Circulating Microemboli in 33 Patients with Intracranial Arterial Stenosis

Dw, Droste; Junker, Kirsten; Hansberg, Tjark; Dittrich, Ralf; Ritter, Martin; Eb, Ringelstein

doi:10.1159/000047742

Cited by 26 publications

(25 citation statements)

References 22 publications

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“…This is supported by the observations of Droste et al, 20 who reported that microemboli in intracranial stenosis were found only in symptomatic patients with severe stenosis.…”

Section: Discussionsupporting

confidence: 81%

Diabetes, Intracranial Stenosis and Microemboli in Asymptomatic Carotid Stenosis

Lam

Lammers

Munoz³

et al. 2013

Can. J. Neurol. Sci.

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With more intensive medical therapy, the risk of stroke or death in patients with asymptomatic carotid stenosis is now so low that most patients will not benefit from endarterectomy or stenting 1 . It is therefore important to have methods to identify the small proportion who could benefit from intervention 1,2 , or who may require special consideration in choice of medical therapy. We have previously reported that carotid plaque area 3 , microemboli on transcranial Doppler 4,5 (TCD), and carotid plaque ulceration on 3-dimensional ultrasound 5 predict the risk of cardiovascular events, particularly of stroke. The predictive value of TCD microembolus detection in patients with ABSTRACT: Background: The risk of stroke in patients with asymptomatic carotid stenosis (ACS) is now so low that it is important to have methods to identify those patients most likely to benefit from intervention, or who may require special consideration in choice of medical therapy. We studied the prediction of stroke, death or transient ischemic attacks (stroke/death/TIA) in patients with ACS by intracranial arterial stenosis, and microemboli on transcranial Doppler (TCD), and the effect of diabetes mellitus on microemboli, intracranial stenosis and risk of events. Methods: Patients with ACS > 60% by Doppler ultrasound were recruited from the Stroke Prevention Clinic of University Hospital, London, Canada. All 339 participants underwent TCD for detection of intracranial stenosis and detection of microemboli, and carotid ultrasound to measure extracranial stenosis and total carotid plaque area. Participants were followed for three years, to determine the risk of stroke/death/TIA. Results: Stroke/death/TIA occurred in 38% of patients with microemboli versus 10% without (p=0.0001), and in 18% of patients with intracranial stenosis, versus 10% without (p=0.042). Diabetics were significantly more likely to have intracranial stenosis (45% vs. 29%, p =0.014), microemboli (38% vs. 10%, p <0.0001), and had significantly higher risk of stroke/death/TIA over three years (21% vs. 11% without; p=0.024). Survival free of stroke, TIA or death was significantly better without microemboli or intracranial stenosis (p<0.0001). Conclusions: Diabetes, microemboli and intracranial stenosis predicted higher risk of stroke, death or TIA than did extracranial stenosis or total plaque area; diabetics may need more intensive therapy.RÉSUMÉ: Diabète, sténose intracrânienne et microembolies dans la sténose carotidienne asymptomatique. Contexte : Le risque d'accident vasculaire cérébral (AvC) chez les patients porteurs d'une sténose carotidienne asymptomatique (SCA) est maintenant si faible qu'il est important d'établir des critères pour identifier les patients qui sont les plus susceptibles de bénéficier d'une intervention ou chez qui on doit porter une attention particulière au choix du traitement médical. nous avons examiné si la présence d'une sténose artérielle intracrânienne et de microembolies au Doppler transcrânien (DTC) étaient des facteurs de prédiction de ...

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“…This is supported by the observations of Droste et al, 20 who reported that microemboli in intracranial stenosis were found only in symptomatic patients with severe stenosis.…”

Section: Discussionsupporting

confidence: 81%

Diabetes, Intracranial Stenosis and Microemboli in Asymptomatic Carotid Stenosis

Lam

Lammers

Munoz³

et al. 2013

Can. J. Neurol. Sci.

