1,721,003 research outputs found
Tubular resection of a deep-seated motor cortex lesion: an illustrative clinical case
No full textResumen no disponibleFil: Revuelta Barbero, Juan M. Ohio State University; Estados Unidos.Fil: Yanez-Siller, Juan C. Ohio State University; Estados Unidos.Fil: Villalonga, Juan Francisco. Fleni. Departamento de Neurocirugía; Argentina.Fil: Prevedello, Daniel M. Ohio State University; Estados Unidos
Injury of the Internal Carotid Artery During Endoscopic Skull Base Surgery: Prevention and Management Protocol
No full textInjury of the internal carotid artery during endoscopic endonasal skull base surgery is a feared and perilous scenario. This article discusses perioperative strategies to prevent or manage an internal carotid artery injury to optimize outcomes. Meticulous preoperative planning is crucial in preventing its occurrence and minimizing its consequences. An effective plan of action relies on a well-prepared protocol, availability of proper instruments and devices, and an experienced multidisciplinary team. Intraoperative control of hemorrhage and stabilization of the patient's cardiovascular status is followed by an angiography and endovascular treatment whenever possible. Close clinical and radiologic monitoring of the patient prevents early and late complications
Brief history of endoscopic transsphenoidal surgery--from Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery
No full textSince its inception, one of the major issues in transsphenoidal surgery has been the adequate visualization of anatomical structures. As transsphenoidal surgery evolved, technical advancements improved the surgical view of the operative field and the orientation. The operating microscope replaced Cushing's headlight and Dott's lighted speculum retractor, and fluoroscopy provided intraoperative imaging. These advances led to the modern concept of microsurgical transsphenoidal procedures in the early 1970s. For the past 30 years the endoscope has been used for the treatment of diseases of the sinus and, more recently, in the surgical treatment of pituitary tumors. The collaboration between neurological and otorhinolaryngological surgeons has led to the development of novel surgical procedures for the treatment of various pathological conditions in the skull base. In this paper the authors review the history of the endoscope--its technical development and its application--from the first endoscope described by Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery held in 2005 in Pittsburgh, Pennsylvania. Specifically, in this review the history of endoscopy and its application in endonasal neurosurgery are presented
Brain Herniation After Endoscopic Transnasal Resection of Anterior Skull Base Malignancies
No full textBACKGROUND:
Endoscopic endonasal approaches, when appropriate, allow a less invasive method to remove anterior skull base cancer than traditional external transfacial/craniofacial approaches. The resultant skull base defect can be significantly large, potentially extending from the posterior table of the frontal sinus to the tuberculum sellae in the sagittal plane, and from one lamina papyracea to the other in the coronal plane. However, frontal lobe herniation after such expanded endoscopic resection has been considered more of a theoretical than a practical occurrence.
OBJECTIVE:
To report the occurrence of frontal lobe herniation into the sinonasal cavity after expanded endonasal approaches, and to analyze causes and pathogenetic mechanisms of this unusual complication, proposing how it could have been prevented.
METHODS:
Two cases have been observed in 2 different skull base referral centers in the United States and Italy. Surgical and perioperative complications, postoperative course, and need for revisions were analyzed.
RESULTS:
Available data support the hypothesis that this complication is not attributable to the size of the anterior skull base defect, to the surgical technique, or to the materials used for the reconstruction. We found that 1 possible contributing factor may be the presence of increased intracranial pressure associated with obesity and obstructive sleep apnea, observed in both patients.
CONCLUSION:
Frontal lobe herniation must be considered as a possible, albeit rare, complication of expanded endoscopic anterior skull base resection. Preoperative investigations concerning the presence of obstructive sleep symptoms as well as proper identification of neuroimaging signs of intracranial hypertension are recommended for such cases
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
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