Frequency of asymptomatic microbleeds on T2*-weighted MR images of patients with recurrent stroke: association with combination of stroke subtypes and leukoaraiosis

BACKGROUND AND PURPOSE: Asymptomatic microbleeds shown by T2*-weighted MR imaging are associated with small-artery diseases, especially with intracerebral hemorrhage. Few studies have focused on the prevalence of microbleeds in patients with recurrent stroke. We investigated frequency of microbleeds in patients with recurrent stroke and association of presence of microbleeds with a combination of stroke subtypes and severity of leukoaraiosis. METHODS: The study population consisted of 102 patients with primary stroke and 54 patients with recurrent stroke. Microbleeds were counted and classified by using T2*-weighted MR imaging with a 1.0-T system. RESULTS: Patients with recurrent stroke showed a significantly higher prevalence of microbleeds (68.5%) than did patients with primary stroke (28.4%) (P <.0001). Among patients with recurrent stroke, the highest frequency of microbleeds occurred in those with intracerebral hemorrhage alone (92.3%), with the next highest frequency occurring in those with a combination of intracerebral hemorrhage and ischemic stroke (76.5%) and then those with ischemic stroke alone (50.0%) (P <.05). Leukoaraiosis was more severe in patients with recurrent stroke than in patients with primary stroke, and correlations between grade of microbleeds and severity of leukoaraiosis were found in patients with primary stroke (r = 0.367, P <.001) and in patients with recurrent stroke (r = 0.553, P <.0001). Logistic regression analysis identified recurrent stroke (odds ratio, 4.487; 95% confidence interval, 1.989-10.120) and leukoaraiosis (odds ratio, 5.079; 95% confidence interval, 2.125-12.143) as being significantly and independently associated with microbleeds. CONCLUSION: Asymptomatic microbleeds are observed to occur frequently in patients with recurrent stroke, either hemorrhagic or ischemic stroke, and are closely associated with the severity of leukoaraiosis.     

MR of cerebral abnormalities concomitant with primary intracerebral hematomas.

PURPOSETo determine whether arteriolar vessel wall degeneration in primary intracerebral hematomas might be associated with ischemic brain lesions and clinically silent (apparently intracerebral) previous hemorrhages.METHODSThe MR images of 120 consecutive patients (mean age, 60 years; age range, 22 to 84 years) with their first stroke caused by a primary intracerebral hematoma were reviewed retrospectively for coexisting ischemic damage and previous bleeds.RESULTSEarly confluent to confluent white matter hyperintensities, lacunes, or infarction were present in 83 (69%) of the patients, and 39 (33%) had had previous hemorrhages consisting of microbleeds or old hematomas. Extensive white matter hyperintensities and lacunes were most frequent in patients with thalamic primary intracerebral hematomas. There was no relationship between the frequency of old hemorrhages and the location of subsequent primary intracerebral hematomas.CONCLUSIONClinically silent ischemic lesions and previous hemorrhages are a common finding on MR images of patients with primary intracerebral hematoma. They may therefore serve as evidence of diffuse microangiopathy with a possible increased risk for cerebral hemorrhage.     

Association between cerebral microbleeds on T2*-weighted MR images and recurrent hemorrhagic stroke in patients treated with warfarin following ischemic stroke

BACKGROUND AND PURPOSE: Although accumulating evidence suggests the presence of microbleeds as a risk factor for intracerebral hemorrhage (ICH), little is known about its significance in anticoagulated patients. The aim of this study was to determine whether the presence of microbleeds is associated with recurrent hemorrhagic stroke in patients who had received warfarin following atrial fibrillation–associated cardioembolic infarction.MATERIALS AND METHODS: A total of 87 consecutive patients with acute recurrent stroke, including 15 patients with ICH and 72 patients with cerebral infarction, were enrolled in this study. International normalized ratios (INRs), vascular risk factors, and imaging characteristics, including microbleeds on T2*-weighted MR images and white matter hyperintensity (WMH) on T2-weighted MR images, were compared in the 2 groups.RESULTS: Microbleeds were noted more frequently in patients with ICH than in patients with cerebral infarction (86.7% versus 38.9%, P = .0007). The number of microbleeds was larger in patients with ICH than in patients with cerebral infarction (mean, 8.4 versus 2.1; P = .0001). INR was higher in patients with ICH than in patients with cerebral infarction (mean, 2.2 versus 1.4; P < .0001). The frequency of hypertension was higher in patients with ICH than in patients with cerebral infarction (86.7% versus 45.8%, P = .0039). Multivariate analysis revealed that the presence of cerebral microbleeds (odds ratio, 7.383; 95% confidence interval, 1.052–51.830) was associated with ICH independent of increased INR and hypertension.CONCLUSION: The presence of cerebral microbleeds may be an independent risk factor for warfarin-related ICH, but more study is needed because of strong confounding associations with elevated INR and hypertension.