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“…21 Droste et al reported that MES were mainly observed in patients with recent symptomatic intracranial atherosclerosis and severe stenosis only. 30 The short delay between symptoms and TCD may explain the relatively high prevalence of MES in the present study.…”

Section: Discussion Prevalence Of Mesmentioning

confidence: 57%

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

Gao

Wong

Hansberg

et al. 2004

Stroke

Self Cite

114

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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 2 Pϭ0.02). 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; Pϭ0.01) 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. Key Words: arterial occlusive disease Ⅲ cerebral ischemia Ⅲ embolism Ⅲ microembolic signals Ⅲ outcome Ⅲ stroke Ⅲ transcranial Doppler E xtracranial carotid artery occlusive disease is a major cause of ischemic stroke in whites. However, intracranial artery occlusive disease, especially middle cerebral artery (MCA) stenosis, is more prevalent in Asians. [1][2][3][4] Understanding the mechanisms underlying ischemic stroke is crucial for therapeutic decisions. Hemodynamic compromise and arteryto-artery embolism have been suggested as the 2 major underlying mechanisms in patients with internal carotid artery stenosis. Nevertheless, the pathogenesis of ischemic stroke caused by intracranial artery occlusive disease remains unknown.With the development of transcranial Doppler ultrasound, it is possible to detect an embolus passing through the insonated artery. 5-9 It has been suggested that they represent thrombi and platelet fibrin aggregates. 6,7 Microembolic signals (MES) are found more frequently in symptomatic than in asymptomatic patients with internal carotid artery stenosis. 10 -14 Moreover, the clinical significance of embolic signals has also been reported to be an independent predictor of future stroke. [15][16][17][18] A...

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“…The clinical impact of artery-to-artery embolism may increase in the presence of hemodynamic compromise that exists in patients with steno-occlusive lesions and insufficient collateral blood supply. Under these conditions, impaired microemboli wash-out due to hemodynamic compromise may augment the risk for the occurrence of cerebral infarctions as shown in patients with middle cerebral artery stenosis or carotid artery occlusion [7, 8, 9]. …”

Section: Introductionmentioning

confidence: 99%

Hemodynamic Reserve and High-Intensity Transient Signals in Moyamoya Disease

Horn¹,

Lanczik²,

Vajkoczy³

et al. 2005

Cerebrovasc Dis

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Background: Moyamoya disease (MMD) as a rare obstructive cerebrovascular disease is assumed to present with ischemic symptoms due to hemodynamic compromise. However, alternative mechanisms, such as cerebral embolism in low-flow territories, may also contribute to clinical symptoms. The incidence of high-intensity transient signals (HITS) and the degree of hemodynamic compromise were studied in symptomatic patients with MMD. Methods: Twenty-four patients (17 female, 7 male; mean age 33 ± 13 years) with clinical symptoms attributable to cerebral ischemia and the angiographic features of MMD (21 definite form, 3 probable MMD; 22 patients ‘late stage’ MMD, 2 patients ‘early stage’ MMD) in 45 affected hemispheres were enrolled in the present study. Patients underwent parallel estimation of hemodynamic compromise by means of functional blood flow (rCBF) studies using SPECT, PET or xenon-CT and HITS detection by TCD. Results: Hemodynamic compromise was observed in 37/40 (92%) hemispheres studied. During TCD monitoring, HITS were detected in 3 patients (12.5%), with a total frequency of 3 (6.6%) in the 45 hemispheres investigated. All patients with HITS showed hemodynamic compromise in functional rCBF studies. In these patients, HITS were recorded ipsilateral to the symptomatic hemisphere. HITS occurred in late stage MMD patients only once, while both cases with early stage MMD demonstrated multiple HITS. Conclusions: The incidence of HITS in patients with MMD appears to be lower compared to patients with atherosclerotic or atherothrombotic arterial obstructions. In addition, ischemia-related symptoms in ‘late stage’ MMD seem to be caused by hemodynamic compromise in the majority of these patients.

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Circulating Microemboli in 33 Patients with Intracranial Arterial Stenosis

Cited by 26 publications

References 22 publications

Diabetes, Intracranial Stenosis and Microemboli in Asymptomatic Carotid Stenosis

Diabetes, Intracranial Stenosis and Microemboli in Asymptomatic Carotid Stenosis

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

Hemodynamic Reserve and High-Intensity Transient Signals in Moyamoya Disease

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