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Acute Ischemic Stroke (acute + ischemic_stroke)
Terms modified by Acute Ischemic Stroke Selected AbstractsPostprocedure Intravenous Eptifibatide Following Intra-Arterial Reteplase in Patients with Acute Ischemic StrokeJOURNAL OF NEUROIMAGING, Issue 1 2008Adnan I. Qureshi MD ABSTRACT BACKGROUND AND PURPOSE Early use of intravenous platelet glycoprotein IIB/IIIA antagonists after intra-arterial (IA) thrombolysis may reduce the risk of reocclusion and microvascular compromise. METHODS We performed a retrospective study to determine the in-hospital outcomes using serial neurological evaluations and imaging among patients treated with intravenous eptifibatide administered as a 135 microg/kg single-dose bolus, followed by 0.5 microg/kg/min infusions for 20 to 24 hours following treatment with IA reteplase. RESULTS Twenty patients were treated (mean age ± standard deviation, 68.4 ± 14.5 years; median National Institutes of Health Stroke Scale [NIHSS] score was 17). The dose of reteplase ranged from 0.5 to 4 units. Eleven patients demonstrated early neurological improvement, defined as a decline of ,4 points on the 24 hours NIHSS score compared with initial NIHSS score; neurological deterioration, defined as an increase of ,4 points on the 24 hours NIHSS score as compared with initial NIHSS score, was observed in one patient. Two asymptomatic intracerebral hemorrhages were observed while no symptomatic hemorrhages were observed on serial computed tomographic scans. CONCLUSIONS The use of intravenous eptifibatide within 24 hours in selected patients after IA thrombolysis is feasible and safe. Further studies are required to determine the benefit of early use of intravenous eptifibatide following thrombolysis. [source] Aortic Dissection Presenting as an Acute Ischemic Stroke for ThrombolysisJOURNAL OF NEUROIMAGING, Issue 3 2005Ken Uchino MD ABSTRACT Thrombolysis for the treatment of acute ischemic stroke requires careful selection of patients. The authors report a case of aortic dissection presenting with acute ischemic stroke for which emergent ultrasonographic evaluation was helpful in the diagnosis and subsequent treatment. The patient presented with acute middle cerebral artery ischemic stroke symptoms and complained of bilateral ear and chest pain. Chest x-ray, cardiac enzymes, and transthoracic echocardiogram were normal, and she was considered for thrombolytic therapy. Carotid ultrasound revealed right common carotid occlusion that led to the diagnosis of aortic dissection, confirmed by chest computed tomography. An experienced sonographer with skills to perform rapid intra- and extracranial examinations may help to change the treatment plan for acute stroke patients. [source] Comparison of Transcranial Color-Coded Sonography and Magnetic Resonance Angiography in Acute Ischemic StrokeJOURNAL OF NEUROIMAGING, Issue 4 2001Li-Ming Lien MD ABSTRACT Background and Purpose. This study was designed to assess the accuracy of transcranial color-coded sonography (TCCS) as compared to magnetic resonance angiography (MRA) for detecting intracranial arterial stenosis in patients with acute cerebral ischemia. Methods. The authors prospectively identified 120 consecutive patients admitted with acute ischemic stroke and performed both TCCS and MRA with a mean interval of 1 day. TCCS data (sampling depth, peak systolic and end diastolic angle-corrected velocity, mean angle-corrected velocity, and pulsatility index) for middle cerebral arteries (MCAs) were compared to MRA data and classified into 4 grades: normal (grade 1): normal caliber and signal; mild stenosis (grade 2): irregular lumen with reduced signal; severe stenosis (grade 3): absent signal in the stenotic segment (flow gap) and reconstituted distal signal; and possible occlusion (grade 4): absent signal. The cutoffs were chosen to maximize diagnostic accuracy. Results. Interobserver agreement for MRA grading resulted in a weighted-kappa value of 0.776. The rate of poor temporal window was 37% (89/240). Doppler signals were obtained in 135 vessels, and the angle-corrected velocities (peak systolic, end diastolic, mean) were significantly different (P= .001, P= .006, P < .001) among the MRA grades: grade 1 (100, 47, 68 cm/s), grade 2 (171, 72, 110 cm/s), grade 3 (226, 79, 134 cm/s), grade 4 (61, 26, 39 cm/s). Additionally, an angle-corrected MCA peak systolic velocity ,120 cm/s correlates with intracranial stenosis on MRA (grade 2 or worse) with high specificity (90.5%; 95% confidence interval = 78.5%,96.8%) and positive predictive value (93.9%) but relatively low sensitivity (66.7%; 95% confidence interval = 61.2%,69.5%) and negative predictive value (55.1%). Conclusion. Elevated MCA velocities on TCCS correlate with intracranial stenosis detected on MRA. An angle-corrected peak systolic velocity ,120 cm/s is highly specific for detecting intracranial stenosis as defined by significant MRA abnormality. [source] Baseline Computed Tomography Changes and Clinical Outcome After Thrombolysis With Recombinant Tissue Plasminogen Activator in Acute Ischemic StrokeJOURNAL OF NEUROIMAGING, Issue 2 2001Jorge E. Mendizabal MD ABSTRACT Objective. Intravenous recombinant tissue plasminogen activator (rt-PA) is the only therapy of proven value for patients with acute ischemic stroke (AIS). Controversy exists with regard to the prognostic significance of early computed tomography (CT) changes in patients receiving rt-PA for AIS. The authors retrospectively reviewed all cases of AIS who received intravenous rt-PA for AIS in University of South Alabama hospitals between January 1996 and May 1999. A neuroradiologist, blinded to clinical outcomes, reviewed all baseline CT scans for the presence of