One of the major complications of warfarin treatment following atrial fibrillation–related cardioembolic infarction is the occurrence of intracerebral hemorrhage (ICH). With advancing age, the incidence of both atrial fibrillation–related cardioembolic infarction and warfarin-related ICH increases.Cerebral microbleeds detected by gradient-echo T2*-weighted MR imaging, which are shown as signal-intensity loss, represent hemosiderin deposit^1,2 and are associated with occurrence of ICH.^3–19 Although accumulating evidence suggests that the presence of microbleeds is a risk factor for ICH in patients treated by antiplatelet therapy^13,20 and hemorrhagic complications of anticoagulation in patients with prior ICH and atrial fibrillation have been reported,²¹ little is known about the significance of microbleeds in anticoagulated patients because, to our knowledge, no studies have focused on the association between cerebral microbleeds and anticoagulation therapy in a large number of patients. On the other hand, previous studies focusing on radiographic characteristics have shown that the presence of microangiopathy (leukoaraiosis) detected by CT is a risk factor for warfarin-related ICH.²² However, considering the close association between cerebral microbleeds and leukoaraiosis (white matter hyperintensity [WMH]),^{7,8,11,14–16,19,23,24} one could hypothesize that cerebral microbleeds, which represent bleeding from small vessels, may be more closely associated with ICH than WMH is. Therefore, the present study was performed to determine whether the presence of microbleeds is associated with recurrent hemorrhagic stroke in patients who have received warfarin treatment following atrial fibrillation–associated cardioembolic infarction.     

MRI of carotid atherosclerosis to identify TIA and stroke patients who are at risk of a recurrence

Purpose:

To evaluate the potential of carotid plaque MRI to predict transient ischemic attack (TIA) and stroke recurrence in previously symptomatic patients.

Materials and Methods:

One hundred twenty‐six TIA/stroke patients with ipsilateral 30–69% carotid stenosis underwent multisequence carotid plaque MRI. The presence of a lipid‐rich necrotic core (LRNC), fibrous cap (FC) status, and intraplaque hemorrhage (IPH) were assessed. Patients were followed to determine the recurrence of ipsilateral TIA and/or stroke within 1 year after inclusion.

Results:

Thirteen patients suffered from recurrent ipsilateral clinical ischemic events (10 TIAs and 3 strokes). Carotid stenosis grade was not associated with recurrent events (hazard ratio [HR] for 50–69% versus 30–49% stenosis = 1.198; 95% confidence interval [CI], 0.383 to 3.749; P = 0.756). The presence of an LRNC (HR = 3.2001; 95% CI, 1.078 to 9.504; P = 0.036), a thin and/or ruptured FC (HR = 5.756; 95% CI, 1.913 to 17.324; P = 0.002), and IPH (HR = 3.542; 95% CI, 1.058 to 11.856; P = 0.040) were associated with recurrence.

Conclusion:

The presence of MRI‐depicted LRNC, a thin and/or ruptured FC, and IPH are associated with the recurrence of clinical cerebrovascular ischemic events in TIA and stroke patients with carotid atherosclerosis. J. Magn. Reson. Imaging 2013;37:1189–1194. © 2013 Wiley Periodicals, Inc.     

