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Rüdiger von Kummer

Publications and source records attributed to Rüdiger von Kummer.

14 recordsLinked to original sources
PubMed2006

Extent of early ischemic changes on computed tomography (CT) before thrombolysis: prognostic value of the Alberta Stroke Program Early CT Score in ECASS II.

BACKGROUND AND PURPOSE: The significance of early ischemic changes (EICs) on computed tomography (CT) to triage patients for thrombolysis has been controversial. The Alberta Stroke Program Early CT Score (ASPECTS) semiquantitatively assesses EICs within the middle cerebral artery territory using a10-point grading system. We hypothesized that dichotomized ASPECTS predicts response to intravenous thrombolysis and incidence of secondary hemorrhage within 6 hours of stroke onset. METHODS: Data from the European-Australian Acute Stroke Study (ECASS) II study were used in which 800 patients were randomized to recombinant tissue plasminogen activator (rt-PA) or placebo within 6 hours of symptom onset. We retrospectively assessed all baseline CT scans, dichotomized ASPECTS at < or =7 and >7, defined favorable outcome as modified Rankin Scale score 0 to 2 after 90 days, and secondary hemorrhage as parenchymal hematoma 1 (PH1) or PH2. We performed a multivariable logistic regression analysis and assessed for an interaction between rt-PA treatment and baseline ASPECTS score. RESULTS: We scored ASPECTS >7 in 557 and < or =7 in 231 patients. There was no treatment-by-ASPECTS interaction with dichotomized ASPECTS (P=0.3). This also applied for the 0- to 3-hour and 3- to 6-hour cohorts. However, a treatment-by-ASPECTS effect modification was seen in predicting PH (0.043 for the interaction term), indicating a much higher likelihood of thrombolytic-related parenchymal hemorrhage in those with ASPECTS < or =7. CONCLUSIONS: In ECASS II, the effect of rt-PA on functional outcome is not influenced by baseline ASPECTS. Patients with low ASPECTS have a substantially increased risk of thrombolytic-related PH.

Aged↗
PubMed2006

Early ischemic edema on cerebral computed tomography: its relation to diffusion changes and hypoperfusion within 6 h after human ischemic stroke. A comparison of CT, MRI and PET.

BACKGROUND: Brain tissue hypoattenuation on early computed tomography is frequently included in decision making in acute stroke management. However, its pathophysiological counterpart needs further evaluation. METHODS: By comparative imaging with diffusion-weighted imaging and 15O-water positron emission tomography we aimed to interpret early (<6 h) hypoattenuation. RESULTS: In 11 patients, the hypoattenuation corresponded to a decreased proton diffusion (median 115.9% relative DWI value) measured by magnetic resonance imaging and to a severe hypoperfusion (below 12 ml/100 g/ min) assessed by positron emission tomography. The volume of parenchymal hypoattenuation correlated to the tissue with disturbed diffusion (Spearman's rho=0.73), but largely underestimated the hypoperfusion below 20 ml/100 g/min. CONCLUSIONS: Early hypoattenuation reflects the coupling of the severity of ischemia and resulting diffusion changes. It allows an estimate of the infarct core but underestimates the penumbral hypoperfusion.

Adult↗
PubMed2006

Classification and pathogenesis of cerebral hemorrhages after thrombolysis in ischemic stroke.

BACKGROUND AND PURPOSE: Brain hemorrhage after ischemic stroke is a serious complication of treatment; however, its pathology is poorly understood. A classification based on brain imaging may help to better understand and avoid causal factors. METHODS: Review of the results of controlled randomized trials and the available literature. RESULTS: Hemorrhagic infarctions have no impact on clinical outcome and are probably not associated with the thrombolytic itself and the type of reperfusion strategy. They are associated with the extent of ischemic damage and most probably to an ischemic vasculopathy. Parenchymal hematomas are often clinically relevant. Their incidence is affected by the thrombolytic itself, the type, and probably the time point of reperfusion strategy. The loss of hemostatic control seems important in their pathogenesis. Extraischemic hematomas (remote from the infarct), unique or multiple, suggest pre-existing brain pathology, especially cerebral amyloid angiopathy. CONCLUSIONS: The radiological description of 3 different types of brain hemorrhage is useful to better understand the specific pathology and the impact on clinical outcome. It may help to avoid clinically relevant brain hemorrhages.

Brain↗
PubMed2005

Prophylaxis of thrombotic and embolic events in acute ischemic stroke with the low-molecular-weight heparin certoparin: results of the PROTECT Trial.

