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Vestibulo ocular reflex

Chun Wai Yip, Michael Strupp
The Dizziness Handicap Inventory (DHI) is believed to quantitate the handicap related to the presence or severity of underlying vestibular dysfunction. However, patients with chronic vestibular diseases may manifest various degrees of behavioural and physiological adaptation resulting in variances of the DHI. Our primary study objective is to evaluate the correlation between the DHI and measurable vestibular parameters. Secondarily, we compared DHI among different vestibular disorders (central, peripheral and functional), and different types of anatomic deficits (semicircular canal vs otolithic)...
March 20, 2018: Journal of Neurology
Parthena Soupiadou, Francisco Branoner, Hans Straka
Vestibulo-ocular reflexes (VOR) are mediated by three-neuronal brainstem pathways that transform semicircular canal and otolith sensory signals into motor commands for the contraction of spatially specific sets of eye muscles. The vestibular excitation and inhibition of extraocular motoneurons underlying this reflex is reciprocally organized and allows coordinated activation of particular eye muscles and concurrent relaxation of their antagonistic counterparts. Here, we demonstrate in isolated preparations of Xenopus laevis tadpoles that the discharge modulation of superior oblique motoneurons during cyclic head motion derives from an alternating excitation and inhibition...
March 19, 2018: Journal of Neurology
Alessandro Micarelli, Andrea Viziano, David Della-Morte, Ivan Augimeri, Marco Alessandrini
OBJECTIVE: Considering the altered multisensory signal compensation during senescence, the aim of the present study was to evaluate the integration rearrangements in unilateral vestibular hypofunction (UVH) during age-related cognitive decline. STUDY DESIGN: Cross-sectional study. SETTING: Longitudinal cohort study unit and of University tertiary referral center. PATIENTS: Older UVH individuals ≥ 55 years with Mild Cognitive Impairment (MCI) or Alzheimer Disease (AD) and matched UVH control group with age-appropriate cognitive function...
March 15, 2018: Otology & Neurotology
Sofia Waissbluth, Angela Chuang, Álvaro Del Valle, Marcela Cordova
OBJECTIVES: Platinum-based chemotherapy treatments are effective against a variety of pediatric malignancies. However, its use can lead to permanent hearing loss. The aim of this study was to evaluate the long-term effect of platinum chemotherapy on hearing and evaluate its progression. METHODS: Prospective cohort study. All records of pediatric patients receiving platinum-based chemotherapy between 2001 and 2006 were reviewed. Demographics and audiograms performed before, during, and following chemotherapy were analyzed...
April 2018: International Journal of Pediatric Otorhinolaryngology
Jeong-Yoon Choi, Hyo-Jung Kim, Ji-Soo Kim
The head impulse test (HIT) is used to evaluate the vestibulo-ocular reflex (VOR) during a high-velocity head rotation. Corrective catch-up saccades that occur during or after the HITs usually indicate peripheral vestibular hypofunction, whereas in acute vestibular syndrome, normal clinical (bedside) HITs should prompt a search for a central lesion. However, recent quantitative studies that evaluated HITs using magnetic search coils or video-based techniques have demonstrated that specific patterns of HIT abnormalities are associated with central vestibular disorders...
February 28, 2018: Neurology
N L Kunel'skaya, E V Baibakova, A L Guseva, Ya Yu Nikitkina, M A Chugunova, E A Manaenkova
AIM: The objective of the present study was to elucidate the mechanisms behind the compensation of the vestibular ocular reflex and evaluate the effectiveness of vestibular rehabilitation in the patients presenting with vestibular neuritis (VN) with the application of the video head-impulse test (vHIT) and the dynamic visual acuity test (DVAT). METHODS: The study included 26 patients with vestibular neuritis whose condition was assessed by scoring based on the dizziness handicap inventory, the dynamic visual acuity test, and the video head-impulse test with the evaluation of saccades and the degree of eye-head movement coordination (gain) before and after the course of vestibular rehabilitation...
2018: Vestnik Otorinolaringologii
Jorge Rey-Martinez, Angel Batuecas-Caletrio, Eusebi Matiño, Gabriel Trinidad-Ruiz, Xabier Altuna, Nicolas Perez-Fernandez
Background: Visually enhanced vestibulo-ocular reflex (VVOR) is a well-known bedside clinical test to evaluate visuo-vestibular interaction, with clinical applications in patients with neurological and vestibular dysfunctions. Owing to recently developed diagnostic technologies, the possibility to perform an easy and objective measurement of the VVOR has increased, but there is a lack of computational methods designed to obtain an objective VVOR measurement. Objectives: To develop a method for the assessment of the VVOR to obtain a gain value that compares head and eye velocities and to test this method in patients and healthy subjects...