MR梯度回波T2^＊WI检出脑微出血

目的：MR梯度回波T2^＊WI可检出无症状性脑微出血,本研究旨在探讨脑微出血的发生率、部位以及与高血压、脑卒中、脑室周围白质高信号的相关性。方法：在1年时间内共有375例患者在常规MRI／序列的基础上加扫T2^＊加权序列,排除了存在脑血管畸形出血、颅内占位、外伤、手术史等病例,共有324例进行分析处理。结果：脑微出血37例,总的发生率为11．4％,尤其位于基底节／放射冠（n=22）、丘脑（n=15）、小脑（n=14）和脑叶区域（n=15）,脑微出血主要见于存在脑中风史病例,与年龄、高血压、脑白质疏松症（脑室周围白质高信号）存在相关性（P〈0．001）。在2年多的影像学随访过程中,共发现2例（5．4％）出现新鲜脑出血。结论：MR T2^＊加权像可用于检出脑微出血,其发生提示存在脑微小血管病变,存在继发出血的可能性,建议对于60岁以上的老年人尤其是存在脑中风的病例,MR T2^＊加权应作为常规扫描序列。     

Prediction and Detection of Secondary Hemorrhages after Thrombolytic Therapy in Ischemic Stroke

Abstract It is well established that thrombolytic therapy increases the risk of secondary intracerebral hemorrhage in ischemic stroke patients. However, the term “intracerebral hemorrhage” (ICH) covers a wide spectrum from tiny spots of blood to massive space-occupying hematoma. We will review the etiology and clinical consequences of secondary hemorrhage after thrombolysis in ischemic stroke patients and discuss the ability of magnetic resonance imaging (MRI) to predict this phenomenon. MRI is a highly sensitive tool for detection of hemorrhagic transformation after ischemic stroke. The definitions of a so-called symptomatic hemorrhage after ischemic infarction differ considerably and will also be described. Attributing a causal relationship of a clinical deterioration to a secondary hemorrhage is not easy and should be only addressed when it exceeds at least 30% of the infarct volume. In other patients, secondary hemorrhage might be regarded as side effect of reperfusion within the region with the most severe perfusion deficit. Cerebral microbleeds (CMBs) are a frequent finding in patients with leukoaraiosis and appear to be a general marker of various types of bleeding- prone small vessel disease and a predictor of recurrent vascular events. Current data do not support the hypothesis that the detection of CMBs is a useful diagnostic criterion for the exclusion of patients with CMBs from thrombolytic therapy. However, an increased risk for the rare patients with numerous CMBs can not be ruled out.      

Brain microhemorrhages detected on T2*-weighted gradient-echo MR images

BACKGROUND AND PURPOSE: Multifocal microhemorrhages have been reported to be commonly found in the brain of patients with systemic hypertension and spontaneous brain hemorrhage. The factors associated with these lesions detected on T2*-weighted gradient-echo images were examined to determine whether these lesions serve to indicate different types of microangiopathy and to predict a patient's risk for symptomatic hemorrhage. METHODS: The study population consisted of 2164 patients who underwent 2416 consecutive brain MR imaging studies performed during 3 years. The patients with intracerebral hemorrhages due to vascular malformations, neoplasms, trauma, or intracranial surgery and those with incomplete medical records were excluded; 2019 cases were analyzed. RESULTS: The overall incidence of microhemorrhages was 9.8%, predominantly in the lentiform nucleus (n = 96), thalamus (n = 88), and cortical-subcortical region (n = 93). Presence of microhemorrhages had the highest significant correlation with history of hemorrhagic stroke (P <.0001); advancing age, hypertension, and prominent white matter hyperintensity on T2-weighted images had the next highest significant correlation. Cortical-subcortical microhemorrhages were more frequently observed in patients who had previous lobar hemorrhagic stroke (P <.005). Among 139 patients with microhemorrhages who could be clinically followed up for more than 1 month, four (2.9%) had new hemorrhagic stroke. CONCLUSION: The presence of microhemorrhages may be not only a direct marker of bleeding-prone small-vessel diseases but also an indicator of different types of microangiopathy and a predictor of further hemorrhagic stroke.     

Significance of increased oxygen extraction fraction in five-year prognosis of major cerebral arterial occlusive diseases.