the following signs: hyperdense middle cerebral artery (HMCA), loss of gray-white differentiation (LGWD), insular ribbon sign (IRS), parenchymal hypodensity (PH), and sulcal effacement (SE). Modified Rankin Scale (mRS) score was recorded 90 days after thrombolysis, and clinical outcome was dichotomized as favorable (0,1) or unfavorable (2,6). The authors performed both univariate and multivariate analyses to investigate the relationship between early CT signs, baseline clinical variables, and functional outcome as measured by the 90-day mRS scores. Any one early CT finding was detected in 23 (64%) patients. The frequency of specific findings were as follows: SE in 13 patients (36%), LGWD in 12 patients (33%), PH in 9 patients (25%), HMCA in 4 patients (11%), and IRS in 3 patients (8%) patients. There was no statistically significant association between the occurrence of these imaging findings and subsequent functional outcome after thrombolysis. The data suggest that the presence of subtle acute CT changes in AIS patients is not predictive of clinical outcome following administration of rt-PA as per National Institute of Neurological Disorders and Stroke protocol. [source] Evaluating Patients with Acute Ischemic Stroke with Special Reference to Newly Developed Atrial Fibrillation in Cerebral EmbolismPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2007MINORU TAGAWA M.D. Background:Cardioembolic strokes are extensive and have a poor prognosis. To identify the cardiovascular risk factors of cardioembolic stroke, we evaluated the cardiovascular status with special reference to persistent atrial fibrillation (AF) and paroxysmal atrial fibrillation (PAF) combined with the type of acute ischemic stroke. Methods:We divided 315 consecutive patients admitted to our Department of Neurosurgery with an acute ischemic stroke into four types of brain infarction using clinical history, onset pattern of stroke, and brain imaging: cardioembolic (group E, n = 105), lacunar (group L, n = 92), atherothrombotic (group T, n = 111), and unclassified (n = 7). All patients underwent standard electrocardiography (ECG), a 24-hour ECG recording (Holter ECG) and transthoracic echocardiography (UCG). Results:Persistent AF or PAF was detected in 97 patients (31.5%) using Holter ECG: more frequently in group E (67.6%) than in groups L (15.2%) or T (9.2%). Persistent AF or PAF was first diagnosed on admission using a standard ECG in 16 patients (5.2%) with no previous history and 14 of these patients belonged to group E (13.3%). PAF was newly detected on Holter ECG in another 26 patients (8.4%) and 13 of these patients (12.4%) belonged to group E. Concerning UCG, left atrial enlargement and mitral regurgitation were more frequent in group E than in group L or T. Conclusion:Holter ECG in addition to ECG on admission is important for detecting persistent AF or PAF in patients with ischemic stroke, especially with cardioembolism as diagnosed by neuroimaging. [source] Endothelial Microparticle Levels Are Similar in Acute Ischemic Stroke and Stroke Mimics Due to Activation and Not Apoptosis/NecrosisACADEMIC EMERGENCY MEDICINE, Issue 8 2007Justin B. Williams MD BackgroundEndothelial microparticles (EMPs) are <2-,m membranous blebs from endothelial cell membranes that have been demonstrated to be elevated in vasculopathic conditions. One study has demonstrated elevated EMPs in acute ischemic stroke (AIS) versus age- and comorbidity-matched controls. ObjectivesTo determine the level of EMPs in stroke mimics and AIS and determine if EMPs are released as a result of activation or apoptosis/necrosis in AIS. MethodsEMP levels in plasma of patients with AIS and stroke mimic patients were quantified by flow cytometry. Stroke status was verified in all patients by magnetic resonance imaging. Patients were matched for age and comorbidities. Markers for apoptosis/necrosis (platelet/endothelial cell adhesion molecule-1 [PECAM-1]/CD31 antigen) and activation (E-selectin/CD62e antigen) were compared. A PECAM-1/E-selectin ratio of >4.0 was used to determine whether EMPs were generated via activation or apoptosis/necrosis. Data were compared between groups using the Mann-Whitney U test. ResultsEMP levels were similar in stroke mimic patients when compared with AIS; there was no difference between groups (PECAM-1, p = 0.393; E-selectin, p = 0.579). The PECAM-1/E-selectin ratio was also similar for AIS and stroke mimics, and all were >4.0. ConclusionsEMP levels were similar in patients with AIS and stroke mimic patients. The PECAM-1/E-selectin ratio demonstrated that EMPs were generated via activation and not apoptosis/necrosis. This suggests that EMPs may not be a good marker for AIS, given the inability to discriminate between stroke mimics and AIS. [source] Acute ischemic stroke and transient ischemic attack in the very old , risk factor profile and stroke subtype between patients older than 80 years and patients aged less than 80 yearsEUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2007J. I. Rojas Old age groups have different risk profile and stroke features compared to younger groups. Our aim was to examine the risk factor profile and stroke subtype in patients older than 80 years with ischemic stroke. Data of 535 patients with ischemic stroke or transient ischemic attack (TIA) were prospectively recorded. Cardiovascular risk factors and stroke subtype in individuals aged 80 years or older were compared with patients under 80. Of 535 patients a total of 179 were over 80 years (33.5%). The mean age was 84.4 ± 4.4 years (61.8%; 111 women). The most common risk factors included hypertension (82.7%) and hyperlipidemia (40.2%). Lacunar stroke was the most frequent subtype of stroke (41.7%). When the groups were