Karsten Overgaard

European Stroke Organisation (ESO) guidelines for the management of spontaneous intracerebral hemorrhage

Background Intracerebral hemorrhage (ICH) accounted for 9% to 27% of all strokes worldwide in the last decade, with high early case fatality and poor functional outcome. In view of recent randomized controlled trials (RCTs) of the management of ICH, the European Stroke Organisation (ESO) has updated its evidence-based guidelines for the management of ICH. Method A multidisciplinary writing committee of 24 researchers from 11 European countries identified 20 questions relating to ICH management and created recommendations based on the evidence in RCTs using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results We found moderate- to high-quality evidence to support strong recommendations for managing patients with acute ICH on an acute stroke unit, avoiding hemostatic therapy for acute ICH not associated with antithrombotic drug use, avoiding graduated compression stockings, using intermittent pneumatic compression in immobile patients, and using blood pressure lowering for secondary prevention. We found moderate-quality evidence to support weak recommendations for intensive lowering of systolic blood pressure to <140 mmHg within six-hours of ICH onset, early surgery for patients with a Glasgow Coma Scale score 9–12, and avoidance of corticosteroids. Conclusion These guidelines inform the management of ICH based on evidence for the effects of treatments in RCTs. Outcome after ICH remains poor, prioritizing further RCTs of interventions to improve outcome.

The influence of body temperature on infarct volume and thrombolytic therapy in a rat embolic stroke model.

The effect of body temperature on cerebral infarcts and thrombolytic therapy was investigated in 91 rats embolized in the right carotid territory. Hypothermia of 32 degrees C for 2 h with preembolic onset (n = 15) or hyperthermia of 39 degrees C for 2 h with postembolic onset (n = 22) was compared to normothermic controls (n = 17). After 48 h of survival, neuropathological evaluation with measurement of infarct volume was performed. Median infarct volume in percent of affected hemisphere volume was 11% (9-21, quartiles) in rats treated with hypothermia alone, compared to 46% (14-59, quartiles) in normothermic controls (P = 0.04). Hyperthermia for 2 h increased median infarct volume to 65% (37-75, quartiles). There was a positive and significant correlation between infarct volume and body temperature (R = 0.53, P = 0.0002, n = 54). Mortality rate was significantly higher among rats treated with hyperthermia compared to normothermic controls (P = 0.005). A subset of 37 rats exposed to the same temperature regimen were treated with tissue plasminogen activator (20 mg/kg i.v. during 45 min) 2 h after embolization. Judged by posttreatment carotid angiography, hyperthermic rats (n = 11) had the best degree of recanalization (P = 0.03) compared to controls (n = 17), but median infarct volume in this group was (58% (27-67, quartiles)) significantly larger (P < 0.02) than normothermic (21% (15-39, quartiles), n = 14) and hypothermic (13% (7-31, quartiles), n = 12) rats treated with thrombolytic therapy. Thrombolytic therapy following 2 h of hypothermia, could not improve the effect of hypothermia alone.(ABSTRACT TRUNCATED AT 250 WORDS)

A rat model of reproducible cerebral infarction using thrombotic blood clot emboli

The purpose of this study was the development of a model of embolic stroke with high reproducibility concerning infarct volume. In 37 male Sprague–Dawley rats, the internal carotid artery was embolized with in vitro preformed suspensions of autologous microemboli resembling arterial thrombi. With a method of continuous flow through the carotid arterial catheter, reflux of blood with uncontrolled clotting and embolization was avoided, thereby providing control animals free of ischemic damage. The embolized animals had arterial occlusions on angiograms immediately after embolization and no spontaneous recanalization on angiograms 2 h later. The cerebral blood flow measured by the intraarterial 133Xe injection method decreased to 21–37% of baseline values. All embolized animals developed hemiparesis with spontaneous circling behavior, embolization with more than 150 μl clot suspension resulted in hemispherical infarcts. There was a strong statistically significant correlation between amount of emboli, rate of vascular occlusion, and volume of infarcted tissue. This is the first model presented utilizing autologous in vitro microemboli imitating “white” arterial thrombi. The animals developed infarction, resembling human stroke.

Safety of Intravenous Thrombolysis for Acute Ischemic Stroke in Patients Receiving Antiplatelet Therapy at Stroke Onset

