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off vertical axis nystagmus

Avery H Weiss, John P Kelly, Richard A Hopper, James O Phillips
PURPOSE: To characterize conjugate eye movements in Crouzon syndrome (CS) patients with and without strabismus. METHODS: Smooth pursuit, saccades, horizontal optokinetic nystagmus (OKN), and horizontal vestibulo-ocular reflex (VOR) were recorded using binocular video-oculography (VOG) in 10 children with CS (5 orthotropic, 5 strabismic) and 12 age-matched controls. Hess-Lancaster plots were generated from Orbit 1.8 using rectus muscle pulley locations from computed tomography imaging...
July 2015: Investigative Ophthalmology & Visual Science
N Shimizu, S Wood, K Kushiro, S Yanai, A Perachio, T Makishima
The central vestibular system plays an important role in higher neural functions such as self-motion perception and spatial orientation. Its ability to store head angular velocity is called velocity storage mechanism (VSM), which has been thoroughly investigated across a wide range of species. However, little is known about the mouse VSM, because the mouse lacks typical ocular responses such as optokinetic after nystagmus or a dominant time constant of vestibulo-ocular reflex for which the VSM is critical. Experiments were conducted to examine the otolith-driven eye movements related to the VSM and verify its characteristics in mice...
January 29, 2015: Neuroscience
Nicholas J Cutfield, Sian Cousins, Barry M Seemungal, Michael A Gresty, Adolfo M Bronstein
Studies of compensation of injury to the human vestibular system have, in the main, focused on the vestibular-ocular reflex. Probing vestibular perception allows more of the sensory pathway to be assessed. We present a novel paradigm for simultaneously testing vestibular perceptual and nystagmic thresholds to angular acceleration around an earth vertical axis. The perceptual thresholds can be modulated asymmetrically in normal subjects by DC galvanic stimulation with the head flexed in the roll plane, as expected from the main torsional plane of action of the galvanic stimulus...
September 2011: Annals of the New York Academy of Sciences
Mitsuya Suzuki, Takio Goto, Akinori Kashio, Takuya Yasui, Takashi Sakamoto, Ken Ito, Tatsuya Yamasoba
A 58-year-old man, in whom the cochlear implant (CI) had been inserted into the left ear, had right middle-ear cancer. The CI was removed immediately before receiving subtotal removal of right temporal bone. Four months later, the CI was again inserted in his left cochlea. Because of obliterated scala tympani, the 22 active electrodes of the CI were placed into the scala vestibuli. After the surgery, the patient complained that he experienced rotary vertigo and "jumbling of vertical direction" of objects on walking...
October 2011: Auris, Nasus, Larynx
Mingjia Dai, Ted Raphan, Bernard Cohen
The angular vestibulo-ocular reflex (aVOR) and optokinetic nystagmus (OKN) were elicited simultaneously at low frequencies to study effects of habituation of the velocity storage time constant in the vestibular system on motion sickness. Twenty-nine subjects, eleven of whom were susceptible to motion sickness from common transportation, were habituated by sinusoidal rotation at 0.017 Hz at peak velocities from 5 to 20°/s, while they watched a full-field OKN stimulus. The OKN stripes rotated in the same direction and at the same frequency as the subjects, but at a higher velocity...
May 2011: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Mingjia Dai, Sofronis Sofroniou, Mikhail Kunin, Theodore Raphan, Bernard Cohen
We tested the hypothesis that motion sickness is produced by an integration of the disparity between eye velocity and the yaw-axis orientation vector of velocity storage. Disparity was defined as the magnitude of the cross product between these two vectors. OVAR, which is known to produce motion sickness, generates horizontal eye velocity with a bias level related to velocity storage, as well as cyclic modulations due to re-orientation of the head re gravity. On average, the orientation vector is close to the spatial vertical...
July 2010: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Heather Bossong, Michelle Swann, Adrian Glasser, Vallabh E Das
PURPOSE: This study was designed to use infrared photorefraction to measure accommodation in awake-behaving normal and strabismic monkeys and describe properties of photorefraction calibrations in these monkeys. METHODS: Ophthalmic trial lenses were used to calibrate the slope of pupil vertical pixel intensity profile measurements that were made with a custom-built infrared photorefractor. Day to day variability in photorefraction calibration curves, variability in calibration coefficients due to misalignment of the photorefractor Purkinje image and the center of the pupil, and variability in refractive error due to off-axis measurements were evaluated...