compared, we observed the following risk factors more frequently in the group older than 80: female patients (P = <0.001), hypertension (OR = 1.62), atrial fibrillation (OR = 2.64); whereas diabetes (OR = 0.54), hyperlipidemia (OR = 0.57), smoking (OR = 0.17) and obesity (OR = 0.58) were more frequent in the group younger than 80. In the old group we found a high incidence of ischemic stroke in women. We also found a higher frequency of hypertension and atrial fibrillation. The available and future epidemiological data will provide a better knowledge about the effect of typical risk factors in old people. [source] Therapeutic Yield and Outcomes of a Community Teaching Hospital Code Stroke ProtocolACADEMIC EMERGENCY MEDICINE, Issue 4 2004Andrew W. Asimos MD Objectives: To describe the experience of a community teaching hospital emergency department (ED) Code Stroke Protocol (CSP) for identifying acute ischemic stroke (AIS) patients and treating them with tissue plasminogen activator (tPA) and to compare outcome measures with those achieved in the National Institute of Neurological Disorders and Stroke (NINDS) trial. Methods: This study was a retrospective review from a hospital CSP registry. Results: Over a 56-month period, CSP activation occurred 255 times, with 24% (n= 60) of patients treated with intravenous (IV) tPA. The most common reasons for thrombolytic therapy exclusion were mild or rapidly improving symptoms in 37% (n= 64), intracerebral hemorrhage (ICH) in 23% (n= 39), and unconfirmed symptom onset time for 14% (n= 24) of patients. Within 36 hours of IV tPA treatment, 10% (NINDS = 6%) of patients (n= 6) sustained a symptomatic ICH (SICH). Three months after IV tPA treatment, 60% of patients had achieved an excellent neurologic outcome, based on a Barthel Index of ,95 (NINDS = 52%), while mortality measured 12% (NINDS = 17%). Among IV tPA-treated patients, those developing SICH were significantly older and had a significantly higher mean initial glucose value. Treatment protocol violations occurred in 32% of IV tPA-treated patients but were not significantly associated with SICH (Fisher's exact test). Conclusions: Over the study period, the CSP yielded approximately one IV tPA-treated patient for every four screened and, despite prevalent protocol violations, attained three-month functional outcomes equal to those achieved in the NINDS trial. For community teaching hospitals, ED-directed CSPs are a feasible and effective means to screen AIS patients for treatment with thrombolysis. [source] Treatment of Acute Stroke with Recombinant Tissue Plasminogen Activator and AbciximabACADEMIC EMERGENCY MEDICINE, Issue 12 2003Daniel C. Morris MD Objectives: Preclinical data suggest that treatment of acute ischemic stroke (AIS) with the combination of recombinant tissue plasminogen activator (rt-PA) and abciximab may increase efficacy and decrease the rate of symptomatic intracranial hemorrhage (sICH). The authors report pilot data of five AIS patients with half-dose rt-PA and abciximab as part of an ongoing phase I safety trial with sICH as the primary outcome. Methods: Five patients with AIS were treated with the combination of half-dose rt-PA (0.45 mg/kg) and abciximab (0.25 mg/kg bolus followed by a 0.125 ,g/kg/min infusion over 12 hours). Head computed tomographic scan was obtained after 24 hours of treatment onset. Results: Four patients received the combination of half-dose abciximab and rt-PA without major complications. One patient experienced a parenchymal hematoma type-1 ICH without significant decline of his neurological status. The average National Institutes of Health Stroke Scale change at discharge in comparison with pretreatment was ,5.4 ± 7.0, and the median change was 6 points with a range of 4 points (worsening) to ,13 points (improvement) (p = 0.07) based on a one-sided t-test. Conclusions: Administration of rt-PA and abciximab to AIS patients was completed without difficulty. No sICH were observed; however, 20% (1 out of 5) experienced an asymptomatic ICH. Based on our observation of five patients, there was a trend of treatment efficacy; however, these results need to be confirmed in a larger-scale placebo-controlled clinical trial. [source] Thrombolysis in patients with acute ischemic stroke due to arterial extracranial dissectionEUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2009M. D. I. Vergouwen 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. [source] ADP-induced platelet aggregation in acute ischemic stroke patients on aspirin therapyEUROPEAN JOURNAL OF NEUROLOGY, Issue 12 2008J.-K. Cha Background and purpose:, Aspirin is an important therapeutic regimen to prevent the recurrent ischemic events or death after acute ischemic stroke. In this study, we evaluated the relationship between the extent of adenosine diphosphate (ADP) -induced platelet aggregation and outcome in acute ischemic stroke patients on aspirin therapy. Methods:, We selected 107 acute ischemic stroke patients who had been prescribed aspirin and evaluated platelet function test by using optic platelet aggregometer test after 5 days of taking it and investigated the prognosis 90 days after ischemic events. Kaplan,Meyer curve was used for survival analysis. Results:, After stratification of the subjected patients by tertiles of ADP-induced platelet aggregation, the events rates were 7.4%, 9.3% and 30.8% (P = 0.023). In multiple logistic regression analysis, old age over 70 years (OR, 13.7; 95% CI, 2.14,88.07; P = 0.001) and the increased ADP-induced platelet aggregation had independent significance to the risk of primary end-points after acute ischemic stroke (OR, 1.1; 95% CI 1.01 to 1.20; P = 0.026). Conclusions:, This study showed that the increased ADP-induced platelet