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1.
BACKGROUND: The clinical relevance of the microembolic signals (MES) detected by transcranial Doppler sonography (TCD) in acute stroke remains unclear. In a prospective study the authors analyzed the relationship between MES and the findings on diffusion-weighted magnetic resonance imaging (DWI) in acute stroke patients. METHODS: We performed TCD for a period of 30 min to detect MES in patients within 24 h of stroke onset, and DWI was done within the initial 7 days. MES were assessed from Doppler waves obtained from the middle cerebral artery contralateral to the side of the neurological deficits. The acute ischemic lesions observed on DWI were classified by their diameter (small, medium or large) and by their site (cortical, superficial perforator territory, internal borderzone or deep perforator territory). RESULTS: We obtained Doppler waves from 39 vessels in 37 patients; 2 patients had bilateral deficits. MES were detected in 12 vessels (MES-positive group) and not detected in 27 vessels (MES-negative group). No significant differences in clinical features were observed between the 2 groups. The number of small lesions was significantly higher in the MES-positive group than in the MES-negative group (p = 0.02). The numbers of cortical and superficial perforator infarcts were significantly higher in the MES-positive group than in the MES-negative group (p = 0.002 and 0.02, respectively). CONCLUSION: In acute ischemic stroke, MES detected by TCD in the acute phase may produce small cortical and subcortical lesions found on DWI.  相似文献   

2.
The occurrence of microembolic signals (MES) in patients with transient ischemic attack (TIA) or stroke has already been described; the influence of the time interval between onset of symptoms and transcranial Doppler monitoring (TCD) on the MES rate or MES prevalence and the possible prognostic value of the early detected MES rate on the outcome of TIA or stroke symptoms in a 3 month interval are discussed. In a prospective study we evaluated 61 patients consecutively admitted to our stroke unit after their first ischemic neurological deficit involving the vascular territory of MCA and/or ACA. All of the patients underwent a 30-minute bilateral transcranial Doppler monitoring of their MCAs for the identification of MES. Monitoring was performed within 12.3 + -9.3 (average mean + -SD) hours of stroke onset for the first time, the second time 48 hours after first TCD monitoring. Prognosis for the recovery of neurological deficits was evaluated by using the Barthel index (BI) and Scandinavian Stroke Scale (SSS) at the time of admission of the patient to the stroke unit, and with Barthel indices after one month and after 3 months. As a result, 56% of all patients showed MES in at least one of the two registrations. MES were recorded not only on the symptomatic side. The MES prevalence between both TCD monitorings was significantly different (total MES prevalence: 1st TCD: 26 patients: 2nd TCD: 13 patients; p < 0.04; ipsilateral MES prevalence: 1st TCD: 19 patients; 2nd TCD: 9 patients; p < 0.01). The regression analysis showed a significant influence of the total MES rate on both neurological scores at admission (SSS: 0.03; Barthel index: 0.04), but not for the Barthel scores after one and three months. In conclusion, we found an influence of the time interval between onset of neurological symptoms of TIA or stroke on the MES rate and the prevalence of MES. The prevalence of MES or the MES rate, found after a short time interval to the onset of symptoms, did not have a prognostic value on the outcome of neurological deficits up to a three month follow-up.  相似文献   

3.
目的研究以急性多发脑梗死为首发表现的隐匿性躯体恶性肿瘤患者的临床表现、实验室检查、影像学、微栓子监测检查特点,探讨其可能的发病机制。方法纳入以急性多发性脑梗死为首发表现的隐匿性躯体恶性肿瘤患者12例,收集其临床资料,分析其实验室血液学、头颅MRI、微栓子监测结果及其治疗和预后。结果所有患者均以局灶性神经功能缺损为主要表现,包括偏瘫、失语、偏身感觉障碍、构音障碍、眩晕、肢体抽搐等。头颅DWI示急性多发脑梗死,病灶播散性分布,不符合单支动脉供血区,同时累及双侧前循环或前后循环。11例行D-dimer检查者8例升高。7例行微栓子监测有5例阳性。隐匿性躯体恶性肿瘤包括:肺癌5例,胰腺癌3例,胃癌、结肠癌、子宫内膜癌、转移性低分化粘液腺癌原发肿瘤部位不明各1例;诊断时就已有远处转移者10例。病程中缺血性卒中复发者7例,急性心肌梗死4例,住院期间死亡3例,预后差。结论对于不符合单支动脉供血区的多发急性脑梗死,需要考虑可能合并隐匿性躯体恶性肿瘤,凝血功能筛查高凝状态和微栓子阳性可能是诊断提示线索。  相似文献   