February 2009: Investigative Ophthalmology & Visual Science
G Bertolini, C J Bockisch, D Straumann, D S Zee, S Ramat
To investigate the contribution of the vestibular velocity-storage mechanism (VSM) to the vertical rotational vestibulo-ocular reflex (rVOR) we recorded eye movements evoked by off-vertical axis rotation (OVAR) using whole-body constant-velocity pitch rotations about an earth-horizontal, interaural axis in four healthy human subjects. Subjects were tumbled forward, and backward, at 60 deg/s for over 1 min using a 3D turntable. Slow-phase velocity (SPV) responses were similar to the horizontal responses elicited by OVAR along the body longitudinal axis, ('barbecue' rotation), with exponentially decaying amplitudes and a residual, otolith-driven sinusoidal response with a bias...
2008: Progress in Brain Research
J Ventre-Dominey, M Luyat, P Denise, C Darlot
This article addresses the relationships between motion sickness (MS) and three-dimensional (3D) ocular responses during otolith stimulation. A group of 19 healthy subjects was tested for motion sickness during a 16 min otolith stimulation induced by off-vertical axis rotation (OVAR) (constant velocity 60 degrees /s, frequency 0.16 Hz). For each subject, the MS induced during the session was quantified, and based on this quantification, the subjects were divided into two groups of less susceptible (MS-), and more susceptible (MS+) subjects...
August 26, 2008: Neuroscience
Suzanne A E Nooij, Jelte E Bos, Eric L Groen
Prolonged exposure to hypergravity in a human centrifuge can lead to post-rotary spatial disorientation and motion sickness. These symptoms are mainly provoked by tilting head movements and resemble the Space Adaptation Syndrome. We hypothesized that the occurrence of these post-rotary effects might be related to changes in the velocity storage (VS) mechanism, which is suggested to play an important role in spatial orientation. In particular, we investigated whether the re-orientation of the eye velocity vector (EVV) towards gravity during off-vertical optokinetic stimulation was affected by centrifugation...
September 2008: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Sébastien G Tanguy, Gaëlle M Quarck, Olivier M Etard, Antoine F Gauthier, Pierre Denise
The aim of this study was to investigate whether figure skaters, as individuals who experience intense vestibular stimulation, presented modification of the otolith-ocular reflex. The reflexes of 12 figure skaters were assessed using off vertical axis rotation (OVAR). Horizontal otolith-ocular reflex during OVAR is characterized by two parameters: the eye velocity horizontal modulation, assumed to compensate for perceived lateral linear translation, and the bias, assumed to compensate for the perceived rotation...
March 26, 2008: Neuroreport
Akemi Sugita-Kitajima, Izumi Koizuka
The vestibulo-ocular reflex (VOR) was studied via sinusoidal off-vertical axis rotation (OVAR) to evaluate otolith function in patients with benign paroxysmal positional vertigo (BPPV). Subjects were sinusoidally rotated with eyes open in complete darkness at frequencies of 0.4 and 0.8 Hz with a maximum angular velocity of 60 degrees /s in earth vertical axis rotation (EVAR) and OVAR. Ten patients with BPPV patients were investigated. We performed OVAR tests for all patients for the following different points and compared otolith function: (1) The point at which patients had typical nystagmus; we call this state 'Before', that is, before recovery...
May 9, 2008: Neuroscience Letters
Mitsuya Suzuki, Yuki Saito, Munetaka Ushio, Tatsuya Yamasoba, Izumi Hatta, Masako Nakamura
A 60-year-old woman, who has suffered from bilateral deafness throughout her life, visited our outpatient clinic. Computed tomography (CT) revealed inner ear malformations, which comprise cochlear aplasia with hypoplastic vestibule in the right ear and a common cavity in the left ear, and narrow internal auditory canals. We performed electronystagmography with caloric stimulation and stimulation of earth-vertical axis rotation (EVAR) or off-vertical axis rotation (OVAR), and studied vestibular evoked myogenic potentials (VEMPs) and vestibular ocular reflex (VOR)...
November 2007: Acta Oto-laryngologica
Jun Maruta, John I Simpson, Theodore Raphan, Bernard Cohen
Sinusoidal translation while rotating at constant angular velocity about a vertical axis (translation while rotating, TWR) produces centripetal and translational accelerations along the direction of translation and an orthogonal Coriolis acceleration due to the translation in the rotating frame. Thus, a Coriolis acceleration is produced along the bitemporal axis when oscillating along the naso-occipital axis, and along the naso-occipital axis when oscillating along the bitemporal axis. Together, these components generate an elliptically rotating acceleration vector that revolves around the head in the direction of rotation at the frequency of oscillation...
