Search results for "circular"
showing 10 items of 856 documents
Are postural restrictions necessary for management of posterior canal benign paroxysmal positional vertigo?
2011
Objectives: An important component of management of benign paroxysmal positional vertigo (BPPV) has been the application of postural restrictions after use of a canalith repositioning maneuver (CRM) to prevent the return of otolithic debris into the posterior semicircular canal (PSC). This study was designed to explore the effectiveness of postural restrictions in patients with BPPV caused by otolithic debris in the PSC. Methods: Seventy-four adult patients with unilateral PSC BPPV were enrolled into this study. All patients were managed with a CRM — Either the modified Epley maneuver or the Semont maneuver. The patients were divided randomly into 2 groups: Group A, with postural restrictio…
Management of benign paroxysmal positional vertigo of lateral semicircular canal by Gufoni's manoeuvre
2009
Abstract Benign paroxysmal positional vertigo (BPPV) of lateral semicircular canal (LSC) is one of the rarer forms of BPPV as compared to posterior semicircular canal BPPV. Various particle repositioning manoeuvres have been described in the literature as a mode of treating this condition. Purpose Evaluation and discussion of the procedure of the Gufoni's manoeuvre and its advantages in the treatment of BPPV of LSC. Material and methods Prospective study of 58 patients affected by LSC BPPV who were office-treated with Gufoni's manoeuvre. Results Seventy-nine percent of the patients so treated had complete resolution of symptoms, and 6.9% did not show any improvement in their symptoms. The r…
Comparison of repositioning maneuvers for benign paroxysmal positional vertigo of posterior semicircular canal: advantages of hybrid maneuver.
2012
Objective: The prevalence of benign paroxysmal positional vertigo (BPPV) is becoming more frequent in elderly population. The presence of comorbid factors has to be considered before assessment as well as before commencing any repositioning treatment. Our aims were evaluation of the maneuvers efficacy and evaluation of the applicability of hybrid maneuver (HM) in patients with physical limitation. Study design and setting: This is a randomized study in 2 tertiary referral centers. Intervention: This is a therapeutic intervention. Patients: All consecutive patients with diagnosis of BPPV of posterior canal matching the inclusion criteria were enrolled. Patients underwent treatment soon after…
Diagnostic performance of reformatted isotropic thin-section helical CT images in the detection of superior semicircular canal dehiscence
2017
Purpose The purpose of this article is to assess the diagnostic performance of computed tomography (CT) reformatted images for detection of superior semicircular canal (SSC) dehiscence. Material and methods Forty-two patients, with sound- and/or pressure-induced vestibular symptoms, and 42 control participants underwent helical CT examination with a highly collimated beam (0.5 mm). Reformatted images of the vestibular labyrinth were obtained in the standard axial and coronal planes (group A images), and in a plane parallel and perpendicular to the SSC (group B images). Diagnostic performance obtained by evaluating the group A images alone and the group B images alone was analyzed by using t…
Treatment of Ménière's disease by low-dosage intratympanic gentamicin application: effect on otolith function.
2007
Objectives: The intratympanic application of a low dosage of gentamicin is increasingly favored as treatment for Meniere's disease. While posttreatment observations have confirmed a long-term success of the therapy of vertigo attacks, clear differences in the posttreatment recovery interval can be observed. In addition to differences in central-vestibular compensation, the degree of peripheral vestibular damage, i.e., to the saccule, utricle, and semicircular canal ampullae, varies among patients. This study provides comprehensive pre- and posttreatment results from unilateral functional tests of the individual vestibular receptors and of the cochlea in patients with Meniere's disease. Stud…
Otosclerosis associated with type B-1 inner ear malformation
2010
Malformations of bony inner ear are rare anomalies occurring in approximately 20% of patients with congenital sensorineural hearing loss. Conductive hearing loss is usually associated with abnormalities of the external and middle ear. Recent reports of patients with lateral semicircular canal malformations indicate inner ear malformations to be associated with sensorineural or conductive hearing loss. Differential diagnosis of conductive hearing loss should include otosclerosis, isolated ossicular deformities, inner ear anomalies or a combination of these. In this report, a case is described with right vestibule-lateral semicircular canal dysplasia presenting at our centre with bilateral ot…
Effects of Air Tightness Tests on Steel Thin-Wall Box Structures with Circular and Rectangular Cross Sections
2019
In this paper, the effects of air tightness tests on steel box structures with rectangular or circular cross sections typical of port cranes (legs, arms, and crosspieces) are analyzed. Legs and arms are generally made with elements with profiles having a square or rectangular cross section, while the diagonal struts are made with profiles having circular cross sections. To verify the air tightness of these elements, a necessary requirement to protect them from corrosion if they are not protected with other protection techniques, air tightness tests are performed. These tests, in the framework of durability tests, must be carried out while maintaining the structure elasticity well below the …
The first sorbicillinoid alkaloids, the antileukemic sorbicillactones A and B, from a sponge-derived Penicillium chrysogenum strain
2005
The saltwater culture of a Penicillium chrysogenum strain isolated from the Mediterranean sponge Ircinia fasciculata yielded three new sorbicillin-derived compounds (1-3), whose structures were elucidated mainly by 2D NMR and mass spectrometry. Among them, sorbicillactones A (1) and B (2) are the first sorbicillinoid natural products that contain nitrogen. Compound 1 is anti-HIV active and it exhibits a strong cytotoxic activity against L5178y leukemic cells, combined with a relatively low toxicity to cervical carcinoma HeLa S3 cells and pheochromocytoma PC 12 cells. The absolute configurations of I and 2 were elucidated by quantum chemical calculation of circular dichroism (CD) spectra. An…
Elliptic convolution operators on non-quasianalytic classes
2001
For those nonquasianalytic classes in which an extension of the classical Borel's theorem holds we show that every elliptic convolution operator is the composition of a translation and an invertible ultradifferential operator. This answers a question asked by Chou in: La transformation de Fourier complexe et l'equation de convolution, LNM 325, Berlin-Heidelberg-New York (1973).
Periodic Polynomial Splines
2018
In this chapter, the spaces of periodic polynomial splines and the Spline Harmonic Analysis (SHA) in these spaces are briefly outlined. The stuff of this chapter is used for the design of periodic discrete-time splines and discrete-time-spline-based wavelets and wavelet packets. For a detailed description of the subject we refer to (Averbuch, Neittaanmaki and Zheludev, Spline and Spline Wavelet Methods with Applications to Signal and Image Processing, Springer, Berlin, 2014) [1]. Periodic polynomial splines provide an example of mixed discrete-continuous circular convolution.