levels were compared between MES-positive (MES+) and MES-negative (MES-) patients.

RESULTS

Eight patients (27%) with asymptomatic carotid stenosis had 1-26 MES/h. Degree of stenosis was 78 +/- 10% in MES- and 88 +/- 8% in the MES+ (p=0.01). There were no differences in percentages of PA. P-selectin and thrombospondin surface expression was lower in MES+, but this was not significant. sPS levels were higher in MES+ (122 +/- 27 ng/ml versus 80 +/- 25 ng/ml in MES-, p=0.01). Seven (44%) patients with stroke had 1-39 MES/h. There were no differences in percentages of PA. MES+ had higher sPS levels (178 +/- 43 versus 121 +/- 44 ng/ml, p=0.02) and less P-selectin surface expression than MES- (9.0 +/- 3.4 versus 4.5 +/- 1.6%, p=0.004).

CONCLUSION

High levels of sPS in MES+ and lower expression of platelet activation markers on platelets' surface suggest shedding of activation markers from the platelets' surface and thus enhanced activation of platelets of MES+ compared with MES-. PA are probably not the clinical correlates of MES, but platelets seem to be the main cellular element of solid cerebral microemboli.

Diffusion weighted MRI imaging and MES detection in the assessment of stroke origin

OBJECTIVES

This study compares the additional benefit of diffusion-weighted MRI (DWI) and microembolus detection by transcranial Doppler ultrasonography (TCD) in the assessment of stroke etiology.

METHODS

Fifty-five acute anterior circulation stroke or TIA patients were investigated by both cranial DWI and bilateral TCD of the middle cerebral arteries (1 hour).

RESULTS

In one of the 13 patients without acute ischemic lesions visualized on DWI, microembolic signal (MES) detection was positive. However, in 33 out of 44 patients without MES, DWI revealed at least one lesion. In two patients with unilateral territorial infarction and otherwise normal cardiovascular work-up, bilateral MES were found thus localizing the embolic source into the aortic arch or the heart. In a further patient with a dissection, the occurrence of contralateral MES raised doubts on a dissection to be the cause of the infarct.

DISCUSSION

There is a contribution of both techniques to the understanding of stroke etiology. The impact of DWI is, however, superior to that of MES detection. Longer TCD recording times may diminish this discrepancy.

Creutzfeldt-Jakob disease with slow progression. A mimickry of progressive supranuclear palsy

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.

[Restless legs syndrome]

About 7% of the population are affected by the restless legs syndrome (RLS). The most invalidating subjective complaints are dysesthesia / pain / an urge to move the legs (46%), an alteration of sleep (38%), and difficulties in performing activities of daily life (7%). The onset of the disease is variable, ranging from childhood (often unrecognised) to old age. The clinical course is generally chronic with phases of spontaneous remission. The cause of RLS is probably mainly genetic with a dysfunction of iron and dopamine metabolism accentuated by peripheral factors (neuropathy, radiculopathy, and temperature). There are secondary forms of RLS, such as iron deficiency (under debate), side effects of drugs (that can be stopped), renal insufficiency, radiculopathy, and neuropathy. RLS can come up during pregnancy, in particular in the last trimenon. Treatment of aggravating factors and sleep hygiene are general measures. Drug treatment of the RLS comprises levodopa, dopaminergic drugs, opioids, and antiepileptic drugs; however, drug treatment is only necessary in about a third of the affected.

The Use of Embolic Signal Detection in Multicenter Trials to Evaluate Antiplatelet Efficacy

BACKGROUND AND PURPOSE

The CARESS (Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic carotid Stenosis) trial proved the effectiveness of the combination of clopidogrel and aspirin compared with aspirin alone in reducing presence and number of microembolic signals (MES) in patients with recently symptomatic carotid stenosis. The present study aimed at installing primary and secondary quality control measures in CARESS because MES evaluation relies on subjective judgment by human experts.

METHODS

As primary quality control, centers participating in CARESS evaluated a reference digital audio tape (DAT) before the study containing both MES and artifacts. Interobserver agreement of classifying signals as MES was expressed as proportions of specific agreement of positive ratings (ps+/-values). For all DATs included in CARESS (n=300), online number of MES and off-line number of MES read by the central reader were compared using correlation coefficients. As secondary control, a sample of 16 of 300 DATs was cross-validated by another independent reader (post-trial validator).

RESULTS

For the reference tape, the cumulative ps+/-value was 0.894 based on 12 of 14 observers. Two observers with very different results improved after a training procedure. Agreement between post-trial validator and central reader was ps+=0.805, indicating very good agreement. Correlation between online evaluation and off-line evaluation of DATs was very good overall (cumulative rho=0.84; P<0.001).

