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saccule eye movements

A M F Wong
The otolith organs consist of the utricle and saccule. The utricle mediates the utriculo-ocular reflex by detecting horizontal head translation and static head tilt. Skew deviation is a vertical strabismus caused by imbalance of the utriculo-ocular reflex pathway and is commonly caused by lesions in the brainstem or cerebellum. It is associated with abnormal utriculo-ocular reflexes including asymmetric reduction of the translational vestibulo-ocular and ocular counterroll responses. Skew deviation is also associated with head position-dependent changes in ocular torsion and vertical strabismus...
February 2015: Eye
Ian S Curthoys, Vedran Vulovic, Ann M Burgess, Leonardo Manzari, Ljiljana Sokolic, Jacob Pogson, Mike Robins, Laura E Mezey, Samanthi Goonetilleke, Elaine D Cornell, Hamish G MacDougall
Extracellular single neuron recording and labelling studies of primary vestibular afferents in Scarpa's ganglion have shown that guinea-pig otolithic afferents with irregular resting discharge are preferentially activated by 500 Hz bone-conducted vibration (BCV) and many also by 500 Hz air-conducted sound (ACS) at low threshold and high sensitivity. Very few afferent neurons from any semicircular canal are activated by these stimuli and then only at high intensity. Tracing the origin of the activated neurons shows that these sensitive otolithic afferents originate mainly from a specialized region, the striola, of both the utricular and saccular maculae...
May 2014: Clinical and Experimental Pharmacology & Physiology
Aurore C Paillard, Karolina Kluk, Neil P M Todd
OBJECTIVE: To evaluate methods for estimating thresholds of vestibular evoked myogenic potentials (VEMPs) and ocular VEMPs (OVEMPs) produced by impulsive transmastoid acceleration (ITA). DESIGN: VEMPs and OVEMPs were obtained simultaneously from subjects in supine posture with both head and eyes elevated. Thresholds to ITA were measured using four different response identification methods. STUDY SAMPLE: Twelve adult subjects with no history of auditory or vestibular deficits...
February 2014: International Journal of Audiology
Topi Jutila, Heikki Aalto, Timo P Hirvonen
The study aimed to measure utricular function by directly quantifying head tilt in vestibular schwannoma (VS) patients using regular video-oculography (VOG) equipment with integrated head-position sensor, and to correlate the results with patients' symptoms and signs. We recorded head tilting after exclusion of visual cues (static head tilt), and after returning to the centre following lateral head rolls towards each side [subjective head vertical (SHV)]. Head tilt in 43 patients was measured preoperatively and approximately 4 months postoperatively, and compared to that of 20 healthy subjects...
June 2014: European Archives of Oto-rhino-laryngology
Sarah Khan, Richard Chang
INTRODUCTION: A sense of proper sensory processing of head motion and the coordination of visual and postural movements to maintain equilibrium is critical to everyday function. The vestibular system is an intricate organization that involves multiple levels of sensory processing to achieve this goal. PURPOSE: This chapter provides an overview of the anatomical structures and pathways of the vestibular system. SUMMARY: The five major vestibular structures are located in the inner ear and include: the utricle, the saccule, and the lateral, superior, and posterior semicircular canals...
2013: NeuroRehabilitation
Chi-Hsuan Huang, Yi-Ho Young
OBJECTIVE: This study applied ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests in Ménière's patients with Tumarkin falls to investigate the etiologic role of the saccule/utricle in the event of Tumarkin falls. STUDY DESIGN: Retrospective study. SETTING: University hospital. SUBJECTS: Twenty unilateral definite Ménière's patients were divided into 2 age- and sex-matched groups. Ten patients had a history of drop attacks, and 10 had no history of drop attacks...
September 2012: Otology & Neurotology
Isaac H Bianco, Leung-Hang Ma, David Schoppik, Drew N Robson, Michael B Orger, James C Beck, Jennifer M Li, Alexander F Schier, Florian Engert, Robert Baker
BACKGROUND: Although adult vertebrates sense changes in head position by using two classes of accelerometer, at larval stages zebrafish lack functional semicircular canals and rely exclusively on their otolithic organs to transduce vestibular information. RESULTS: Despite this limitation, we find that larval zebrafish perform an effective vestibulo-ocular reflex (VOR) that serves to stabilize gaze in response to pitch and roll tilts. By using single-cell electroporations and targeted laser ablations, we identified a specific class of central vestibular neurons, located in the tangential nucleus, that are essential for the utricle-dependent VOR...
