1,721,058 research outputs found
Foramen rotundum approach with endoscopic transsinusoidal transpterygopalatine route in trigeminal neuralgia treatment
No full textFizyopatolojisi kesin olarak bilinmeyen trigeminal nevralji tedavisinde birçok yöntem denenmesine rağmen fikir birliği sağlanmış bir seçenek yoktur. Bu çalışma ile, ilaca dirençli trigeminal nevralji hastalığının cerrahi tedavisine minimal invaziv endoskopik yeni bir yaklaşım ortaya konması amaçlanmıştır. Endoskopik endonazal transmaksiller transptreygopalatin yolla, foramen rotunduma çevre vasküler ve nöral dokulara zarar vermeden ulaşılması için kraniometrik ölçümler yapılmış, nirengi noktaları belirlenmiştir. Bu nirengi noktaları ve bu noktaların foramen rotundum ile olan ilişkileri araştırılarak endoskopik yaklaşım ile güvenli ve hedefe yönelik minimal invaziv cerrahi alan oluşturmak amaçlanmıştır Bu çalışma Medipol Üniversitesi Tıp Fakültesi Anatomi Anabilim Dalın'da 5 adet fikse edilmemiş kadavra başı kullanılarak yapılmıştır. Bütün kadavralara aynı cerrahi prosedür uygulandı. İlk çalışılan kadavra başında pterigopalatin fossaya giriş noktasını tespit etmek amaçlı bilateral olarak subtemporal kraniotomi yapılarak ekstradural ilerlendi ve foramen rotundum bulundu. Foramen rotundumdan sitilet gönderilerek transnazal olarak ulaşacağımız nokta önceden teyit edildi. Endoskopik olarak transnazal olarak girildikten sonra sfeniod ostium bulundu duvarları teyit edildi. Posterior sfenoidotomi yapılarak optik protuberens, karotid protuberens ve sfenoid sinüs lateral duvarı ortaya konuldu. Orta konka medialize edildikten sonra maksiller sinüsün anterior duvarı açıldı. İlk kadavrada ekstradural olarak gönderilen sitilet tanınarak maksiller sinüsün posterior duvarı açıldı ve foramen rotundumun önceden belirlenen landmarklara uzaklıkları ölçüldü ve n. maksillarisin pozisyonu belirlendi. Daha sonraki kadavralarda sitilet kullanılmadan ölçümler tamamlandı. Yapılan ölçümler doğrultusunda sfenoid sinüs lateral duvarının maksiller sinüsün posterior duvarı arasındaki mesafe ortalama 4.32 mm SD : 1.29 mm olarak hesaplandı. Sfenopalatin arterin foramen rotundum ile arasındaki mesafe ortalama 3.7 mm SD: 0.81 mm olarak hesaplandı. Foramen rotundumun ölçülen çapları ortalaması 2.57 mm SD: 0.74 mm olarak bulundu. Pterigopalatin kanal – fissür ile foramen fotundum arasındaki ölçülen ortalama mesafe 1.36 mm SD: 0.47mm olarak saptandı. 2 Maksiller sinir çıkış pozisyonu olarak foramen rotundumun inferiolateralinde tespit edilmiştir. Çalışmamızda belirttiğimiz gibi, endoskopik endonazal transmaksiller transptreygopalatin yolla, foramen rotunduma ulaşılırken sfenoid sinüs lateral duvarı , sfenopalatin arter ve pterigopalatin kanal önemli kılavuz anatomik noktalardır. Bu çalışma ile gösterildiği üzere, foramen rotundum ortaya konduktan sonra maxiller sinir panoromik olarak vizüalize edilebilmekte ve maksiller sinir trasessi açıkça anlaşılmaktadır. Bu kadaverik çalışma amaçlanan yeni endoskopik cerrahi tedavilerin yöntemlerinin önünün açılmasıdır. Endoskopik taze kadavra çalışmaları yüksek deneyim ve cerrahi nosyon gerektirdiğinden bu alanda daha fazla çalışma yapılarak yaklaşımın geliştirilmesi ve klinikte uygulanmaya başlanması ile birlikte cerrahi prensipler yerine oturacaktır.Although many methods have been tried in the treatment of trigeminal neuralgia with unknown physiopathology, there is no consensus option. The aim of this study is to introduce a minimally invasive endoscopic approach to the surgical treatment of drug-resistant trigeminal neuralgia. By endoscopic endonasal transmaxillary transptreygopalatine route, craniometric measurements were performed to reach the foramen rotundum without damaging the surrounding vascular and neural tissues. Also the landmark points of this approach were determined. The aim of this study was to investigate the relationship between this landmark poinst and the foramen rotundum, and to provide a safe and targeted minimally invasive surgical field with endoscopic approach. This study was carried out with 5 fresh cadaver heads in Anatomy Laboratory of Medipol University Medical Faculty. The same surgical procedure was applied to all cadavers. In the first step of this study, a subtemporal craniotomy was performed bilaterally in order to determine the entry point of the pterygopalatine fossa. The transnasal approach was confirmed in advance by sending a stilet guide from the foramen rotundum. In second step of this study, with endoscopic transnazal approach found sfenoid ostium and confirmed the walls of the sfeniod ostium. Posterior sphenoidotomy performed to revealed optical protuberence, carotid protuberens and lateral wall of sphenoid sinus. After then middle turbinate medialized, and anterior wall of maxillary sinus was opened; the distances of the foramen rotundum to the predetermined landmark were measured and defined position of maxillar nerve. Other cadavers measurements were completed without the use of stilet guide. The distance between the posterior wall of the maxillary sinus and the lateral wall of the sphenoid sinus was calculated as approximately 4.32 mm SD: 1.29 mm. The distance between the sphenopalatine artery and the foramen rotundum was calculated as approximately 3.7 mm SD: 0.81 mm. The mean diameter of the foramen rotundum was 2.57 mm SD: 0.74 mm. The mean distance between the pterygopalatine channel - fissure and the foramen photundum was 1.36 mm SD: 0.47 mm. The maxillary nerve was identified in the inferolateral position of the foramen rotundum as the main exit position. 