In major cerebral arterial occlusive diseases, patients with increased oxygen extraction fraction (OEF), which is measured with PET, may be at increased risk for cerebral ischemia. However, the clinical significance of increased OEF remains unclear. This study investigated whether increased OEF is an independent predictor of 5-y risk of subsequent stroke. METHODS: We prospectively evaluated the relationship between the regional hemodynamic status of cerebral circulation and the subsequent risk of stroke in 40 patients with symptomatic internal carotid or middle cerebral arterial occlusive diseases who underwent PET. Patients were divided into two hemodynamic categories according to the mean hemispheric value of OEF-in the hemisphere supplied by the artery with symptomatic disease: one group with increased OEF and one with normal OEF. All patients were followed for 5 y with medical treatment until the recurrence of stroke or death. RESULTS: During 5 y, 11 total and 9 ipsilateral ischemic strokes occurred. The incidences of all ischemic strokes in patients with increased OEF and in those with normal OEF were 5 of 7 and 6 of 33 patients, respectively. There were 4 ipsilateral ischemic strokes in patients with increased OEF and 5 in those with normal OEF. Kaplan-Meier analysis revealed that the risks of all stroke and ipsilateral ischemic stroke in patients with increased OEF were significantly higher than in those with normal OEF (log-rank test; P<0.0002 and P<0.0018, respectively). Multivariate analysis with the Cox proportional hazards model showed that increased OEF significantly increased stroke recurrence: the relative risk was 7.2 (95% confidence interval [CI], 2.0-25.5; P<0.005) for all stroke and 6.4 (95% CI, 1.6-26.1; P<0.01) for ipsilateral stroke. An increase in the absolute OEF value was a better predictor of recurrent ischemic stroke than was OEF asymmetry. CONCLUSION: These findings suggest that an increased OEF is an independent predictor of 5-y risk of subsequent stroke. Identification of patients with increased OEF may have clinical significance in preventing recurrent stroke.     

Clinical and Angiographic Features and Stroke Types in Adult Moyamoya Disease

BACKGROUND AND PURPOSE:This study was conducted to elucidate the association between clinical and angiographic characteristics and stroke types in adult Moyamoya disease that has been rarely evaluated.MATERIALS AND METHODS:We analyzed the clinical and radiologic data obtained from a retrospective adult Moyamoya disease cohort with acute strokes, which were classified into 7 categories: large-artery infarct, hemodynamic infarct, perforator infarct, deep intracerebral hemorrhage, lobar intracerebral hemorrhage, intraventricular hemorrhage, and SAH. With conventional angiography, which was performed in the hemispheres with acute strokes, the Suzuki angiographic stage, intracranial aneurysm, major artery occlusion, and collateral vessel development were confirmed within 1 month of stroke onset.RESULTS:This study included 79 patients with acute ischemic stroke and 96 patients with acute hemorrhagic stroke. The angiographic stage had a strong tendency to be more advanced in the hemorrhagic than the ischemic patients (P = .061). Intracranial aneurysms were more frequently found in the hemorrhagic than ischemic or control hemispheres (P = .002). Occlusions of the anterior cerebral artery and development of fetal-type posterior cerebral artery were more frequently observed in the hemorrhagic than the ischemic (P = .001 and .01, respectively) or control hemispheres (P = .011 and .013, respectively). MCA occlusion (P = .039) and collateral flow development, including the ethmoidal Moyamoya vessels (P = .036) and transdural anastomosis of the external carotid artery (P = .022), occurred more often in the hemorrhagic than the ischemic hemispheres. Anterior cerebral artery occlusion occurred more frequently in patients with deep intracerebral hemorrhage or intraventricular hemorrhage than with lobar intracerebral hemorrhage (P = .009).CONCLUSIONS:In adult Moyamoya disease, major artery occlusion and collateral compensation occurred more often in the hemorrhagic than in the ischemic hemispheres. Thus, anterior cerebral artery occlusion with or without MCA occlusion and intracranial aneurysms may be the main contributing factors to hemorrhagic stroke in adult patients with Moyamoya disease.

