1,720,963 research outputs found
A Case of Foramen Magnum and C1–C2 Meningiomas: Double Challenge, One Approach
No full textObjectives We present a challenging case of a 61-year-old male patient with a double meningioma. The first one was located on the right side of foramen magnum and the second one was located on left anterolateral side of C1–C2. Background Patient referred at our institution for a progressive spastic paraparesis from approximately 1 year with a recent onset of numbness in right hand. Neuroradiological imaging showed an extra-axial enhancing tumor with a dural tail on the right border of foramen magnum and another contralateral extra-axial enhancing lesion at C1–C2 level (►Fig. 1). Results We have chosen a park bench position. Neurophysiological monitoring was used during both positioning and surgery. A linear skin incision in the occipital region extended to C7 was performed and a suboccipital craniotomy with the laminectomy of C1–C3 was performed (►Fig. 2). Videofluroangiography was performed to the best visualization of the vertebral artery position during microsurgical dissection and exposure of craniovertebral junction region. An Y-shape dural opening was executed and two meningiomas was resected with the classical four D steps (devascularize, detach, debulking, and dissect). All anatomical structures were respected and there were no changes at neuromonitoring. Patient was discharged after 10 days in good neurological condition. Conclusion a single approach for multiple meningiomas of the craniovertebral junction and upper cervical spine region is feasible and effective. Videofluoroangiography as a way to achieve better visualization and control of the vertebral artery, and neurophysiological monitoring are crucial tools to reduce the morbidity of this surgical challenge. The link to the video can be found at: https://youtu.be/4w9HCfQZkgg
Thalamomesencephalic cavernoma: anterior transcallosal transchoroidal approach
No full textWe present a case of a 62-year-old man with acute onset of diplopia, headache, and vomiting for a bleeding thalamomesencephalic cavernoma. The lesion was removed via the anterior transcallosal transchoroidal approach. His head was slightly flexed and a right paramedian craniotomy for an interhemispheric approach was performed. The interhemispheric fissure was split and, after callosotomy, the choroidal fissure was opened along the tenia fornicis to enter the velum interpositum and enlarge the foramen of Monro. The cavernoma was then identified and resected. There were no long-term postoperative neurological deficits. This approach is a valid alternative for thalamomesencephalic lesions. The video can be found here: https://youtu.be/DJdorbzDnH0
Pros and cons of a minimally invasive percutaneous subdural drainage system for evacuation of chronic subdural hematoma under local anesthesia
No full textObjective: Chronic subdural hematoma (CSH) is a common neurosurgical disease among elderly population with concomitant degenerative neurological disorders. This is a retrospective series-control analysis of prospectively collected data, aiming to show advantages and indications of a minimally invasive, percutaneous drainage system for CSH. Patients and methods: We retrospectively analyse the clinical and radiological data of a minimally invasive, percutaneous draining system (Integra TM) used in fifteen patients (Group A; mean age: 75.7) with CSH, and compare them with those obtained from two retrospective series of patients: the first one (Group B 15 patients, mean age 77.1) treated with standard, single-burr hole technique for subdural drainage under general anaesthesia; the second one (Group C 15 patients, mean age 76.4) treated with standard, single-burr hole technique for subdural drainage under local anaesthesia and mild sedation. All The percutaneous procedures (Group A) were performed under local anaesthesia. Results: Mean follow-up was 10.9 (range 3–14), 18.2 (range 10–29) and 15.2 (range 8–28) months in Group A, B and C respectively. Three of 15 and in Group B experienced a worsening of pre-existing neurodegenerative disorders after general anaesthesia. One patient in group C suffering from Parkinson's disease experienced a worsening of gait disturbances. Post-operative CT scans were performed at 48 h and 21 days after the operation. An early post-operative CT-scan, obtained immediately after surgical procedure, was performed in all Group A patients. No differences in CSH evacuation were observed comparing the three groups. Two recurrent hematomas, one in group A and one in group B, required revision. Post-operative hospitalization was similar (5.1 vs 5.7 vs 5.6 days, respectively, in group A, B and C) but analgesics use was lower in Group A. Conclusion: Pre-operative evaluation of radiological features of CSDHs is crucial in determining the right indication for a minimally invasive drainage. Minimally invasive treatments of CSH may reduce the use of anaesthetic drugs and worsening of pre-existing neurodegenerative disorders
Brain abscess after percutaneous therapy for trigeminal neuralgia
Full text linkWe report a case of brain abscess following the percutaneous treatment for trigeminal neuralgia. This procedure envisages the access with a needle into the middle cranial fossa through the oral cavity. Thus, in this case, the bacterial infection can be more likely ascribed to the possible contamination of the needle inside the oral cavity rather than to other frequent and more controllable causes of infection like an imperfect sterilization of surgical instruments or an inadequate antiseptic preparation of both operator's hands and patient's skin. The subsequent brain abscess was treated with antibiotic therapy (Vancomycin 2 gr a day and Meropenem 8 g a day for 22 days before the surgical procedure and 30 days after, until complete normalization of laboratory parameters, clinical parameters, and neurological symptoms) and surgical drainage, although the culture of the abscess capsule and the purulent material resulted sterile. In conclusion, the percutaneous therapy for trigeminal neuralgia can be objectively related to risks, even if performed by expert hands. Therefore, it is important that the patient should be advised regarding risks/benefits and/or septic complications of such procedures, even if they occur very seldom. An association of surgery and antibiotic therapy results as effective treatment for this pathologic condition
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
Supramarginal resection of glioblastoma: 5-ALA fluorescence, combined intraoperative strategies and correlation with survival
No full textINTRODUCTION: Glioblastoma treatment requires a multidisciplinary approach involving oncologists, radiotherapists and surgeons. Surgery constitutes the initial step of the therapeutic strategy and its efficacy is dependent on the extent of resection (EOR). Over the last decade, the goal of surgical treatment was the resection of the contrast enhancement on T1 MRI, defined as gross-total resection (GTR). More recently, an increasing number of studies reports a positive impact on survival parameters of a more aggressive surgical strategy aiming to resect all peritumoral infiltrated areas. These areas are histologically characterized by the presence of pathological cells infiltrating normal white matter and surround the neoplastic core of glioblastoma identified by gadolinium enhancement in T1-weighted MR. Intuitively, the major risk of the so called supramarginal resection is related to the possibility of resecting functionally eloquent brain tissue. Several strategies have been proposed to maximize the safety of resection and minimize the occurrence of postoperative functional deficits. The aim of this review was to focus on the clinical impact of supramarginal resection of glioblastomas, highlighting the role of image-guided surgery combined with neuromonitoring to increase surgical safety and efficacy. EVIDENCE ACQUISITION: The MEDLINE database has been queried for the literature research. EVIDENCE SYNTHESIS: Ten studies matched the inclusion criteria, reporting a global number of 3221 patients. CONCLUSIONS: The current evidence suggests a positive correlation between a more extensive resection based on FLAIR abnormal areas and overall survival
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
- …