CONCLUSIONS

Multicenter studies using MES as outcome parameter are feasible. However, primary and secondary quality control procedures are important.

Benefit of Echocontrast-Enhanced Transcranial Arterial Color-Coded Duplex Ultrasound

OBJECTIVES

Proper assessment of the intracranial arteries by transcranial color-coded duplex sonography (TCCD) is occasionally made difficult by an insufficient temporal bone window, an unfavorable insonation angle, or low flow velocity or volume. In these cases, echocontrast could be helpful to increase the diagnostic confidence or to make the diagnosis at all.

MATERIAL AND METHODS

We investigated 67 temporal windows of 47 patients with insufficient native transtemporal insonation conditions before and after the application of the second-generation (gas-filled) microbubble contrast agent Sonovue (in 20 patients out of these 47, both temporal windows were insufficient, in the remaining 27 only one side).

RESULTS

As compared to the precontrast scans, echocontrast allowed for more segments to be evaluated by pulsed Doppler sonography (p < 0.0001) and for longer lumen segments to be displayed on color mode (p < 0.0001). With the help of contrast medium, flow velocity in the middle cerebral artery could be measured through 65 windows as compared to only 26 windows before contrast was applied (p < 0.0001).

CONCLUSIONS

In patients with poor precontrast visualization of intracranial arteries, echocontrast-enhanced TCCD is very helpful.

Surgical Closure of Combined Symptomatic Patent Foramen Ovale and Atrial Septum Aneurysm for Prevention of Recurrent Cerebral Emboli

BACKGROUND

Patients with patent foramen ovale (PFO) have an undefined but certainly considerable risk of repeated cerebral ischemia due to paradoxical embolism. Especially, if a cerebrovascular event has already occurred and the combination with an atrial septum aneurysm (ASA) is present this risk increases tremendously. The aim of this study was to demonstrate that surgical closure of PFO in combination with an ASA is safe and useful in preventing recurrent strokes.

METHODS

Ten patients with previous cerebral ischemia, proven by CT or MRI, and PFO in combination with an ASA were prospectively scheduled for surgical closure. Patients with extracardiac sources of embolic disease were excluded from this study. However, one patient suffered from a hypercoagulability syndrome.

RESULTS

All patients (mean age 35.5 +/- 19.1 years) underwent direct suture of the PFO and plication of the ASA with the aid of cardiopulmonary bypass and cardioplegic arrest (n = 3) or ventricular fibrillation (n = 7). Mean operation time was 123.1 +/- 20.2 minutes; mean bypass time was 34.5 +/- 9.9 minutes. There was no mortality or significant postoperative morbidity. Mean hospital stay was 5.1 +/- 1.5 days. During a follow-up of >4 years, no recurrent stroke or transient ischemic attack occurred and no patient received anticoagulation therapy.

CONCLUSION

Our data suggest that surgical closure of PFO in combination with ASA in patients with previous stroke is safe and efficacious to prevent recurrent strokes and avoids lifelong anticoagulation.

Dual Antiplatelet Therapy With Clopidogrel and Aspirin in Symptomatic Carotid Stenosis Evaluated Using Doppler Embolic Signal Detection

Background— Evidence for efficacy of dual antiplatelet therapy in stroke is limited. Symptomatic carotid stenosis patients are at high risk of early recurrent stroke. In this group, asymptomatic microembolic signals (MES), detected by transcranial Doppler ultrasound (TCD), are markers of future stroke and transient ischemic attack (TIA) risk. They offer a surrogate marker to evaluate antiplatelet therapy, but no multicenter study has evaluated the feasibility of this approach.

Methods and Results— Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Stenosis (CARESS) is a randomized, double-blind study in subjects with recently symptomatic ≥50% carotid stenosis. Patients were screened with TCD, and if MES were detected, they were randomized to clopidogrel and aspirin or aspirin monotherapy. Repeated TCD recordings were made on days 2 and 7. MES were detected in 110 of 230 patients by online analysis at baseline, of whom 107 were randomized. Intention-to-treat analysis revealed a significant reduction in the primary end point: 43.8% of dual-therapy patients were MES positive on day 7, as compared with 72.7% of monotherapy patients (relative risk reduction 39.8%; 95% CI, 13.8 to 58.0; P =0.0046). The secondary end point of MES frequency per hour was reduced (compared with baseline) by 61.4% (95% CI, 31.6 to 78.2; P =0.0013) in the dual-therapy group at day 7 and by 61.6% (95% CI, 34.9 to 77.4; P =0.0005) on day 2. There were 4 recurrent strokes and 7 TIAs in the monotherapy group versus no stroke and 4 TIAs in the dual-therapy group that were treatment emergent and ipsilateral to the qualifying carotid stenosis; 2 additional ipsilateral TIAs occurred before treatment started. MES frequency was greater in the 17 patients with recurrent ipsilateral events compared with the 90 without (mean±SD: 24.4±27.7 versus 8.9±11.5 per hour; P =0.0003).