4.
BACKGROUND AND PURPOSE: There are few data on the occurrence of microembolic signals (MES) in the acute phase of ischaemic stroke. The objective of our work was to systematically study the frequency of MES in non-selected patients with a first-ever hemispheric transient ischemic attack (TIA) or acute cerebral infarction, and to evaluate the clinical usefulness of MES detection. METHODS: 182 consecutive patients with hemispheric TIA or acute cerebral infarction, and 54-age-matched healthy controls were studied. Bilateral transcranial Doppler ultrasound (TCD) monitoring was performed for at least 30 min with a mean time from stroke onset to TCD of 69 h. Stroke severity on admission, early recurrent stroke and dependency on discharge were investigated. RESULTS: MES were detected in 20.5% of patients with arterial sources of embolism, 17. 1% of patients with potential sources of cardioembolism and 5% of patients with cryptogenic stroke. They were not registered, however, in lacunar infarctions (p < 0.001). Stroke severity on admission of patients with MES was greater than that of patients without MES (47. 1 vs. 19.4% with the Canadian Stroke Scale < or =6.5; p = 0.009). Early recurrent stroke was more frequent in patients with MES (11.8%) than in those without MES (4.2%) although the difference was not statistically significant. Multiple logistic regression analysis showed that MES increased the risk of dependency on discharge (odds ratio, 4.2; 95% CI, 1.2-14.9; p = 0.01) independently of age, stroke severity on admission and presence of an arterial or cardiac embolic source. CONCLUSIONS: There is a strong association of MES in the acute phase of stroke with known potential arterial and cardiac embolic sources. MES have an independent predictive value of poor outcome.  相似文献   

5.
Polycythemia rubra vera (PRV) is a rare myeloproliferative disorder with a high risk of ischemic stroke. Although thrombosis of large cerebral arteries is the most frequently presumed pathomechanism, various infarct patterns have been described in patients with PRV and ischemic stroke. We report two patients with mild acute ischemic strokes and known PRV, in whom a scattered lesion pattern was detected by diffusion-weighted magnetic resonance imaging (DWI), but was not visible on computed tomography (CT) and conventional magnetic resonance imaging (MRI). Further diagnostic work-up including extra- and transcranial Doppler sonography (ECD, TCD), transesophageal echocardiography (TEE), magnetic resonance angiography and Holter monitoring revealed no obvious sources of cerebral embolism in both cases. However, TEE in one patient demonstrated spontaneous echo contrast (SEC) in the left atrium. In both patients the symptomatology resolved completely. The detection of a scattered infarct pattern by DWI in patients with PRV and acute ischemic stroke has not been reported previously. DWI findings together with the SEC in one patient emphasize the assumption that a prothrombotic state with subsequent arterial embolism rather than local arterial thrombosis may be the underlying pathomechanism of stroke in some patients with PRV. Adding DWI to the diagnostic work-up may help to clarify etiology in patients with PRV and acute ischemic stroke.  相似文献   

6.
The rate and risk factors for early ischemic recurrence in patients with internal carotid artery dissection (ICAD) are largely unknown. Serial transcranial Doppler (TCD) monitoring of microembolic signals (MES) was performed in 28 consecutive patients with acute ICAD. MES were identified in 13 patients, and early ischemic recurrence occurred in 7. Six of 13 patients with MES and 1 of 15 without MES experienced early ischemic recurrence (p = 0.029). MES detection on serial TCD monitoring may be associated with an increased risk of early ischemic recurrence in patients with acute ICAD.  相似文献   

7.
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.  相似文献   

8.
BACKGROUND AND PURPOSE: Microembolic signals (MES) on transcranial Doppler ultrasonography (TCD) are occasionally detected in acute ischemic stroke patients and gradually decrease over time. If MES is detectable at 7 days after stroke onset, embolic source lesions may still be active. We hypothesized that presence of MES at 7 days after stroke onset is strongly associated with stroke recurrence. METHODS: Subjects comprised 143 patients with acute ischemic stroke who were prospectively examined for the presence of MES using TCD both within 24 h and at 7 days after stroke onset. Stroke recurrence was assessed within 3 months of stroke onset. The association between presence of MES and stroke recurrence was investigated. RESULTS: MES was detected in 70 of 143 patients (49%) within 24 h of stroke onset and in 34 patients (24%) at 7 days. Stroke recurrence was observed in 6 patients after 7 days and in 10 patients between 7 days and 3 months after stroke onset. Presence of MES within 24 h of stroke was not associated with stroke recurrence (10% for MES-positive vs. 12% for MES-negative, p=0.792). At 7 days after onset, stroke recurrence was more frequent in the MES-positive group at 7 days than in the MES-negative group (24% vs. 7%, p<0.0001). Cox's proportional hazard analysis demonstrated presence of MES as an independent factor of stroke recurrence (hazard ratio, 6.4; 95% confidence interval, 1.4-28; p=0.015). CONCLUSION: Presence of MES detected on TCD at 7 days of stroke onset should be a predictor of stroke recurrence.  相似文献   

