scholarly journals Age-Related Changes in Human Vestibulo-Ocular Reflexes: Sinusoidal Rotation and Caloric Tests

1990 ◽  
Vol 1 (1) ◽  
pp. 49-59 ◽  
Author(s):  
R.J. Peterka ◽  
F.O. Black ◽  
M.B. Schoenhoff
Keyword(s):  
Human Subjects ◽  
Normal Population ◽  
Poor Correlation ◽  
Caloric Test ◽  
Compensatory Response ◽  
Ocular Reflex ◽  
Age Related ◽  
Test Parameters ◽  
Vestibulo Ocular Reflex ◽  
Effects Of Aging

The dynamic response properties of horizontal vestibulo-ocular reflex (VOR) were characterized in 216 human subjects ranging in age from 7 to 81 y. The effects of aging on VOR dynamics and parameter distributions that describe VOR responses to caloric and to sinusoidal rotational stimuli were determined in a putatively normal population. Caloric test parameters showed no consistent trend with age. Rotation test parameters showed declining response amplitude and slightly less compensatory response phase with increasing age. The magnitudes of these changes were not large relative to the variability within the population. The age-related trends in VOR were not consistent with the anatomic changes in the periphery reported by others that showed an increasing rate of peripheral hair cell and nerve fiber loss in subjects over 55 y. The poor correlation between physiological and anatomical data suggest that adaptive mechanisms in the central nervous system are important in maintaining the VOR.

scholarly journals Age-Related Changes in Human Vestibulo-Ocular and Optokinetic Reflexes: Pseudorandom Rotation Tests

1990 ◽  
Vol 1 (1) ◽  
pp. 61-71 ◽  
Author(s):  
R.J. Peterka ◽  
F.O. Black ◽  
M.B. Schoenhoff
Keyword(s):  
Visual Information ◽  
Human Subjects ◽  
Normal Population ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Optokinetic Reflex ◽  
Age Related ◽  
Vestibulo Ocular Reflex ◽  
Time Required ◽  
Effects Of Aging

The dynamic response properties of horizontal vestibulo-ocular reflex (VOR) and optokinetic reflex (OKR) were characterized in 216 human subjects ranging in age from 7 to 81 y. The object of this cross-sectional study was to determine the effects of aging on VOR and OKR reflex dynamics, and to identify the distributions of parameters that describe VOR and OKR responses to pseudorandom stimuli in a putatively normal population. In general, VOR and OKR response parameters changed in a manner consistent with declining function with increasing age. For the VOR this was reflected in declining response amplitudes, although the magnitude of the decline was small relative to the variability of the data. For the OKR the lag time of the response, probably associated with the time required for visual information processing, increased linearly with age at a rate of about 1 ms per year.

The vertical vestibulo-ocular reflex, and its interaction with vision during active head motion: Effects of aging

2001 ◽  
Vol 11 (1) ◽  
pp. 3-12
Author(s):  
Ji Soo Kim ◽  
James A. Sharpe
Keyword(s):  
Smooth Pursuit ◽  
Low Frequency ◽  
The Elderly ◽  
Head Motion ◽  
Head Tracking ◽  
Elderly Age ◽  
Ocular Reflex ◽  
Visual Enhancement ◽  
Vestibulo Ocular Reflex ◽  
Effects Of Aging

The effects of aging on the vertical vestibulo-ocular reflex (VOR), and its interactions with vision during active head motion had not been investigated. We measured smooth pursuit, combined eye-head tracking, the VOR, and its visual enhancement and cancellation during active head motion in pitch using a magnetic search coil technique in 21 younger (age < 65) and 10 elderly (age ⩾ 65) subjects. With the head immobile, subjects pursued a target moving sinusoidally with a frequency range of 0.125 to 2.0 Hz, and with peak target accelerations (PTAs) ranging from 12 to 789Âř/s 2 . Combined eye-head tracking, the VOR in darkness, and its visual enhancement during fixation of an earth-fixed target (VVOR) were measured during active sinusoidal head motion with a peak-to-peak amplitude of 20Âř at frequencies of 0.25, 0.5, 1.0 and 2.0 Hz. The efficacy of VOR cancellation was determined from VOR gains during combined eye-head tracking. VOR and VVOR gains were symmetrical in both directions and did not change with aging, except for reduced gains of the downward VOR and VVOR at low frequency (0.25 Hz). However, in the elderly, smooth pursuit, and combined eye-head tracking gains and the efficacy of cancellation of the VOR were significantly lower than in younger subjects. In both the young and elderly groups, VOR gain in darkness did not vary with the frequency of active head motion while the gains of smooth pursuit, combined eye-head tracking, and VVOR declined with increasing target frequency. VOR and VVOR performance in the elderly implicates relative preservation of neural structures subserving vertical vestibular smooth eye motion in senescence.

