1,721,361 research outputs found
Ruptured lenticulostriate artery aneurysm: a report of a case treated with endovascular embolisation.
No full textA 65-year-old woman presented to the emergency department with sudden onset of left-sided weakness, headache and vomiting. A cerebral CT showed an acute intracerebral haemorrhage involving the right caudate nucleus and lentiform nucleus with mild midline shift and intraventricular extension. CT angiography did not reveal aneurysm or other vascular anomaly. Conventional cerebral angiography demonstrated a 3 mm right medial lenticulostriate branch aneurysm, arising from the right anterior cerebral artery (ACA). Endovascular treatment was performed from the left internal carotid via the anterior communicating artery into the right ACA. Complete occlusion was achieved with injection of N-butyl-2-cyanoacrylate. The patient had neurological rehabilitation during hospitalisation followed by outpatient physical therapy. Two years later, clinical follow-up demonstrated excellent recovery
Endovaskuläre Therapie des ischämischen Hirnschlags
No full textMehrere kürzlich publizierte, prospektive, randomisierte Studien haben die Überlegenheit der
mechanischen Thrombektomie mit Stent-Retrievern in Kombination mit intravenöser Thrombolyse
gegenüber der alleinigen intravenösen Thrombolyse beim akuten ischämischen Hirnschlag auf dem
Boden eines proximalen Hirngefässverschlusses bewiesen. Der folgende Artikel gibt eine Übersicht
über die Entwicklung der endovaskulären Hirnschlagbehandlung mit Fokus auf die kürzlich erschienenen
bahnbrechenden Studien
Developments in mechanical thrombectomy devices for the treatment of acute ischemic stroke
No full textSeveral recent prospective randomized controlled trials of endovascular stroke therapy using latest generation thrombectomy devices, so called stent-retrievers, have shown significantly improved clinical outcome compared to the standard treatment with intra-venous thrombolysis using r-tPA alone. Despite some differences in inclusion criteria between these studies, all required non-invasive vessel imaging to proof occlusion of a major brain supplying vessel. Furthermore, in most studies additional imaging techniques were used to exclude patients with already established large cerebral infarction or unfavorable collateral or penumbral status. Patients with small infarct volume, severe neurological deficits and in whom thrombectomy can be initiated within the first 6 hours after symptom onset seem to benefit the most. Therefore, mechanical thrombectomy using stent-retrievers in addition to intra-venous thrombolysis is recommended for the treatment of acute ischemic stroke with proven major vessel occlusion in the anterior circulation
Invited comment on the work of Benneker L. et al. “A novel multiple-trauma CT-scanning protocol using patient repositioning may increase risks of iatrogenic injuries”
Full text linkGoing 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
Thrombectomy of calcified emboli in stroke. Does histology of thrombi influence the effectiveness of thrombectomy?
No full textBACKGROUND AND PURPOSE
Thrombus composition has been postulated to affect the success of endovascular therapy. Calcified clots are composed of large amounts of calcium phosphate which influences their mechanical properties and may serve as a model for testing this hypothesis. The aim of this study was to evaluate the recanalization and complication rates of calcified thromboemboli in patients with acute ischemic stroke who underwent thrombectomy.
MATERIAL AND METHODS
A retrospective analysis was performed of all calcified intracranial thromboemboli in patients suffering an acute ischemic stroke, referred for endovascular therapy at two centers between January 2013 and July 2016.
RESULTS
Eight patients with a calcified intracranial clot underwent stent retriever thrombectomy (five women; mean age 80 years). Mean clot attenuation was 305 HU (range 150-640 HU). Successful reperfusion defined, as Thrombolysis in Cerebral Infarction grade 2b-3 was achieved in only one patient (12.5%). Two periprocedural adverse events occurred: one peripheral vessel perforation which was coiled and one inadvertent stent retriever detachment due to fracture of the stent retriever wire.
CONCLUSION
Stent retriever thrombectomy of calcified thromboemboli seems less effective than with other types of clots. Different mechanical properties of calcified clots may render them stiffer and less accessible for stent retrievers. When faced with a calcified intracranial thromboembolus in clinical practice, a more contained approach may be warranted in view of low recanalization rates, and the potential for periprocedural adverse events
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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