Dynamics of regional distribution of ischemic lesions in middle cerebral artery trunk occlusion relates to collateral circulation

We describe the regional distribution of acute perfusion, diffusion, and final infarct lesions in middle cerebral artery (MCA) trunk occlusion. A total of 31 patients with acute ischemic stroke and MCA trunk occlusion were studied by multiparametric magnetic resonance imaging. Probabilistic maps of lesion distribution were generated. The probability of initial and final infarcts was highest in the central MCA region with decreasing probability toward the periphery where the probability of the tissue at risk of infarction to be saved was highest. The probability of brain regions being involved in acute diffusion lesions and evolving into or escaping from the final infarct relates to the anatomy of arterial blood supply.     

急性缺血性脑卒中患者神经源性丝氨酸蛋白酶抑制剂的表达与其预后的关系

目的探讨急性缺血性脑卒中(AIS)患者神经源性丝氨酸蛋白酶抑制剂(NSP)的表达与其预后的关系。方法选择发病72 h之内的119例AIS住院患者(AIS组)作为研究对象,用双抗体夹心酶联免疫分析法测定其入院时血清NSP含量,并以改良Rankin量表(mRS)作为脑卒中3个月后的预后评判标准,将mRS≥2分者为预后不良(45例),mRS2分为预后良好(74例)。同时选择104例老年体检者为对照组。结果 AIS组NSP水平较对照组升高(P=0.000);预后良好患者其入院时梗死灶体积和美国国立卫生研究院卒中量表评分(NIHSS)明显小于预后不良患者(P0.05);且预后良好患者入院时NSP水平高于预后不良患者(P0.05)。对预后有影响且差异有统计学意义的各项指标经Logistic回归分析,NSP水平与预后有明显关系(OR=0.497 9,95%CI:0.269 8~0.918 8,P0.05)。结论 AIS患者的NSP表达可能与其预后有关。     

Recurrent artery-to-artery embolism during intravenous t-PA therapy for acute ischemic stroke

Introduction: Treatment of acute ischemic stroke with systemic thrombolysis in the presence of a proximal thrombo-embolic source carries a theoretical risk of thrombus fragmentation and recurrent embolization. Intracardiac thrombus has received the most attention as a potential source of recurrent emboli, and in the past, it was considered a relative contra-indication to tissue plaminogen activator (t-PA) treatment. More recent data show that recurrent embolization from a cardiac source during t-PA infusion is rare. Case Report: This article describes recurrent symptomatic basilar artery embolization during t-PA infusion from acute thrombus in the proximal cervical vertebral artery. Discussion: This case provides evidence that intravenous t-PA must be used cautiously in the presence of large proximal thrombo-embolic sources and that intraluminal thrombus in a large cervical artery should be considered one such source.     

MRI before intraarterial therapy in ischemic stroke: feasibility,impact, and safety

Intraarterial therapy (IAT) in acute ischemic stroke is effective for opening occlusions of major extracranial or intracranial vessels. Clinical efficacy data are lacking pointing to a need for proper patient selection. We examined feasibility, clinical impact, and safety profile of magnetic resonance imaging (MRI) for patient selection before IAT. In this single-center study, we collected epidemiologic, imaging, and outcome data on all intraarterial-treated patients presenting with anterior circulation occlusions at our center from 2004 to 2011. Magnetic resonance imaging was the first imaging choice. Computer tomography (CT) was performed in the presence of a contraindication. We treated 138 patients. Mean age was 64 years and median National Institutes of Health Stroke Scale (NIHSS) was 17. Major reperfusion (thrombolysis in cerebral infarction (TICI) 2b+3) was achieved in 52% and good outcome defined as modified Rankin Scale (mRS) score 0 to 2 at 90 days was achieved in 41%. Mortality at 90 days was 10%. There was only one symptomatic hemorrhage. Recanalization, age, and stroke severity were associated with outcome. Preprocedure MRI was obtained in 83%. Good outcome was significantly associated with smaller diffusion-weighted imaging (DWI) lesion size at presentation and not with the size of the perfusion lesion. It is feasible to triage patients for IAT using MRI with acceptable rates of poor outcome and symptomatic hemorrhage.     