July 24, 2012: Current Biology: CB
Tarandeep Grewal, Tye Dawood, Elie Hammam, Kenny Kwok, Vaughan G Macefield
We have previously shown that sinusoidal galvanic vestibular stimulation, a means of selectively modulating vestibular afferent activity, can cause partial entrainment of sympathetic outflow to muscle and skin in human subjects. However, it influences the firing of afferents from the entire vestibular apparatus, including the semicircular canals. Here, we tested the hypothesis that selective stimulation of one set of otolithic organs-those located in the utricle, which are sensitive to displacement in the horizontal axis-could entrain sympathetic nerve activity...
July 2012: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
I S Curthoys, V Vulovic, L Manzari
A new test for utricular function has recently been introduced and validated, namely the ocular vestibular-evoked myogenic potential (oVEMP), which refers to the myogenic potentials recorded by surface EMG electrodes beneath both eyes in response to bone conducted vibration (BCV) of the head or air conducted sound (ACS). The oVEMP test differs from another vestibular-evoked myogenic potential recorded by surface EMG electrodes over the sternocleidomastoid muscles in that the cervical vestibular-evoked myogenic potential (cVEMP) due to saccular activation is measured...
February 2012: Acta Otorhinolaryngologica Italica
Seong-Hae Jeong, Eung Kyu Kim, Jun Lee, Kwang-Dong Choi, Ji Soo Kim
To explore the patterns and mechanisms of jerky seesaw nystagmus in internuclear ophthalmoplegia (INO), we analyzed the nystagmus patterns in 33 patients with dissociated torsional-vertical nystagmus and INO. In 11 (33%) patients, the nystagmus was ipsiversive torsional in both eyes with vertical components in the opposite directions. In contrast, 18 (55%) patients showed ipsiversive torsional nystagmus with a larger upbeat component in the contralesional eye. Four (12%) patients exhibited ipsiversive torsional nystagmus with a greater downbeat component in the ipsilesional eye...
September 2011: Annals of the New York Academy of Sciences
I S Curthoys, V Vulovic, A M Burgess, E D Cornell, L E Mezey, H G Macdougall, L Manzari, L A McGarvie
Extracellular single neuron recordings of primary vestibular neurons in Scarpa's ganglion in guinea pigs show that low-intensity 500 Hz bone-conducted vibration (BCV) or 500 Hz air-conducted sound (ACS) activate a high proportion of otolith irregular neurons from the utricular and saccular maculae but few semicircular canal neurons. In alert guinea pigs, and humans, 500 Hz BCV elicits otolith-evoked eye movements. In humans, it also elicits a myogenic potential on tensed sternocleidomastoid muscles. Although BCV and ACS activate both utricular and saccular maculae, it is possible to probe the functional status of these two sense organs separately because of their differential neural projections...
September 2011: Annals of the New York Academy of Sciences
Kuei-You Lin, Yi-Ho Young
CONCLUSION: The static subjective visual horizontal (SVH) test correlates with the dynamic ocular vestibular-evoked myogenic potential (oVEMP) test in healthy and pathological ears, and further confirms that both tests may, at least in part, share the same utricular reflex pathway. OBJECTIVE: This study correlated the SVH test results with those of the oVEMP and cervical VEMP (cVEMP) tests to investigate their relationships. METHODS: Twenty healthy subjects underwent the SVH test at a view pattern angle of 30° or 70° horizontal tilt under various background distractions to establish the optimal stimulation mode for SVH test...
February 2011: Acta Oto-laryngologica
K I Buytaert, S A E Nooij, X Neyt, P-F Migeotte, R Vanspauwen, P H Van de Heyning, F L Wuyts
The utricle plays an important role in orientation with respect to gravity. The unilateral centrifugation test allows a side-by-side investigation of both utricles. During this test, the subject is rotated about an earth-vertical axis at high rotation speeds (e.g. 400°/s) and translated along an interaural axis to consecutively align the axis of rotation with the left and the right utricle. A simple sinusoidal translation profile (0.013 Hz; amplitude = 4 cm) was chosen. The combined rotation and translation induces ocular counter rolling (OCR), which is measured using 3-D video-oculography...