Background and Purpose— Antiplatelets (APs) may increase the risk of symptomatic intracerebral hemorrhage (ICH) following intravenous thrombolysis after ischemic stroke. Methods— We assessed the safety of thrombolysis under APs in 11 865 patients compliant with the European license criteria and recorded between 2002 and 2007 in the Safe Implementation of Treatments in Stroke (SITS) International Stroke Thrombolysis Register (SITS-ISTR). Outcome measures of univariable and multivariable analyses included symptomatic ICH (SICH) per SITS Monitoring Study (SITS-MOST [deterioration in National Institutes of Health Stroke Scale ≥4 plus ICH type 2 within 24 hours]), per European Cooperative Acute Stroke Study II (ECASS II [deterioration in National Institutes of Health Stroke Scale ≥4 plus any ICH]), functional outcome at 3 months and mortality. Results— A total of 3782 (31.9%) patients had received 1 or 2 AP drugs at baseline: 3016 (25.4%) acetylsalicylic acid (ASA), 243 (2.0%) clopidogrel, 175 (1.5%) ASA and dipyridamole, 151 (1.3%) ASA and clopidogrel, and 197 (1.7%) others. Patients receiving APs were 5 years older and had more risk factors than AP naïve patients. Incidences of SICH per SITS-MOST (ECASS II respectively) were as follows: 1.1% (4.1%) AP naïve, 2.5% (6.2%) any AP, 2.5% (5.9%) ASA, 1.7% (4.2%) clopidogrel, 2.3% (5.9%) ASA and dipyridamole, and 4.1% (13.4%) ASA and clopidogrel. In multivariable analyses, the combination of ASA and clopidogrel was associated with increased risk for SICH per ECASS II (odds ratio, 2.11; 95% CI, 1.29 to 3.45; P=0.003). However, we found no significant increase in the risk for mortality or poor functional outcome, irrespective of the AP subgroup or SICH definition. Conclusion— The absolute excess of SICH of 1.4% (2.1%) in the pooled AP group is small compared with the benefit of thrombolysis seen in randomized trials. Although caution is warranted in patients receiving the combination of ASA and clopidogrel, AP treatment should not be considered a contraindication to thrombolysis.

Reduction of infarct volume and mortality by thrombolysis in a rat embolic stroke model.

Background and Purpose Thrombolytic therapy with recombinant tissue plasminogen activator was tested in a rat embolic stroke model. Methods The rat carotid territory was embolized with arterial-like microthrombi formed under pressure. Hemispheric cerebral blood flow before and after embolization was measured by the intraarterial Xenon-133 injection method. Fifteen minutes after embolization, 24 rats were treated with 3 mg/kg or 10 mg/kg tissue plasminogen activator, and 27 were treated with saline. Carotid angiography displayed the rate of occlusion of the cerebral arterial supply before and after treatment. Brains were fixed and evaluated neuropathologically and infarct volume was measured. Results Cerebral blood flow was reduced 70–86% after embolization. The comparison of pretreatment and posttreatment angiography showed significant (p=0.0005) reperfusion in the treated rats. Thrombolytic therapy significantly reduced the infarct volume from 55.1% to 24.4% of embolized hemisphere volume (p=0.007) and increased the survival rate from 0.48 to 0.96 (p=0.0004). Fifty-three percent of the embolized rats recanalized completely after thrombolytic treatment and developed almost no infarction (median volume 2.8%), and all survived. No hemorrhagic complications were observed. Conclusions Early thrombolytic therapy induced recanalization and reduced mortality and infarct volume after embolic stroke in this model.

Effect of Delayed Thrombolysis with rt-PA in a Rat Embolic Stroke Model

The effect of delayed thrombolysis with recombinant tissue plasminogen activator was tested in an embolic stroke model. The carotid territory was embolized in 103 rats with fibrin-rich clots formed and washed in polyethylene tubes. Hemispheric cerebral blood flow before and after embolization was measured by the intra arterial 133Xe injection method. At five delay times, 15–240 min after embolization, 69 animals were treated with tissue plasminogen activator, 20 mg/kg, and 34 animals with saline. Carotid angiography displayed the grade of occlusion of the cerebral arterial supply before and after treatment. Brains were fixed after 2 days, evaluated neuropathologically, and infarct volume measured. Cerebral blood flow was reduced by 56–71% after embolization. Reperfusion induced by thrombolytic therapy was demonstrated by comparing the posttreatment angiography of the pooled five treatment groups to control animals. Thrombolytic therapy significantly reduced the infarct volume and improved the prekill clinical score by up to 2 h of treatment delay, and treatment might have been beneficial even after 4 h delay. Prolonging the delay of treatment increased the infarct volume (p < 0.001, Jonckheere–Terpstra test). Only a few hemorrhagic complications were observed. Thus, thrombolytic therapy in embolic stroke induced recanalization. The effect on clinical outcome and infarct volume was dependent on delay time.

Neuroprotection by excitatory amino acid antagonist augments the benefit of thrombolysis in embolic stroke in rats.