Conclusions— In patients with recently symptomatic carotid stenosis, combination therapy with clopidogrel and aspirin is more effective than aspirin alone in reducing asymptomatic embolization. Doppler MES detection is a feasible method to evaluate the efficacy of antiplatelet therapy in multicenter studies.

Role of cerebral amyloid angiopathy in intracerebral hemorrhage in hypertensive patients

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.

Measuring carotid artery stenosis

OBJECTIVE

Five different calliper methods for assessing the degree of carotid artery stenosis and visual estimation ("eyeballing") of postmortem carotid arteriograms were compared with the planimetric gold standard of the area reduction at the site of the stenosis.

METHODS

During autopsy 53 carotid specimens were removed in toto from 31 neurological patients. Carotid arteries were ligated and redistended to a physiological degree for standardised three-plane arteriography. Afterwards, the entire specimen was filled with an embedding medium under the same conditions and sectioned. Slices at the site of stenoses were histologically processed. Computerised planimetric analysis of the lumen area reduction was performed and compared with the arteriographic findings. Arteriograms were evaluated by two independent observers by means of linear Common Carotid Artery (CC), the European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET), and squared measurements (NASCET2, ECST2) after applying the pi r2 function. Further, three independent observers performed eyeballing of the degree of stenosis from the postmortem arteriographies.

RESULTS

Planimetry was carried out in 29 internal carotid artery (ICA) and 17 common carotid artery (CCA) stenoses ranging from 8.5 to 100%. The smallest mean differences of the degree of stenosis in % between planimetry and arteriography were -0.5 and 0.6%. The narrowest 95 %-limits of agreement covered a range of +/-24.1 and 26.3% of stenoses, and the highest correlation coefficients were both 0.9 for the CC and ECST2 techniques, respectively. By eyeballing, the degree of stenosis was underestimated by 13.5 to 15.8% on average. The narrowest limits of agreement between two observers for eyeballing covered a range of 35%.

CONCLUSION

Three-plane arteriography has only a moderate accuracy and reproducibility in detecting and measuring carotid artery stenosis independent of the technique of measurement used.

Microembolic Signal Predicts Recurrent Cerebral Ischemic Events in Acute Stroke Patients With Middle Cerebral Artery Stenosis

BACKGROUND AND PURPOSE

Cerebral embolism is a common cause of stroke. Microembolic signals (MES) detected by transcranial Doppler represent ongoing embolisms, but the lack of reliable data about its clinical relevance hinders its widespread use in clinical practice.

METHODS

We prospectively monitored 114 consecutive acute ischemic stroke patients with middle cerebral artery (MCA) stenosis for MES. The signals on digital audio tape were analyzed by an independent observer who was blinded to all other data. All patients were followed-up for the occurrence of recurrent stroke or transient ischemic attack (TIA) in the indexed MCA territory.

RESULTS

MES was detected in 25 (22%) patients. The mean number of MES was 18 (range, 1 to 102). MES were more common in patients with severe stenosis (10/21, 48%) than in those with mild-moderate stenosis (4/26, 15%) (Pearson chi2 P=0.02). During follow-up for a mean of 13.6 months (range, 1 to 32), 12 (12%) patients had further ischemic events (10 strokes and 2 TIAs) in the affected MCA region during follow-up. Among these, 7 (58%) had recurred within 1 month (1 recurred within 1 week, the other 6 patients had recurrences in week 3 or 4 after discharge), 3 within 6 months, 1 within 6 to 12 months, and the remaining 1 recurred after 1 year. The presence of MES was the only predictor of a further ischemic stroke/TIA by Cox regression (adjusted odds ratio, 8.45; 95% CI, 1.69 to 42.22; P=0.01) even after controlling for age, sex, diabetes, hypertension, previous stroke, smoking, and acute treatment.

CONCLUSIONS

In acute stroke patients with MCA stenosis, MES predicts further cerebral ischemia. This procedure should be considered as part of routine investigation and might identify a group of patients who are most likely to benefit from antithrombotic treatment.

Solid or gaseous circulating brain emboli: are they separable by transcranial ultrasound?

