1,720,972 research outputs found
Intramedullary epidermoid cyst: preoperative diagnosis and surgical management after MRI introduction. Case report and updating of the literature.
No full textMany patients with spinal tumours of developmental origin do not receive preoperative diagnosis and the surgical management, especially as for capsule resection, is often unplanned. Like other uncommon tumours, the intramedullary epidermoid cyst is often an operative or histological finding. Since magnetic resonance imaging (MRI) introduction, evidence has accumulated that they may be preoperatively suspected. In reporting the case of a young patient with a T3-T4 intramedullary epidermoid cyst, the authors present an overview of the clinical, radiological and surgical aspects of such tumors and review the latest literature in which MRI and microsurgical excision were performed. Despite the introduction of new diagnostic and surgical instrumentation, the preoperative diagnosis and surgical management of such tumours need further discussion
Acute brainstem dissection of syringomyelia associated with cervical intramedullary neurinoma.
No full textAbstract Intramedullary tumors and syringomyelia typically
present with slowly progressing deficits. More rarely,
they are characterized by acute presentation or worsening,
at timesmimicking othermore common etiologies. The acute
onset of syringomyelia is most likely attributable to an acute
increase in cerebrospinal fluid and epidural venous pressure
that results in impulsive fluid movement and, ultimately, in
the rupture of the syrinx and dissection into the spinal cord
or brainstem. Reported here is a case of acute presentation
of a small cervical intramedullary neurinoma due to the upward
dissection of its associated syrinx. Critical questions
are: (1) how can a small tumor produce a large syrinx? and
(2) in the absence of craniospinal interferences, which mechanismunderlies
the acute expansion of the cavity, resulting in
a rapid onset? The authors examined the pathophysiology of
syrinx formation and enlargement in intramedullary tumors
and reviewed the literature, emphasizing the relationship
between spinal cordmovements and intramedullary pressure.
On the basis of current pathogenetic concepts, the authors
concluded that tumor-related syringomyelia might be caused
by an association of mechanisms, both from within (obstruction
of perivascular spaces; increase in extracellular fluid
viscosity due to the tumor itself; intramedullary pressure
gradients among different cord levels and between the cord
and the subarachnoid space) and from without (the cerebrospinal
fluid entering the tissue). All these factors may be
amplified, as in the reported case, by a tumor located dorsally
at the cervical level.Abnormal postures of the spine, such as a
prolonged and excessive flexed neck position,may ultimately
contribute to the acute dissection of the syrinx.
Keywords Acute presentation . Intramedullary
neurinoma . Intramedullary tumors . Syringobulbia .
Syringomyeli
Multibody modelling of the cervical spine in the simulation of flexion-extension after disc arthroplasty
No full text
Epidermoid and dermoid tumors
No full textThe authors report their experience in the surgical treatment of intracranial dermoid and epidermoid tumors. These lesions are rare but may, in most of the occasions, be completely resected allowing a complete cure of the patient. The usefulness of the most recent diagnostic tools is discussed and the surgical indications, complications and results are reviewed in comparison to the most significant literature reports
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
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