1,720,967 research outputs found
Sudden post-traumatic sciatica caused by a thoracic spinal meningioma
Spinal meningiomas usually present with slowly progressive symptoms of cord and root compression, while a sudden clinical onset is very rare. A 35-year-old previously symptom-free woman presented sudden right sciatica and weakness of her right leg following a fall with impact to her left foot. A neurological examination showed paresis of the right quadriceps, tibial and sural muscles, increased bilateral knee and ankle reflexes and positive Babinski sign. Magnetic resonance imaging (MRI) revealed the presence of a spinal T11 meningioma in the left postero-lateral compartment of the spinal canal; at this level, the spinal cord was displaced to the contralateral side with the conus in the normal position. At surgery, a meningioma with dural attachment of the left postero-lateral dural surface was removed. The intervention resulted in rapid remission of both pain and neurological deficits. Spinal meningiomas may exceptionally present with sudden pain and neurological deficits as result of tumour bleeding or post-traumatic injury of the already compressed nervous structures, both in normal patients and in those with conus displacement or tethered cord. In this case, the traumatic impact of the left foot was transmitted to the spine, resulting in stretching of the already compressed cord and of the contralateral lombosacral roots. This case suggests that low thoracic cord compression should be suspected in patients with post-traumatic radicular leg pain with normal lumbar spine MRI
Reconstruction of artery wall in experimental giant aneurysms
AIM: This study describes five experimental techniques for the surgical treatment of giant aneurysms based on the resection of the aneurysm sac and reconstruction of the arterial wall.
METHODS: The aneurysm was realized with a venous graft implanted with end-to-side anastomosis on the common carotid artery on 50 rabbits (with each technique realized in 10 rabbits). The first two experimental techniques (A and B) involve the reconstruction of the artery wall by a synthetic dural patch and by direct suture reinforced by a venous patch, respectively. In the model C a collateral branch arising from the aneurysm is resected and reimplanted on the parent artery after aneurysm resection. In the experimental model D the arterial defect is closed by a venous patch surrounding the whole arterial wall and sutured with the aid of fibrin glue. In the model E clamping of the parent artery proximal to the aneurysm site and termino-lateral anastomosis with the contralateral artery lead to the thrombosis of the aneurysm fulled only by refluent flow.
RESULTS AND CONCLUSION: The venous pouch experimental models are useful to realize giant aneurysms. The above described techniques allow to realize the reconstruction of the arterial wall without stenosis and shortening the clamping time
From the Champion to the Team: New Treatment Paradigms in Contemporary Neurosurgery
: In our discipline, neurosurgery, the role of the leader has evolved and has been complemented by the collaboration of specific professionals of different disciplines, aiming at the overall result of curing people and defeating the disease. Indeed, the multidisciplinary cooperation and the innovative strength of a team composed of different specialists such as radiologists, anesthesiologists, pathologists, molecular biologists, geneticists, oncologists, psychologists, physiatrists, physiotherapists, neurologists, engineers, mathematics, statisticians, and economists, greatly has changed the way we see the patient and treat pathology: from a single to multiperspective vision, thus generating a synergy that improves the surgeon's and the overall work. An old African adage goes like this: "If you want to go fast, go alone. if you want to go far, go together," which in our opinion fully summarizes the sense of our contribution on the state of the art in neurosurgical contemporary practice
Influence of nutritional status on the clinical outcome of patients with chronic subdural hematoma: a prospective multicenter clinical study
Background: Elderly patients present a higher risk of developing chronic subdural hematomas (CSDHs) together with increased risk of malnutrition. The nutritional status may affect outcomes, response to treatments, and prognosis. Influence on other kinds of diseases was investigated showing an increased risk of mortality, morbidity, and adverse outcomes. However, no studies are available on its possible role for the outcome of patients with CSDH. This study aims to evaluate a possible relationship between the nutritional status and the clinical outcome of patients who underwent CSDH surgery. Methods: This is a multicenter prospective study enrolling all patients treated for CSDH. Demographic and clinical data were collected. For nutritional status evaluation, we used the Mini Nutritional Assessment (MNA). Chi-square test was used for comparing clinical variables of patients and logistic regression analysis was used for defining the impact of the aforementioned variables on the clinical outcome. Results: We enrolled 178 patients. Modified Rankin scale (mRS) was 0-2 pre-operatively in 23.6% of patients and post-operatively in 61.2% of patients. Total assessment MNA score was >23.5 in 47.8% of patients. Ninety-three patients (52.2%) presented a normal nutritional status, 63 (35.4%) were at risk of malnutrition and 22 (12.4%) were malnourished. The mean follow-up was 2.6 months. Malnourished patients were at higher risk of a worse outcome (OR 81; CI = 9-750). Conclusion: This study suggests that nutritional status represents a strong predictor of outcome. Our results, albeit preliminary, demonstrated malnutrition is correlated to the risk of worse clinical outcome for patients undergoing surgery for chronic subdural hematoma. Further investigations with wider casuistry and multiple nutritional scores are required to validate our data
Expression of p40 (∆Np63) protein in meningiomas, an unexpected finding: immunohistochemical study and evaluation of its possible prognostic role
According to the 2007 WHO (World Health Organization) Classification, meningiomas are divided into three grades of malignancy, with different recurrence rate, based exclusively on histopathological parameters. Loss/reduction of PgR (Progesterone Receptor) expression and increased Ki67 L.I. (Labeling Index) have been proven as possible prognostic factors able to predict the relapse of the disease. However, they sometimes result unreliable, especially when discordant. p40 is the short form of the p53 homologue gene p63, also named ∆Np63, and its antibody has recently been introduced as a highly specific diagnostic marker of the squamous cell carcinoma of the lung. Nevertheless its expression has been found in many other unconventional sites (e.g. placenta, urotheluim, etc). Herein we assessed the immuno-expression of p40 protein in a series of 72 meningiomas (35 grade I and 37 grade II) and analyzed its correlation with clinicopathological parameters, overall survival and recurrence free interval. We found that a high p40 score correlated with high histological grade, presence of recurrence, increased Ki67 L.I. and loss/reduction of PgR signal. Moreover, a higher expression of p40 was shown to be a significant prognostic factor for the development of recurrences and resulted a prognostic independent variable in multivariate analysis. Overall, for the first time, we investigated the expression of p40 protein in meningiomas and explored its usefulness as prognostic marker in addition to PgR and Ki67 L.I
Parasellar Schwannomas: Extradural vs Extra-Intradural Surgical Approach
Schwannomas of the parasellar region may arise from the trigeminal, oculomotor, trochlear, and abducens nerves
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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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