Search results for "Semicircular canal"
showing 10 items of 19 documents
Benign paroxysmal positional vertigo following whiplash injury: a myth or a reality?
2011
Abstract Objective The aim of the study was to evaluate the true incidence, diagnosis, and treatment of benign paroxysmal positional vertigo (BPPV) arising after whiplash injury and to distinguish this type of posttraumatic vertigo from other types of dizziness complained after trauma. Methods This was a retrospective study comprising patients referred to our center after whiplash injury. The patients were evaluated with neurotologic examination including bedside and instrumental tests. A Dizziness Handicap Inventory evaluating the symptoms of patients was submitted before and after treatment and was evaluated. The BPPV patients were separately evaluated from those with cervicogenic vertigo…
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 Specific Types of Nystagmus
2007
■ The function of the ocular motor system is to hold images stable on the fovea. The vestibular system and the vestibulo-ocular reflex (VOR) also play an important role in this function. The VOR connects the peripheral vestibular endorgans – the semicircular canals and otoliths – with their appropriate pair of eye muscles via a three-neuronal arc.
Nature of a Pigmented Substance in the Labyrinth
1964
The pigment existing in the loose connective tissue of the posterior labyrinth is originated by hemorrhage, pathological or “physiological” inflammations and wearing out of tissues. Such pigment is contained in macrophages.
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…
Benign paroxysmal positional vertigo as a complication of osteotome expansion of the maxillary alveolar ridge.
2001
Benign paroxysmal positional vertigo (BPPV) is a common vestibular end organ disorder characterized by short, often recurrent episodes of vertigo that are triggered by certain head movements in the plane of the posterior semicircular canals. BPPV may be idiopathic or secondary to a number of underlying conditions such as head injury, viral labyrinthitis, stapes surgery, and chronic suppurative otitis media. 1,2 The most commonly accepted theory postulates the development of BPPV as a result of canalolithiasis, 3 heavy, inorganic particles detached from the otoconial layer by degeneration or head trauma gravitate into the posterior semicircular canal and act as a plunger on the endolymph and…
Nonlinear nystagmus processing causes torsional VOR nonlinearity.
2003
The eye movement component that rotates around the line of sight, i.e., the ocular torsion, is in many aspects different from horizontal and vertical eye movements. While ocular torsion is mediated only by reflexive pathways like the torsional vestibulo-ocular and optokinetic reflexes (TVOR and OKN, respectively), horizontal and vertical components are also subject to intentional control mechanisms that are mediated by the saccadic and the pursuit systems. Dynamic properties of torsional eye movements are also very distinct. While horizontal and vertical VOR components show a gain close to unity and a small neural integration leakage with a time constant around pi=30 s, the TVOR shows a sma…
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…
A MODEL FOR VESTIBULAR FUNCTION IN ALTERED GRAVITATIONAL STATES
1979
ABSTRACT During evolution, the vestibular organ was made to serve mainly two purposes: 1) to guide eye movements during sharp turns, so that the point of fixation in the visual field can be kept steady, a function accomplished by the semicircular canal system and 2) to indicate the terrestrial vertical, so that upright posture and gait can be maintained even in the dark. The otolith system serves the latter purpose. Since the function of the semicircular canal system does not depend on gravity, it is not grossly disturbed by gravitational levels different from 1 g . The proper function of the otolith system depends entirely on the presence of a gravitational force vector of 9.8/m/sec2 direc…
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…