1,720,962 research outputs found
Nerve origin of vestibular schwannoma: a prospective study.
No full textOBJECTIVE:
The origin of vestibular schwannoma has always been a matter of debate. The aim of our study was to identify the nerve origin of this tumour.
STUDY DESIGN:
Prospective case review. This study was conducted at Gruppo Otologico, a private referral centre for neurotology and skull base surgery.
METHODS:
A total of 200 cases of vestibular schwannoma were included in the study. All the tumours were removed surgically utilising the translabyrinthine approach. The origin of the tumour was sought at the fundus of the internal auditory canal.
RESULTS:
A total of 200 consecutive cases was included in the study. The origin of the tumour was limited to one nerve at the fundus in 152 cases (76 per cent). Out of these cases, the tumour originated from the inferior vestibular nerve in 139 cases (91.4 per cent), from the superior vestibular nerve in nine cases (6 per cent), from the cochlear nerve in two cases (1.3 per cent) and from the facial nerve in two cases (1.3 per cent).
CONCLUSION:
The vast majority of vestibular schwannomas originate from the inferior vestibular nerve; the incidence of involvement of this nerve increases as the tumour size increases. An origin of vestibular schwannoma from the inferior vestibular nerve can be considered as one of the explanatory factors for the poor functional outcome of the extended middle cranial fossa approach, and probably accounts also for the better hearing preservation rate reported in some series for the retrosigmoid approach
Giant hypervascular lesion of the sinonasal tract invading the anterior skull base and orbit: a puzzling case.
No full textAuditory brainstem implant in a child with severely ossified cochlea.
No full textOBJECTIVE:
The hearing outcome after implanting a severely ossified cochlea has always been less satisfactory than implanting a patent one. The aim of our study is to present a case where brainstem implantation was successfully performed as an alternative to cochlear implantation in a child with bilateral severe ossification of the cochlea.
STUDY DESIGN:
Case presentation. This study was conducted at Gruppo Otologico, Rome, Italy, a private referral center for neurotology and skull base surgery.
METHODS:
The subject of our study was a 12-year-old female child with postmeningitic deafness and bilaterally ossified cochleae. This case is the first brainstem implantation performed at our center with the indication of severe ossification of the cochlea.
RESULTS:
Successful brainstem implantation of a device was carried out, and the hearing of the patient was restored to the degree that she can freely use the telephone after 8 months of implantation.
CONCLUSION:
Although more cases are needed before establishing the exact outcome of brainstem implantation in cases of deafness in the presence of severe bilateral cochlear ossification, preliminary results show the superiority of brainstem implants to conventional or even customized cochlear implants
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
Endoscopic surgery for malignant tumors of the sinonasal tract and adjacent skull base: a 10-year experience.
No full textBACKGROUND:
The increasing expertise in the field of transnasal endoscopic surgery recently has expanded its indications to include the management of sinonasal malignancies. We report our experience with the endoscopic management of nasoethmoidal malignancies possibly involving the adjacent skull base.
METHODS:
A retrospective analysis was performed of patients treated by an exclusive endoscopic approach (EEA) or a cranioendoscopic approach (CEA) from 1996 to 2006 managed by two surgical teams at the Departments of Otorhinolaryngology of the University of Brescia, and the University of Pavia/Insubria-Varese, Italy.
RESULTS:
One-hundred eighty-four patients were considered eligible for the present analysis. An EEA was performed in 134 patients and the remaining 50 patients underwent the CEA. The most frequent histotypes encountered were adenocarcinoma (37%), squamous cell carcinoma (13.6%), olfactory neuroblastoma (12%), mucosal melanoma (9.2%), and adenoid cystic carcinoma (7.1%). Overall, 86 (46.7%) patients received some form of adjuvant treatment. The patients were followed up for a mean of 34.1 months (range, 2-123 months). The 5-year disease-specific survival was 91.4 +/- 3.9% and 58.8 +/- 8.6% (p = 0.0004) for the EEA and CEA group, respectively.
CONCLUSION:
To the best of our knowledge, this is the largest series reported to date of malignant tumors of the sinonasal tract and adjacent skull base treated with pure endoscopic or cranioendoscopic techniques. A 5-year disease-specific survival of 91.4% and 58.8% for the EEA and the CEA groups, respectively, seem to indicate that endoscopic surgery, when properly planned and in expert hands, may be a valid alternative to standard surgical approaches for the management of malignancies of the sinonasal tract
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