An ischemic stroke during intravenous recombinant tissue plasminogen activator infusion for evolving myocardial infarction

A 56-year-old man without a previous history of stroke received intravenous recombinant tissue plasminogen activator (tPA) for an evolving myocardial infarction. During the infusion, the patient developed aphasia and right hemiparesis. The CT and MRI confirmed an ischemic stroke without evidence of hemorrhage. Although the cerebral hemorrhage after tPA infusion is relatively more common, in rare cases, tPA infusion may result in fragmentation of a cardiac thrombus resulting in an ischemic cerebral stroke.     

Intravenous thrombolytic treatment in a patient with transient ischemic attack associated with mural carotid thrombi

A 77-year old man experiencing frequent transient ischemic attacks for five days was admitted to our hospital. Radiological examinations including brain computed tomography, supraaortic computed tomography angiography were performed. Supraaortic computed tomography angiography revealed two thrombi in common carotid artery. Thrombi were located proximally, one of which was elongated and adhared to the arterial wall and the other one was located below bifurcation of left carotid artery. Since the case has been categorized as a high risk patient for ischemic stroke despite the normal neurological status, intravenous recombinant tissue plasminogen activator was given. Ischemic attacks completely ceased soon after thrombolysis. Control computed tomography angiography revealed normal findings with patent carotid artery, without any clot. To our knowledge this is the only case of transient ischemic attack treated with intravenous recombinant tissue plasminogen activator in the literature with the score of 0 on the National Institutes of Health Stroke Scale.     

重组组织型纤溶酶原激活剂静脉治疗轻型缺血性卒中患者的疗效分析

目的 观察轻型缺血性卒中患者重组组织型纤溶酶原激活剂（recombinant tissue plasminogen activator,rt-PA）静脉溶栓治疗的疗效及安全性。      

Emergency physician attitudes toward thrombolytic therapy in acute stroke

Background: Intravenous use of tissue plasminogen activator (TPA) is the only currently approved treatment for acute ischemic stroke. Methods: To determine emergency physician attitudes and practices with regard to thrombolysis for ischemic stroke, a questionnaire was sent to program directors of accredited emergency medicine residencies in the United States. Results: There were 73 program directors who responded to the survey; 71% of medical centers have used TPA for treatment of stroke. The reported major complication rate for cerebral hemorrhage and death averaged 7%. For nontreating centers, two major factors cited were lack of appropriate patients and concerns regarding the safety of TPA; 48% of the facilities do not have an acute stroke team. Delayed patient arrival and the perceived narrow risk/benefit ratio of TPA were identified as the two greatest obstacles to more widespread use of TPA. Conclusion: Although the majority of medical centers that responded in this study have some experience with thrombolytic therapy for acute ischemic stroke, almost one half do not have an acute stroke team and considerable uncertainty exists regarding the safety of intravenous TPA. More uniform national treatment of acute stroke will require greater consensus among emergency physicians and further analysis of the risk/benefit ratio of thrombolytic treatment.     

磁共振血管成像-弥散成像不匹配对预测急性缺血性脑卒中缺血半暗带的价值

目的研究急性缺血性脑卒中（AIS）超早期磁共振血管成像（MRA）一弥散成像（DWI）不匹配对预测缺血半暗带的价值。方法选择在发病6h内完成MRA、DWI及灌注成像（PWI）检查的大脑中动脉供血区脑梗死患者，MRA—DWI桓Ⅱ体女不匹配定义为MRA示大脑中动脉M1段闭塞，DWI的梗死体积〈25ml；MRA—DWI梗Ⅱ部＆不匹配定义为M1段闭塞，DWI的梗死部位评分（以Alberta梗死早期CT评分评价）≥7。结果共入选78例患者，MRA—DWI梗死体积不匹配预测：PWI—DWI不匹配的特异度为100％，灵敏度仅为46％。MRA—DWI梗Ⅱ部＆不匹配预测：PWI—DWI不匹配的特异度为100％，灵敏度为42．9％。结论AIS超早期MRA．DWI不匹配预测缺血半暗带有很高的特异度，可作为筛选进行溶栓治疗患者的手段。     

