otoliths center of pressure

BACKGROUND: Balance assessments that intentionally alter the reliability of visual and proprioceptive feedback (e.g., standing on foam with eyes closed) have become a standard approach for identifying vestibular mediated balance dysfunction in older adults. However, such assessments cannot discern which specific element of the vestibular system (e.g., semicircular canal, otolith, or combined canal-otolith) underlies the observed age-related changes in balance performance. The present study was designed to determine the associations between specific sources of vestibular noise and quantitative measures of quiet stance postural control measured during standard "vestibular" balance conditions...

INTRODUCTION: The vestibular system integrates signals related to vision, head position, gravity, motion, and body position to provide stability during motion through the environment. Disruption in any of these systems can reduce agility and lead to changes in ability to safely navigate one's environment. Causes of vestibular decline are diverse; however, excessive noise exposure can lead to otolith organ dysfunction. Specifically, 120 decibel (dB) sound pressure level (SPL) 1.5 kHz-centered 3-octave band noise (1...

PURPOSE: To delineate the association between otolithic dysfunction and orthostatic hypotension (OH). METHODS: We retrospectively reviewed the medical records of 382 patients who presented with orthostatic dizziness at a tertiary dizziness center between July 2017 and December 2021. Patients were included for analyses when they had completed ocular (oVEMP) and/or cervical vestibular-evoked myogenic potentials (cVEMP), and head-up tilt table test with a Finometer (n = 155)...

This paper describes a series of studies resulting from the finding that when free floating in weightless conditions with eyes closed, all sense of one's spatial orientation with respect to the aircraft can be lost. But, a touch of the hand to the enclosure restores the sense of spatial anchoring within the environment. This observation led to the exploration of how light touch of the hand can stabilize postural control on Earth even in individuals lacking vestibular function, and can override the effect of otherwise destabilizing tonic vibration reflexes in leg muscles...

Patients with bilateral vestibular failure (BVF) suffer from postural and gait unsteadiness with an increased risk of falls. The aim of this study was to elucidate the differential role of otolith, semicircular canal (SSC), visual, proprioceptive, and cognitive influences on the postural stability of BVF patients. Center-of-pressure displacements were recorded by posturography under six conditions: target visibility; tonic head positions in the pitch plane; horizontal head shaking; sensory deprivation; dual task; and tandem stance...

Achilles tendon vibration generates proprioceptive information that is incongruent with the actual body position; it alters the perception of body orientation leading to a vibration-induced postural response. When a person is standing freely, vibration of the Achilles tendon shifts the internal representation of the verticality backward thus the vibration-induced postural response realigned the whole body orientation with the shifted subjective vertical. Because utricular otoliths information participates in the creation of the internal representation of the verticality, changing the natural orientation of the head-neck system during Achilles tendon vibration could alter the internal representation of the earth vertical to a greater extent...

OBJECTIVES/HYPOTHESIS: Repair of superior canal dehiscence (SCD) often results in the resolution of preoperative auditory and vestibular symptoms; however, many patients experience dizziness in the postoperative period. Postoperative dizziness may be the result of new-onset benign paroxysmal positional vertigo (BPPV). This study aims to investigate the prevalence of BPPV before and following SCD repair. STUDY DESIGN: Retrospective chart review at a tertiary care center...

Most fish studied to date efficiently compensate for a hypercapnic acid-base disturbance; however, many recent studies examining the effects of ocean acidification on fish have documented impacts at CO2 levels predicted to occur before the end of this century. Notable impacts on neurosensory and behavioral endpoints, otolith growth, mitochondrial function, and metabolic rate demonstrate an unexpected sensitivity to current-day and near-future CO2 levels. Most explanations for these effects seem to center on increases in Pco2 and HCO3- that occur in the body during pH compensation for acid-base balance; however, few studies have measured these parameters at environmentally relevant CO2 levels or directly related them to reported negative endpoints...

INTRODUCTION: Physical disability is the most common disability (10.3 %) in the central area of Chile. The cerebral palsy is one of the diseases that generates motor deficits and loss of balance. Balance is crucial for maintaining postural stability. OBJECTIVE: To establish the differences in area and average velocity of the center of pressure between typically developing children and cerebral palsy patients, and to determine the degree of use of different sensory systems...