aggregation under using aspirin is associated with poor outcome after acute ischemic stroke. [source] Thrombotic occlusion of the common carotid artery (CCA) in acute ischemic stroke treated with intravenous tissue plasminogen activator (TPA)EUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2007V. K. Sharma Although common carotid artery (CCA) occlusions are rare, acute clinical presentations vary from mild to devastating strokes primarily due to tandem occlusions in the intracranial arteries. Three patients with acute CCA occlusions were treated with systemic tissue plasminogen activator (TPA). Blood pressures were kept at the upper limits allowed with TPA therapy with fluid balance and the ,head-down' position. Recanalization occurred in intracranial vessels only. Marked early neurological improvement occurred in two of three patients. CCA occlusions should not be considered contra-indication to systemic thrombolysis. [source] Real-time monitoring of recanalization after intravenous thrombolysis for acute ischemic strokeEUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2006R. Delgado-Mederos No abstract is available for this article. [source] Assessment of corticodiaphragmatic pathway and pulmonary function in acute ischemic stroke patientsEUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2000E. M. Khedr This study investigates the effect of stroke on the corticodiaphragmatic pathway and attempts to clarify the relationship between neurophysiological data and degree of motor disability, site of infarction in computerized tomography (CT) scan, diaphragmatic excursion, blood gases and pulmonary function in stroke patients. Using magnetic stimulation of the scalp sites and cervical roots, an assessment of corticodiaphragmatic pathway was made. The study included 34 sequentially selected patients from a total of 250 patients with acute ischemic stroke. Twenty-five (age- and sex-matched) volunteers served as controls. Sixteen patients had cortical infarction, 13 had subcortical infarction and five had both cortical and subcortical infarction. The mean according to the Scandinavian Stroke Scale was 32.2. Decreased diaphragmatic excursion was observed in 41% of the patients. Twenty-four patients (70.5%) had abnormal magnetic evoked potentials (MEPs) in the affected hemisphere. In five patients MEPs could not be elicited from the affected hemisphere; the remaining 19 patients had abnormal values of both cortical latency and central conduction time (CCT). Cortical latency, CCT, amplitude of compound muscle action potentials (CMAPs) and excitability threshold of the affected hemisphere were significantly altered compared with both the unaffected hemisphere and the control group. Those patients with hemiplegia had a greater degree of hypoxia, hypocapnia and decreased serum bicarbonate level compared with the control group. Also, hemiplegic patients had different degree of respiratory dysfunction. A statistically significant association was found between neurophysiological data and disability score, diaphragmatic excursion, site of infarction in CT scan and degree of respiratory dysfunction. Central diaphragmatic impairment may occur in acute stroke and could contribute to the occurence of hypoxia in those patients. [source] Association Between Migraine and Headache Attributed to Stroke: A Case,Control StudyHEADACHE, Issue 10 2008Katiuscia Nardi MD Background., Several studies were carried out to investigate the occurrence of headache attributed to acute stroke in patients with a lifetime history of migraine. Methods., In a case,control series of 96 acute stroke patients with a lifetime history of migraine (M+) and 96 stroke patients without (M,), ischemic stroke patients only, without secondary infarction, were selected. The headache attributed to acute ischemic stroke was then analyzed. Results., (M+) patients complained of headache more often than (M,) patients (P < .0001), mainly in the 24 hours before stroke onset (P < .0001). Migraine-like features of headache were recognized in a greater proportion of cases in the (M+) patient group with ischemic stroke (P < .018). A preferential brainstem location of ischemic stroke in (M+) patients emerged compared with (M,) patients (P = .014). Discussion., The high prevalence of headache attributed to stroke in (M+) patients, in a relevant proportion of cases presenting as a sentinel headache, suggests that cerebral ischemia lowers the threshold for head pain more easily in these "susceptible" patients. The most frequent involvement of the brainstem in (M+) patients with ischemic infarction concurs with recent reports that emphasized a greater headache frequency when cerebral infarctions are localized in this structure or deep brain gray matter. [source] New pathways for evaluating potential acute stroke therapiesINTERNATIONAL JOURNAL OF STROKE, Issue 2 2006Marc Fisher Many neuroprotective drugs and a few other thrombolytics were evaluated in clinical trials, but none demonstrated unequivocal success and were approved by regulatory agencies. The development paradigm for such therapies needs to provide convincing evidence of efficacy and safety to obtain approval by the Food and Drug Administration (FDA). The FDA modernization act of 1997 stated that such evidence could be derived from one large phase III trial with a clinical endpoint and supportive evidence. Drugs being developed for acute ischemic stroke can potentially be approved under this act by coupling a major phase III trial with supportive evidence provided by a phase IIB trial demonstrating an effect on a relevant biomarker such as magnetic resonance imaging or computed tomography assessment of ischemic lesion growth. Statistical approaches have been developed to