1,720,972 research outputs found
B-mode transorbital ultrasononography for the diagnosis of acute optic neuritis. A systematic review
No full textOBJECTIVE: In patients with acute optic neuritis (AON) transorbital sonography may reveal a thickening of the retrobulbar portion of the optic nerve. Our aim was to systematically review the diagnostic accuracy of ultrasonography of optic nerve diameter (OND) for assessment of AON.
METHODS: MEDLINE, EMBASE (1966-October 2014) was searched to identify studies reporting data on patients with AON (with/without multiple sclerosis) assessed by B-mode transorbital ultrasonography. Thereafter, the studies retrieved were screened based on predefined inclusion and exclusion criteria. Data were extracted and the quality of the included studies was evaluated.
RESULTS: Seven studies (162 patients) were included. The OND was significantly thicker in the affected eye compared with its unaffected fellow or controls. An increased OND was found in 78-100% of patients. Four studies determined papilledema in 6-43% of patients.
CONCLUSIONS: Transorbital sonography is a sensitive, highly accessible and user-friendly technique for the detection of significant optic nerve thickening on the side affected by AON and represents an adjunctive tool for the diagnosis of AON. Compared to visual evoked potentials, TOS may provide different, though complementary, information on the pathophysiology of AON.
SIGNIFICANCE: B-mode transorbital ultrasonography provides promising support for the clinical diagnosis of AON
Prediction of Outcome in Embolic Strokes of Undetermined Source
No full textBACKGROUND AND AIM: Predicting outcome after stroke is a major goal and research field. The Embolic Stroke of Undetermined Source (ESUS) is a recently introduced clinical construct, and the prediction of outcome in this population has to be further explored. The aim of the study was to evaluate the prognostic validity and accuracy of the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) score in patients with ESUS. METHODS: Consecutive patients hospitalized for acute ischemic stroke who met the ESUS diagnostic criteria were identified and the ASTRAL scores estimated. The study endpoint was the 3-month unfavorable outcome (modified Rankin Scale>2). Predictive performance was investigated through logistic regression analysis and discrimination and calibration tests. RESULTS: Among 202 patients with ESUS, 67 (33.2%) had unfavourable 3-month outcome. The ASTRAL score was an independent predictor of poor outcome [adjOR = 1.44, 95% confidence interval (CI) 1.30-1.60, P < .001], showed good discriminatory power (area under the receiver operating characteristic curve .913, 95% CI .871-.956) and was well calibrated (Hosmer-Lemeshow test P = .496). CONCLUSIONS: The ASTRAL score was an independent predictor of 3-month functional outcome and showed high predictive accuracy in patients with ESUS
Clinical phenotypes of embolic strokes of undetermined source
No full textBackground and purpose: The embolic stroke of undetermined source (ESUS) represents a heterogeneous clinical entity. The aim of this study was to investigate whether distinct clinical phenotypes may be identified in the ESUS population.
Methods: We retrospectively identified consecutive patients hospitalized for acute ischemic stroke who met the ESUS diagnostic criteria. Baseline characteristics and diagnostic workup findings were collected. Hierarchical cluster analysis was carried out to classify clinical features and identify different groups of ESUS patients.
Results: One hundred twenty-seven patients with a mean age of 68.6 (12.5) years were included. Three main clusters were identified. The first cluster associated young age, male sex, presence of patent foramen ovale, and posterior circulation infarct. The second phenotype linked hypertension, severe stroke, left atrial cardiopathy, diabetes mellitus, and involvement of multiple vascular territories. The third cluster gathered smoking, dyslipidemia, ipsilateral vulnerable sub-stenotic carotid plaque, and infarct of anterior vascular territory.
Conclusions: Distinct clinical phenotypes have been identified within the ESUS population, which may supply clues to the underlying pathogenic mechanisms
Erratum to: Feasibility and usefulness of ultrasonography in idiopathic intracranial hypertension or secondary intracranial hypertension
Full text linkTransorbital sonography (TOS) has been proven to be able to non-invasively detect elevated intracranial pressure. In this condition TOS shows an increase in optic nerve sheath diameter (ONSD). It has been suggested that internal jugular vein valve insufficiency (IJVVI) may represent a factor contributing to the pathogenesis of idiopathic intracranial hypertension (IIH). The aim of this study was to investigate whether patients with IIH or secondary IH have higher ONSD values and higher frequency of IJVVI compared to subjects without IH
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
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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