UNLABELLED: Benign Paroxysmal Positional Vertigo is highly prevalent in the elderly population, triggering major changes in body balance. OBJECTIVE: To compare the results obtained from static posturography in the elderly before and after otoliths repositioning maneuvers and 12 months after treatment onset. DESIGN: longitudinal, descriptive and analytical study. METHOD: Elderly patients with clinical diagnosis of BPPV submitted to Balance Rehabilitation Unit static posturography in 10 sensory conditions at three time intervals: before and after the repositioning maneuver and12 months after the treatment RESULTS: We studied 23 subjects with a mean age of 68...

The responses to vestibular stimulation of brain stem neurons that regulate sympathetic outflow and blood flow have been studied extensively in decerebrate preparations, but not in conscious animals. In the present study, we compared the responses of neurons in the rostral ventrolateral medulla (RVLM), a principal region of the brain stem involved in the regulation of blood pressure, to whole body rotations of conscious and decerebrate cats. In both preparations, RVLM neurons exhibited similar levels of spontaneous activity (median of ∼17 spikes/s)...

CONTEXT: Sport training enhances the ability to use somatosensory and otolithic information, which improves postural capabilities. Postural changes are different according to the sport practiced, but few authors have analyzed subjects' postural performances to discriminate the expertise level among highly skilled athletes within a specific discipline. OBJECTIVE: To compare the postural performance and the postural strategy between soccer players at different levels of competition (national and regional)...

Benign paroxysmal positional vertigo (BPPV) is a mechanical disorder of the vestibular system in which calcite particles called otoconia interfere with the mechanical functioning of the fluid-filled semicircular canals normally used to sense rotation. Using hydrodynamic models, we examine the two mechanisms proposed by the medical community for BPPV: cupulolithiasis, in which otoconia attach directly to the cupula (a sensory membrane), and canalithiasis, in which otoconia settle through the canals and exert a fluid pressure across the cupula...

We present a multisensory postural control model based on experiments where the balance in normal subjects and vestibular loss patients was perturbed by application of external torque produced by force-controlled pull stimuli. The stimuli were applied while subjects stood on a stationary or body-sway-referenced motion platform with eyes closed and auditory cues masked. Excursions of the center of mass (COM) and the center of pressure (COP) were analyzed using a systems analysis approach. The results were compared to an 'inverted pendulum' model of posture control...

To better understand the mechanisms of human adaptation to rotating environments, we exposed 19 healthy subjects and 8 vestibular-deficient subjects ("abnormal"; four bilateral and four unilateral lesions) to an interaural centripetal acceleration of 1 g (resultant 45 degrees roll-tilt of 1.4 g) on a 0.8-m-radius centrifuge for periods of 90 min. The subjects sat upright (body z-axis parallel to centrifuge rotation axis) in the dark with head stationary, except during 4 min of every 10 min, when they performed head saccades toward visual targets switched on at 3- to 5-s intervals at random locations (within +/- 30 degrees) in the earth-horizontal plane...

Our goal was to provide some insights into how the CNS controls and maintains an upright standing posture, which is an integral part of activities of daily living. Although researchers have used simple performance measures of maintenance of this posture quite effectively in clinical decision making, the mechanisms and control principles involved have not been clear. We propose a relatively simple control scheme for regulation of upright posture that provides almost instantaneous corrective response and reduces the operating demands on the CNS...

In the clupeid fishes, the functionally specialized utricle and cephalic lateral line respond to sound pressure by virtue of their mechanical coupling to the auditory bullae. The cytoarchitecture of, and primary inputs to, the octavolateralis area were studied in the gizzard shad, Dorosoma cepedianum, in order to determine whether first-order acoustic and lateral line areas of the medulla are likewise specialized. The octavolateralis area of Dorosoma is composed of the nuclei that have been observed in other teleosts: nucleus medialis, the descending and anterior octaval nuclei, nucleus magnocellularis, nucleus tangentialis, and a caudal granular-cell region that likely represents nucleus caudalis and the posterior octaval nucleus...

In the present work 30 normal adult subjects (20 males, 10 females; age range 25-40 years) having no signs or symptoms of vestibular involvement were studied in order to verify whether posturographic parameters could be influenced by the static stimulation of cervical and otolithic receptors. The posturographic evaluation was carried out using a stabilometric platform (Bertec) with the subject standing and the head in one of the following positions: median position, turned left (45 degrees), turned right (45 degrees), tilted left (40 degrees), tilted right (40 degrees), with eyes both opened and closed...