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Sensing gravity through the otolith receptors is crucial for bipedal stability and gait. The overall contribution of the otolith organs to eye movements, postural control, and perceptual functions is the basis for clinical testing of otolith function. With such a wide range of contributions, it is important to recognize that the functional outcomes of these tests may vary depending on the specific method employed to stimulate the hair cells. In this article, we review common methods used for clinical evaluation of otolith function and discuss how different aspects of physiology may affect the functional measurements in these tests. We compare the properties and performance of various clinical tests with an emphasis on the newly developed video ocular counter roll (vOCR), measurement of ocular torsion on fundus photography, and subjective visual vertical or horizontal (SVV/SVH) testing. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To determine whether patients with acute unilateral peripheral vestibulopathy (PVP), often called "vestibular neuritis/neuronitis or neuropathy" (VN) have a vestibular lesion pattern consistent with the distribution of the neurological afferents. BACKGROUND: Much is known about the clinical nature of PVP, however less so about its etiology and pathogenesis. Due to the frequency with which VN is used to describe the syndrome, an inflammation of the vestibular nerve or of one of its branches is often assumed to be the cause of PVP, though there is insufficient data so far to support this assumption. METHODS: We conducted a retrospective study of 25 patients who had presented to our clinic with PVP and had all vestibular receptor organs tested shortly after start of symptoms. We analysed their vestibular lesion patterns in order to determine whether they were consistent with the neuritis hypothesis (NH). RESULTS: The lesion patterns varied conspicuously. 76% did not follow an innervation pattern, thereby contradicting the NH and only 24% had a lesion pattern that either definitely (16%) or probably (8%) supported the NH. CONCLUSION: These results should remind us to be careful before jumping to quick conclusions about the pathogenetic nature of PVP. With any reason to question VN as the only cause of PVP, we should reconsider the treatment approach to PVP. If the cause probably or even possibly lies inside the vestibular labyrinth, an intratympanic steroid injection might prove to be a more effective measure, even in first-line treatment. If the etiology is unsure, a combination of systemic and intratympanic steroid treatment may be adequate. [ABSTRACT FROM AUTHOR]

Background: Dizziness is frequently encountered in medical practice, often takes a chronic course and can impair the health related quality of life (HRQoL). However results on the extent of this impairment of HRQoL are mixed. Furthermore, the relationship between dizziness and the HRQoL is only partially understood. The role of clinical symptoms of dizziness and psychosocial factors such as emotional distress on this relationship is for the most part unknown. Methods: The cross-sectional study evaluated the HRQoL in 203 patients suffering from dizziness, using the Medical Outcomes Studies 36-Item Short-Form Health-Survey (SF-36). The results were correlated with the severity of dizziness, using the Dizziness Handicap-Inventory (DHI), with emotional distress, using the Hospital Anxiety and Depression-Scale (HADS) and with further clinical symptoms and psychosocial parameters. In a multivariate hierarchical regression analysis associated variables which explain significant variance of the mental and physical HRQoL (MCS-36, PCS-36) were identified. Results: Patients suffering from dizziness showed a markedly reduced mental and physical HRQoL. Higher DHI and HADS scores were correlated with lower MCS-36 and PCS-36 scores. Taken together DHI and vertigo characteristics of dizziness explained 38% of the variance of PCS-36. Overall explained variance of PCS-36 was 45%. HADS and living with a significant other explained 66% of the variance of MCS-36 (overall variance explained: 69%). Conclusion: Both the physical and mental HRQoL are significantly impaired in patients with dizziness. While the impairment in PCS-36 can be explained by clinical symptoms of the dizziness, MCS-36 impairment is largely associated with psychosocial factors. To improve the patient’s overall well-being significantly and permanently doctors have to keep in mind both, the clinical symptoms and the psychosocial factors. Therefore, in addition to the physical examination doctors should integrate a basic psychological examination into the daily routine with dizziness patients. [ABSTRACT FROM AUTHOR]

Conclusion: In spite of its absence in the control population, there is questionable evidence for the alteration c.114C->T in the HMX3 gene being implicated in the development of superior semicircular canal dehiscence (SSCD). However, the concept of a complex disease is valid for SSCD and a possible molecular origin can neither be confirmed nor excluded by the results of this study. Objectives: SSCD was first described in 1998 by Minor et al. While the etiology is not clear, findings from both temporal bone CT and histologic studies suggest a congenital or developmental origin. In recent years, a couple of genes regulating inner ear morphogenesis have been described. Specifically, Netrin-1 and HMX3 have been shown to be critically involved in the formation of the SCC. Molecular alterations in these two genes might lead to a disturbed development of this canal and might represent an explanation for SSCD. Methods: DNA was extracted from whole blood of 15 patients with SSCD. The coding sequences of Netrin-1 and HMX3 were amplified by PCR and sequenced. Results: One sequence alteration, heterozygous c.114C->T (conservative change without alteration of amino acid) in exon 1 of HMX3, was detected in 2 of 15 patients but not in 300 control chromosomes. The study was supported in part by the Emilia-Guggenheim-Schnurr-Foundation, Basel, Switzerland. [ABSTRACT FROM AUTHOR]

