Visual-Vestibular Interaction Upon Nystagmus Slow Phase Velocity In Man

1978 ◽  
Vol 85 (1-6) ◽  
pp. 397-410 ◽  
Author(s):  
E. Koenig ◽  
J. H. J. Allum ◽  
J. Dichgans
1983 ◽  
Vol 91 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Carsten Wennmo ◽  
Nils Gunnar Henriksson ◽  
Bengt Hindfelt ◽  
Ilmari PyykkÖ ◽  
MÅNs Magnusson

The maximum velocity gain of smooth pursuit and optokinetic, vestibular, and optovestibular slow phases was examined in 15 patients with pontine, 10 with medullary, 10 with cerebellar, and 5 with combined cerebello — brain stem disorders. Marked dissociations were observed between smooth pursuit and optokinetic slow phases, especially in medullary disease. A cerebellar deficit enhanced slow phase velocity gain during rotation in darkness, whereas the corresponding gain during rotation in light was normal.


1999 ◽  
Vol 9 (1) ◽  
pp. 59-61
Author(s):  
Kate H. McDermott ◽  
Anna J. Matheson ◽  
Nikoli Titov ◽  
Cynthia L. Darlington ◽  
Paul F. Smith

Previous studies have shown that experience with optokinetic stimulation can alter a subject's sensitivity to illusions such as circularvection (CV). The aim of the present experiment was to compare optokinetic nystagmus (OKN), optokinetic afternystagmus (OKAN), and sensitivity to CV between 2 groups of sportspeople: 1) squash players (n=16), who regularly experience vigorous optokinetic stimulation while engaging in their sporting activity, and 2) weightlifters (n=16), whose sport does not involve the same degree of optokinetic stimulation as squash, but who nevertheless have to achieve a high degree of physical skill. OKN, OKAN (frequency, slow phase velocity, and timeconstant), and latency to CV (Stage 2 and Stage 3) were measured using electro-oculographic recording inside an optokinetic drum. Contrary to predictions,there were no significant differences in OKN, OKAN, or latency to CV between the 2 groups. These results suggest that 1) the practice effects that alter the sensitivity to CV may decay relatively quickly, and 2) differences in recreational sporting activities between subjects may not be a significant confounding factor in visual-vestibular interaction experiments.


2020 ◽  
Vol 29 (2) ◽  
pp. 188-198
Author(s):  
Cynthia G. Fowler ◽  
Margaret Dallapiazza ◽  
Kathleen Talbot Hadsell

Purpose Motion sickness (MS) is a common condition that affects millions of individuals. Although the condition is common and can be debilitating, little research has focused on the vestibular function associated with susceptibility to MS. One causal theory of MS is an asymmetry of vestibular function within or between ears. The purposes of this study, therefore, were (a) to determine if the vestibular system (oculomotor and caloric tests) in videonystagmography (VNG) is associated with susceptibility to MS and (b) to determine if these tests support the theory of an asymmetry between ears associated with MS susceptibility. Method VNG was used to measure oculomotor and caloric responses. Fifty young adults were recruited; 50 completed the oculomotor tests, and 31 completed the four caloric irrigations. MS susceptibility was evaluated with the Motion Sickness Susceptibility Questionnaire–Short Form; in this study, percent susceptibility ranged from 0% to 100% in the participants. Participants were divided into three susceptibility groups (Low, Mid, and High). Repeated-measures analyses of variance and pairwise comparisons determined significance among the groups on the VNG test results. Results Oculomotor test results revealed no significant differences among the MS susceptibility groups. Caloric stimuli elicited responses that were correlated positively with susceptibility to MS. Slow-phase velocity was slowest in the Low MS group compared to the Mid and High groups. There was no significant asymmetry between ears in any of the groups. Conclusions MS susceptibility was significantly and positively correlated with caloric slow-phase velocity. Although asymmetries between ears are purported to be associated with MS, asymmetries were not evident. Susceptibility to MS may contribute to interindividual variability of caloric responses within the normal range.


1979 ◽  
Vol 88 (1) ◽  
pp. 79-85 ◽  
Author(s):  
James W. Wolfe

Twenty-five normal subjects and 173 clinical patients received standard bithermal caloric testing. Vestibular nystagmus was evaluated for cumulative slow phase velocity from the summated horizontal eye recording and independent recording of the left and right eye. These data revealed that cold water stimulation produced more intense activation of the ipsilateral eye. Simultaneous closed-circuit video and D.C. electro-oculographic recordings from eight normal rhesus monkeys in response to cold water irrigations confirmed the fact that this stimulus leads to differential activation of the extraocular muscles. A possible explanation for this finding is discussed.


2008 ◽  
Vol 17 (5-6) ◽  
pp. 313-321
Author(s):  
E.I. Matsnev ◽  
E.E. Sigaleva

The purpose of this investigation was to evaluate the efficacy of the histaminergic drug "Betahistine dihydrochloride" in experimental motion sickness in 10 healthy volunteers (mean age 19.4 y.o.) with high susceptibility to motion sickness. Motion sickness was modeled using Coriolis (precession) accelerations (cumulative Coriolis stimulation test – CCST). Each subject took 32 mg of "Betahistine dihydrochloride" or placebo under "double – blind" conditions 1 hour before testing. The duration and slow phase velocity of the post-rotational nystagmus, the pursuit eye tracking test, and the latency, velocity and accuracy of saccades were estimated. The tolerability level of the CCST in volunteers in the betahistine series was shown to be significantly (p < 0.001) higher, as compared to placebo and baseline. The mean illusory sensations score for the experimental series was significantly lower than that in the placebo and baseline series (p < 0.01). It was found that "Betahistine" demonstrated antimotion sickness efficacy and improved oculomotor activity (increased gain during pursuit movements, faster and more accurate saccades).


1982 ◽  
Vol 96 (7) ◽  
pp. 599-612 ◽  
Author(s):  
P. G. Davey ◽  
E. S. Harpur ◽  
F. Jabeen ◽  
D. Shannon ◽  
P. M. Shenoi

AbstractExperiments were performed on 25 otoneurologically ‘normal’ subjects to evaluate the hot caloric test as a screening test for aminoglycoside vestibular toxicity.Using portable equipment under non-ideal conditions, it was found that there was a large inter-subject variability in nystagmic response and that, instead of a random test-retest variability, a systagmic variation in response occurred on repeated caloric stimulation with water at 44°C.A response deline (habituation) evident in both the maximum slow phase velocity and the maximum frequency occurred at second test, although the inter-test interval ranged from 24 to 72 hours.After a 3-month interval with no intervening tests, the mean value of the maximum frequency reverted back to the original level. However, there was still a significant reduction in maximum slow phase velocity at this time. Some individuals had a sustanined reduction in both parameters.Hence it is concluded that the hot caloric test, used under the conditions described in this study, is not a suitable serial screening method for aminoglycoside vestibular toxicity. The reproducibility of this test under other conditions, or any other caloric test, should be established in normal subjects befre employing, it as a serial screen for aminoglycoside vestibular toxicity.


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