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Background: In acute stroke, the magnetic resonance (MR) imaging-based mismatch concept is used to select patients with tissue at risk of infarction for reperfusion therapies. There is however a controversy if non-deconvolved or deconvolved perfusion weighted (PW) parameter maps perform better in tissue at risk prediction and which parameters and thresholds should be used to guide treatment decisions., Methods: In a group of 22 acute stroke patients with consecutive MR and quantitative positron emission tomography (PET) imaging, non-deconvolved parameters were validated with the gold standard for penumbral-flow (PF) detection 15O-water PET. Performance of PW parameters was assessed by a receiver operating characteristic curve analysis to identify the accuracy of each PWI map to detect the -upper PF threshold as defined by PET cerebral blood flow <20 mL/100 g/min., Results: Among normalized non-deconvolved parameters, PW-first moment without delay correction (FM without DC) > 3.6 s (area under the curve [AUC] = 0.89, interquartile range [IQR] 0.85-0.94), PW-maximum of the concentration curve (Cmax) < 0.66 (AUC = 0.92, IQR 0.84-0.96) and PW-time to peak (TTP) > 4.0 s (AUC = 0.92, IQR 0.87-0.94) perform significantly better than other non-deconvolved parameters to detect the PF threshold as defined by PET., Conclusions: Non-deconvolved parameters FM without DC, Cmax and TTP are an observer-independent alternative to established deconvolved parameters (e.g., Tmax) to guide treatment decisions in acute stroke., (© 2018 S. Karger AG, Basel.)

Background: With regard to acute stroke, patients with unknown time from stroke onset are not eligible for thrombolysis. Quantitative diffusion weighted imaging (DWI) and fluid attenuated inversion recovery (FLAIR) MRI relative signal intensity (rSI) biomarkers have been introduced to predict eligibility for thrombolysis, but have shown heterogeneous results in the past. In the present work, we investigated whether the inclusion of easily obtainable clinical-radiological parameters would improve the prediction of the thrombolysis time window by rSIs and compared their performance to the visual DWI-FLAIR mismatch., Methods: In a retrospective study, patients from 2 centers with proven stroke with onset <12 h were included. The DWI lesion was segmented and overlaid on ADC and FLAIR images. rSI mean and SD, were calculated as follows: (mean ROI value/mean value of the unaffected hemisphere). Additionally, the visual DWI-FLAIR mismatch was evaluated. Prediction of the thrombolysis time window was evaluated by the area-under-the-curve (AUC) derived from receiver operating characteristic (ROC) curve analysis. Factors such as the association of age, National Institutes of Health Stroke Scale, MRI field strength, lesion size, vessel occlusion and Wahlund-Score with rSI were investigated and the models were adjusted and stratified accordingly., Results: In 82 patients, the unadjusted rSI measures DWI-mean and -SD showed the highest AUCs (AUC 0.86-0.87). Adjustment for clinical-radiological covariates significantly improved the performance of FLAIR-mean (0.91) and DWI-SD (0.91). The best prediction results based on the AUC were found for the final stratified and adjusted models of DWI-SD (0.94) and FLAIR-mean (0.96) and a multivariable DWI-FLAIR model (0.95). The adjusted visual DWI-FLAIR mismatch did not perform in a significantly worse manner (0.89). ADC-rSIs showed fair performance in all models., Conclusions: Quantitative DWI and FLAIR MRI biomarkers as well as the visual DWI-FLAIR mismatch provide excellent prediction of eligibility for thrombolysis in acute stroke, when easily obtainable clinical-radiological parameters are included in the prediction models., (© 2016 S. Karger AG, Basel.)

Background: While the application of intravenous systemic thrombolysis (IVT) with rt-PA (recombinant tissue plasminogen activator) in older patients is currently moving into the focus of epidemiological studies, only few data are available regarding the application in young patients ≤40 years. Single-center data of a thrombolysis register were analyzed with respect to safety and efficacy of the treatment of young patients., Methods: In a retrospective subgroup analysis of 450 patients treated by IVT within a 3-hour time window, patients ≤40 years were identified (n = 20). Clinical data [age, pretherapeutic stroke severity (National Institute of Health Stroke Scale, NIHSS), OTT (onset to-treatment time), rt-PA-dose, DNT (door[-]to[-]needle time), rate of symptomatic intracranial hemorrhages] and medical history were determined. The clinical outcome was assessed by the mRS (modified Rankin Scale). The results were compared to those of patients >40 years (n = 430)., Results: Twenty patients ≤40 years (mean age 32 years) out of 450 patients (4%) were treated by IVT. The percentage of predisposing diseases and vascular risk factors was significantly lower when compared to patients >40 years (p < 0.05). In contrast, the percentage of smokers was significantly higher (55 vs. 24%; p < 0.05). In comparison to patients >40 years, OTT, DNT and NIHSS at admission were not significantly different. After 3 months, 11 of 20 young patients (55%) showed a favorable outcome (mRS 0-1) and 80% were functionally independent (mRS 0-2). In the group of patients >40 years (n = 430), the respective percentages were significantly lower [p < 0.05; 34% (mRS 0-1) and 52% (mRS 0-2), respectively]. Symptomatic intracranial hemorrhages were not observed (in patients >40 years: 4%, p < 0.05)., Conclusions: In comparison to the cohort of patients >40 years, IVT in young patients is safe and leads to a significantly better outcome after 3 months. Our data therefore encourage the use of IVT in young patients., (Copyright © 2010 S. Karger AG, Basel.)

Background: Predictors of outcome and safety in intravenous thrombolysis within 3 h in clinical routine is a matter of ongoing debate. Available reports contain small patient numbers or summarize heterogeneous multicenter data., Methods: Four hundred and fifty patients received intravenous thrombolysis within 3 h after stroke. Pretreatment NIHSS score and detailed medical history were analyzed. Noncontrast CT was performed before thrombolysis, 24-36 h later and in case of clinical deterioration. Symptomatic intracranial hemorrhage (SICH; any bleeding with an NIHSS increase of > or =4 points) and clinical outcome (modified Rankin Scale, mRS) after 3 months were recorded. Logistic regression identified parameters predictive of independence (mRS 0-2) and SICH., Results: Median onset to admission, door to needle and onset to treatment time was 75, 50 and 135 min, respectively. Direct presentation by emergency service (64%) was the fastest way of referral. Median pretreatment NIHSS was 11 points. Independence (mRS 0-2) was reached by 53%. Mortality was 11% (7% intracerebral, 4% extracerebral complications). Logistic regression identified low NIHSS, low age and absent diabetes as predictors of independence. Overall hemorrhagic complications and SICH were found in 18 and 4% of the patients, respectively. Extracerebral bleeding complications and allergic reactions were found in 3 and 1%, respectively., Conclusion: This largest single center report presents a sample in the range of the 3 h rt-PA cohort of all randomized controlled trials. Outcome was comparable to randomized studies with a higher rate of independence and a lower rate of mortality and SICH.

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., (Copyright (c) 2006 S. Karger AG, Basel.)