scholarly journals New advances regarding adaptation of the vestibulo-ocular reflex

2019 ◽  
Vol 122 (2) ◽  
pp. 644-658 ◽  
Author(s):  
Michael C. Schubert ◽  
Americo A. Migliaccio
Keyword(s):  
Training Session ◽  
Whole Body ◽  
Velocity Error ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Vor Adaptation ◽  
Effects Of Aging ◽  
Repeated Training ◽  
Head Rotations ◽  
Efferent Vestibular System

This is a review summarizing the development of vestibulo-ocular reflex (VOR) adaptation behavior with relevance to rehabilitation over the last 10 years and examines VOR adaptation using head-on-body rotations, specifically the influence of training target contrast, position and velocity error signal, active vs. passive head rotations, and sinusoidal vs. head impulse rotations. This review discusses optimization of the single VOR adaptation training session, consolidation between repeated training sessions, and dynamic incremental VOR adaptation. Also considered are the effects of aging and the roles of the efferent vestibular system, cerebellum, and otoliths on angular VOR adaptation. Finally, this review examines VOR adaptation findings in studies using whole body rotations.

Plasticity in the adult vestibulo-ocular reflex arc

1977 ◽  
Vol 278 (961) ◽  
pp. 319-334 ◽  
Keyword(s):  
Human Subjects ◽  
Neural Model ◽  
Reflex Response ◽  
Normal Vision ◽  
Ocular Reflex ◽  
Field Of Vision ◽  
Reflex Arc ◽  
Vestibulo Ocular Reflex ◽  
Plastic Changes

Human subjects with maintained reversal of their horizontal field of vision exhibit very substantial adaptive changes in their ‘horizontal’ vestibulo-ocular reflex (v.o.r.). Short durations (8 min) of vision reversal during natural head movement led to 20 % v.o.r. attenuation while long periods (4 weeks) eventually led to approximate reversal of the reflex. The reversed condition is approached by a complex, but highly systematic, series of changes in gain and phase of the reflex response relative to normal. Recovery after return to normal vision exhibits a similar duration, but different pattern, to that of the original adaptation. A chronic cat preparation with long-term optical reversal of vision has now been developed and shows similar adaptive and recovery changes at low test stimulus amplitudes, but different patterns of adaptive response at high amplitudes. An adaptive neural model employing mown vestibulo-ocular pathways is proposed to account for these experimentally observed plastic changes. The model is used to predict the adapted response to patterns of stimulation extending beyond the range of experimental investigation.

S223 – Effect of Myopia on the Caloric Test

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P150-P150
Author(s):  
Alok Thakar
Keyword(s):  
Retinal Image ◽  
Contact Lenses ◽  
Significant Proportion ◽  
Control Group ◽  
Caloric Test ◽  
Case Group ◽  
Direct Evaluation ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
The Impact

Objectives To assess the impact of corrected myopia on the caloric test. Correction of myopia with spectacles or contact lenses results in alteration of the size of the retinal image. Previous laboratory experiments have demonstrated that gross changes in the size of the retinal image can result in recalibration or suppression of the vestibulo-ocular reflex (VOR). Methods Case-control study. 17 evaluable healthy volunteers with myopia corrected either by spectacles or contact lenses (case group) compared to 17 volunteers with no refractive error (control group). Complete Electro-Nystagmography inclusive of bithermal caloric testing undertaken for cases and controls. Assessment of hypoactive caloric responses based on normative laboratory values. Results 7 of 17 cases and 1 of 17 controls demonstrated hypoactive caloric responses. In the spectacle users group, 6 of 11 (55%) had hypoactive responses. Spectacle users were significantly more likely than emmetropic controls to have hypoactive caloric responses (p<0.01; relative risk 9.3 {95 % Confidence Interval 1.3 to 66.9}). Conclusions 1) A significant proportion of myopes using spectacles have suppression of the vestibulo-ocular reflex as demonstrated by the caloric test. This has implications for the interpretation of ENG results, and also as a cause of vestibular impairment. 2) Further studies in myopes are warranted for precise and direct evaluation of the VOR by rotation or impulse testing.

