1,721,165 research outputs found
Does aneurysm side influence the infarction side and patients' outcome after subarachnoid hemorrhage?
No full textBackground: The prognostic factors and outcome of aneurysms appear to be dependent on its locations. Therefore, we compared left- and right- sided aneurysms in patients with aneurysmal subarachnoid hemorrhage (SAH) in terms of differences in outcome and prognostic factors.
Methods: Patients with SAH were entered into a prospectively collected database. A total of 509 patients with aneurysmal subarachnoid hemorrhage were retrospectively selected and stratified in two groups depending on side of ruptured aneurysm (right n = 284 vs. left n = 225). Midline aneurysms of the basilar and anterior communicating arteries were excluded from the analysis. Outcomes were assessed using the modified Rankin Scale (mRS; favorable (mRS 0–2) vs. unfavorable (mRS 3–6)) six months after SAH.
Results: We did not identify any differences in outcome depending on left- and right-sided ruptured aneurysms. In both groups, the significant negative predictive factors included clinical admission status (WFNS IV+V), Fisher 3- bleeding pattern in CT, the occurrence of delayed cerebral ischemia (DCI), early hydrocephalus and later shunt-dependence. The side of the ruptured aneurysm does not seem to influence patients´ outcome. Interestingly, the aneurysm side predicts the side of infarction, with a significant influence on patients´ outcome in case of left-sided infarctions. In addition, the in multivariate analysis side of aneurysm was an independent predictor for the side of cerebral infarctions.
Conclusion: The side of the ruptured aneurysms (right or left) did not influence patients’ outcome. However, the aneurysm-side predicts the side of delayed infarctions and outcome appear to be worse in patients with left-sided infarctions
MRI-detection rate and incidence of lumbar bleeding sources in 190 patients with non-aneurysmal SAH
No full textBackground: Up to 15% of all spontaneous subarachnoid hemorrhages (SAH) have a non-aneurysmal SAH (NASAH). The evaluation of SAH patients with negative digital subtraction angiography (DSA) is sometimes a diagnostic challenge. Our goal in this study was to reassess the yield of standard MR-imaging of the complete spinal axis to rule out spinal bleeding sources in patients with NASAH.
Methods: We retrospectively analyzed the spinal MRI findings in 190 patients with spontaneous NASAH, containing perimesencephalic (PM) and non-perimesencephalic (NPM) SAH, diagnosed by computer tomography (CT) and/or lumbar puncture (LP), and negative 2nd DSA.
Results: 190 NASAH patients were included in the study, divided into PM-SAH (n = 87; 46%) and NPM-SAH (n = 103; 54%). Overall, 23 (22%) patients had a CT negative SAH, diagnosed by positive LP. MR-imaging of the spinal axis detected two patients with lumbar ependymoma (n = 2; 1,05%). Both patients complained of radicular sciatic pain. The detection rate raised up to 25%, if only patients with radicular sciatic pain received an MRI.
Conclusion: Routine radiological investigation of the complete spinal axis in NASAH patients is expensive and can not be recommended for standard procedure. However, patients with clinical signs of low-back/sciatic pain should be worked up for a spinal pathology
Measurement values of residual aneurysm (raw data) and parent artery.
Full text linkA. Residual aneurysm measured by TR-MRA: The measurement values of three parameters 1) Neck length, 2) Largest diameter, 3) Smallest diameter as well as the volume of residual aneurysm, which was calculated by the image-processing application “Aquarius iNtuition®” are listed. B. Residual aneurysm measured by DSA: The measurement values of the same parameters described above were listed. C. Diameter of the parent artery: The size of the parent artery at the proximal neck was compared between the TR-MRA and the 2D DSA. (PDF)</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Differences in bleeding patterns and outcome after intracerebral hemorrhage due to vascular malformations
No full textBackground: Atypical intracerebral hemorrhage is a common form of primary manifestation of vascular malformations.
Objective: The aim of the present study is to determine clues to the cause of bleeding according to hemorrhage pattern (lobar, basal ganglia, infratentorial).
Methods: We retrospectively evaluated 343 consecutive neurosurgical patients with intracerebral hemorrhage (ICH), who were admitted to our neurosurgical department between 2006 and 2016. The study cohort includes only neurosurgical patients. Patients who underwent treatment by neurologists are not represented in this study. We assessed location of hemorrhage, hematoma volumes to rule out differences and predicitve variables for final outcome.
Results: In 171 cases (49.9%) vascular malformations, such as arteriovenous malformations (AVMs), cavernomas, dural fistulas and aneurysms were the cause of bleeding. 172 (50.1%) patients suffered from an intracerebral hemorrhage due to amyloid angiopathy or long standing hypertension. In patients with infratentorial hemorrhage a malformation was more frequently detected as in patients with supratentorial hemorrhage (36% vs. 16%, OR 2.9 [1.8;4.9], p<0.001). Among the malformations AVMs were most common (81%). Hematoma expansion was smaller in vascular malformation than non-malformation caused bleeding (24.1 cm3 vs. 64.8 cm3, OR 0.5 [0.4;0.7], p < 0.001,). In 6 (2.1%) cases diagnosis remained unclear. Final outcome was more favorable in patients with vascular malformations (63% vs. 12%, OR 12.8 [4.5;36.2], p<0.001).
Conclusion: Localization and bleeding patterns are predictive factors for origin of the hemorrhage. These predictive factors should quickly lead to appropriate vascular diagnostic measures. However, due to the inclusion criteria the validity of the study is limited and multicentre studies with further testing in general ICH patients are required
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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