Moyamoya disease (MMD) is a chronic, progressive cerebrovascular disorder with bilateral stenosis or occlusion of the supraclinoid ICA and its major branches at the surrounding area of the circle of Willis.¹ MMD exhibits diverse symptoms, such as TIA, recurrent TIAs, cerebral infarct, intracranial hemorrhage, headache, seizure, cognitive decline, ataxia, or choreiform movements; it can also be asymptomatic. In adult MMD, approximately half of the patients have intracranial hemorrhage, and the rest of the patients have TIA or cerebral infarct.^2,3 Recently, MMD was reported to exhibit a bimodal peak of symptom onset in the ischemic type and a unimodal peak in the hemorrhagic type.⁴ However, the cause of differential onset and the distinct presentation in MMD are not completely understood. Although angiographic factors causing intracranial hemorrhage in adult MMD, such as dilation and branch extension of the anterior choroidal artery or posterior communicating artery have also been reported,^5–7 direct comparison studies on the angiographic features according to stroke type in adult MMD have been limited.We hypothesized that there may be differences in major artery occlusion and collateral patterns according to stroke type. Because understanding differences in the angiographic characteristics of ischemic and hemorrhagic stroke types may be helpful to prevent future strokes and make a good prognosis in adult patients with MMD, this study aimed to compare the angiographic features of adult MMD with ischemic and hemorrhagic stroke.     

卒中患者脑微出血的MRI特点及其临床意义

目的 探讨卒中患者脑微出血（CMBs）的MRI特点及其临床意义，并比较MRI不同扫描序列检出CMBs的能力。方法 卒中患者60例，分为脑缺血组（34例）和脑出血组（26例），以同期查体的60岁以上健康老年人为对照组（30例）。采用常规MRI（包括SE T1WI和FSE T2WI）、扩散加权成像（DWI）、梯度回波T2加权成像（GRE-T2WI）和平面回波成像（EPI）检查，分别统计各组CMBs、腔隙性梗死、脑白质稀疏情况，同时记录卒中患者的高血压、糖尿病、卒中病史，比较不同扫描序列检出CMBs的差异。结果 CMBs在缺血组、出血组和对照组的发生率分别为29．4％，61．5％和6．7％。CMBs最常见于基底节／丘脑区。CMBs与高血压、卒中病史相关（P〈0．01），而与糖尿病无关（P〉0．05）。CMBs的数目与腔隙性脑梗死的数目和脑白质的改变程度成正相关（P〈0．01）。常规MRI和DWI均不能显示CMBs，EPI与GRE-T2WI检出CMBs的差异无统计学意义（P〉0．05）。结论 脑卒中患者多发性CMBs的存在提示微血管病变的严重程度和出血倾向，对于临床治疗决策具有重要的指导意义。GRE-T2WI是检测CMBs的首选方法，EPI可作为GRE-T2WI的补充手段。     

MR imaging enhancement patterns as predictors of hemorrhagic transformation in acute ischemic stroke

BACKGROUND AND PURPOSE: Early parenchymal gadolinium enhancement on T1-weighted MR images is predictive of hemorrhagic transformation (HT) in rodent focal ischemia models, but its value in humans is unknown. We sought to investigate gadolinium enhancement in acute ischemic stroke patients to determine their association with subsequent HT. METHODS: We retrospectively examined 22 patients with ischemic stroke who underwent MR imaging within 4.9 hours (+/-1.4) of symptom onset. Patients receiving intravenous tissue plasminogen activator (tPA) (n = 6) were included. Twenty-one patients underwent repeat MR studies at 48 hours, 13 underwent additional MR imaging at 1 week, and one underwent follow-up head CT at 24 hours. Initial images were analyzed for enhancement patterns (vascular, meningeal, parenchymal). Follow-up T2- and T2*-weighted images were evaluated for hemorrhage. RESULTS: In all patients, initial MR images showed vascular enhancement in the vascular territory of the stroke lesion: 19 with vascular enhancement alone and three with vascular and parenchymal enhancement. All three patients with both enhancement patterns had HT: two large and symptomatic, and one asymptomatic (petechial hemorrhage). They received tPA before MR imaging. None of the patients without early parenchymal enhancement developed symptomatic hemorrhage. Six (32%) patients with vascular enhancement alone had petechial hemorrhage at follow-up imaging. In this limited sample, initial mean volumes on diffusion-weighted images, National Institute of Health Stroke Scale scores, and intervals from stroke onset to imaging did not differ between patients with vascular and parenchymal enhancement versus those with vascular enhancement alone. CONCLUSION: Early parenchymal enhancement of stroke lesions may be a good predictor of subsequent symptomatic HT may help identify patients at risk, especially after thrombolytic therapy.     