High-intensity transient signals (HITS) detected by transcranial Doppler (TCD) ultrasound may correspond to artifacts or to microembolic signals, the latter being either solid or gaseous emboli. The goal of this study was to assess what can be achieved with an automatic signal processing system for artifact/microembolic signals and solid/gas differentiation in different clinical situations. The authors studied 3,428 HITS in vivo in a multicenter study, i.e., 1,608 artifacts in healthy subjects, 649 solid emboli in stroke patients with a carotid stenosis, and 1,171 gaseous emboli in stroke patients with patent foramen ovale. They worked with the dual-gate TCD combined to three types of statistical classifiers: binary decision trees (BDT), artificial neural networks (ANN), and support vector machines (SVM). The sensitivity and specificity to separate artifacts from microembolic signals by BDT reached was 94% and 97%, respectively. For the discrimination between solid and gaseous emboli, the classifier achieved a sensitivity and specificity of 81% and 81% for BDT, 84% and 84% for ANN, and 86% and 86% for SVM, respectively. The current results for artifact elimination and solid/gas differentiation are already useful to extract data for future prospective clinical studies.

Does ultrasound contrast agent improve the diagnostic value of colour and power Doppler sonography in superficial lymph node enlargement?

OBJECTIVE

to analyse whether ultrasound contrast agent (UCA) improves the diagnostic accuracy to differentiate between benign and malignant superficial lymph node enlargement by using colour-coded duplex sonography (CCDS) and power Doppler (PD).

METHODS

32 patients with suspected malignant superficial lymph node enlargement prospectively underwent standardised ultrasound examinations using B-mode sonography and native and contrast-enhanced CCDS and PD immediately before biopsy. Solbiati-Index (longitudinal-transverse diameter ratio) and intranodal flow patterns by using different vascularisation types were assessed. Histological and sonographical findings were correlated.

RESULTS

27 malignant and 5 benign lymph nodes were found. Solbiati-Index was lower in malignant lymph nodes than in benign nodes (mean 1.5 vs. 2.4, P<0.045). More intranodal flow patterns could be detected after UCA (53 vs. 43) but the number of correctly identified malignant nodes decreased after UCA (26 vs. 24) and the number of correctly identified benign nodes remained constant compared with native CCDS and PD. In 31% of the colour-mode studies, PD was considered to visualise more clearly intranodal vascular flow patterns than CCDS.

CONCLUSION

despite depicting more intranodal vascular patterns, the use of an ultrasound contrast agent seems not to improve the diagnostic value of CCDS and PD compared with native colour-mode studies in superficial lymph node enlargement.

[Cerebral apoplexy--importance of diagnosis and therapy in acute stroke]

Every day occur about 4 strokes in the Grand-Duchy of Luxemburg. Stroke is the third cause of death and the first cause of acquired handicap. Stroke constitutes a major individual and social problem. Stroke and TIA are neurological emergency conditions that warrant immediate hospitalisation on a stroke unit, where a dedicated equipe of neurologists, nurses, speech and occupational therapists, physiotherapists and social workers in collaboration with other medical and surgical specialties provide up-to-date diagnostic and therapeutic measures. These include the diagnostic work-up of stroke aetiology and the vascular status, monitoring to ensure the maintenance of homeostasis, thrombolysis and revascularisation, antithrombotic drug treatment relying on individual stroke pathophysiology, treatment of risk factors and early rehabilitation. By treatment on a stroke unit, death and disability can be reduced by 27%, in the case of intravenous thrombolysis even by 45%.

Right-to-Left-Shunts Detected by Transesophageal Echocardiography and Transcranial Doppler Sonography

BACKGROUND

Transesophageal echocardiography (TEE) and transcranial Doppler sonography (TCD) can identify right-to-left-shunts that predispose to paradoxical embolism. In a large cohort we compared the results of both techniques.

METHODS

222 patients were investigated by both techniques using the contrast agent Echovist-300 and performing each test once without and once with the Valsalva maneuver (VM).

RESULTS

TEE-proven right-to-left-shunts were detected by TCD with a high sensitivity of 94%. In addition, TCD revealed shunts not noted during TEE in about 20% of all patients studied. These shunts are in general smaller than those concordantly identified; however, 9% of the patients without a TEE-proven shunt presented with a shunt that allows a considerable amount of contrast medium to pass. There were 12% more microbubbles detected in the right middle cerebral artery than in the left middle cerebral artery during the TCD test performed with VM, but not during the TCD test performed without VM.

CONCLUSIONS

Contrast-enhanced TEE and TCD are complementary methods in the assessment of stroke and stroke-prone patients. The side difference of microbubbles may indicate a selective streaming of cardiac emboli during VM.

Reduction of circulating microemboli in the subclavian vein of patients undergoing haemodialysis using pre-filled instead of dry dialysers

BACKGROUND

Chronic microembolization that can be demonstrated by pulsed Doppler ultrasound may give rise to pulmonary side-effects during haemodialysis by direct vessel obstruction, increased complement activation or platelet aggregation. The objective of the present investigation was to study whether the use of pre-filled instead of dry dialysers would help to minimize the number of microemboli.