Objective: We investigated the effect of alcohol on the cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs). As alcohol produces gaze-evoked nystagmus (GEN), we also tested the effect of nystagmus independent of alcohol by recording oVEMPs during optokinetic stimulation (OKS)., Methods: The effect of alcohol was tested in 14 subjects over multiple rounds of alcohol consumption up to a maximum breath alcohol concentration (BrAC) of 1.5‰ (mean 0.97‰). The effect of OKS was tested in 11 subjects at 5, 10 and 15deg/sec., Results: oVEMP amplitude decreased from baseline to the highest BrAC level by 27% (range 5-50%, P<0.001), but there was no significant effect on oVEMP latency or cVEMP amplitude or latency. There was a significant negative effect of OKS on oVEMP amplitude (16%, P=0.006)., Conclusions: We found a selective effect of alcohol on oVEMP amplitude, but no effect on the cVEMP. Vertical nystagmus elicited by OKS reduced oVEMP amplitude., Significance: Alcohol selectively affects oVEMP amplitude. Despite the effects of alcohol and nystagmus, both reflexes were reliably recorded in all subjects and conditions. An absent response in a patient affected by alcohol or nystagmus indicates a vestibular deficit., (Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

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.

Background: The aim of his study was to evaluate the reliability and validity of the Expanded Timed Get-up-and-Go (ETGUG) test in patients with bilateral vestibular loss (BVL)., Methods: 21 BVL patients (58 ± 14 years) were recruited and measured twice by two raters. After a one hour break ETGUG was repeated by the first rater. 21 age matched controls (CON; 58 ± 14 years) were measured once by the first rater. All time scores of the ETGUG for the separate tasks and gait speed calculated from tasks 3 and 5 were analysed to determine relative and absolute reliability, smallest detectable change (SDC) and discriminatory capabilities., Results: The ETGUG scores showed good to excellent inter-rater (ICC2,1 = 0.85-0.97) and test-retest reliability (ICC3,1 = 0.86-0.98) following log-transformation for tasks 2-6. Task1 scored fair r = 0.46-0.68. The SDCs were small (SDC = 0.05-0.21 seconds). Bland-Altman plots demonstrated good agreement between the measurements. There were significant differences between BVL and CON in ETGUG scores for tasks 1, 3, 4, 5, 6 & overall time. Task 2 showed no difference between the groups. BVL patients walked slower compared to the age-matched controls., Discussion: Good reliability of the ETGUG in BVL and an indication for the discriminatory capabilities for the separate tasks suggest that the ETGUG could facilitate the study of functional deficits in BVL patients. Good reliability, small measurement error and values of SDC warrant the further utilisation of the ETGUG for the evaluation of physical functioning in BVL patients.

Introduction: Unrealistic optimism refers to the pervasive tendency of healthy individuals to underestimate their likelihood of future misfortune, including illness. The phenomenon shares a qualitative resemblance with anosognosia, a neurological disorder characterized by a deficient appreciation of manifest current illness or impairment. Unrealistic optimism and anosognosia have been independently associated with a region of right inferior frontal gyrus, the pars opercularis. Moreover, anosognosia is temporarily abolished by vestibular stimulation, particularly by irrigation of the left (but not right) ear with cold water, a procedure known to activate the right inferior frontal region. We therefore hypothesized that left caloric stimulation would attenuate unrealistic optimism in healthy participants., Methods: Thirty-one healthy right-handed adults underwent cold-water caloric vestibular stimulation of both ears in succession. During each stimulation episode, and at baseline, participants estimated their own relative risk of contracting a series of illnesses in the future., Results: Compared to baseline, average risk estimates were significantly higher during left-ear stimulation, whereas they remained unchanged during right-ear stimulation. Unrealistic optimism was thus reduced selectively during cold caloric stimulation of the left ear., Conclusions: Our results point to a unitary mechanism underlying both anosognosia and unrealistic optimism, and suggest that unrealistic optimism is a form of subclinical anosognosia for prospective symptoms., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the effectiveness of systemic high-dose dexamethasone therapy for sudden sensorineural hearing loss in comparison to the previous treatment regimen at our clinic with systemic prednisone 100 mg daily for 7 days analyzed in a previous study., Methods: We conducted a retrospective review of an electronic patient data base of 79 patients with idiopathic sudden sensorineural hearing loss. The standard treatment was orally applied dexamethasone (1st to 3rd day: 40 mg daily, 4th to 6th day: 10 mg daily) in an ambulant setting. The primary endpoint was change in hearing threshold from the initial audiogram to an audiogram at least 4 weeks later. Factors that were analyzed included patient's age, interval between onset of symptoms and start of treatment, presence or absence of dizziness and tinnitus, the audiogram pattern, severity of hearing loss and hearing in the opposite ear. Hearing gain was expressed either as absolute or relative hearing gain. Functionally relevant recovery of hearing was defined as the final pure-tone average (PTA) of 30 dB or less (or the same as the PTA of the opposite ear ± 10 dB). Furthermore, we calculated the percentage of patients with complete, partial and no recovery as defined in the recently published Clinical Practice Guideline of the American Academy of Otolaryngology - Head and Neck Surgery Foundation. We then compared our results with the previous treatment regimen carried out at our clinic., Results: The average initial PTA hearing loss in the affected ear compared to baseline PTA of the unaffected ear was 51.5 ± 20.9 dB (mean ± SD). The mean absolute hearing gain was 44.4 ± 18.1 dB. The mean relative hearing gain was 86 ± 19%. Of the total, 87% had functionally relevant recovery of hearing. All of our patients showed partial (24%) or complete recovery (76%). No difference in recovery rate could be detected between patients with start of therapy within 24 h and patients with beginning of therapy within 7 days. We found a correlation between the severity of hearing loss and functionally relevant recovery. A mild hearing loss was noted in 34% of patients, with an average relative hearing gain of 89% and a functionally relevant recovery in 96% of them; the 9% of patients with initial deafness showed a mean relative hearing gain of 69% and a functionally relevant recovery in 43%. The audiogram pattern with low- or high-frequency hearing loss showed the best recovery rate; the poorest recovery rate was found in patients with initial deafness., Conclusion: Application of high-dose orally applied dexamethasone seems to improve the recovery outcomes in comparison to prednisone 100 mg p.o. for 7 days., (Copyright © 2013 S. Karger AG, Basel.)