optimize the design of such an imaging-based phase IIB study, for example approaches that modify randomization probabilities to assign larger proportions of patients to the ,winning' strategy (i.e. ,pick the winner' strategies) with an interim assessment to reduce the sample size requirement. Demonstrating a treatment effect on a relevant imaging-based biomarker should provide supportive evidence for a new drug application, if a subsequent phase III trial with a clinical outcome demonstrates a significant treatment effect. [source] Neuroprotection in acute ischemic stroke: are we there yet?INTERNATIONAL JOURNAL OF STROKE, Issue 2 2006Ashfaq Shuaib [source] Management of blood pressure after acute ischemic stroke: An evidence-based guide for the hospitalistJOURNAL OF HOSPITAL MEDICINE, Issue 4 2007Ethan Cumbler MD Abstract Hospitalists are frequently called upon to manage blood pressure after acute ischemic stroke. A review of both post infarction cerebral perfusion physiology and the data from randomized trials of antihypertensive therapy is necessary to explain why consensus guidelines for blood pressure management after stroke differ from those of other hypertensive emergencies. The peri-infarct penumbra is the central concept in understanding post ischemic cerebral perfusion. This area of impaired cerebral blood flow is dependent on mean arterial blood pressure and acute reduction of blood pressure may expand the area of infarction. Review of clinical trials fails to show benefit from reduction of blood pressure after ischemic stroke and current guidelines suggest antihypertensive therapy be employed if the systemic blood pressure is greater than 180/105 mmHg after tPA is employed, or 220/120 mmHg when tPA is not used. Induced hypertension remains a promising but unproven therapy in the acute setting, but the evidence for long term control of blood pressure to less than 140/80 mmHG for secondary prevention of stroke is strong. Adherence to guidelines is poor but it is recognized that current evidence is limited by a lack of trials in which blood pressure is titrated to a pre-specified goal, as is common in clinical practice. Journal of Hospital Medicine 2007;2:261,267. © 2007 Society of Hospital Medicine. [source] Effect of b value on contrast during diffusion-weighted magnetic resonance imaging assessment of acute ischemic strokeJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 5 2002Raoul S. Pereira PhD Abstract Purpose To examine the effect of varying the diffusion encoding strength (b value) on the contrast (signal difference, ,S) between damaged and normal tissue during diffusion-weighted magnetic resonance imaging (DWI) assessment of acute ischemic stroke. Materials and Methods Phantoms with diffusion values approximating those expected in acutely infarcted and normal tissue were constructed from a mixture of agar and formaldehyde and imaged at varying b values (0,3000 mm,2 second). Ten patients were imaged with multiple b values (500,2500 mm,2 second) within 12 hours of stroke onset. Results Theoretical calculations showed that for any combination of diffusion coefficients there existed an optimal b value that was higher than the standard setting of 1000 mm,2 second, and this was confirmed by the phantom studies. In the patients, increasing b from 1000 to 1500 mm,2 second increased ,S (average, 22.4%; P = 0.001), but no consistent benefit was seen at b = 2000 mm,2 second (P = 0.408). This compared favorably with the average optimal b value of 1662 mm, 2 second calculated from the patients. Conclusion These results suggest that increasing the b value from 1000 to 1500 mm,2 second would increase contrast between infarcted and normal tissue in the setting of acute ischemic stroke. J. Magn. Reson. Imaging 2002;15:591,596. © 2002 Wiley-Liss, Inc. [source] Signaling, delivery and age as emerging issues in the benefit/risk ratio outcome of tPA For treatment of CNS ischemic disordersJOURNAL OF NEUROCHEMISTRY, Issue 2 2010William M. Armstead J. Neurochem. (2010) 113, 303,312. Abstract Stroke is a leading cause of morbidity and mortality. While tissue-type plasminogen activator (tPA) remains the only FDA-approved treatment for ischemic stroke, clinical use of tPA has been constrained to roughly 3% of eligible patients because of the danger of intracranial hemorrhage and a narrow 3 h time window for safe administration. Basic science studies indicate that tPA enhances excitotoxic neuronal cell death. In this review, the beneficial and deleterious effects of tPA in ischemic brain are discussed along with emphasis on development of new approaches toward treatment of patients with acute ischemic stroke. In particular, roles of tPA-induced signaling and a novel delivery system for tPA administration based on tPA coupling to carrier red blood cells will be considered as therapeutic modalities for increasing tPA benefit/risk ratio. The concept of the neurovascular unit will be discussed in the context of dynamic relationships between tPA-induced changes in cerebral hemodynamics and histopathologic outcome of CNS ischemia. Additionally, the role of age will be considered since thrombolytic therapy is being increasingly used in the pediatric population, but there are few basic science studies of CNS injury in pediatric animals. [source] Association of Pretreatment ASPECTS Scores with tPA-Induced Arterial Recanalization in Acute Middle Cerebral Artery OcclusionJOURNAL OF NEUROIMAGING, Issue 1 2008Georgios Tsivgoulis MD ABSTRACT BACKGROUND AND PURPOSE The Alberta Stroke Program Early CT-Score (ASPECTS) assesses early ischemic changes within the middle cerebral artery (MCA) and predicts poor outcome and increased risk for thrombolysis-related symptomatic ICH. We evaluated the