METHODS

The study cohort consisted of 23 patients undergoing maintenance haemodialysis. Using a 2 MHz pulsed ultrasound device, the subclavian vein downstream to the dialysis fistula was investigated for 10 min during the dialysis session. The ultrasound examination was performed twice during two successive dialysis sessions, using a pre-filled or a dry dialyser in randomized order.

RESULTS

In all patients investigated, numerous microembolic signals (MES) could be observed in the subclavian vein. Treatment with pre-filled dialysers was associated with significantly less MES (82 +/- 94) as compared with dry dialysers (268 +/- 296; P = 0.002).

CONCLUSIONS

In comparison to dry dialysers, the use of pre-filled dialysers leads to a significant reduction in microembolization, which may prevent repeated damage to the pulmonary vasculature and, thus, cause less pulmonary damage.

Microembolus Detection in Four Patients with Fabry’s Disease: Further Support for a Primarily Microangiopathic Origin of Early Cerebrovascular Symptoms

Fabry's disease is a sex-linked recessive storage disorder leading to cerebrovascular symptoms in many cases. Whether the primary origin of cerebrovascular symptoms in these patients is due to autochthonous thrombosis of small vessels or embolic infarction from large vessels is under debate. Microembolic signals (MES) indicative of an active embolic source can be recorded by transcranial Doppler sonography. We report four patients (34, 44, 62 and 66 years old) with Fabry's disease from one kindred in whom we carried out microembolus detection recordings to disclose active embolic sources. Three of the patients had had transient focal neurological deficits. Two patients had angina pectoris and one had exercise dyspnea, but no patient had clear evidence of disease of the large coronary vessels or brain-supplying arteries. No MES were found in 1-hour recordings in any patients, supporting the hypothesis that early cerebrovascular symptoms arise from small vessel occlusion and not from embolic sources as an indicator of disease of large brain-supplying arteries or cardiac embolism.

Image quality of the temporal bone window examined by transcranial Doppler sonography and correlation with postmortem computed tomography measurements

BACKGROUND AND PURPOSE

The major limitation of native transcranial colour-coded duplex sonography (TCCS) in older stroke patients is the relatively frequent occurrence of an insufficient temporal window. Our goal was to investigate the relationship between the in vivo Doppler ultrasound image quality of the temporal bone, and computed tomography (CT)-determined thickness, density, and homogeneity of cadaver temporal bone.

METHODS

Thirty-three moribund neurological patients who eventually died were examined by TCCS using the transtemporal approach. The sonographer categorized the quality of the TCCS image (excellent, intermediate, and poor). During autopsy, a rectangular sample of the temporal squama was removed, which corresponded to the area of the in vivo acoustic window. The thickness of the whole temporal bone, cortical, and cancellous (= diploe) bone as well as the density and homogeneity were determined by high-resolution CT.

RESULTS

Thirty-seven temporal bones were obtained. The quality of the acoustic window was classified as excellent in 13, intermediate in 6 and poor in 18 cases. A significant correlation between the complete bone thickness, as well as between the absolute thickness of the diploe and the quality of the acoustic window was found: the thinner the bone/diploe, the better the colour Doppler signal. The thickness of the cortical plates and the homogeneity of the bones were identical in the three image quality categories.

CONCLUSION

The transtemporal TCCS image quality depends mainly on the thickness of the cancellous component of the temporal bone.

On the origin of microembolic signals

BACKGROUND AND PURPOSE

Clinically silent circulating microembolic signals (MES) can be identified by transcranial Doppler ultrasound (TCD). It is not yet clear whether their occurrence is always linked to the presence of embolic sources.

METHODS

24 terminally ill patients (7 women, 17 men; mean age 68 years) were investigated by TCD of the middle cerebral arteries. These findings were correlated with a complete post-mortem examination of potential embolic pathways.

RESULTS

Four patients out of the 24 under investigation showed MES, 2 of them bilaterally. All these 4 MES-positive patients had a definite embolic source, i. e. bilateral carotid artery occlusive disease, endocarditis with thrombotic valvular adhesions and severe plaques in the aortic arch, dilated left atrium and a patent foramen ovale, or severe plaques in the aortic arch and a dilated left atrium, respectively.

CONCLUSION

In the investigated patient group, we could demonstrate that MES can only be found when an embolic source is present. The finding of MES justifies an extensive clinical and laboratory search for potential embolic sources including extracranial and intracranial colour-coded duplex ultrasound, ECG, Holter-ECG, and TEE.

Arterial hypertension and ischaemic stroke

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.