Predictive Mechanisms of Head-Eye Coordination and Vestibulo-Ocular Reflex Suppression in Humans

1992 ◽  
Vol 2 (3) ◽  
pp. 193-212 ◽  
Author(s):  
G.R. Barnes ◽  
M.A. Grealy
Keyword(s):  
Peak Velocity ◽  
Human Subjects ◽  
Head Movements ◽  
Whole Body ◽  
Head Velocity ◽  
The Gaze ◽  
Ocular Reflex ◽  
Sinusoidal Motion ◽  
Smooth Component ◽  
Vestibulo Ocular Reflex

Head and eye movements of human subjects have been recorded during head-free pursuit in the horizontal plane of a target executing sinusoidal motion at a frequency of 0.26 to 0.78 Hz and a peak velocity of ±96∘/s. The target was not presented continuously but was exposed for brief durations of 120 to 320 ms as it passed through the centre of the visual field at peak velocity. This technique allowed the timing of each response to be assessed in relation to the onset of target appearance. During the first 3 to 4 target presentations, there was a progressive buildup of both head velocity and the smooth component of gaze velocity, while, simultaneously, the responses became more phase-advanced with respect to target onset. In the steady state, similar temporal response trajectories were observed for head and gaze velocity, which were initiated approximately 500 ms prior to target on-set, rose to a peak that increased with the duration of target exposure, and then decayed with a time constant of 0.5 to 1 s. Whenever the target failed to appear as expected, the gaze and head velocity trajectories continued to be made, indicating that predictive suppression of the vestibulo-ocular reflex (VOR) was taking place in darkness. In a further experiment, subjects attempted to suppress the VOR during whole body oscillation at 0.2 or 0.4 Hz on a turntable by fixating, a head-fixed target that appeared for 10 to 160 ms at the time of peak head velocity. Again, VOR suppression was initiated prior to target appearance in the same manner as for natural head movements, and when the target suddenly disappeared but rotation continued, predictive VOR suppression was observed in darkness. The similarity of these predictive effects to those obtained previously for head-fixed pursuit provides further support for the hypothesis that both pursuit and visual suppression of the VOR are controlled primarily by identical visual feedback mechanisms.

Age-Related Vestibular Dysfunction; Vestibulo-Ocular Reflex, Dynamic Visual Acuity, Dizziness and Falls: A Review

2021 ◽  
pp. 279-292
Keyword(s):  
Visual Acuity ◽  
Balance Control ◽  
Vestibular Dysfunction ◽  
Posture Control ◽  
Complex Nature ◽  
Dynamic Visual Acuity ◽  
Ocular Reflex ◽  
Gaze Stability ◽  
Age Related ◽  
Vestibulo Ocular Reflex

Background: Vestibular and vision functions are important contributors to posture control and fall avoidance. This review examines how the vestibulo-ocular reflex can be rehabilitated to help restore postural control. Methods: PubMed searches (7th April 2021) using the terms ‘vestibulo-ocular reflex’, ‘imbalance and vestibular dysfunction’, ‘vestibular dysfunction and dizziness’, ‘dynamic visual acuity’, ‘vestibular dysfunction rehabilitation’, and ‘gaze stabilization exercises’ yielded 4986, 495, 3576,1830, 3312, and 137 potentially useful publications respectively. Selections of those which were found to be the most relevant and representative of a balanced and current account of these topics, as well as selections from the most relevant reports referenced in those publications, were included in this review. Results: Just as there are age-related losses of static visual acuity even when there are no specific visual pathologies diagnosed, patients may also present with age-related loss of vestibular functions in the absence of specific vestibular pathologies. For example, cases of dizziness which are diagnosed as idiopathic might be usefully classified as age-related as the basis for the initiation of rehabilitation exercises. Conclusions: Apart from age-related loss of vestibular functions, cases diagnosed as having a particular form of vestibular pathology may have that condition exacerbated by age-related losses of vestibular functions. The effects of vestibular rehabilitation gaze stability exercises in patients with vestibular dysfunction are well established and include both improved dynamic acuity and postural stability. Improvements in posture control following rehabilitation of the vestibulo-ocular reflex are apparently due to improved peripheral and/or central vestibular balance control which has occurred in conjunction with enhanced gaze stability. The complex nature of increased fall risk suggests that an interdisciplinary approach to rehabilitation that includes vestibulo-ocular reflex rehabilitation appears likely to be associated with optimum outcomes for both pathological and age-related cases.