BACKGROUND AND PURPOSE: Patients with stroke are at substantial risk of thromboembolic complications and therefore require antithrombotic prophylaxis. To show the noninferiority of the low-molecular-weight heparin certoparin to unfractionated heparin (UFH) for the prevention of thromboembolic complications, we performed a randomized, double-blind, active-controlled multicenter trial in patients with acute ischemic stroke. METHODS: Overall, 545 patients were randomized within 24 hours of stroke onset to treatment with certoparin (3000 U anti-Xa OD; n=272) or UFH (5000 U TID; n=273) for 12 to 16 days. Patients with paresis of a leg and an National Institutes of Health Stroke Scale score of 4 to 30 points were included. The primary end point was a composite outcome of proximal deep vein thrombosis, pulmonary embolism, or death related to venous thromboembolism during treatment. Computed tomography was performed at trial entry, after 7 days, and when clinical deterioration occurred. RESULTS: The per-protocol analysis revealed 17 (7.0%) primary events in the certoparin group compared with 24 (9.7%) in the UFH group, thereby demonstrating noninferiority (P=0.0011), confirmed by intention-to-treat analysis (6.6% versus 8.8%; P=0.008). Major bleeding occurred during treatment in 3 patients allocated to certoparin (1.1%) and 5 patients allocated to UFH (1.8%). CONCLUSIONS: Certoparin (3000 U anti-Xa OD) is at least as effective and safe as UFH (TID) for the prevention of thromboembolic complications in patients with acute ischemic stroke.

Adolescent↗
PubMed2004

Association of outcome with early stroke treatment: pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials.

BACKGROUND: Quick administration of intravenous recombinant tissue plasminogen activator (rt-PA) after stroke improved outcomes in previous trials. We aimed to analyse combined data for individual patients to confirm the importance of rapid treatment. METHODS: We pooled common data elements from six randomised placebo-controlled trials of intravenous rt-PA. Using multivariable logistic regression we assessed the relation of the interval from stroke onset to start of treatment (OTT) on favourable 3-month outcome and on the occurrence of clinically relevant parenchymal haemorrhage. FINDINGS: Treatment was started within 360 min of onset of stroke in 2775 patients randomly allocated to rt-PA or placebo. Median age was 68 years, median baseline National Institute of Health Stroke Scale (NIHSS) 11, and median OTT 243 min. Odds of a favourable 3-month outcome increased as OTT decreased (p=0.005). Odds were 2.8 (95% CI 1.8-4.5) for 0-90 min, 1.6 (1.1-2.2) for 91-180 min, 1.4 (1.1-1.9) for 181-270 min, and 1.2 (0.9-1.5) for 271-360 min in favour of the rt-PA group. The hazard ratio for death adjusted for baseline NIHSS was not different from 1.0 for the 0-90, 91-180, and 181-270 min intervals; for 271-360 min it was 1.45 (1.02-2.07). Haemorrhage was seen in 82 (5.9%) rt-PA patients and 15 (1.1%) controls (p<0.0001). Haemorrhage was not associated with OTT but was with rt-PA treatment (p=0.0001) and age (p=0.0002). INTERPRETATION: The sooner that rt-PA is given to stroke patients, the greater the benefit, especially if started within 90 min. Our results suggest a potential benefit beyond 3 h, but this potential might come with some risks.

Aged↗
PubMed2004

Brain tissue water uptake after middle cerebral artery occlusion assessed with CT.

BACKGROUND AND PURPOSE: To study whether computed tomography (CT) can measure the water content of early ischemic edema. METHODS: The authors obtained cranial CT in 5 groups of rats subjected to 1 hour (n = 8), 2 hours (n = 11), 3 hours (n = 13), 4 hours (n = 13), or 6 hours (n = 14) of right middle cerebral artery (MCA) occlusion. Immediately after CT, the authors removed the rats' brains and determined tissue water content by the dry-wet weight method. They correlated brain x-ray attenuation with brain tissue water content. RESULTS: Mean brain tissue water content remained constant in the nonischemic left hemispheres at 77.9% +/- 0.6% and increased up to 79.3% +/- 1.0% in the right hemispheres after 6 hours of permanent right MCA occlusion. X-ray attenuation remained constant in the left hemispheres at 75.6 + 2.2 Hounsfield units (HU) and decreased to 71.7 +/- 3.4 HU in the right hemispheres after 6 hours of right MCA occlusion. The decrease in x-ray attenuation correlated significantly with the increase in ischemic brain tissue water content (y = 217.3 - 1.8x x; r = .55, P < .0001). That means that a 1% increase in hemispheric tissue water content causes a decrease in x-ray attenuation of 1.8 HU. CONCLUSIONS: After MCA occlusion, immediate brain tissue net water uptake is associated with a decrease in x-ray attenuation. CT can monitor ischemic edema in an acute stroke.

Animals↗