potential relationship between pretreatment ASPECTS and tPA-induced recanalization in patients with MCA occlusions. SUBJECTS & METHODS Consecutive patients with acute ischemic stroke due to MCA occlusion were treated with standard IV-tPA and assessed with transcranial Doppler (TCD) for arterial recanalization. Early recanalization was determined with previously validated Thrombolysis in Brain Ischemia (TIBI) flow-grading system at 120 minutes after tPA-bolus. All pretreatment CT-scans were prospectively scored by trained investigators blinded to TCD findings. Functional outcome at 3 months was evaluated using the modified Rankin Scale (mRS). RESULTS IV-tPA was administered in 192 patients (mean age 68 ± 14 years, median NIHSS-score 17). Patients with complete recanalization (n= 51) had higher median pretreatment ASPECTS (10, interquartile range 2) than patients with incomplete or absent recanalization (n= 141; median ASPECTS 9, interquartile range 3, P= .034 Mann-Whitney U-test). An ASPECTS ,6 was documented in 4% and 17% of patients with present and absent recanalization, respectively (P= .019). Pretreatment ASPECTS was associated with complete recanalization (OR per 1-point increase: 1.54; 95% CI 1.06,2.22, P= .023) after adjustment for baseline characteristics, risk factors, NIHSS-score, pretreatment TIBI grades and site of arterial occlusion on baseline TCD. Complete recanalization (OR: 33.97, 95% CI 5.95,185.99, P < .001) and higher ASPECTS (OR per 1-point increase: 1.91; 95% CI 1.17,3.14, P= .010) were independent predictors of good functional outcome (mRS 0,2). CONCLUSIONS Higher pretreatment ASPECT-scores are associated with a greater chance of complete recanalization and favorable long-term outcome in tPA-treated patients with acute MCA occlusion. [source] Aortic Dissection Presenting as an Acute Ischemic Stroke for ThrombolysisJOURNAL OF NEUROIMAGING, Issue 3 2005Ken Uchino MD ABSTRACT Thrombolysis for the treatment of acute ischemic stroke requires careful selection of patients. The authors report a case of aortic dissection presenting with acute ischemic stroke for which emergent ultrasonographic evaluation was helpful in the diagnosis and subsequent treatment. The patient presented with acute middle cerebral artery ischemic stroke symptoms and complained of bilateral ear and chest pain. Chest x-ray, cardiac enzymes, and transthoracic echocardiogram were normal, and she was considered for thrombolytic therapy. Carotid ultrasound revealed right common carotid occlusion that led to the diagnosis of aortic dissection, confirmed by chest computed tomography. An experienced sonographer with skills to perform rapid intra- and extracranial examinations may help to change the treatment plan for acute stroke patients. [source] Comparison of Transcranial Color-Coded Sonography and Magnetic Resonance Angiography in Acute Ischemic StrokeJOURNAL OF NEUROIMAGING, Issue 4 2001Li-Ming Lien MD ABSTRACT Background and Purpose. This study was designed to assess the accuracy of transcranial color-coded sonography (TCCS) as compared to magnetic resonance angiography (MRA) for detecting intracranial arterial stenosis in patients with acute cerebral ischemia. Methods. The authors prospectively identified 120 consecutive patients admitted with acute ischemic stroke and performed both TCCS and MRA with a mean interval of 1 day. TCCS data (sampling depth, peak systolic and end diastolic angle-corrected velocity, mean angle-corrected velocity, and pulsatility index) for middle cerebral arteries (MCAs) were compared to MRA data and classified into 4 grades: normal (grade 1): normal caliber and signal; mild stenosis (grade 2): irregular lumen with reduced signal; severe stenosis (grade 3): absent signal in the stenotic segment (flow gap) and reconstituted distal signal; and possible occlusion (grade 4): absent signal. The cutoffs were chosen to maximize diagnostic accuracy. Results. Interobserver agreement for MRA grading resulted in a weighted-kappa value of 0.776. The rate of poor temporal window was 37% (89/240). Doppler signals were obtained in 135 vessels, and the angle-corrected velocities (peak systolic, end diastolic, mean) were significantly different (P= .001, P= .006, P < .001) among the MRA grades: grade 1 (100, 47, 68 cm/s), grade 2 (171, 72, 110 cm/s), grade 3 (226, 79, 134 cm/s), grade 4 (61, 26, 39 cm/s). Additionally, an angle-corrected MCA peak systolic velocity ,120 cm/s correlates with intracranial stenosis on MRA (grade 2 or worse) with high specificity (90.5%; 95% confidence interval = 78.5%,96.8%) and positive predictive value (93.9%) but relatively low sensitivity (66.7%; 95% confidence interval = 61.2%,69.5%) and negative predictive value (55.1%). Conclusion. Elevated MCA velocities on TCCS correlate with intracranial stenosis detected on MRA. An angle-corrected peak systolic velocity ,120 cm/s is highly specific for detecting intracranial stenosis as defined by significant MRA abnormality. [source] Baseline Computed Tomography Changes and Clinical Outcome After Thrombolysis With Recombinant Tissue Plasminogen Activator in Acute Ischemic StrokeJOURNAL OF NEUROIMAGING, Issue 2 2001Jorge E. Mendizabal MD ABSTRACT Objective. Intravenous recombinant tissue plasminogen activator (rt-PA) is the only therapy of proven value for patients with acute ischemic stroke (AIS). Controversy exists with regard to the prognostic significance of early computed tomography (CT) changes in patients receiving rt-PA for AIS. The authors retrospectively reviewed all cases of AIS who received intravenous rt-PA for AIS in University of South Alabama hospitals between January 1996 and May 1999. A neuroradiologist, blinded to clinical outcomes, reviewed all baseline CT scans for the presence of