Benefit of Intravenous Thrombolysis in Acute Ischemic Stroke Patients With High Cerebral Microbleed Burden

BACKGROUND AND PURPOSE: Cerebral microbleeds (CMBs) are a risk factor for intracranial hemorrhage. Whether intravenous thrombolysis (IVT) improves functional outcome in acute ischemic stroke patients with CMBs is unknown. We aimed to estimate the treatment effect of IVT in patients with acute ischemic stroke and a high burden (>10) of CMBs. METHODS: We devised a multistep algorithm to model 90-day modified Rankin Scale scores in patients with ≤10 versus >10 CMBs who do or do not receive IVT. Parameters were extracted from recently published meta-analyses and included pairwise relationships between CMBs, IVT, 3-month functional outcome, and intracranial hemorrhage. Uncertainty was quantified in probabilistic sensitivity analyses. RESULTS: In patients with >10 CMBs as compared with ≤10 CMBs, point estimates of the odds ratios for favorable outcome (modified Rankin Scale ≤2) associated with IVT were 7% to 10% lower but still >1 (range, 1.03–1.51). On the other hand, IVT in patients with >10 CMBs significantly increased the odds of mortality. The point estimates for the net treatment effect of IVT (change in the utility-weighted modified Rankin Scale score) in patients with >10 CMBs were in favor of withholding IVT in older patients with more severe strokes and longer treatment delays. However, because the general pretest probability of >10 CMBs is low (0.6%–2.7%), pretreatment magnetic resonance imaging to quantify CMB burden would be justified only if it delayed IVT by <10 minutes. CONCLUSIONS: High CMB burden modifies the treatment effect of IVT. In patients with >10 CMBs, IVT is associated with higher mortality and, in older patients with severe strokes and longer treatment delays, a net utility loss. Patients with higher-than-average pretest probability of >10 CMB might profit from magnetic resonance imaging screening if it does not increase the treatment time

European Stroke Organisation (ESO) guideline on screening for subclinical atrial fibrillation after stroke or transient ischaemic attack of undetermined origin

We aimed to provide practical recommendations for the screening of subclinical atrial fibrillation (AF) in patients with ischaemic stroke or transient ischaemic attack (TIA) of undetermined origin. These guidelines are based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. Five relevant Population, Intervention, Comparator, Outcome questions were defined by a multidisciplinary module working group (MWG). Longer duration of cardiac rhythm monitoring increases the detection of subclinical AF, but the optimal monitoring length is yet to be defined. We advise longer monitoring to increase the rate of anticoagulation, but whether longer monitoring improves clinical outcomes needs to be addressed. AF detection does not differ from in- or out-patient ECG-monitoring with similar monitoring duration, so we consider it reasonable to initiate in-hospital monitoring as soon as possible and continue with outpatient monitoring for more than 48 h. Although insertable loop recorders (ILR) increase AF detection based on their longer monitoring duration, comparison with non-implantable ECG devices for similar monitoring time is lacking. We suggest the use of implantable devices, if feasible, for AF detection instead of non-implantable devices to increase the detection of subclinical AF. There is weak evidence of a useful role for blood, ECG and brain imaging biomarkers for the identification of patients at high risk of AF. In patients with patent foramen ovale, we found insufficient evidence from RCT, but prolonged cardiac monitoring in patients >55 years is advisable for subclinical AF detection. To conclude, in adult patients with ischaemic stroke or TIA of undetermined origin, we recommend longer duration of cardiac rhythm monitoring of more than 48 h and if feasible with IRL to increase the detection of subclinical AF

Open Database of Epileptic EEG with MRI and Postoperational Assessment of Foci—a Real World Verification for the EEG Inverse Solutions

