Journal of Vestibular Research - Volume 24, issue 4

Article Type: Editorial

DOI: 10.3233/VES-140521

Citation: Journal of Vestibular Research, vol. 24, no. 4, pp. 265-265, 2014

Authors: De Sá Teixeira, Nuno Alexandre | Hecht, Heiko

Article Type: Research Article

Abstract: Background: When people are asked to indicate the vanishing location of a moving target, errors in the direction of motion (representational momentum) and in the direction of gravity (representational gravity) are usually found. These errors possess a temporal course wherein the memory for the location of the target drifts downwards with increasing temporal intervals between target's disappearance and participant's responses (representational trajectory). Objective: To assess if representational trajectory is a body-referenced or a world-referenced phenomenon. Methods: A behavioral localization method was employed with retention times between 0 and 1400 ms systematically imposed after the …target's disappearance. The target could move horizontally (rightwards or leftwards) or vertically (upwards or downwards). Body posture was varied in a counterbalanced order between sitting upright and lying on the side (left lateral decubitus position). Results: In the upright task, the memory for target location drifted downwards with time in the direction of gravity. This time course did not emerge for the decubitus task, where idiotropic dominance was found. Conclusions: The dynamic visual representation of gravity is neither purely body-referenced nor world-referenced. It seems to be modulated instead by the relationship between the idiotropic vector and physical gravity. Show more

Keywords: Representational momentum, representational gravity, representational trajectory, internal model of gravity, idiotropic vector, spatial perception

DOI: 10.3233/VES-140511

Citation: Journal of Vestibular Research, vol. 24, no. 4, pp. 267-279, 2014

Authors: Jarisch, R. | Weyer, D. | Ehlert, E. | Koch, C.H. | Pinkowski, E. | Jung, P. | Kähler, W. | Girgensohn, R. | Kowalski, J. | Weisser, B. | Koch, A.

Article Type: Research Article

Abstract: Background: Seasickness is a risk aboard a ship. Histamine is postulated as a causative agent, inversely related to the intake of vitamin C. Persons with mastocytosis experienced improvement of nausea after the intake of vitamin C. Objective: To determine whether vitamin C suppresses nausea in 70 volunteers who spent 20 minutes in a life raft, exposed to one-meter-high waves in an indoor pool. Method: Double-blind placebo-controlled crossover study. Two grams of vitamin C or placebo was taken one hour before exposure. Blood samples were taken one hour before and after exposure to determine histamine, …diamine oxidase, tryptase, and vitamin C levels. Symptom scores were noted on a visual analog scale. On the second day the test persons were asked which day they had felt better. Results: Seven persons without symptoms were excluded from the analysis. Test persons had less severe symptoms after the intake of vitamin C (p< 0.01). Scores on the visual analog scale were in favor of vitamin C, but the difference was not significant. Twenty-three of 63 persons wished to leave the raft earlier: 17 after the intake of placebo and 6 after the intake of vitamin C (p< 0.03). Women (p< 0.02) and men below 27 years of age (p< 0.02) had less pronounced symptoms after the intake of vitamin C. Histamine (p< 0.01) and DAO levels were increased after the intake of vitamin C (p< 0.001) and after placebo (n.s.). The fact that the second test day was rated less stressful by most volunteers is indicative of habituation. Conclusions: Some of the data show that vitamin C is effective in suppressing symptoms of seasickness, particularly in women and men younger than 27 years of age, and is devoid of side effects. Histamine levels were initially increased after the test persons had been exposed to waves. Show more

Keywords: Seasickness, histamine, diamine oxidase, vitamin C, German Navy

DOI: 10.3233/VES-140509

Citation: Journal of Vestibular Research, vol. 24, no. 4, pp. 281-288, 2014

Authors: Roth, Thomas N. | Weber, Konrad P. | Wettstein, Vincent G. | Marks, Guy B. | Rosengren, Sally M. | Hegemann, Stefan C.A.

Article Type: Research Article

Abstract: Ethanol affects many parts of the nervous system, from the periphery to higher cognitive functions. Due to the established effects of ethanol on vestibular and oculomotor function, we wished to examine its effect on two new tests of the vestibulo-ocular reflex (VOR): the video head impulse test (vHIT) and dynamic visual acuity (DVA). We tested eight healthy subjects with no history of vestibular disease after consumption of standardized drinks of 40% ethanol. We used a repeated measures design to track vestibular function over multiple rounds of ethanol consumption up to a maximum breath alcohol concentration (BrAC) of 1.38 per mil. …All tests were normal at baseline. VOR gain measured by vHIT decreased by 25% at the highest BrAC level tested in each subject. Catch-up saccades were negligible at baseline and increased in number and size with increasing ethanol consumption (from 0.13° to 1.43° cumulative amplitude per trial). DVA scores increased by 86% indicating a deterioration of acuity, while static visual acuity (SVA) remained unchanged. Ethanol consumption systematically impaired the VOR evoked by high-acceleration head impulses and led to a functional loss of visual acuity during head movement. Show more

Keywords: Ethanol, vestibular, video head impulse test, dynamic visual acuity, vestibulo-ocular reflex (VOR), Saccade

DOI: 10.3233/VES-140520

Citation: Journal of Vestibular Research, vol. 24, no. 4, pp. 289-295, 2014

Authors: Hafstrom, A. | Patel, M. | Modig, F. | Magnusson, M. | Fransson, P.A.