Effects of the ultrasound contrast-enhancing agent Levovist on the detection of intracranial arteries and stenoses in chinese by transcranial Doppler ultrasound

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.

Therapy of Sneddon syndrome

We report the case of a young woman with progressive cognitive decline and epilepsy. She showed ischemic cerebrovascular disease and proximal livedo racemosa. Antiphospholipid antibody (aPL) could not be detected and there were no microemboli on continuous transcranial Doppler ultrasonography monitoring. Histology of cerebral vessels showed intimal hyperplasia in small leptomeningeal venous vessels and micronecrosis of grey and white matter. We subsequently made the diagnosis of aPL-negative Sneddon Syndrome (SNS). Anticoagulation with warfarin could not be initiated because of a drug-resistant epilepsy with the risk of falls and subsequent bleeding; immunosuppression with steroids and azathioprine was ineffective, as was initial antiplatelet therapy with clopidogrel alone. However, when we intensified antiplatelet therapy by combining clopidogrel and ASS, a slowing of disease progression, as assessed by neuropsychological testing and magnetic resonance imaging, was noted on a follow-up after 6 months. Therapeutic options in SNS in both aPL-positive and aPL-negative patients with SNS are discussed.

Contrast transcranial Doppler ultrasound in the detection of right-to-left shunts: comparison of Echovist-200 and Echovist-300, timing of the Valsalva maneuver, and general recommendations for the performance of the test

BACKGROUND AND PURPOSE

Cardiac right-to-left shunts (RLS) can be identified by transesophageal echocardiography (TEE) as well as by transcranial Doppler ultrasound (TCD) using contrast agents, such as Echovist-200 or Echovist-300 in conjunction with a Valsalva maneuver (VM) as provocation procedure. Both Echovist preparations are in use. Currently, the appropriate timing of the VM is still under debate.

METHODS

Sixty-four patients were investigated by both TEE and bilateral TCD of the middle cerebral arteries. The following protocol was applied in a randomized way: (1) no VM, (2) VM for 5 s starting with the beginning of Echovist-300 injection, (3) VM for 5 s starting 5 s after the beginning of Echovist-300 injection, (4) VM for 5 s starting 10 s after the beginning of Echovist-300 injection, and (5) VM for 5 s starting 5 s after the beginning of Echovist-200 injection.

RESULTS

In 27 patients, an RLS was demonstrated by both TEE and contrast TCD (shunt-positive). Twenty-two patients were negative in both investigations, no patient was positive on TEE but negative on TCD, 15 patients were only positive on at least one TCD investigation but negative on TEE. Tests 3 and 5 were the most appropriate ones; test 3 was slightly superior to test 5.

CONCLUSIONS

TCD using Echovist-300 or Echovist-200 is a sensitive method to identify TEE-proven cardiac RLS. To achieve the best diagnostic accuracy, the VM should be performed for a duration of 5 s starting at 5 s following the beginning of contrast injection.

Microembolus detection by transcranial doppler sonography

Microembolic signals can be detected by transcranial ultrasound as signals of high intensity and short duration. These signals represent circulating gaseous or solid particles. To optimize the differentiation from artefacts and the background signal and to facilitate the clinical use, several attempts have been made to automatize the detection of microemboli. Microemboli occur spontaneously in various clinical situations but their clinical impact and possible therapeutical implications are still under debate. This article provides a review of the actual literature concerning the current state of technical and clinical aspects of microembolus detection.

Detection of carotid artery stenosis by in vivo duplex ultrasound: correlation with planimetric measurements of the corresponding postmortem specimens

BACKGROUND AND PURPOSE

The correct detection and quantification of carotid artery disease are of decisive impact on patient prognosis and adequate treatment. In this study, we evaluated the ability of ultrasonography to detect and to grade carotid artery stenosis through a comparison of the in vivo ultrasound findings with the planimetric analysis of the corresponding postmortem specimens.

METHODS

Shortly before their death, 59 critically ill neurological patients (mean age, 70 years) were prospectively examined by extracranial and intracranial Doppler sonography and color-coded duplex ultrasound. Carotid stenosis was classified by hemodynamic and morphological ultrasound criteria. Carotid specimens were removed in toto during autopsy. Under standardized conditions, specimens were redistended, sectioned, and histologically processed. Computerized planimetric measurements of the arteries were carried out and compared with the ultrasound findings. Correlation of the ultrasound and postmortem planimetric findings was available in 93 carotid bifurcations.

RESULTS

Through both techniques, 46 carotid arteries were found to be normal. Steno-occlusive carotid lesions ranged from 8.5% to 100% lumen reduction. Overall, r=0.96 and adjusted R(2)=0.90. For the steno-occlusive carotid lesions, r=0.91.

