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Hydromyelia Associated With Spinal Lipoma of the Conus Case Report
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STUDY DESIGN: A case report and literature review of the treatment of "noncommunicating" syringomyelia. OBJECTIVE.: The aim of this report is to document the timing and the treatment of hydromyelia holocord after surgical treatment for both tethering and retethering of spinal lipoma.
SUMMARY OF BACKGROUND DATA: Syringomyelia associated with spinal lipoma presents a different pathogenesis and treatment in comparison to the "communicating" hydromyelia in the myelomeningocele. After the primary retethering operation performed in symptomatic patients, recurrent retethering can occur with an increase of the syringomyelia signs and symptoms.
METHODS: Syringomyelia treated with a thin silastic tube passed from the syrinx to the subarachnoidal space for drainage and decompression. Prior operations were: (1) initial untethering at birth, (2) second untethering at 5 years of age, (3) posterior fossa and cervical decompression.
RESULTS: Magnetic resonance imaging 6 months post shunt operation demonstrated decompression of the hydromyelia holocord and syringobulbia with improvement of motor function of the legs and improvement in sensory symptoms.
CONCLUSION: Usefulness of syrinx-subarachnoidal shunt is demonstrated in this case report after unsuccessful decompression and detethering. When the enlargement of the ependymal channel is greater than 50% of the spinal cord's diameter, neurologic, and urological symptoms are evident and the patient benefitted from cord untethering and syrinx drainage. (1) The terminal "noncommunicating" syringomyelia in lumbar sacral lipoma has been reported to be associated with retethering in spinal lipoma in the 25% of the cases. (2) The rise of distal syringomyelia isn't only linked to the kind of the spinal lipoma, but also to the difficulty to obtain the untethering and a smooth cerebrospinal fluid flow between the subarachnoidal space and the ependymal canal. (3) In patients with hydromyelia holocord greater than the 50% of the spinal cord's diameter a myelotomy and insert an ependymal channel/syrinx to the subarachnoidal space shunt can resolve of the syrinx. In this case, the enlargement of the ependymal channel in "noncommunicating" syringomyelia associated with lumbosacral lipoma is greater than 50% of the spinal cord's diameter; neurologic and urological symptoms occurred and the patient benefited from cord untethering and concurrent syrinx drainage
Long-term operative failure of endoscopic third ventriculostomy in pediatric patients: the role of cine phase-contrast MR imaging.
No full textOBJECT:
Although a rarely reported occurrence, late failure of endoscopic third ventriculostomy (ETV) may occur in children as a result of a variety of factors. Delay in recognition of symptoms can lead to harmful deterioration in the patient's condition. The authors undertook this study to assess the capacity of cine phase-contrast MR imaging to identify late failure in asymptomatic pediatric patients treated with ETV for hydrocephalus.
METHODS:
This study was a retrospective evaluation of cases involving patients who underwent ETV between January 1, 1999, and December 31, 2008, at the pediatric neurological surgery service of the University of Padua. Before 2004, patients were routinely followed up with cine MR imaging at 3, 6, and 12 months after ETV. In 2004, a protocol of annual cine MR follow-up was instituted as a result of a case of fatal late failure. The authors evaluated all cases of late failure identified through cine MR imaging and performed a statistical analysis to investigate the relationship between ETV failure and several variables, including the cause of hydrocephalus for which ETV was originally indicated.
RESULTS:
In a series of 84 patients (age range 6 days-16 years), 17 patients had early ETV failure. Of the remaining 67 patients, 5 (7%) were found to have no CSF flow through the fenestration and recurrent ventriculomegaly when assessed with cine MR imaging at 1, 2, 3, 4, and 7 years after ETV. The patient in whom ETV failure was identified 1 year postoperatively had Dandy-Walker malformation. The patients in whom ETV failure was identified 2, 3, and 4 years postoperatively all had undergone ETV for treatment of postinfective hydrocephalus. The patient in whom ETV failure was identified 7 years postoperatively had a cystic arachnopathy in the fourth ventricle after cerebellar astrocytoma removal.
CONCLUSIONS:
Patients who undergo ETV for infective hydrocephalus and Dandy-Walker malformation should receive long-term follow-up, because late closure of the stoma may occur progressively and slowly. Intraoperative observation of thickened arachnoid membranes at the level of the interpeduncular cisterns at the first ETV and a progressive decreasing of CSF flow through the stoma on routine cine MR imaging should be considered unfavorable elements entailing a significant risk of deterioration
Hydrocephalus in Infants Less than Six Months of Age: Effectiveness of Endoscopic Third Ventriculostomy
No full textOBJECTIVE:
Although endoscopic third ventriculostomy (ETV) is a well established procedure for the treatment of congenital and acquired hydrocephalus, there is still a controversy with regard to the higher risk of failure in younger infants compared to older children after such a procedure. The aim of this article is to define the effectiveness of third ventriculostomy for hydrocephalus in infants less than 6 months of age better and to determine possible positive predictive factors.
MATERIALS AND METHODS:
In a series of 126 consecutive patients who underwent ETV between January 2000 and December 2002, 21 procedures were performed on infants ranging in age from 23 to 180 days, and without a previous history of shunting. The follow-up period was 49 to 82 months.
RESULTS:
The overall success rate of ETV was 67% (14/21). All failures occurred in the early postoperative period (average 38 days, range 25-88 days). The success rate varied with the etiology of the patient's hydrocephalus. The best results were obtained in patients with acqueductal stenosis, Dandy-Walker malformation and myelomeningocele. The least favorable results (50% failure rate) occurred in infants treated for post-hemorrhagic and post-meningitic hydrocephalus.
CONCLUSION:
This study does not demonstrate a correlation between the age of the infants and the ETV success rate. The specific etiology of hydrocephalus is the most relevant prognostic factor in infants under six months of age.
Copyright Georg Thieme Verlag KG Stuttgart . New York
Hydrocephalus in infants less than six months of age: effectiveness of endoscopic third ventriculostomy
No full textGoing 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
Occipital plagiocephaly. A study of 64 cases
No full textI.F.: 0.023
ISI: NEUROSCIENCES, NEUROIMAGING, RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGIN
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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