1,720,959 research outputs found
Management of calcified thoracic disc herniation using ultrasonic bone curette SONO-PET®: technical description.
No full textThis paper describes the surgical management of a post-traumatic calcified thoracic disc herniation treated using ultrasonic bone curette SONO-PET®. The case described concerns a young man with a symptomatic calcified thoracic disc herniation, who underwent posterolateral approach and transversoarthropediculectomy. Patient underwent posterolateral approach with excellent postoperative results. Neurophysiological monitoring somato-sensory evoked potential (SSEP) and muscle motor evoked potentials (MMEP), inclination of 30° toward the unaffected side of the operating table, the use of Ultrasonic Bone-Curette SONO-PET® and proper reconstruction of the three floors of the back muscles allows the removal of the disc herniation safer and risk's free, and less invasive for the patient
Post-traumatic Collet-Sicard syndrome: personal observation and review of the pertinent literature with clinical, radiologic and anatomic considerations
No full textStudy design The lesion of the lower four cranial nerves,
commonly called Collet–Sicard syndrome, can be caused
by a blunt head and neck trauma. It may be associated to an
isolated fracture of the occipital condyle or of the atlas.
Objective The aim of this report is to assess the modality
of the trauma, the type of fracture, the anatomic characteristics,
the treatment and clinical results of this syndrome.
Summary of background data We discuss 14 cases of
fracture of occipital condyle and of atlas and 1 personal
case.
Methods We analyzed 14 cases collected from the literature
between 1925 and 2013, reported a further personal
case and performed an anatomical study of the paracondylar,
atlas and styloid process region. The anatomical
dissection was performed to assess the anatomic relationships
in the site of transit in which the nerves IX, X, XI and
XII are injured.
Results A total of 14 cases of p-CSS were collected: 9
caused by a condyle fracture and 5 by an atlas fracture. The
patients were 13 males and only 1 female, 10 of them had a
blunt trauma due to the result of axial loading (force directed
through the top of the head and through the spine) falling on
the head. The nine cases with a condyle fracture were
associated to the dislocation of part of it, while those with
atlas fractures showed the fracture and/or disjunction of the articular mass. The anatomical evaluations reveal that the
lower four cranial nerves, at their emergency, pass through a
close osteo-ligamentous space in relationship to the condyle.
Below they run through a little wider channel between the
articular mass of C1 and the styloid process. Two cases
underwent surgical procedure. All the other cases were
treated conservatively with immobilization of the cervical
spine. During follow-up three cases with condylar fractures
were found to be clinically unchanged and six showed
modest improvements while one case with atlas fracture had
a complete recovery and four improved significantly.
Conclusions The p-CSS is caused by force directed through
the top of the head.Wesuppose that the nerve injuries are due
to their laceration caused by a displacement of a condyle
fragment or to their compression and stretching when they
pass between the lateral mass of the atlas and the styloid
process. Thesemodalities of traumaexplain the better clinical
results in patients affected by C1 fractures. Conservative
treatment is the option of choice. Surgical option, when
choosed, is not considered to fix nerve damages
First description of cervical intradural thymoma metastasis
Get PDFThymoma and thymic carcinoma are rare epithelial tumors, which originate from the thymus gland. According to the World Health Organization there are "organotypic" (types A, AB, B1, B2, and B3) and "non-organotypic" (thymic carcinomas) thymomas. Type B3 thymomas are aggressive tumors, which can metastasize. Due to the rarity of these lesions, only 7 cases of extradural metastasis are described in the literature. We report the first and unique case of a man with cervical intradural B3 thymoma metastasis. A 46-year-old man underwent thymoma surgical removal. The year after the procedure he was treated for a parietal pleura metastasis. In 2006 he underwent cervical-dorsal extradural metastasis removal and C5-Th1 stabilization. Seven years after he came to our observation complaining left cervicobrachialgia and a reduction of strength of the left arm. He underwent a cervical spine magnetic resonance imaging, which showed a new lesion at the C5-C7 level. The patient underwent a surgery for the intradural B3 thymoma metastasis. Neurological symptoms improved although the removal was subtotal. He went through postoperative radiation therapy with further mass reduction. Spinal metastases are extremely rare. To date, only 7 cases of spinal extradural metastasis have been described in the literature. This is the first case of spinal intradural metastasis. Early individuation of these tumors and surgical treatment improve neurological outcome in patients with spinal cord compression. A multimodal treatment including neoadjuvant chemotherapy, surgery and postoperative radiation therapy seems to improve survival in patients with metastatic thymoma
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Quality of Life After Craniovertebral Junction Meningioma Resection: Shaping the Real Neurologic and Functional Expectancies About These Surgeries in a Contemporary Large Multicenter Experience
No full textObjective: Craniovertebral junction (CVJ) meningiomas are one of the most surgically complex conditions in neuro-oncologic surgery. The aim of this work is to correlate our data with clinical outcome to outline factors leading to a worse functional prognosis. Methods: We analyzed sex, age, clinical presentation, topography, surgical approach, Simpson grade resection, postoperative lower cranial nerve deficits, consistency, histology, site of origin, presence of a capsule, and radiologic and clinical follow-up at 1, 6, and 12 months of 61 patients affected by CVJ meningiomas, operated on in our institution from 1992 to 2014. Results: 78.7% of patients were women (mean age, 52.85 years); the onset symptom was pain in 65.5% of cases. The mean preoperative Nurick grade of the sample was 3.78; the most frequent histologic type was endotheliomatous (42.8%). We treated 22 patients with a posterior median approach (5 with lateral and 17 with posterolateral axial topography); in 39 cases (30 anterolateral and 9 anterior) we performed a posterolateral approach. Gross total removal was achieved in 85.2% of cases. We recorded a final follow-up step overall neurologic improvement in the cohort (average preoperative Nurick grade, 3.81, and at 12 months, 2.13). Twenty-nine patients presented with lower cranial nerve deficit (permanent or transient) and no statistically significant association was found between surgical approach and temporary or permanent postoperative complications. Conclusions: We selected, in our experience, some predictors of worse outcome: preoperative sphincter impairment, absence of a capsule, cranial site of origin, a poor preoperative functional status, and firm consistency of the tumor
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