2018: Frontiers in Neurology
M Muntaseer Mahfuz, Michael C Schubert, William V C Figtree, Christopher J Todd, Serajul I Khan, Americo A Migliaccio
The vestibulo-ocular reflex (VOR) is the main vision-stabilising system during rapid head movements in humans. A visual-vestibular mismatch stimulus can be used to train or adapt the VOR response because it induces a retinal image slip error signal that drives VOR motor learning. The training context has been shown to affect VOR adaptation. We sought to determine whether active (self-generated) versus passive (externally imposed) head rotation vestibular training would differentially affect adaptation and short-term retention of the active and passive VOR responses...
February 20, 2018: Journal of the Association for Research in Otolaryngology: JARO
Elisa Galliano, Martijn Schonewille, Saša Peter, Mandy Rutteman, Simone Houtman, Dick Jaarsma, Freek E Hoebeek, Chris I De Zeeuw
In many brain regions involved in learning NMDA receptors (NMDARs) act as coincidence detectors of pre- and postsynaptic activity, mediating Hebbian plasticity. Intriguingly, the parallel fiber (PF) to Purkinje cell (PC) input in the cerebellar cortex, which is critical for procedural learning, shows virtually no postsynaptic NMDARs. Why is this? Here, we address this question by generating and testing independent transgenic lines that overexpress NMDAR containing the type 2B subunit (NR2B) specifically in PCs...
January 2018: ENeuro
Randel L Swanson, Stephen Hampton, Judith Green-McKenzie, Ramon Diaz-Arrastia, M Sean Grady, Ragini Verma, Rosette Biester, Diana Duda, Ronald L Wolf, Douglas H Smith
Importance: From late 2016 through August 2017, US government personnel serving on diplomatic assignment in Havana, Cuba, reported neurological symptoms associated with exposure to auditory and sensory phenomena. Objective: To describe the neurological manifestations that followed exposure to an unknown energy source associated with auditory and sensory phenomena. Design, Setting, and Participants: Preliminary results from a retrospective case series of US government personnel in Havana, Cuba...
February 15, 2018: JAMA: the Journal of the American Medical Association
Jorge Rey-Martinez, Izaskun Thomas-Arrizabalaga, Juan Manuel Espinosa-Sanchez, Angel Batuecas-Caletrio, Gabriel Trinidad-Ruiz, Eusebi Matiño-Soler, Nicolas Perez-Fernandez
OBJECTIVE: To assess whether there are differences in vestibulo-ocular reflex (VOR) gain for suppression head impulse (SHIMP) and head impulse (HIMP) video head impulse test paradigms, and if so, what are their causes. METHODS: Prospective multicenter observational double-blind nonrandomized clinical study was performed by collecting 80 healthy subjects from four reference hospitals. SHIMP data was postprocessed to eliminate impulses in which early SHIMP saccades were detected...
February 15, 2018: Laryngoscope
Anuj Kumar Neupane, Krithika Gururaj, Sujeet Kumar Sinha
BACKGROUND: Motion sickness is a complex autonomic phenomenon caused by the intersensory conflict among the balancing systems, resulting in a mismatch of signals between static physical conditions of the susceptible individual exposed to dynamic environment. PURPOSE: The present study was done to assess the sacculocollic reflex pathway and six semicircular canals in individuals susceptible to motion sickness. RESEARCH DESIGN: Standard group comparison was used...
February 2018: Journal of the American Academy of Audiology
Millard F Reschke, Scott J Wood, Gilles Clément
BACKGROUND: Ground-based studies have reported shifts of the vestibulo-ocular reflex (VOR) slow phase velocity (SPV) axis toward the resultant gravito-inertial force vector. The VOR was examined during eccentric roll rotation before, during and after an 8-day orbital mission. On orbit this vector is aligned with the head z-axis. Our hypothesis was that eccentric roll rotation on orbit would generate horizontal eye movements. METHODS: Two subjects were rotated in a semi-supine position with the head nasal-occipital axis parallel to the axis of rotation and 0...