CONCLUSIONS

Extracranial and intracranial Doppler and color-coded duplex ultrasound permits reliable detection and quantification of carotid artery stenoses and occlusions even under difficult examination conditions in critically ill patients.

Carotid artery auscultation--anachronism or useful screening procedure?

Carotid bruits are supposed to indicate the presence of high-grade common carotid or extracranial internal carotid artery stenosis in a large proportion of patients. Using a stethoscope, we prospectively auscultated 273 carotid arteries of 145 patients blinded to the results of a complete extracranial and intracranial Doppler investigation including extracranial color-coded duplex ultrasound. Fifty-four arteries showed stenosis of > or = 50%-99%, or occlusion of the extracranial internal or the common carotid artery. In 25 of these arteries, a bruit was present. In 9 out of 16 patients with extracranial stenosis from 70%-99%, a bruit was detected. In one additional patient with a middle-grade external carotid artery stenosis, a bruit was also present. In seven additional patients, a bruit was present in the absence of any carotid artery stenosis, cardiac vitium or goiter. The sensitivity of carotid auscultation for the detection of a 70%-99% stenosis of the common or extracranial internal carotid artery was 56% and specificity was 91%. The positive predictive value of a bruit found during carotid auscultation was 27%, and the negative predictive value of a normal auscultation was 97%. Carotid auscultation is a useful screening procedure in the detection of carotid stenosis or occlusion, but requires confirmation by carotid ultrasound.

Optimizing the technique of contrast transcranial Doppler ultrasound in the detection of right-to-left shunts

BACKGROUND AND PURPOSE

A cardiac right-to-left shunt (RLS) can be identified by transesophageal echocardiography and transcranial Doppler ultrasound (TCD) with contrast agents and a Valsalva maneuver (VM) as a provocation procedure. This article applies the modalities of these tests detailed in previous studies to a large patient cohort and compares 2 contrast agents (saline and Echovist-300).

METHODS

Eighty-one patients were investigated by both transesophageal echocardiography and bilateral TCD of the middle cerebral arteries. The following protocol with injections of 10 mL agitated saline was applied in a randomized way: (1) no VM, (2) VM for 5 seconds starting 5 seconds after the beginning of contrast injection, and (3) repetition of the test with VM if the first test with VM was negative. The VM was performed for 5 seconds starting exactly 5 seconds after the beginning of saline injection. Thereafter, the same protocol was repeated with 10 mL Echovist-300 instead of saline.

RESULTS

Thirty-one patients had a cardiac RLS. The Echovist-300 investigation disclosed all these 31 shunts, but saline disclosed only 29 of them. Twenty-two had an RLS only in at least 1 of the above TCD tests, some of them even with a considerable shunt volume.

CONCLUSIONS

Contrast TCD performed with Echovist-300 but not with saline yields a 100% sensitivity to identify transesophageal echocardiography-proven cardiac RLSs. The TCD test should be repeated if negative the first time. This article gives detailed information for the optimization of the contrast TCD technique. Extracardiac shunts detected only during contrast TCD can have a considerable shunt volume and may allow for paradoxical embolism.

Mechanisms of acute cerebral infarctions in patients with middle cerebral artery stenosis: a diffusion-weighted imaging and microemboli monitoring study

Although most therapeutic efforts and experimental stroke models focus on the concept of complete occlusion of the middle cerebral artery as a result of embolism from the carotid artery or cardiac chamber, relatively little is known about the stroke mechanism of intrinsic middle cerebral artery stenosis. Differences in stroke pathophysiology may require different strategies for prevention and treatment. We prospectively studied 30 consecutive acute ischemic stroke patients with middle cerebral artery stenosis detected by transcranial Doppler and magnetic resonance angiography. Patients underwent microembolic signal monitoring by transcranial Doppler and diffusion-weighted magnetic resonance imaging. Characteristics of acute infarct on diffusion-weighted magnetic resonance imaging were categorized according to the number (single or multiple infarcts) and the pattern of cerebral infarcts (cortical, border zone, or perforating artery territory infarcts). The data of microembolic signals and diffusion-weighted magnetic resonance imaging were assessed blindly and independently by separate observers. Diffusion-weighted magnetic resonance imaging showed that 15 patients (50%) had single acute cerebral infarcts and 15 patients had multiple acute cerebral infarcts. Among patients with multiple acute infarcts, unilateral, deep, chainlike border zone infarcts were the most common pattern (11 patients, 73%), and for single infarcts, penetrating artery infarcts were the most common (10 patients, 67%). Microembolic signals were detected in 10 patients (33%). The median number of microembolic signals per 30 minutes was 15 (range, 3-102). Microembolic signals were found in 9 patients with multiple infarcts and in 1 patient with a single infarct (p = 0.002, chi(2)). The number of microembolic signals predicted the number of acute infarcts on diffusion-weighted magnetic resonance imaging (linear regression, adjusted R(2) =0.475, p < 0.001). Common stroke mechanisms in patients with middle cerebral artery stenosis are the occlusion of a single penetrating artery to produce a small subcortical lacuna-like infarct and an artery-to-artery embolism with impaired clearance of emboli that produces multiple small cerebral infarcts, especially along the border zone region.