Bleeding complications after endovascular therapy of cerebral arteriovenous malformations

BACKGROUND AND PURPOSE: Intracerebral hemorrhages after embolization of arteriovenous malformations (AVMs) are the most dreaded complications of this well-established therapy. Apart from the known risk factors, our center noticed a high incidence of complications during postinterventional monitoring in medical intensive care units (ICUs) and stroke units. MATERIALS AND METHODS: We report 125 consecutive interventions performed on 66 patients by using flow-dependent microcatheters and n-butyl cyanoacrylate as the embolic agent. Postinterventional intensive care monitoring was performed in an interdisciplinary operative ICU, a stroke unit, or a medical ICU. Patients were compared with regard to bleeding complications, AVM morphology, embolization result, postinterventional monitoring, and demographic factors. RESULTS: Intracerebral hemorrhages occurred in 7 patients. Significant differences in outcome were found between 66 patients monitored in the interdisciplinary operative ICU from medical ICU or stroke unit. This was also true when adjusted for age and extent of AVM reduction by using exact logistic regression. A partial AVM reduction of >60% was a considerable risk factor for hemorrhage (odds ratio [OR] = 18.8; 95% confidence interval [CI] [1.341, not available]. Age was also an essential risk factor. An age difference of 10 years leads to an OR of 2.545 (95% CI [1.56, 7.35]). DISCUSSION:A considerable AVM reduction in one session appears to increase the risk of hemorrhage technically. This suggests a distribution of the interventions in many partial steps.     

Intra-arterial thrombolysis for acute stroke in patients 80 and older: a comparison of results in patients younger than 80 years

BACKGROUND AND PURPOSE: Intra-arterial fibrinolytic therapy is a promising treatment for acute ischemic stroke. Few data are available on its use in elderly patients. The purpose of this study was to compare the baseline characteristics, complications, and outcomes between intra-arterially treated ischemic stroke patients aged > or = 80 years and their younger counterparts. METHODS: Patients aged > or = 80 years (n = 33) were compared retrospectively with contemporaneous patients aged < 80 years (n = 81) from a registry of consecutive patients treated with intra-arterial thrombolysis over a 9-year period. RESULTS: The very elderly and younger cohorts were very similar in baseline characteristics, including pretreatment stroke severity (National Institutes of Health Stroke Scale [NIHSS] 17 versus 16), differing only in history of stroke/transient ischemic attack (42% versus 22%, P = .01) and weight (66.8 versus 75.8 kg; P = .02). Significant differences in recanalization (TIMI 2-3) rates could not be detected between the very elderly and younger patients (79% versus 68%, P = .10). Rates of major symptomatic hemorrhage (7% versus 8%) and any intracerebral hemorrhage (39% versus 37%) did not differ. Outcomes at 90 days showed lower rates of excellent functional outcome (mRS < or = 1, 26% versus 40%, P = .02) and survival (57% versus 80%, P = .01) among the very elderly. CONCLUSIONS: Intra-arterial fibrinolysis in the elderly can be accomplished with recanalization rates and hemorrhage rates equal to that in younger patients. Although mortality rates are higher and good functional outcomes are lower than in younger persons, nondisabling outcomes may be achieved in a quarter of patients. These findings suggest that the investigation and use of intra-arterial thrombolytic treatment in very elderly patients should not be avoided but pursued judiciously.     

Cerebral microbleeds: a guide to detection and clinical relevance in different disease settings

Cerebral microbleeds have emerged as an important new imaging marker of cerebral small vessel disease. With the development of MRI techniques that are exquisitely sensitive to paramagnetic blood products, such as T2*-weighted gradient-recalled echo and susceptibility-weighted sequences, microbleeds have been detected in ever-increasing numbers of patients in stroke and cognitive clinics, as well as in healthy older people and in a variety of other rarer diseases and syndromes. Detection of cerebral microbleeds has clinical implications with respect to the diagnosis of the underlying small vessel disease, the safety of antithrombotic use, and the risk of symptomatic intracerebral haemorrhage, cognitive impairment and dementia. This article provides a guide to the detection and clinical relevance of cerebral microbleeds in different conditions based on a comprehensive review of the literature and own findings in research and clinical practice.     