4 In our study we suggested; lateral wall of the sphenoid sinus, sphenopalatine artery and pterygopalatine canal are important anatomical landmarks while the foramen rotundum is reached with endoscopic endonasal transmaxillary transptreygopalatine approach. With this study has been demostrated, after the foramen rotundum was opened maxillary nerve was visiluated panaromic and its trajectory clearly understood. This cadaveric study was aimed attempts to open the front by a new endoscopic surgical treatments. As endoscopic fresh cadaveric studies require high experience and surgical notion, more studies in this area will be performed and the surgical principles will be put in place with the development of the approach and application in the clinic
Is external hydrocephalus a possible differential diagnosis when child abuse is suspected? Editorial
Get PDFThis is a retrospective review of 28 infants collected from two different countries and institutions whom their caregivers had been convicted of “child abuse.” The purpose, descriptions, and the conclusion are well accepted but the article as a whole is rather confusing for the general neurosurgical community. The authors speculate that the terms, “benign enlargement of the subarachnoid spaces (BESS)” and subdural collections are sometimes misdiagnosed leading serious medico-legal problems. Subdural collections represent various conditions which are used interchangeably such as subdural hygroma, chronical subdural hematoma, and external hydrocephaly
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
Surgical Methods in Epilepsy Surgery
No full textThe aim of epilepsy surgery is to eliminate or substantially decrease seizure frequency while avoiding additional neurological deficits and improving patients' quality of life. Today the most frequently applied surgical techniques include temporal lobe surgery, extratemporal neocortical resection, multilobar resection, hemispherectomy, lesionectomy, corpus callosotomy and multiple subpial transection. Information regarding indications, complications etc. of different techniques is provided in the text
Prognostic value of Ki-67 index in primary intracranial tumors of infants
No full textObjective Primary intracranial tumors are rare tumors in infants. They differ from those found in other pediatric age groups in terms of clinical presentation, histopathological diagnosis, adjuvant therapies, and outcome. Ki-67 index has also shown promising results as a prognostic factor in different types of intracranial tumors in children and adults. However, the importance and the best cutoff point of Ki-67 index in primary intracranial tumors of infants remains unclear. We aimed to analyze prognostic value of Ki-67 index in primary intracranial tumors of infants. Methods This study retrospectively reviewed the records of 28 infants undergoing surgical resection for primary intracranial tumors between April 2016 and March 2021. We analyzed clinical characteristics, tumor location, extent of resection, histopathological diagnosis, Ki-67 index, and overall survival (OS). To define the most relevant cutoff value for Ki-67 index, "Cutoff Finder " was used. Results The median age at diagnosis was 188 days for all patients. Fifteen of the patients were boys and 13 were girls. Tumors were located supratentorial in 13 patients and infratentorial in 15 patients. Gross total resection was performed in 7 of 13 supratentorial tumors and 9 of 15 infratentorial tumors. The mean Ki-67 index of the supratentorial tumors was 49.6%, the median was 55%; for infratentorial tumors, the mean was 49.9%, and the median was 70%. Tumor grade (p = 0.019) and Ki-67 index (p = 0.003) were found as significant predictors of OS in log-rank testing for Kaplan-Meier survival analysis. Univariate cox regression analysis identified high Ki-67 index as prognostic factor for worse OS, with hazard ratio of 8.852 (95% CI 1.95-64.80; p = 0.0108). High Ki-67 index was found as independent prognostic factor for worse OS in multivariate cox regression analysis (HR 7.036; 95% CI 1.229-65.82; p = 0.0457). Conclusion High-grade and high Ki-67 index were associated with worse outcome. Ki-67 index did show a distinct prognostic value for OS within our cohort at a cutoff value of 72.5%
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
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