1,720,957 research outputs found
Supratentorial embryonal tumors in the elderly: Diagnostic pitfalls and clinical prognosis
No full textSupratentorial embryonal tumors are very rare malignant tumors of neuroectodermal origin, characterized by an aggressive clinical behavior. They occur prevalently in children. They have been sporadically described in adults and represent an even rarer occurrence in elderly patients, raising many issues on the diagnostic pitfalls and their appropriate management. We present an unusual case of embryonal tumor in a 62-year-old man who presented with speech disorder, and partial deficit of the left 3rd and 5th cranial nerves secondary to a left temporo-insular embryonal tumor: the clinico-radiological features, histopathological insights, therapeutic options and results are discussed along with a review of the most relevant literature, addressing the specific issue of differential diagnosis and the expected results in the elderly population
L'influenza dell'ematoma sottodurale cronico nel decorso clinico del paziente con demenza
No full textChylous fistula: management of a rare complication following right anterior cervical spine approach
No full textPurposeChylorrhea resulting from injury of the lymphatic system during neck dissection is a well-known complication. It is an uncommon occurrence in spinal surgery, and only one case after right anterior cervical spine surgery has been described so far. Despite its rarity, chylous leakage deserves a particular attention since it may become a serious and occasionally fatal complication if not detected early and managed appropriately. MethodsWe report the case of a 42-year-old man who underwent a standard anterior cervical discectomy and fusion according to Cloward approach for a C6-C7 disk herniation. The patient developed a delayed prevertebral chyle collection on postoperative day 5, presenting with mild breathing and swallowing difficulties. ResultsHe was managed with conservative care, including bed rest, low-fat diet and drainage pouch positioning, which led to the complete resolution of the fluid collection.ConclusionsKnowledge of the normal anatomy of the lymphatic system and of its variations is essential when planning an anterior spinal procedure, and represents the first measure to be adopted in order to avoid such complication. The prompt identification of a postoperative chylous fistula and the applicability of an individually based management's protocol may help in the majority of the cases to reduce the potential morbidity, without significant long-term effects
Isolated subarachnoid hemorrhage after evacuation of chronic bilateral subdural hematoma: Case report and review of the literature
No full textBackground: Chronic subdural hematoma (CSDH) is frequently encountered in neurosurgical practice. Evacuation through one or two burr holes is the most common surgical treatment. Hemorrhagic complications such as acute subdural hematoma (ASDH) or intracerebral hemorrhage (ICH) has been reported as rare but severe complications. Nonetheless, isolated subarachnoid hemorrhage (SAH), developed after burr-hole evacuation of CSDH, without other hemorrhagic complications, is an extremely rare finding reported only in two previous reports. Case description: A 64 year's old man was referred to our department for mental confusion, disorientation, dizziness and walking disability. CT scans showed a bilateral fronto-parietal CSDH. He underwent bilateral parietal burr-hole craniectomy and subdural drainage positioning. The day after surgery, the patient developed intense headache and vomit and a CT scan revealed a SAH in the temporal and parietal lobe located in both hemispheres. A CT angiogram excluded the presence of intracranial aneurysms. The drainage systems were removed and the patient underwent conservative management with clinical improvement. He was discharged in day 7 without neurological deficits. The one-month follow-up showed the patient was in good conditions and the CT scan revealed complete resolution of the previous hemorrhagic findings. Conclusion: We suppose the rapid brain shift occurred during surgery was the main cause of development of SAH in our patient, but several possible pathological mechanisms are discussed. Although CSDH evacuation is considered a routinely procedure, neurosurgeons must be aware of this rare complication avoiding perioperative overdrainage of subdural hematomas
Current management of central nervous system metastasis from cholangiocarcinoma: the neurosurgical perspective. Literature review
No full textPurpose: Central nervous system (CNS) metastasis from cholangiocarcinoma (CCA) are extremely rare and associated prognosis is poor. The involvement of the CNS by metastatic CCA may discourage any further treatment; however, data from the literature are discordant, due to recent reports of exceptionally long follow-up after surgical resection of a brain metastasis. Material and Methods: Electronic databases, such as PubMed/MEDLINE and Google Scholar, were analyzed for studies published up to October 2018 using the search term "cholangiocarcinoma and central nervous system metastasis or brain metastasis". Results: We found a total of 18 studies cited in the literature of the 30 year span analyzed, and we added a new case we treated at our Institution, reaching a series of 32 patients. Among these, 7 patients had leptomeningeal dissemination and 25 presented solid CNS metastasis. We analyzed the treatment options and the outcomes, addressing also histopathological insights on tumoral markers possibly involved in the mechanism of metastases of cholangiocarcinomas Conclusions: According to the literature data, the outcome remains poor, particularly for those with leptomeningeal diffusion. Nevertheless, long term follow-up is reported in case of surgical resection of CNS metastasis, when there is a good control of the primary tumor. Actually, the majority of patients are often in advanced state of disease at diagnosis and not suitable for initial resective procedure; in these cases neo adjuvant and adjuvant therapies have provided a slight improvement of the outcome
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
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
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