This paper introduces a freely accessible database http://eeg.pl/epi, containing 23 datasets from patients diagnosed with and operated on for drug-resistant epilepsy. This was collected as part of the clinical routine at the Warsaw Memorial Child Hospital. Each record contains (1) pre-surgical electroencephalography (EEG) recording (10–20 system) with inter-ictal discharges marked separately by an expert, (2) a full set of magnetic resonance imaging (MRI) scans for calculations of the realistic forward models, (3) structural placement of the epileptogenic zone, recognized by electrocorticography (ECoG) and post-surgical results, plotted on pre-surgical MRI scans in transverse, sagittal and coronal projections, (4) brief clinical description of each case. The main goal of this project is evaluation of possible improvements of localization of epileptic foci from the surface EEG recordings. These datasets offer a unique possibility for evaluating different EEG inverse solutions. We present preliminary results from a subset of these cases, including comparison of different schemes for the EEG inverse solution and preprocessing. We report also a finding which relates to the selective parametrization of single waveforms by multivariate matching pursuit, which is used in the preprocessing for the inverse solutions. It seems to offer a possibility of tracing the spatial evolution of seizures in time

Behavior of QQ-Plots and Genomic Control in Studies of Gene-Environment Interaction

Genome-wide association studies of gene-environment interaction (GxE GWAS) are becoming popular. As with main effects GWAS, quantile-quantile plots (QQ-plots) and Genomic Control are being used to assess and correct for population substructure. However, in GE work these approaches can be seriously misleading, as we illustrate; QQ-plots may give strong indications of substructure when absolutely none is present. Using simulation and theory, we show how and why spurious QQ-plot inflation occurs in GE GWAS, and how this differs from main-effects analyses. We also explain how simple adjustments to standard regression-based methods used in GE GWAS can alleviate this problem

Phylogenetic Diversity and Genotypical Complexity of H9N2 Influenza A Viruses Revealed by Genomic Sequence Analysis

H9N2 influenza A viruses have become established worldwide in terrestrial poultry and wild birds, and are occasionally transmitted to mammals including humans and pigs. To comprehensively elucidate the genetic and evolutionary characteristics of H9N2 influenza viruses, we performed a large-scale sequence analysis of 571 viral genomes from the NCBI Influenza Virus Resource Database, representing the spectrum of H9N2 influenza viruses isolated from 1966 to 2009. Our study provides a panoramic framework for better understanding the genesis and evolution of H9N2 influenza viruses, and for describing the history of H9N2 viruses circulating in diverse hosts. Panorama phylogenetic analysis of the eight viral gene segments revealed the complexity and diversity of H9N2 influenza viruses. The 571 H9N2 viral genomes were classified into 74 separate lineages, which had marked host and geographical differences in phylogeny. Panorama genotypical analysis also revealed that H9N2 viruses include at least 98 genotypes, which were further divided according to their HA lineages into seven series (A–G). Phylogenetic analysis of the internal genes showed that H9N2 viruses are closely related to H3, H4, H5, H7, H10, and H14 subtype influenza viruses. Our results indicate that H9N2 viruses have undergone extensive reassortments to generate multiple reassortants and genotypes, suggesting that the continued circulation of multiple genotypical H9N2 viruses throughout the world in diverse hosts has the potential to cause future influenza outbreaks in poultry and epidemics in humans. We propose a nomenclature system for identifying and unifying all lineages and genotypes of H9N2 influenza viruses in order to facilitate international communication on the evolution, ecology and epidemiology of H9N2 influenza viruses

Overlapping regional security institutions in South America: The case of OAS and UNASUR

The Union of South American Nations (UNASUR) has positioned itself as a regional security organization aimed at reducing the influence of the Organization of American States (OAS) in South America. At the same time, the OAS paradoxically serves as a model for UNASUR because of its operational capacity and its legitimacy as a regional organization. This article analyzes the seemingly contradictory tendencies of replication and dissociation that UNASUR exhibits towards the OAS in terms of security conceptions and practices. In the first part of the paper, we will draw on recent debates on international regime complexity to develop a framework to study institutional overlap. The second part analyzes to what extent and in which respects UNASUR, and particularly its Defense Council, overlaps with the OAS in terms of security conceptions and practices, while the third part examines the causes of the emergence of a “competitor” for the OAS in South America