Visual-Vestibular Interaction in Humans During Active and Passive, Vertical Head Movement1

1993 ◽  
Vol 3 (2) ◽  
pp. 101-114
Author(s):  
Joseph L. Demer ◽  
John G. Oas ◽  
Robert W. Baloh
Keyword(s):  
Head Movement ◽  
Human Subjects ◽  
Single Frequency ◽  
Normal Vision ◽  
Frequency Range ◽  
Gain Enhancement ◽  
Ocular Reflex ◽  
Sinusoidal Motion ◽  
Visual Vestibular Interaction ◽  
Vestibulo Ocular Reflex

We studied visual-vestibular interaction (VVI) in 9 normal human subjects using active and passive vertical head rotations. Gain and phase of the vertical vestibulo-ocular reflex (VOR) and visually enhanced vestibulo-ocular reflex (VVOR) were measured for single frequency sinusoidal motion, as well as for sinusoidal motion of continuously increasing frequency, over the range of 0.4 to 4.0 Hz. In addition to measurement of VVOR during normal vision, telescopic spectacles having a magnification of 1.9× were used to challenge VVI to facilitate measurement of visual enhancement of VOR gain. In the mid-frequency range (1.6 to 2.4 Hz), the active VOR exhibited gain closer to compensatory than did the passive VOR; at other frequencies, active and passive VOR gains were similar. VVOR gain during normal vision was compensatory for both active and passive motion throughout the frequency range tested. VVOR gain with 1.9× telescopic spectacles was greater than VOR gain at all frequencies tested, including up to 3.2 Hz for passive bead movements, and up to 4.0 Hz for active head movement. However, gain enhancement with telescopic spectacles was consistently greater during active than during passive head movement. Phase errors for the VOR and VVOR were small under all testing conditions. Although active VOR and VVOR were directionally symmetrical, gain of upward slow phases differed from that of downward slow phases for passive VOR and VVOR in a manner depending on rotational frequency. For both active and passive testing, gain and phase values obtained during swept frequency rotations were similar to those obtained during single frequency sinusoidal testing. These data indicate that VVI can enhance gain of the passive vertical VOR even at frequencies above what is usually considered to be the upper limit of visual pursuit tracking. The additional enhancement observed during active bead movements at these high frequences is attributable to use of efference copy of the skeletal motor command to neck musculature.

Effect of aging on the otolith-ocular reflex

2001 ◽  
Vol 11 (2) ◽  
pp. 91-103
Author(s):  
Joseph M. Furman ◽  
Mark S. Redfern
Keyword(s):  
Semicircular Canal ◽  
Head Tilt ◽  
Vestibular Function ◽  
Vertical Axis ◽  
Ocular Reflex ◽  
Age Related ◽  
Vestibulo Ocular Reflex ◽  
Older Subjects ◽  
Axis Rotation ◽  
Reflex Time

We assessed the influence of age on the otolith-ocular reflex and semicircular canal-otolith interaction. Healthy young (n=30) and healthy older (n=60) subjects were rotated about an earth vertical axis, and about a 30 degree off-vertical axis. Eye movements during and following rotation were recorded using electro-oculography. Results indicated that there were statistically significant changes in the otolith-ocular reflex and semicircular canal-otolith interaction as a function of age. The modulation component during off-vertical axis rotation (OVAR) was greater in the older group compard to the young adults, whereas the bias component was smaller with advanced age. The foreshortening of the vestibulo-ocular reflex time constant induced by post-rotatory head tilt following cessation of rotation was less prominent in the older group. There were no consistent changes in the semicircular canal-ocular reflex. Overall, response parameters showed more variability in the older subjects. We conclude that age related changes in the otolith-ocular reflex and semicircular canal-otolith interaction are a result primarily of a degradation of central vestibular processing of otolith signals rather than a decline of peripheral vestibular function.

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