2018: Journal of Vestibular Research: Equilibrium & Orientation
László T Tamás, Yunxia W Lundberg, Béla Büki
BACKGROUND: When viewing a far target, the gain of the horizontal vestibulo-ocular reflex (VOR) is around 1.0, but when viewing a near target there is an increased response. It has been shown that while this convergence-mediated modulation is unaffected by canal plugging and clinically practical transmastoid galvanic stimulation, it is eliminated by a partial peripheral gentamicin lesion. OBJECTIVE: The aim of this study was to determine if convergence increases the gain during peripheral hyposensitivity elicited by cold thermal irrigation...
2018: Journal of Vestibular Research: Equilibrium & Orientation
Yawen Yu, Richard T Lauer, Carole A Tucker, Elizabeth D Thompson, Emily A Keshner
The current study aimed to explore the impact of visual dependence on sensorimotor coupling of postural sway and visual motion in adults and teens with spastic cerebral palsy (CP). We hypothesized that individuals with CP would exhibit greater magnitudes of sway than healthy individuals, and the presence of visual dependence (VD) would produce instability in the direction of visual motion. Participants stood in a virtual environment in which the visual scene remained static or continuously rotated 30 degree/second in pitch-up or pitch-down...
January 17, 2018: Developmental Neurorehabilitation
Yusuke Kimura, Takeshi Masuda, Kimitaka Kaga
OBJECTIVES: To evaluate the relationship between vestibular function and gross motor development in children with inner ear malformations. METHODS: A total of 195 children (average age: 2.4 ± 1.6 yr) with profound hearing loss, defined as a hearing threshold greater than 80 dB, participated in this study. Evaluation of vestibular function was assessed in all children using a damped rotational chair test. Gross motor development was assessed by examining the age of acquisition of head control and independent walking...
February 2018: Otology & Neurotology
R Hermann, D Pelisson, O Dumas, Ch Urquizar, E Truy, C Tilikete
The vestibulo-ocular reflex maintains gaze stabilization during angular or linear head accelerations, allowing adequate dynamic visual acuity. In case of bilateral vestibular hypofunction, patients use saccades to compensate for the reduced vestibulo-ocular reflex function, with covert saccades occurring even during the head displacement. In this study, we questioned whether covert saccades help maintain dynamic visual acuity, and evaluated which characteristic of these saccades are the most relevant to improve visual function...
December 16, 2017: Cerebellum
Nils Guinand, Raymond Van de Berg, Samuel Cavuscens, Maurizio Ranieri, Erich Schneider, Floor Lucieer, Herman Kingma, Jean-Philippe Guyot, Angélica Pérez Fornos
The purpose of this study was to evaluate whether it is possible to restore the high-frequency angular vestibulo-ocular reflex (aVOR) in patients suffering from a severe bilateral vestibulopathy (BV) and implanted with a vestibular implant prototype. Three patients (S1-3) participated in the study. They received a prototype vestibular implant with one to three electrode branches implanted in the proximity of the ampullary branches of the vestibular nerve. Five electrodes were available for electrical stimulation: one implanted in proximity of the left posterior ampullary nerve in S1, one in the left lateral and another one in the superior ampullary nerves in S2, and one in the right lateral and another one in the superior ampullary nerves in S3...
2017: Frontiers in Neurology
Britta K Ischebeck, Jurryt de Vries, Jan Paul van Wingerden, Gert Jan Kleinrensink, Maarten A Frens, Jos N van der Geest
To investigate the influence of the amount of cervical movement on the cervico-ocular reflex (COR) and vestibulo-ocular reflex (VOR) in healthy individuals. Eye stabilization reflexes, especially the COR, are changed in neck pain patients. In healthy humans, the strength of the VOR and the COR are inversely related. In a cross-over trial the amplitude of the COR and VOR (measured with a rotational chair with eye tracking device) and the active cervical range of motion (CROM) was measured in 20 healthy participants (mean age 24...
November 17, 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Jorge C Kattah, Cindy Guede, Bahareh Hassanzadeh
BACKGROUND: Bilateral medial vestibular nuclei (MVN) is a common target in thiamine depletion and results in acute vestibular failure. Involvement of the MVN was present in 27 out of 38 brainstem sections reported in the largest thiamine deficiency autopsy cohort with Wernicke's encephalopathy. METHOD: Serial clinical, imaging and vestibulo-ocular reflex gain measured with the video head impulse (vHIT) in one patient with acute thiamine deficiency. RESULTS: Low horizontal VOR gain correlated with an abnormal manual head impulse and with MRI evidence of MVN in an alcohol-dependent patient with low thiamine levels...
January 2018: Journal of Neurology
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