the following signs: hyperdense middle cerebral artery (HMCA), loss of gray-white differentiation (LGWD), insular ribbon sign (IRS), parenchymal hypodensity (PH), and sulcal effacement (SE). Modified Rankin Scale (mRS) score was recorded 90 days after thrombolysis, and clinical outcome was dichotomized as favorable (0,1) or unfavorable (2,6). The authors performed both univariate and multivariate analyses to investigate the relationship between early CT signs, baseline clinical variables, and functional outcome as measured by the 90-day mRS scores. Any one early CT finding was detected in 23 (64%) patients. The frequency of specific findings were as follows: SE in 13 patients (36%), LGWD in 12 patients (33%), PH in 9 patients (25%), HMCA in 4 patients (11%), and IRS in 3 patients (8%) patients. There was no statistically significant association between the occurrence of these imaging findings and subsequent functional outcome after thrombolysis. The data suggest that the presence of subtle acute CT changes in AIS patients is not predictive of clinical outcome following administration of rt-PA as per National Institute of Neurological Disorders and Stroke protocol. [source] Association of growth factors with arterial recanalization and clinical outcome in patients with ischemic stroke treated with tPAJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2010T. SOBRINO Summary.,Background: Growth factors (GF) such as vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and granulocyte-colony stimulating factor (G-CSF) have been associated with greater efficacy of tissue plasminogen activator (tPA) in experimental studies. Objectives: To study the association of these GF with arterial recanalization and clinical outcome in patients with acute ischemic stroke treated with tPA. Methods: We prospectively studied 79 patients with ischemic stroke attributable to MCA occlusion treated with i.v. tPA within the first 3 h from onset of symptoms. Continuous transcranial color-coded sonography (TCCS) was performed during the first 2 h after tPA bolus to assess early MCA recanalization. Hemorrhagic transformation (HT) was classified according to ECASS II definitions. Good functional outcome was defined as a Rankin scale score of 0,2 at 90 days. GF levels were determined by ELISA. Results: Mean serum levels of VEGF, G-CSF and Ang-1 at baseline were significantly higher in patients with early MCA recanalization (n = 30) (all P < 0.0001). In the multivariate analysis, serum levels of VEGF (OR, 1.03), G-CSF (OR, 1.02) and Ang-1 (OR, 1.07) were independently associated with early MCA recanalization (all P < 0.0001). On the other hand, patients with parenchymal hematoma (PH) (n = 20) showed higher levels of Ang-1 (P < 0.0001). Ang-1 (OR, 1.12; P < 0.0001) was independently associated with PH, whereas patients with good outcome (n = 38) had higher levels of G-CSF (P < 0.0001). G-CSF was independently associated with good outcome (OR, 1.12; P = 0.036). Conclusions: These findings suggest that GF may enhance arterial recanalization in patients with ischemic stroke treated with t-PA, although they might increase the HT. [source] Prevention of venous thromboembolism after acute ischemic strokeJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2005P. W. KAMPHUISEN Summary., Venous thromboembolism (VTE) is a common complication after acute ischemic stroke. When screened by 125I fibrinogen scanning or venography, the incidence of deep-vein thrombosis (DVT) in stroke patients is comparable with that seen in patients undergoing hip or knee replacement. Most stroke patients have multiple risk factors for VTE, like advanced age, low Barthel Index severity score or hemiplegia. As pulmonary embolism is a major cause of death after acute stroke, the prevention of this complication is of crucial importance. Prospective trials have shown that both unfractionated heparin (UFH) and low molecular weight heparin (LMWH) are effective in reducing DVT and pulmonary embolism in stroke patients. Current guidelines recommend the use of these agents in stroke patients with risk factors for VTE. Some clinicians are concerned that the rate of intracranial bleeding associated with thromboprophylaxis may outweigh the benefit of prevention of VTE. Low-dose LMWH and UFH seem, however, safe in stroke patients. Higher doses clearly increase the risk of cerebral bleeding and should be avoided for prophylactic use. Both aspirin and mechanical prophylaxis are suboptimal to prevent VTE. Graduated compression stockings should be reserved to patients with a clear contraindication to antithrombotic agents. [source] Evaluating Patients with Acute Ischemic Stroke with Special Reference to Newly Developed Atrial Fibrillation in Cerebral EmbolismPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2007MINORU TAGAWA M.D. Background:Cardioembolic strokes are extensive and have a poor prognosis. To identify the cardiovascular risk factors of cardioembolic stroke, we evaluated the cardiovascular status with special reference to persistent atrial fibrillation (AF) and paroxysmal atrial fibrillation (PAF) combined with the type of acute ischemic stroke. Methods:We divided 315 consecutive patients admitted to our Department of Neurosurgery with an acute ischemic stroke into four types of brain infarction using clinical history, onset pattern of stroke, and brain imaging: cardioembolic (group E, n = 105), lacunar (group L, n = 92), atherothrombotic (group T, n = 111), and unclassified (n = 7). All patients underwent standard electrocardiography (ECG), a 24-hour ECG recording (Holter ECG) and transthoracic echocardiography (UCG). Results:Persistent AF or PAF was detected in 97 patients (31.5%) using Holter ECG: more frequently in group E (67.6%) than in groups L (15.2%) or T (9.2%). Persistent AF or PAF was first diagnosed on admission using a standard ECG in 16 patients (5.2%) with no previous history and 14 of these patients belonged to group E (13.3%). PAF was newly detected on Holter ECG in another 26 patients (8.4%) and 13 of these patients (12.4%) belonged to group E. Concerning UCG, left atrial enlargement and mitral regurgitation were more frequent in group E than in group L or T. Conclusion:Holter ECG in addition to ECG on admission is important for detecting persistent AF or PAF in patients with ischemic stroke, especially with cardioembolism as diagnosed by neuroimaging. [source] Coagulopathy and embolic signal in cancer patients with ischemic strokeANNALS OF NEUROLOGY, Issue 2 2010Jin Myoung Seok MD Objective It has been reported that embolic signal (ES) detected by transcranial Doppler (TCD) has clinical significance, especially in patients with recent stroke attributable to arterial or cardiac embolism. Therefore, we conducted this study to determine whether the prevalence of ES is high in ischemic stroke patients with cancer and related to hypercoagulopathy. Methods We prospectively studied cancer patients with acute ischemic stroke within the middle cerebral artery (MCA) distribution on diffusion-weighted imaging. Conventional stroke mechanisms (CSMs) were determined using cardiologic and vascular studies. Additionally, the coagulation status was assessed based on the serum D-dimer levels, and TCD monitoring was performed on both MCAs for 30 minutes to detect ES. Clinical features including vascular risk factors, characteristics of ischemic stroke, and cancer and laboratory findings associated with the presence of ES were evaluated. Results A total of 74 patients were finally included in this study. ES was more commonly observed in patients without CSMs (22 of 38 patients, 57.9%) than in those with CSMs (12 of 36 patients, 33.3%) (p = 0.034). Moreover, ES was more commonly detected in patients with high D-dimer levels (p < 0.001), and D-dimer levels were significantly correlated with the number of ESs in patients without CSMs (r = 0.732, p < 0.001), but were poorly correlated in patients with CSMs (r = 0.152, p = 0.375). Higher levels of D-dimer (odds ratio [OR], 1.082 per 1,g/ml increase; 95% confidence interval [CI], 1.014,1.154) and adenocarcinoma (OR, 3.829; 95% CI, 1.23,13.052) were independently associated with the presence of ES. The use of anticoagulants dramatically decreased the D-dimer levels. Interpretation A high prevalence of ES was observed in cancer patients with ischemic stroke, especially in those without CSMs. Elevated D-dimer levels were independently associated with ES, and decreased dramatically with the use of anticoagulants. ANN NEUROL 2010;68:213,219 [source] T2*-weighted magnetic resonance imaging with hyperoxia in acute ischemic strokeANNALS OF NEUROLOGY, Issue 1 2010Krishna A. Dani MBChB Objective We describe the first clinical application of transient hyperoxia ("oxygen challenge") during T2*-weighted magnetic resonance imaging (MRI), to detect differences in vascular deoxyhemoglobin between tissue compartments following stroke. Methods Subjects with acute ischemic stroke were scanned with T2*-weighted MRI and oxygen challenge. For regions defined as infarct core (diffusion-weighted imaging lesion) and presumed penumbra (perfusion-diffusion mismatch [threshold = Tmax ,4 seconds], or regions exhibiting diffusion lesion expansion at day 3), T2*-weighted signal intensity,time curves corresponding to the duration of oxygen challenge were generated. From these, the area under the curve, gradient of incline of the signal increase, time to maximum signal, and percentage signal change after oxygen challenge were measured. Results We identified 25 subjects with stroke lesions >1ml. Eighteen subjects with good quality T2*-weighted signal intensity,time curves in the contralateral hemisphere were analyzed. Curves from the diffusion lesion had a smaller area under the curve, percentage signal change, and gradient of incline, and longer time to maximum signal (p < 0.05, n = 17) compared to normal tissue, which consistently showed signal increase during oxygen challenge. Curves in the presumed penumbral regions (n = 8) showed varied morphology, but at hyperacute time points (<8 hours) showed a tendency to greater percentage signal change. Interpretation Differences in T2*-weighted signal intensity,time curves during oxygen challenge in brain regions with different pathophysiological states after stroke are likely to reflect differences in deoxyhemoglobin concentration, and therefore differences in metabolic activity. Despite its underlying complexities, this technique offers a possible novel mode of metabolic imaging in acute stroke. ANN NEUROL 2010;68:37,47 [source] Retinal fractals and acute lacunar strokeANNALS OF NEUROLOGY, Issue 1 2010Ning Cheung MBBS This study aimed to determine whether retinal fractal dimension, a quantitative measure of microvascular branching complexity and density, is associated with lacunar stroke. A total of 392 patients presenting with acute ischemic stroke had retinal fractal dimension measured from digital photographs, and lacunar infarct ascertained from brain imaging. After adjusting for age, gender, and vascular risk factors, higher retinal fractal dimension (highest vs lowest quartile and per standard deviation increase) was independently and positively associated with lacunar stroke (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.49,12.17 and OR, 1.85; 95% CI, 1.20,2.84, respectively). Increased retinal microvascular complexity and density is associated with lacunar stroke. ANN NEUROL 2010;68:107,111 [source] | ||||||||||||||||||||||