9.
BACKGROUND AND PURPOSE: Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) have been used increasingly in recent years to evaluate acute stroke in the emergency setting. In the present study, we compared DWI and PWI findings in acute stroke patients with and without severe extracranial internal carotid artery (ICA) disease. METHODS: Twenty-seven patients with nonlacunar ischemic stroke were selected for this analysis. DWI, PWI, and conventional MRI were performed in all patients within 24 hours of symptom onset and after 1 week. To exclude patients with partial or complete reperfusion, we included only patients with a PWI deficit larger than the DWI lesion. Severe ICA disease (>70% stenosis) was present unilaterally in 9 and bilaterally in 2 patients. Acute DWI lesion volume, the size of the acute PWI/DWI mismatch, and final infarct size (on T2-weighted images) were determined. RESULTS: The PWI/DWI mismatch was significantly larger in patients with severe ICA disease than in patients without extracranial carotid stenosis, both when time-to-peak and mean transit time maps (P<0.01) were used to calculate the mismatch. Quantitative analysis of the time-to-peak delay in the mismatch indicated that a relatively smaller fraction of the total mismatch was critically ischemic in patients with carotid stenosis than in those without. Average lesion volume increased less in the stenosis group (P=0.14), despite the larger PWI/DWI mismatch, and final infarct size was smaller in the stenosis group (P<0.05). In the 2 patients with bilateral ICA disease, variable hemodynamic involvement of the contralateral hemisphere was found in addition to the ipsilateral PWI deficit. CONCLUSIONS: In most acute stroke patients with severe ICA stenosis, a considerably smaller fraction of the total PWI/DWI mismatch is at risk than in patients without carotid disease.  相似文献   

10.
Jayanta Roy  MD  DM    Naveed Akhtar  MD    Timothy Watson  MD  FRCPC    rew M. Demchuk  MD  FRCPC    Maher Saqqur  MD  FRCPC 《Journal of neuroimaging》2007,17(4):350-352
Arterial dissection is the underlying stroke mechanism in approximately 2.5% of all strokes and the second leading cause of stroke in patients younger than 45 years of age. Controversy exists regarding the medical management of carotid dissection. Both anticoagulants and antiplatelet agents have been used with no compelling data supporting one therapy over the other. Transcranial Doppler (TCD) emboli monitoring may help in establishing the diagnosis and guide the treatment by measuring the frequency of microembolic signals (MES). We present two cases of carotid dissection where TCD monitoring for MES helped in establishing the diagnosis and proved useful in identifying that standard anticoagulation treatment was not preventing emboli. Both cases were also monitored for emboli count reduction with subsequent antiplatelet therapy.  相似文献   

11.
The clinical predictors and potential therapeutic implications of microembolic signals (MES) were investigated in 104 patients with ischemic stroke or transient ischemic attack associated with high-risk (n = 60) or low-risk (n = 44) cardiac emboligenic conditions. Patients with artificial valves and carotid stenosis were excluded. MES counts were based on 30-min bilateral middle cerebral artery transcranial Doppler (TCD) monitoring recordings. MES were detected in 15 subjects (14%). The mean number of MES per hour was 1.9. MES prevalence and counts were influenced neither by age, gender or type of cerebral event, nor by cardiac disease. MES were more frequently detected and greater in number in patients with multiple cerebral ischemic events and in subjects monitored within 1 month of the last event. By multiple logistic regression, TCD recording within 1 month of the last event [Odds ratio (OD) = 13.5; 95% confidence intervals (CI) = 3.3-54.3] and multiple cerebral events (OD = 4.7; 95% CI = 1.3-17.3) were the best MES predictors. MES were detected in 40% (4/10) of patients on heparin, 5% (2/4) of untreated subjects and 13% (5/39) of those on antiplatelet drugs. For patients on warfarin, MES counts and prevalence were similar in subjects with international normalized ratios (INR) below and within/above the therapeutic range. MES were detected in only 2 out of 16 subjects with INR <2 and in 1 with INR >2. MES detection can be potentially relevant to the selection of antithrombotic treatment in acute stroke associated with cardioembolic disease, but further studies are necessary to assess its effectiveness as an additional guide to monitor oral anticoagulant intensity.  相似文献   