2010: Audiology & Neuro-otology
Alexander A Tarnutzer, Christopher J Bockisch, Dominik Straumann
We compared the variability of the subjective visual vertical (SVV) and static ocular counterroll (OCR), and hypothesized a correlation between the measurements because of their shared macular input. SVV and OCR were measured simultaneously in various whole-body roll positions [upright, 45 degrees right-ear down (RED), and 75 degrees RED] in six subjects. Gains of OCR were -0.18 (45 degrees RED) and -0.12 (75 degrees RED), whereas gains of compensation for body roll in the SVV task were -1.11 (45 degrees RED) and -0...
June 2009: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
A Kern, K Seidel, H H A Oelschläger
Toothed whales (Odontocetes; e.g., dolphins) are well-known for efficient underwater locomotion and for their acrobatic capabilities. Nevertheless, in relation to other mammals including the human and with respect to body size, their vestibular apparatus is reduced, particularly the semicircular canals. Concomitantly, the vestibular nerve and most of the vestibular nuclei are thin and small, respectively, in comparison with those in terrestrial mammals. In contrast, the lateral (Deiters') vestibular nucleus is comparatively well developed in both coastal and pelagic dolphins...
2009: Brain, Behavior and Evolution
Neil P M Todd, Sally M Rosengren, James G Colebatch
OBJECTIVE: Recent work has demonstrated the existence of ocular vestibular evoked myogenic potentials (OVEMPs), which likely reflect projections underlying the translational vestibular ocular reflex (TVOR). We examined extraocular muscle activity associated with impulsive acceleration of the head in the transmastoid plane. METHODS: Accelerometry was measured in 4 subjects in response to acceleration impulses produced by a gamma function delivered with a Minishaker (4810, Bruel & Kjaer)...
July 2008: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Kenya Inukai, Izumi Koizuka, Sugata Takahashi
OBJECTIVE: One of the pathologic conditions underlying benign paroxysmal positional vertigo (BPPV) is degeneration of the otolith organs. In this study, we examined changes in the parameters of stabilometry under an upright condition and head-tilt conditions in patients with BPPV. METHODS: We performed stabilometry on 21 patients with right BPPV, on 21 patients with left BPPV and on 21 controls. First, the subject stood barefoot in an upright position with both feet together on the platform with eyes closed...
March 2008: Auris, Nasus, Larynx
Shirley G Diamond, Charles H Markham, Andrew H Clarke
CONCLUSION: Most of the subjects studied had eye torsion responses to pitch, although the direction of torsion varied between subjects. Opposite responses may be the result of individual variation in anatomical or physiological vector orientations of hair cells in the anterior or posterior utricle or in the saccule. OBJECTIVE: This study aimed to determine whether systematic changes in eye torsion occur when subjects are rotated in forward and backward pitch. MATERIALS AND METHODS: Twenty-one normal subjects were seated in a dual axis human rotator, positioned so that the interaural axis was aligned with the axis of pitch rotation...
March 2006: Acta Oto-laryngologica
Dietmar Basta, Ingo Todt, Hans Scherer, Andrew Clarke, Arne Ernst
It was the aim of the present paper to investigate the influence of otolith disorders on human postural control by different methods. The 33 patients of our study had undergone a minor head injury and suffered subsequently from an utricular or sacculo-utricular disorder as evidenced by vestibular evoked myogenic potential recordings and eccentric rotation recordings of the otolith-ocular responses. Postural control was assessed by performing stance/gait tests (standard balance deficit test, SBDT) and by evaluating trunk sway (using angular velocity sensors)...
April 2005: Human Movement Science
Juno Kim, Ian S Curthoys
Previous studies in humans and animals which have shown that DC galvanic vestibular stimulation (GVS) induces horizontal and torsional eye movements have been interpreted as being due to a preferential activation of primary vestibular afferents innervating the horizontal semicircular canals and otoliths by GVS. The present study sought to determine in guinea pigs whether GVS does indeed selectively activate primary horizontal canal and otolith afferents. Constant-current GVS was passed between electrodes implanted in the tensor-tympani muscle of each middle ear or between electrodes on the skin over the mastoid...
September 30, 2004: Brain Research Bulletin
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