June 2005: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Bernhard J M Hess, Karin Jaggi-Schwarz, Hubert Misslisch
We have examined the spatiotemporal characteristics of postrotatory eye velocity after roll and pitch off-vertical axis rotations (OVAR). Three rhesus monkeys were placed in one of 3 orientations on a 3-dimensional (3D) turntable: upright (90 degrees roll or pitch OVAR), 45 degrees nose-up (45 degrees roll OVAR), and 45 degrees left ear-down (45 degrees pitch OVAR). Subjects were then rotated at +/-60 degrees /s around the naso-occipital or interaural axis and stopped after 10 turns, in one of 7 final head orientations, each separated by 30 degrees ...
March 2005: Journal of Neurophysiology
Steven T Moore, Gilles Clément, Mingjai Dai, Theodore Raphan, David Solomon, Bernard Cohen
In this paper we review space flight experiments performed by our laboratory. Rhesus monkeys were tested before and after 12 days in orbit on COSMOS flights 2044 (1989) and 2229 (1992-1993). There was a long-lasting decrease in post-flight ocular counter-rolling (70%) and vergence (50%) during off-vertical axis rotation. In one animal, the orientation of optokinetic after-nystagmus shifted by 28 degrees from the spatial vertical towards the body vertical early post-flight. Otolith-ocular and perceptual responses were also studied in four astronauts on the 17-day Neurolab shuttle mission (STS-90) in 1998...
2003: Journal of Vestibular Research: Equilibrium & Orientation
Y Koizumi, M Kimura, E Mokuno, T Yagi
OBJECTIVE: It has been reported that the eye movements induced by off vertical axis rotation (OVAR) are composed of two components: a bias component (BIC) and a modulation component (MOC). It was suggested that the MOC compensates for changes in head orientation with respect to gravity and that the BIC is related to the velocity storage mechanism. However, the characteristics of the otolith organs remain obscure. In order to investigate these characteristics, we performed a 3D analysis of eye movements induced by human sinusoidal s-OVAR, and compared the result with that of eye movements induced by constant c-OVAR...
January 2003: Acta Oto-laryngologica
J M Furman, M S Redfern
This study assessed visual-otolith interaction in healthy older humans and compared responses from older subjects to those of younger subjects. Using off-vertical axis rotation (OVAR) to stimulate the otolith organs, eye movement responses, measured using electro-oculography, were recorded during rotation in the dark, rotation with an earth-fixed lighted visual surround, and rotation with a subject-fixed fixation target. Results indicated that older subjects, like young subjects, exhibit a modulation component that was as large during rotation with a lighted earth-fixed visual surround as that seen in the dark and a modulation component during rotation with a subject-fixed visual target that was incompletely suppressed...
0: Journal of Vestibular Research: Equilibrium & Orientation
Keisuke Kushiro, Mingjia Dai, Mikhail Kunin, Sergei B Yakushin, Bernard Cohen, Theodore Raphan
Nystagmus induced by off-vertical axis rotation (OVAR) about a head yaw axis is composed of a yaw bias velocity and modulations in eye position and velocity as the head changes orientation relative to gravity. The bias velocity is dependent on the tilt of the rotational axis relative to gravity and angular head velocity. For axis tilts <15 degrees, bias velocities increased monotonically with increases in the magnitude of the projected gravity vector onto the horizontal plane of the head. For tilts of 15-90 degrees, bias velocity was independent of tilt angle, increasing linearly as a function of head velocity with gains of 0...
November 2002: Journal of Neurophysiology
B. J. M. Hess, N. Dieringer
Pigmented, head restrained rats were rotated on a turntable about a tilted axis (off-vertical axis rotation; OVAR) in darkness. Evoked eye movements in the horizontal, vertical and torsional planes were recorded simultaneously with a dual search coil in a magnetic field, horizontal response components of both eyes were recorded with a coil on either eye. OVAR resulted in a persisting horizontal, unidirectional ocular nystagmus, compensatory in direction for the rotation of head in space. Superimposed upon this nystagmus were slower cyclic responses of the eye in the vertical and torsional movement planes, that were tightly phase locked with changing head positions in space: ocular depression/elevation with right ear up/down and ocular intorsion/extorsion with nose up/down...
October 1990: European Journal of Neuroscience
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