12.
A rapid and complete recanalization of the occluded artery is the ideal goal when intravenous (IV) recombinant tissue plasminogen activator (rt-PA) is administrated to patients with acute ischemic stroke, i.e., limiting the ongoing ischemia to achieve a better outcome. We explored the effect of complete versus partial recanalization of the occluded intracranial artery after IV thrombolysis on the infarct growth and evaluated the functional impact. Using diffusion-weighted (DWI) volumetric measurements before rt-PA administration (DWI(1)) and 24?h later (DWI(2)), we calculated the infarct growth in 36 consecutive patients with ischemic stroke treated with IV rt-PA, with the formula DWI(2)/DWI(1). Recanalization of the affected artery was assessed by transcranial Doppler (TCD) and magnetic resonance angiography (MRA) within 24?h of stroke onset. Three patients were eliminated from the analysis; 33?patients were fully analyzed (men: n?=?23; mean (SD) age: 72.4?±?16?years; time from stroke onset to rt-PA: 179?±?54?min; mean NIHSS score at admission: 17). Patients achieving full recanalization by TCD had a smaller infarct growth, compared to those who had a partial or persistent occlusion after thrombolysis: 1.86 versus 2.91 (P?=?0.017). This difference was not significant using MRA criteria: 2.01 versus 2.69 (P?=?0.193). In the regression analysis, complete recanalization by TCD was an independent predictor of infarct growth (P?=?0.045). Thus, complete recanalization measured by TCD within 24?h of IV thrombolysis was independently associated with smaller infarct growth.  相似文献   

13.
OBJECTIVE: To compile available studies using microembolic signal (MES) detection by transcranial Doppler sonography in varying sources of arterial brain embolism. We investigated prevalences of MES and whether MES detection is of proven use for risk stratification. METHOD: Studies reporting prevalences of MES and the risk of cerebral ischemic events were pooled for patients with symptomatic or asymptomatic carotid stenosis, intracranial artery stenosis, cervical artery dissection, and aortic embolism. RESULTS: MES were reported in 43% of 586 patients with symptomatic and in 10% of 1066 patients with asymptomatic carotid stenosis. Presence of one MES indicated an increased risk of future events [odds ratio (OR): 7.5, 95% confidence interval (CI): 3.6-15.4, p<0.0001 for symptomatic, and OR: 13.4, 95% CI: 6.5-27.4, p<0.0001 for asymptomatic disease). MES were reported in 25% of 220 patients with symptomatic vs. 0% of 86 patients with asymptomatic intracranial stenosis (p<0.0001), Of 82 patients with cervical artery dissection presenting with TIA or stroke, 50% had MES compared with 13% of 16 patients with local symptoms (p=0.006), In patients with aortic embolism, patients with plaques >or= 4 mm more frequently had MES compared with patients with smaller plaques (p=0.04), Data were insufficient to reliably predict future events in patients with intracranial stenosis, cervical artery dissection, and aortic embolism. CONCLUSION: MES are a frequent finding in varying sources of arterial brain embolism, MES detection is useful for risk stratification in patients with carotid stenosis.  相似文献   

14.
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.  相似文献   

15.
Background and purpose:  The inter-relation between the size of patent foramen ovale (PFO) by transesophageal echocardiography (TEE) and the amount of microembolic signals (MES) on transcranial doppler (TCD) is still not determined.
Methods:  The study group comprised of 104 patients with first-ever ischaemic stroke or transient ischemic attack (TIA). Three groups were formed according to the amount of MES on TCD: a small amount of MES (0–10 MES); a moderate amount of MES (countable MES higher than 10); and multiple MES.
Results:  According to TEE, there were 52 patients (50%) with a small PFO, 37 patients (35.6%) with a moderate PFO, and 15 patients (14.4%) with a large PFO. There were 48 patients (46.1%) with a small amount of MES, 34 patients (32.7%) with a moderate amount of MES, and 22 patients (21.1%) with multiple MES on TCD. A strong relationship between the size of the PFO on TEE and the amount of MES on contrast transcranial Doppler was found ( P  < 0.0001), such that the larger the PFO on TEE, the greater the amount of MES on TCD.
Conclusions:  There is a high correlation between the size of the PFO on TEE and the amount of MES on TCD in stroke and TIA patients.  相似文献   