Effects of Antecedent Intravenous Thrombolysis on Endovascular Treatment of Acute Stroke Using Tirofiban

PurposeTo investigate whether preceding intravenous thrombolysis combined with tirofiban in patients with acute ischemic stroke undergoing endovascular treatment is safe and effective.Materials and MethodsConsecutive data were identified for patients who experienced acute ischemic stroke and were admitted to 2 comprehensive stroke centers from January 2015 to August 2021. All patients were divided into 2 groups—a thrombolytic with tirofiban group and a tirofiban-alone group—on the basis of whether intravenous thrombolysis before emergency endovascular angioplasty was used. Multivariate regression and propensity adjustment analyses were performed to characterize differences in safety and clinical outcomes between the 2 groups.ResultsOf 373 eligible patients, 111 (29.7%) were treated with thrombolysis with tirofiban. There was a significant difference in the rate of any intracerebral hemorrhage (35.1% vs 24.8%; P = .04) but not in the rates of symptomatic intracerebral hemorrhage (16.2% vs 11.5%; P = .23) and reocclusion at 24 hours (5.4% vs 7.6%; P = .51) between the 2 groups. Multivariate regression analysis revealed that intravenous thrombolysis was not associated with any or symptomatic intracerebral hemorrhage, artery occlusion, functional outcome, or death at the 3-month follow-up (all adjusted P > .05). After propensity adjustment, the thrombolytic with tirofiban group showed nonsignificant rates of clinical and safety outcomes compared with those of the tirofiban-alone group (all P > .05).ConclusionsTirofiban may be used without increasing the risk of adverse events in selected patients who experienced ischemic stroke and were treated with intravenous thrombolysis and endovascular therapy.     

Vertebral artery ostial stent placement for atherosclerotic stenosis in 72 consecutive patients: clinical outcomes and follow-up results

Introduction  The study’s purpose is to report the technical and clinical outcomes of a patient cohort that underwent vertebral artery ostium stent placement for atherosclerotic stenosis. Methods  We retrospectively analyzed a prospectively collected database of neurointerventional procedures performed at a single center from 1999 to 2005. Outcome measures included recurrent transient neurological deficits (TNDs), stroke, and death. Kaplan–Meier analysis was used to estimate stroke- and/or death-free survival at 12 months. Cox proportional hazard was used to identify risk factors for recurrent vertebrobasilar ischemic events. Results  Seventy-two patients with 77 treated vertebral ostial lesions were included. The 30-day stroke and/or death rate was 5.2% (n = 4), although no event was directly related to the vertebral ostium stent placement. Three procedure-related strokes were secondary to attempted stent placement at other sites (one carotid artery and two basilar arteries), and the one death was secondary to the presenting stroke severity. The mean clinical follow-up time available for 66 patients was 9 months. There were 14 TNDs (21%), two strokes (3%), and two deaths (3%) recorded in the follow-up. Recurrent vertebrobasilar ischemic events occurred in nine patients (seven TNDs and two strokes). No recurrent stroke and/or deaths were related to the treated vertebral ostium. Stroke- and/or death-free survival rate (including periprocedural stroke and/or death) was 89 ± 5% at 12 months. No vascular risk factor was significantly associated with recurrent vertebrobasilar ischemic events. Conclusions  Vertebral artery ostium stent placement can be safely and effectively performed with a low rate of recurrent stroke in the territory of the treated vessel. Patients who also underwent attempted treatment of a tandem intracranial stenosis appeared to be at highest risk for periprocedure stroke.     

