Observations on Brain Embolism with Special Reference to Hemorrhagic Infarction

Fisher, Charles K.; Adams, R. D.

doi:10.1007/978-1-4471-3129-8_2

Cited by 118 publications

(131 citation statements)

References 6 publications

Supporting

Mentioning

122

Contrasting

Unclassified

Order By: Relevance

“…12 In this regard this model resembles the neuropathological outcome of proximal MCA territory stroke in humans. 35 Although the explanation for microscopic hemorrhage in the single animal from the group of animals studied at 14 days is not known, this finding may imply that attempts to establish reperfusion with thrombolytic agents in ischemic cerebral tissue in this model should be initiated early after the period of MCA occlusion before vascular necrosis develops.…”

Section: Discussionmentioning

confidence: 97%

Experimental acute thrombotic stroke in baboons.

Zoppo¹,

Copeland²,

Harker³

et al. 1986

Stroke

157

138

View full text Add to dashboard Cite

SUMMARY To study the effects of antithrombotic therapy in experimental stroke, we have characterized a baboon model of acute cerebrovascular thrombosis. In this model an inflatable silastic balloon cuff has been implanted by transorbital approach around the right middle cerebral artery (MCA), proximal to the take-off of the lentlculostriate arteries (LSA). Inflation of the balloon for 3 hours in six animals produced a stereotypic sustained stroke syndrome characterized by contralateral hemiparesis. An Infarction volume of 3.2 ± 1 . 5 cm 3 in the ipsilateral corpus striatum was documented by computerized tomographic (CT) scanning at 10 days following stroke induction and 3.9 ± 1 . 9 cm 3 (n = 4) at 14 days by morphometric Deuropathotogic determinations of brain specimens fixed in situ by pressure-perfusion with 10% buffered formalin.Immediate pressure-perfusion fixation following deflation of the balloon was performed in 16 additional animals given Evans blue dye intravenously prior to the 3 hour MCA balloon occlusion. Light microscopy and transmission electron microscopy consistently confirmed the presence of thrombotic material occluding microcirculatory branches of the right LSA in the region of Evans blue stain, but not those of the contralateral corpus striatum.When autologous '"in-platelets were infused intravenously in four animals from the above group prior to the transient 3 hour occlusion of the right MCA, gamma scintillation camera imaging of each perfused-flxed whole brain demonstrated the presence of a single residual focus of '"in-platelet activity involving only the Evans blue-stained right corpus striatum. Focal right hemispheric activity was equivalent to 0.55 ± 0.49 ml of whole blood, and the occlusion score derived from histologic examination of the microcirculatton of the Evans blue-stained corpus striatum averaged 34.8 ± 2.8. Similar "'in-platelct imaging and histologic scoring experiments carried out hi four animals pretreated with the antithrombotic combination heparin and tidopidine showed marked reduction of both "'in-platelet activity (0.01 ± 0.03 ml vs. 0.55 ± 0.49 ml; p < 0.01) and thrombotic occlusion of the microcirculation (10.8 ± 7.4 units vs. 34.8 ± 2.8 units; p < 0.01) in the right corpus striatum following 3 hours of MCA occlusion. In separate control experiments "'inlabeled autologous platelets were infused after the 3 hour period of right MCA occlusion and subsequent balloon deflation hi two animals; no focus of '"in-platelet activity was demonstrated in fixed whole brain.We conclude that thrombi form in situ In the microcirculation of perforating branches of the LSA located in the ipsilateral corpus striatum following a 3 hour period of MCA occlusion and that these thrombi may be prevented when antithrombotic therapy is administered prior to MCA balloon occlusion. This model of acute thrombotic stroke may be useful to assess the safety and efficacy of thrombolytic therapies.

show abstract

Section: Discussionmentioning

confidence: 97%

Experimental acute thrombotic stroke in baboons.

Zoppo¹,

Copeland²,

Harker³

et al. 1986

Stroke

157

138

View full text Add to dashboard Cite

show abstract

“…of acute ischemic stroke is an undesirable complication that occurs in 2.2%-44.0% of clinical cases (1)(2)(3)(4) and in up to 70% of pathology cases (5). Several radiologic and clinical parameters, including baseline stroke severity (6,7), time to reperfusion (8), thrombolytic protocol violations (2,9), tissue plasminogen activator (TPA) treatment (3,6,10), white matter disease burden (11), aspirin use (3), and heparin use (12), are associated with HT.…”