Circulating microemboli in 33 patients with intracranial arterial stenosis

BACKGROUND

Intracranial arterial stenosis is a rare cause of stroke in Caucasians. Detection of clinically silent circulating microemboli by transcranial Doppler sonography is now widely investigated in patients with carotid artery disease in the hope to identify patients at increased risk for stroke.

METHODS

In 33 patients with intracranial internal carotid (n = 12), middle cerebral (n = 18), posterior cerebral (n = 2), or basilar artery stenosis (n = 1), we performed a 1-hour microembolus detection downstream to the stenosis in the middle or in the posterior cerebral artery, respectively. The stenosis was assessed by transcranial Doppler and duplex ultrasound. 18 patients had been symptomatic in the dependent territory.

RESULTS

Five patients with ischaemic symptoms within the last 8 days and with a peak systolic flow velocity of > or =210 cm/s in the stenosis showed microembolic signals at a rate of 3-25 events/h, despite effective anticoagulation. All these 5 patients had a lesion pattern on cranial CT or MRI scan suggesting embolic origin. All the asymptomatic patients (n = 15) and all the patients with a peak systolic intrastenostic velocity of 160 to <210 cm/s (n = 13) did not show microembolic signals at all.

CONCLUSION

Microembolic signals occur in recently symptomatic patients with high-grade intracranial arterial stenosis indicated by a sonographically measured stenotic peak flow velocity of > or =210 cm/s. Therapeutic anticoagulation was not sufficient to suppress microemboli formation.

Evaluation of progression and spread of atherothrombosis

Symptomatic atherothrombosis in one vascular bed is usually indicative of disseminated disease. Indeed, involvement of multiple beds is common in everyday clinical practice, and these patients are at much higher risk of ischaemic events. The prevention of manifestations following atherothrombosis is therefore an important therapeutic goal in these patients. Some causative risk factors demonstrate affinities to particular arterial domains. Cigarette smoking, for example, is particularly associated with atherothrombotic involvement of the pelvic and lower limb arteries, whereas arterial hypertension is associated with the intracranial cerebral arteries. The degree, spread and progression of atherosclerosis can be assessed using various non-invasive and invasive modalities: high-resolution Doppler ultrasound, ankle-brachial index (ABI) measurement, magnetic resonance (MR), computed tomography (CT) and intra-arterial angiography. Indicators of atherothrombotic risk include increased carotid artery intima-media thickness, microembolic signals on transcranial Doppler ultrasonography and low ABI. There is a strong rationale for the inclusion of the ABI measurement as part of the routine clinical examination to assess the cardiovascular risk in patients with identified risk factors. Furthermore, detection of a low ABI should serve as a trigger for patient management with aggressive antiplatelet therapy. The generalized nature of atherothrombosis and the methods for evaluating the spread of disease are illustrated through the case history of a patient with disseminated atherothrombotic disease.

Detection of microemboli in the subclavian vein of patients undergoing haemodialysis and haemodiafiltration using pulsed Doppler ultrasound

BACKGROUND

The pathophysiology leading to pulmonary side effects during haemodialysis and haemodiafiltration is not yet fully understood. Chronic microembolization, which can be demonstrated by pulsed Doppler ultrasound, may be one cause.

METHODS

The study cohort consisted of 24 long-term dialysis patients undergoing haemodialysis (n=21) and online-haemodiafiltration (n=3), respectively. The subclavian vein downstream to the venous access was investigated during different phases of the procedure using a 2-MHz pulsed ultrasound device.

RESULTS

In all periods investigated (connection, dialysis, disconnection), numerous microembolic signals (MES) were found in the subclavian vein. The numbers of MES detected during haemodiafiltration (314-709 MES per 10 min) were higher than during haemodialysis (0-81 MES per 10 min).

CONCLUSIONS

The composition (gaseous or solid) and origin (pump, tubing system or shunt) of the microemboli detected remains unclear. Chronic microembolization may be one cause of pulmonary complications of haemodialysis and haemodiafiltration. The detection method described in this article will help us to better understand this process and to determine what role microemboli might play in pulmonary and central nervous system disorders. It may also help to optimize the devices and techniques used.

Clinically silent circulating microemboli in 20 patients with carotid or vertebral artery dissection

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.