Diffuse axonal injury associated with chronic traumatic brain injury: evidence from T2*-weighted gradient-echo imaging at 3 T

BACKGROUND AND PURPOSE: Diffuse axonal injury is frequently accompanied by tissue tear hemorrhages. We examined whether high field strength T2*-weighted gradient-echo imaging performed during the chronic stage of traumatic brain injury may have advantages in the evaluation of diffuse axonal injury as compared with T1- and T2-weighted MR imaging. METHODS: Prospective MR imaging of 66 patients (age range, 17-57 years) was performed using a 3-T system 3 to 292 months (median, 23.5 months) after traumatic brain injury. T1-, T2-, T2*-hypointense and T2-hyperintense foci of 1- to 15-mm diameter were registered in 10 brain regions by two readers separately. Foci that appeared hypointense both on the T1- and T2- and/or on the T2*-weighted images were defined as traumatic microbleeds. RESULTS: For 46 (69.7%) of the patients, T2*-weighted gradient-echo imaging revealed traumatic microbleeds. Hyperintense foci were observed on the T2-weighted images of only 15 (22.7%) patients. T2*-weighted imaging showed significantly more traumatic microbleeds (P =.000) than did T1- and T2-weighted imaging. Interobserver agreement was strong (kappa = 0.79, tau = 0.749, P =.000). For 14 (21.2%) of the patients, T2*-weighted gradient-echo imaging revealed traumatic microbleeds in the corpus callosum, whereas for only two (3%), hyperintense callosal lesions were seen on the T2-weighted images. Although a significant correlation existed between the total amount and callosal appearance of traumatic microbleeds and Glasgow Coma Scale scores (P =.000), no correlation existed with extended Glasgow Outcome Scale scores. CONCLUSION: T2*-weighted gradient-echo imaging at high field strength is a useful tool for the evaluation of diffuse axonal injury during the chronic stage of traumatic brain injury. Diffuse axonal injury-related brain lesions are mainly hemorrhagic. The relevance of diffuse axonal injury for long-term clinical outcome is uncertain.     

MR imaging of acute hemorrhagic brain infarction

Six patients with acute hemorrhagic brain infarct were imaged using spin-echo (SE) pulse sequences on a 1.5 Tesla MR scanner. Including two patients with repeated MR imaging, a total of eight examinations, all performed within 15 days after stroke, were analyzed retrospectively. Four patients revealed massive hemorrhages in the basal ganglia or cerebellum and three cases demonstrated multiple linear hemorrhages in the cerebral cortex. On T1-weighted images, hemorrhages were either mildly or definitely hyperintense relative to gray matter, while varied from mildly hypointense to hyperintense on T2-weighted images. T1-weighted images were superior to T2-weighted images in detection of hemorrhage. CT failed to detect hemorrhages in two of five cases: indicative of MR superiority to CT in the diagnosis of acute hemorrhagic infarcts.     

脑微出血相关危险因素及临床意义

脑微出血(CMB)属于脑内微小血管病变,由于出血少,临床症状和体征不明显。CMB可发生于脑内任何部位,其分布可能与病因相关。一般认为CMB与高龄、高血压、血压变异性、高脂血症、脑白质病变及基因突变等危险因素有关。研究认为CMB与病人认知功能障碍、抑郁障碍、肾功能障碍及病人体质虚弱的状态等有关。由于CMB能够反映微小血管的出血倾向,是脑出血风险增加的一个标志。重视脑内CMB的存在,有助于对缺血性脑卒中病人选择合适的治疗方案。     

Detection of hyperacute parenchymal hemorrhage of the brain using echo-planar T2*-weighted and diffusion-weighted MRI

We investigated the usefulness of echo-planar imaging (EPI) as well as T2^*-weighted and diffusion-weighted MRI (DWI) to identify hyperacute hemorrhage (within 24 h after ictus) in the brain. Seven patients were examined 3.5 to 24 h after onset of symptoms using a whole-body 1.5-T MR system. Two diffusion-weighted sequences were run to obtain isotropic and anisotropic diffusion images. Apparent diffusion coefficients (ADC) were calculated from the isotropic diffusion images. All DWI images as well as the T2*-weighted EPI images showed the hematomas as either discrete, deeply hypointense homogeneous lesions, or as lesions of mixed signal intensity containing hypointense areas. We conclude that even in the early phase after hemorrhage, sufficient amounts of paramagnetic deoxyhemoglobin are present in intracerebral hemorrhages to cause hypointensity on EPI T2^*-weighted and DWI images; thus, use of ultrafast EPI allows identification of intracerebral hemorrhage. Received: 21 March 2000 Revised: 26 July 2000 Accepted: 27 July 2000