Background and Purpose The effects of delayed thrombolysis with alteplase and neuroprotection with an excitatory amino acid receptor antagonist and their combination were tested in an embolic stroke model. Methods In 61 rats the carotid artery territory was embolized with arterial-like fibrin-rich clots. Hemispheric cerebral blood flow before and after embolization was measured by intra-arterial 133Xe injection method. The animals were assigned to one of the following treatments: (1) vehicle-treated controls (n=15); (2) dizocilpine 1 mg/kg IV 5 minutes after embolization (n=16); (3) alteplase 20 mg/kg as an intravenous continuous infusion starting 2 hours after embolization (n=16); and (4) both agents (n=14). Carotid angiography displayed the site of occlusion of the cerebral arterial tree immediately after and 3 hours after embolization, and the clinical neurological score was assessed after the rats recovered from anesthesia and before the rats were killed. Brains were fixed after 2 days and evaluated neuropathologically; infarct volume affecting cortical and deep brain structures was measured separately. Results Both alteplase and dizocilpine reduced the total infarct volume (P=.05 and P=.04, respectively, Mann-Whitney tests). Dizocilpine reduced the incidence of cortical infarctions by 48% (P < .001, Fishers test). Only the combined treatment significantly reduced deep brain infarctions (P=.03, Mann-Whitney test). The combined treatment also improved the clinical score by 83% compared with controls, by 75% compared with the group treated by dizocilpine alone, and by 50% compared with the group treated by alteplase alone. Sixty-seven percent of thrombolytic-treated animals recanalized completely compared with 39% of those given no thrombolytics (P=.05, Fishers test). The clinical outcome correlated with infarct size (P < .01, Spearman test). Conclusions Our results document comparable efficacy of delayed thrombolysis and excitatory amino acid receptor antagonism in this model and suggest that combination of these two therapeutic approaches may yield additional benefit in treatment of thromboembolic stroke, particularly in cases where deep brain (end-artery-supplied) structures are affected. (Stroke. 1993;24:1702-1708.)

Dysphagia screening and intensified oral hygiene reduce pneumonia after stroke.

ABSTRACTObjectives: Dysphagia occurs in approximately 51%–78% of patients with acute stroke. The incidence of pneumonia caused by aspiration in dysphagic patients increases both mortality and the need for hospitalization. The aim of this study was to investigate whether the incidence of aspiration pneumonia could be reduced in such patients by an early screening for dysphagia and intensified oral hygiene. Material and Methods: In this controlled trial, 146 hospitalized acute stroke patients with moderate or severe dysphagia were included in three groups: an intervention group (n = 58), one internal control group (n = 58, retrospectively selected from same clinic), and one external control group (n = 30) from a comparable stroke unit in a neighboring hospital. The intervention consisted of early screening with a clinical method of dysphagia screening, the Gugging Swallowing Screen, and intensified oral hygiene. Results: The incidence of x-ray verified pneumonia was 4 of 58 (7%) in the intervention group compared with 16 of 58 (28%) in the internal control group (p < .01) and with 8 of 30 (27%) in the external control group (p < .05). Conclusions: Early and systematic dysphagia screening by the Gugging Swallowing Screen method and intensified oral hygiene reduced the incidence of x-ray verified pneumonia.

Enhancing the efficacy of thrombolysis by AMPA receptor blockade with NBQX in a rat embolic stroke model.

Efficacy and safety of combined alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor blockade and thrombolytic therapy with human recombinant tissue plasminogen activator (TPA) was tested in a rat embolic stroke model. Sixty-three rats were embolized in the right internal carotid territory with a 200 microliters suspension of microclots formed by alternate moving of 150 microliters whole blood and 50 microliters of thrombin between two interconnected syringes for 4 min. Sixteen embolized rats served as controls, and 16 rats were treated with NBQX immediately after embolization. Thirty-one rats were treated with TPA 2 h following embolization, and in 16 of these rats additional NBQX treatments were initiated 90 min following embolization. Hemispheric cerebral blood flow (CBF) was measured by an intraarterial 133Xenon injection method before and after embolization. Carotid angiography displayed the rate of occlusion of the cerebral arterial supply before and after treatment. Brains were fixed after 2 days, evaluated neuropathologically, and infarct volumes were measured. Median CBF was reduced by 70-77% in the affected hemispheres following embolization. Significant recanalization occurred in all groups except those treated with NBQX. TPA-treated rats had significantly better reperfusion compared to controls judged by angiography 3 h following embolization (P = 0.04). NBQX alone and TPA alone caused insignificant reduction in infarct volume but, when combined, total infarct volume was reduced by 77% compared to controls (P = 0.02). Separate measurement of cortical infarct revealed significantly smaller infarcts (P = 0.05) in the combined treatment group compared to the TPA treatment group.(ABSTRACT TRUNCATED AT 250 WORDS)

European Research Priorities for Intracerebral Haemorrhage

Over 2 million people are affected by intracerebral haemorrhage (ICH) worldwide every year, one third of them dying within 1 month, and many survivors being left with permanent disability. Unlike most other stroke types, the incidence, morbidity and mortality of ICH have not declined over time. No standardised diagnostic workup for the detection of the various underlying causes of ICH currently exists, and the evidence for medical or surgical therapeutic interventions remains limited. A dedicated European research programme for ICH is needed to identify ways to reduce the burden of ICH-related death and disability. The European Research Network on Intracerebral Haemorrhage EURONICH is a multidisciplinary academic research collaboration that has been established to define current research priorities and to conduct large clinical studies on all aspects of ICH.