1,721,070 research outputs found
Day surgery awake craniotomy for removing brain tumours: technical note describing a simple protocol.
No full textDay surgery awake craniotomy has been recently proposed for patients harbouring supratentorial brain tumours. This technique has been demonstrated to be safe and effective in a large cohort of patients operated by one neurosurgeon at the University of Toronto. The aim of this paper is to present a technical description of the protocol that has been adopted for these patients and a discussion of relevant practical issues which may arise. In particular, patient eligibility criteria are briefly discussed and intra- and post-operative management are presented. Key messages for those who are going to start to perform day surgery awake craniotomies include the preparation of a fast, simple and standardized protocol for the treatment of these patients and cooperation among patients and their care-givers (surgeon, anesthetist, nurses, family members)
Combined Use of DES, EMG and MEP Monitoring, ECoG and EEG for Surgical Resection of Gliomas
No full textSurgery for gliomas aims to remove as much of the tumour mass as possible while at the same time preserving the patient’s functional integrity. This policy particularly applies to resection of gliomas located close to or within the so-called ‘eloquent’ areas, i.e. areas that are involved in motor, language or visuospatial functions. In these cases, extended resection and maximal functional integrity can be achieved by using a cohort of procedures that make up the so-called brain-mapping techniques. These include neuropsychological evaluation, imaging techniques such as functional magnetic resonance imaging (fMRI) and diffusion tensor imaging–fibre tracking (DTI-FT) – generally loaded into the neuronavigation system so as to be available peri-operatively – and a series of neurophysiological techniques available at the time of surgery such as cortical and subcortical direct electrical stimulation (DES), motor-evoked potentials (MEPs), multichannel electromyogram (EMG), electroencephalogram (EEG) and electrocorticogram (ECoG) recordings. In this article we will focus on these neurophysiological adjuncts by describing the protocol in use at our institution for resection of gliomas, and by discussing the rationale and indications for and the results of our experience
Anterior cranial base reconstruction following a complicated nasal septoplasty
No full textWe present a 29 year old man who had unilateral visual loss and 3rd cranial nerve palsy after a nasal septoplasty. Nasal packing was extending from the right nasal cavity into the right frontal lobe passing through the right orbit. A combined trans-cranial and endoscopic endonasal approach was performed to safely remove the nasal packing and to achieve a leak-proof sealing of the anterior cranial base. This surgical technique proved successful in the management of this unique complication and should be considered in the surgical management of foreign body removal from the anterior cranial base
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
Surgery for clival lesions: open resection versus the expanded endoscopic endonasal approach.
No full textObject: Clival lesions pose significant challenges with regard to their surgical management. The expanded endoscopic endonasal (EEE) approach is a promising minimally invasive technique for lesions of the central skull base. The authors' aim in the current paper was to discuss the surgical treatment of clival lesions and to present the technical details, indications, and limitations of the EEE approach. Data from a recent endoscopically treated group will be compared with findings in a previous cohort of patients treated via classic open anterior and lateral approaches. Methods: Since June 2005, 17 patients with clival lesions underwent surgery via the EEE approach. Suitable candidates were chosen according to lesion characteristics, clinical parameters, and surgical goals. Neurological outcomes, Karnofsky Performance Scale scores, the extent of lesion resection, and complications were evaluated among these patients. Eighteen percent of the patients in the endoscopic group presented with recurrent disease. Another series of 43 patients, who had undergone resection of clival lesions via an anterior (rhinotomy, maxillectomy, microscopic transsphenoidal surgery, or transoral surgery) or lateral (pterional, frontoorbitozygomatic, or combined suprainfratentorial retrosigmoid) approach, was similarly reviewed. Twenty-three of these patients (53%) presented with recurrent disease and thus had undergone prior surgery. Results: Following the EEE approach, 11 (79%) of 14 patients who had presented with neurological symptoms experienced improvement, and gross-total resection was achieved in 59% of the patients and subtotal removal in 41%. Complications included CSF leakage (24%), tension pneumocephalus (6%), and intracranial hematoma (6%). The patient with the latter complication was the only one who experienced permanent neurological worsening. In the open resection group, neurological worsening occurred in 33% of the patients (14 of 43). Total and grosstotal removals were achieved in 84% of patients and subtotal removal in 14%. Conclusions: The EEE approach has been shown to be a safe and effective technique for the resection of clival lesions with limited lateral extension. The choice of surgical approach must be tailored according to both patient and tumor characteristics. Although the 2 patient series featured in this paper are not comparable-because of a selection bias-higher rates of neurological morbidity and total and gross-total resections were observed in the open resection group. Given the long survival of some patients, the EEE approach should be favored whenever reasonable
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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