Article Type: Research Article

Abstract: Balance control when standing upright is a complex process requiring input from several partly independent mechanisms such as coordination, feedback and feedforward control, and adaptation. Acute alcohol intoxication from ethanol is recognized as a major contributor to accidental falls requiring medical care. This study aimed to investigate if intoxication at 0.06 and 0.10% blood alcohol concentration affected body alignment. Mean angular positions of the head, shoulder, hip, and knee were measured with 3D-motion analysis and compared with the ankle position in 25 healthy adults during standing with or without perturbations, and with eyes open or closed. Alcohol intoxication had significant …effects on body alignment during perturbed and unperturbed stance, and on adaptation to perturbations. It induced a significantly more posterior alignment of the knees and shoulders, and a tendency for a more posterior and left deviated head alignment in perturbed stance than when sober. The impact of alcohol intoxication was most apparent on the knee alignment, where availability of visual information deteriorated the adaptation to perturbations. Thus, acute alcohol intoxication resulted in inadequate balance control strategies with increased postural rigidity and impaired adaptation to perturbations. These factors probably contribute to the increased risk of falling when intoxicated with alcohol. Show more

Keywords: Ethanol, balance, postural control, vision, adaptation

DOI: 10.3233/VES-140513

Citation: Journal of Vestibular Research, vol. 24, no. 4, pp. 297-304, 2014

Authors: Zur, Oz | Dickstein, Ruth | Dannenbaum, Elizabeth | Carmeli, Eli | Fung, Joyce

Article Type: Research Article

Abstract: Objective: Dynamic visual inputs can cause visual vertigo (VV) in patients with vestibulopathy, leading to dizziness and falls. This study investigated the influence of VV on oculomotor responses. Methods: In this cross-sectional, single-blind study, with experimental and control groups, 8 individuals with vestibulopathy and VV, 10 with vestibulopathy and no VV, and 10 healthy controls participated. Oculomotor responses were examined with 2-dimensional video-oculography. Participants were exposed to dynamic visual inputs of vertical stripes sweeping across a screen at 20 deg/sec, while seated or in Romberg stance, with and without a fixed target. Responses were quantified by optokinetic nystagmus …frequency (OKNf) and gain (OKNg). Results: Seated with no target, VV participants had higher OKNf than controls (37 ± 9 vs. 24 ± 9 peaks/sec; P< 0.05). In Romberg stance with no target, they had higher OKNf than controls (41 ± 9 vs. 28 ± 10 peaks/sec; P< 0.05). With a target, OKNf was higher in VV participants compared to controls (7 ± 7 vs. 1 μ 2 peaks/sec; P< 0.05). In Romberg with no target, OKNg was higher in the VV group (0.8 ± 0.1) compared to controls (0.6 ± 0.2; P=0.024). OKNf and OKNg did not differ according to VV status. Conclusions: VV participants had increased OKNf and OKNg compared to healthy participants. Visual dependency should be considered in vestibular rehabilitation. Show more

Keywords: Oculomotor, visual vertigo, vestibulopathy

DOI: 10.3233/VES-140519

Citation: Journal of Vestibular Research, vol. 24, no. 4, pp. 305-311, 2014

Authors: Sujeet, Kumar Sinha | Niraj, Kumar Singh | Animesh, Barman | Rajeshwari, G. | Sharanya, R.

Article Type: Research Article

Abstract: Auditory neuropathy spectrum disorder is a type of hearing loss where outer hair cell function are normal (as evidenced by the preservation of OAEs and cochlear microphonics), whereas auditory nerve functions are abnormal (as evidenced by abnormal auditory brainstem evoked potentials beginning with wave I of the ABR) and acoustic reflexes to ipsilateral and contralateral tones are absent [32]. It is likely that in cases with auditory neuropathy spectrum disorder not only the cochlear nerve, but also the vestibular nerves might get involved. The present study was conducted with an aim of finding out the inferior and superior vestibular nerve …involvement through cervical vestibular evoked myogenic potentials and Caloric test results respectively in individuals with Auditory Neuropathy Spectrum Disorders. Total 26 participants who fulfilled the criteria of auditory neuropathy spectrum disorder participated for the study. Vestibular evoked myogenic potentials results showed absence of responses from most of the subjects also caloric responses showed bilateral hypofunctional responses in most of the participants, which is suggestive of involvement of both the inferior as well as superior vestibular nerve in individuals with auditory neuropathy spectrum disorders. Additionally there was no association between the pattern and degree of hearing loss to caloric test results and vestibular evoked myogenic potentials results findings. Show more

Keywords: Vestibular, cochlear, VEMP, caloric test

DOI: 10.3233/VES-140510

Citation: Journal of Vestibular Research, vol. 24, no. 4, pp. 313-323, 2014

Article Type: Correction

DOI: 10.3233/VES-140512

Citation: Journal of Vestibular Research, vol. 24, no. 4, pp. 325-325, 2014