16.
目的 对短暂性脑缺血发作(TIAs)病人观察脑循环微栓子信号(MES)发生率及其发生脑卒中的危险率。方法 用经颅多普勒(TCD)监测TIAs病人双侧大脑中动脉(MCA)微栓子信号(MES),并跟踪观察12个月。结果 25例短暂脑缺血发作病人有5例记录到MES(阳性率20%),跟踪观察12个月,5例MES阳性病例中的3例(60%)发生脑梗死;而20例未记录到MES的病人中,仅有2例(10%)发展为脑梗死。结论 可检测到MES的TIAs病人发生梗死的危险性比无MES病人高。  相似文献   

17.
OBJECTIVE: To investigate the occurrence of microembolic signals (MES) and hemodynamic features in patients with acute symptomatic intracranial cerebral artery stenoses by transcranial Doppler (TCD). MATERIAL AND METHODS: Twelve patients with acute hemispheric ischemic events and corresponding intracranial cerebral artery stenoses as identified by TCD, and exclusion of extracranial or cardiac emboli sources were repeatedly studied by TCD monitoring of the affected and the contralateral vessel. The occurrence of MES and MES clusters (> or =3 MES per second) and of flow velocity changes was examined. RESULTS: Nine patients presented with MES in the affected artery during the first measurement. In seven patients sudden flow velocity changes could be detected in the affected vessel. In five patients these changes were accompanied by MES clusters. MES and velocity changes disappeared in all patients during follow-up, and the degree of stenosis decreased in nine patients. CONCLUSIONS: The high prevalence of MES and sudden velocity changes in acute intracranial cerebral artery stenoses indicates that acute intracranial stenoses may be formed at least in part by mobile thrombotic material.  相似文献   

18.
倪俊  高山 《中国卒中杂志》2006,1(3):235-237
本文是采用经颅多普勒超声(TCD)检测大脑中动脉狭窄(MCA)微栓子信号(MES)的研究,选择了114例MCA狭窄的急性缺血性卒中患者,结果发现22%的患者有MES,平均18个(1~102),重度狭窄(48%)患者较轻中度狭窄者(15%)更易出现MES。平均随访13.6个月(1~32个月),其中12例(12.2%)患者再次出现MCA供血区域的缺血事件(10例卒中,2例TIA)。Cox回归分析显示调整其他卒中高危因素后,MES是再发缺血性卒中/TIA的独立预测因子(P=0.01)。检测MES能够预测MCA狭窄的急性卒中患者脑缺血的复发,因此提出应将MES检测作为常规检查的一部分,这或许能识别那些最可能从抗栓治疗中获益的患者。  相似文献   

19.
Micro embolic signals in patients with cerebral ischaemic events   总被引:1,自引:0,他引:1  
The aim of this study was to evaluate the occurrence of micro embolic signals (MES) in patients with a cerebral ischaemia using transcranial doppler monitoring and to find out its diagnostic relevance. We prospectively performed bilateral multigated transcranial doppler monitoring from both middle cerebral arteries in 359 patients with an acute or recent (<4 weeks) cerebral ischaemic event, and in 182 control subjects without a cerebral ischaemic event. MES were analysed according to the standardised protocol. Patients with cerebral ischaemic events had a significantly higher (p<0.00001) rate of MES occurrence (31.8%) than control subjects (5.5%). MES were detected significantly higher in patients with partial or total anterior circulation infarcts (39.1%) than in those with lacunar infarcts (26.0%) or transient ischaemic attacks (27.3%). A correlation of MES and neuroimaging finding was also tried. TCD was found to have a predictive role in microemboli monitoring, predominantly in patients with large vessel territory infarction.  相似文献   

20.
目的依据改良TOAST分型方法作为标准,探讨河北省中南部地区急性缺血性卒中的病因学特征。方法收集2002年1月至2007年6月入住我院神经内科的急性缺血性脑卒中患者作为研究对象,依据改良的TOAST病因分型法作为诊断标准,结合头颅DWI和/或TCD微栓子监测结果确定动脉粥样硬化性血栓(AT)的诊断及病因分型。结果本研究共纳入1164例急性缺血性卒中患者,所有患者M-TOAST亚型构成比例分别为:动脉粥样硬化性血栓71.48%,小动脉病变21.39%,心源性栓塞3.09%,其它病因明确0.86%,不明病因者3.18%。结论河北省中南部地区急性缺血性卒中的病因分型以AT为主。  相似文献   

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