Section: H Emorrhagic Transformation (Ht)mentioning

confidence: 99%

Hemorrhagic Transformation of Ischemic Stroke: Prediction with CT Perfusion

Aviv

d’Esterre²,

Murphy³

et al. 2009

Radiology

152

112

View full text Add to dashboard Cite

Purpose:To determine whether admission computed tomography (CT) perfusion-derived permeability-surface area product (PS) maps differ between patients with hemorrhagic acute stroke and those with nonhemorrhagic acute stroke. Materials and Methods:This prospective study was institutional review board approved, and all participants gave written informed consent. Forty-one patients who presented with acute stroke within 3 hours after stroke symptom onset underwent two-phase CT perfusion imaging, which enabled PS measurement. Patients were assigned to groups according to whether they had hemorrhage transformation (HT) at follow-up magnetic resonance (MR) imaging and CT and/or whether they received tissue plasminogen activator (TPA) treatment. Clinical, demographic, and CT perfusion variables were compared between the HT and non-HT patient groups. Associations between PS and HT were tested at univariate and multivariate logistic regression analyses and receiver operating characteristic (ROC) analysis. Results:HT developed in 23 (56%) patients. Patients with HT had higher National Institutes of Health Stroke Scale (NIHSS) scores (P ϭ .005), poorer outcomes (P ϭ .001), and a higher likelihood of having received TPA (P ϭ .005) compared with patients without HT. Baseline blood flow (P ϭ .17) and blood volume (P ϭ .11) defects and extent of flow reduction (P ϭ .27) were comparable between the two groups. The mean PS for the HT group, 0.49 mL ⅐ min Ϫ1 ⅐ (100 g) Ϫ1 , was significantly higher than that for the non-HT group, 0.09 mL ⅐ min Ϫ1 ⅐ (100 g) Ϫ1 (P Ͻ .0001). PS (odds ratio, 3.5; 95% confidence interval [CI]: 1.69, 7.06; P ϭ .0007) and size of hypoattenuating area at nonenhanced admission CT (odds ratio, 0.4; 95% CI: 0.2, 0.7; P ϭ .002) were the only independent variables associated with HT at stepwise multivariate analysis. The mean area under the ROC curve was 0.918 (95% CI: 0.828, 1.00). The PS threshold of 0.23 mL ⅐ min Ϫ1 ⅐ (100 g) Ϫ1 had 77% sensitivity and 94% specificity for detection of HT. Conclusion:Admission PS measurement appears promising for distinguishing patients with acute stroke who are likely from those who are not likely to develop HT.

show abstract

“…19 Comparisons across trials are limited by varying definitions of HTs. Most previous studies have focused on the symptomatic HTs.…”

Section: Discussion the Frequencies Of Ht Types On Grementioning

confidence: 99%

Impact of Baseline Tissue Status (Diffusion-Weighted Imaging Lesion) Versus Perfusion Status (Severity of Hypoperfusion) on Hemorrhagic Transformation

Bang

Liebeskind

Ovbiagele

et al. 2010

Stroke

View full text Add to dashboard Cite

for the UCLA-Samsung Stroke CollaboratorsBackground and Purpose-The frequency of hemorrhagic transformation (HT) on gradient echo imaging and its impact on stroke outcomes continues to be debated. We investigated the factors associated with HTs and the influence of the HTs observed on gradient echo imaging on the early course after a stroke. Methods-We analyzed the data from a prospectively maintained registry of patients who were eligible for recanalization therapy. Serial diffusion-weighted imaging and perfusion-weighted imaging were performed, and HTs were assessed on follow-up gradient echo imaging. Tmax perfusion lesion maps were generated and hypoperfused regions were divided into severe (Tmax Ն8 seconds) delay and mild (Tmax Ն2 seconds but Tmax Ͻ8 seconds) delay. The factors associated with HTs, including the mode of recanalization therapy, pretreatment diffusion-weighted imaging and perfusionweighted imaging lesion volumes, and reperfusion indices, were evaluated. The early clinical outcome was assessed during the first 7 days of admission. Results-A total of 184 patients were included in this study. HTs were noted in 73 (39.7%) patients. Multiple logistic regression analysis identified aggressive treatment (OR, 5.12; 95% CI, 1.73 to 15.18) and a large area of severe perfusion delay (OR for highest quartile of Tmax Ͼ8 seconds, 12.91; 95% CI, 3.69 to 45.17) as independent predictors of HTs. Neither risk factor profiles nor diffusion-weighted imaging lesion volumes were associated with HTs. There was a poor correlation between the radiological (HT types) and clinical (asymptomatic or symptomatic) categories of HTs. Even a parenchymal hematoma was not always associated with symptomatic worsening or affected the early clinical outcomes. Conclusion-The results of this study indicate that the perfusion status (severe perfusion delay) rather than the tissue status (diffusion-weighted imaging lesions) and aggressive treatment were independently associated with HTs. HT on gradient echo imaging was common but usually associated with severe hypoperfusion and not always associated with clinical deterioration. (Stroke. 2010;41:e135-e142.)

show abstract

Observations on Brain Embolism with Special Reference to Hemorrhagic Infarction

Cited by 118 publications

References 6 publications

Experimental acute thrombotic stroke in baboons.

Experimental acute thrombotic stroke in baboons.

Hemorrhagic Transformation of Ischemic Stroke: Prediction with CT Perfusion

Impact of Baseline Tissue Status (Diffusion-Weighted Imaging Lesion) Versus Perfusion Status (Severity of Hypoperfusion) on Hemorrhagic Transformation

Contact Info

Product

Resources

About