Clot injection technique affects thrombolytic efficacy in a rat embolic stroke model: implications for translaboratory collaborations

Current recommendations encourage the use of embolic stroke (ES) models and replication of results across laboratories in preclinical research. Since such endeavors employ different surgeons, we sought to ascertain the impact of injection technique on outcome and response to thrombolysis in an ES model. Embolic stroke was induced in Male Wistar Kyoto rats (n=166) by a fast or a slow clot injection (CI) technique. Saline or recombinant tissue plasminogen activator (rtPA) was given at 1 hour after stroke. Flow rate curves were assessed in 24 animals. Cerebral perfusion was assessed using laser Doppler flowmetry. Edema corrected infarct volume, hemispheric swelling, hemorrhagic transformation, and neurologic outcome were assessed at 24 hours after stroke. Clot burden was estimated in a subset of animals (n=40). Slow CI resulted in significantly smaller infarct volumes (P=0.024) and better neurologic outcomes (P=0.01) compared with fast CI at 24 hours. Unexpectedly, rtPA treatment attenuated infarct size in fast (P<0.001) but not in slow CI experiments (P=0.382), possibly related to reperfusion injury as indicated by greater hemorrhagic transformation (P<0.001) and hemispheric swelling (P<0.05). Outcome and response to thrombolysis after ES are operator dependent, which needs to be considered when comparing results obtained from different laboratories.     

糖尿病性和非糖尿病性脑梗死患者血浆中纤溶酶原激活物及其抑制剂活性的动态观察

目的 :观察糖尿病性脑梗死 (diabeticischemicstroke ,DIS)和非糖尿病性脑梗死 (non diabeticischemicstroke ,NDIS)患者血浆中纤溶酶原激活物 (plasminogenactivator ,PA)及纤溶酶原激活物抑制剂 (plasminogenactivatorinhibitor ,PAI)的动态变化情况。方法 :应用底物发色法测定血浆中PA和PAI活性 ,以观察DIS和NDIS患者血浆PA和PAI活性的动态变化。结果 :NDIS患者血浆中PA活性在4～ 2 1d较非脑梗死患者升高 ;DIS患者的PA活性在 7h～ 2 1d较NDIS患者为低 ,但PAI活性在各组间无明显差异。结论 :DIS患者血浆中PA活性较NDIS患者降低 ,提示其存在纤溶系统激活的紊乱 ,并可能与DIS症状加重有关。     

Thrombolysis in patients with acute ischemic stroke due to arterial extracranial dissection

Background and purpose: No data of randomized controlled trials investigating the effect of thrombolysis in patients with ischemic stroke caused by an extracranial dissection are available. Previous case series suggested that thrombolysis in this group of patients is safe and improves outcome, however publication bias may play a role. The purpose of the present study was to describe outcome of consecutive patients with ischemic stroke caused by an extracranial dissection treated with recombinant tissue plasminogen activator (rtPA), derived from a well‐defined ischemic stroke cohort. Methods: All consecutive patients with a transient ischemic attack (TIA) or ischemic stroke admitted to the Academic Medical Center Amsterdam between January 1, 2007 and September 1, 2007 were prospectively registered. Cause of TIA/stroke, treatment, and 6‐months outcome were recorded. Results: During the study period 252 patients were evaluated with TIA or ischemic stroke. Eight patients (3%) had an extracranial dissection. Of the six rtPA treated patients, five had good clinical outcome and one patient died. The two patients who were not treated with rtPA, because of minor stroke, had good clinical outcome 6 months after index event. Discussion: Treatment with rtPA seems to be safe and feasible in ischemic stroke patients with an extracranial dissection.