We studied the horizontal oculomotor neural integrator in healthy human subjects during gaze holding in darkness. We found large variability among subjects with respect to the estimated time constants and the integrator's null position. We also found that individual subjects could demonstrate significantly nonlinear drift velocities as a function of eye position. Nevertheless, a consistent trend did not emerge. Consequently, cross subject averaging eliminates idiosyncratic nonlinear patterns and the average can be approximated by a linear function inside the range that was tested.

In acute stages of unilateral vestibular deficit, the imbalanced tonic activity on vestibular afferents evokes spontaneous nystagmus. The slow-phase velocity of this nystagmus varies with eye position, such that it is smaller when looking in the direction of slow-phases. The neural mechanism for this behavior is still not understood. Here, using a simple control system model, we show that plausible changes in the neural responses within the central vestibulo-ocular reflex pathway are adequate to cause eye position dependent effects in the nystagmus pattern. The proposed transformations in population response functions could happen immediately following a lesion and can be useful to stabilize gaze in part of the gaze field.

Visual input is highly relevant for safely stepping over obstacles. In this study, gaze-behaviour was investigated in elderly, middle-aged and young subjects as they walked on a treadmill repeatedly stepping over obstacles, which approached either on the right or left side. In between obstacle-steps, subjects visually fixated a target N or F located two or four steps ahead on the floor, respectively. An acoustic warning signal announced the obstacles, after which subjects were free to look wherever they wanted. Gaze-movements were measured by video-oculography. Four conditions with 20 obstacles were conducted (two with target N, two with target F). In two conditions, high-precision stepping was investigated by asking subjects to step with minimal foot-clearance over the obstacles, while receiving acoustic feedback about their performance. In the high-precision conditions, more subjects (target N: 70%, F: 81%) turned their gaze on the obstacles and for a longer time than in unrestricted conditions. When fixating on the near target N and unrestricted stepping over the obstacles, significantly more elderly subjects (85%) turned their gaze on the obstacle compared to middle-aged (17%) and young subjects (29%). The elderly turned their gaze earlier and longer on the obstacle than middle-aged or young subjects. Our results reveal a different gaze-behaviour strategy of elderly subjects suggesting a greater dependency on visual inputs., (Copyright © 2011 Elsevier B.V. All rights reserved.)

This article presents a detailed case report of a patient who was diagnosed with superior canal dehiscence at 37 years of age, but who had a suspicious history for that syndrome from at least 10 years of age. The authors hypothesize several reasons for this late diagnosis, with the goal of helping pediatricians, otolaryngologists, and neurologists consider this syndrome in their differential diagnosis of children, adolescents, or adults experiencing dizziness., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: We compared vibration-induced ocular vestibular evoked myogenic potentials (OVEMPs) with the visual vertical during whole-body roll tilt and eccentric rotation in healthy subjects and patients with unilateral vestibular loss, to determine which test was most sensitive in discriminating impaired utricle function., Methods: OVEMPs and the visual vertical were measured in 11 patients and 11 healthy subjects. Visual vertical was measured during roll tilts between -9.6° and 9.6°, and during rotation at 400°/s with the head upright and the vertical rotation axis located between ±3.5 cm from the head center., Results: OVEMPs in patients were strikingly asymmetric, whereas they were approximately symmetric in healthy subjects. Patients showed impaired visual vertical gain during eccentric rotation and increased errors for both roll tilt and eccentric rotation tests. OVEMPs were superior at discriminating between patients and healthy subjects, although eccentric rotation performed nearly as well., Conclusions: OVEMPs provide a powerful test for discriminating between healthy subjects and patients with chronic unilateral vestibular loss, and testing the visual vertical testing during eccentric rotation was superior to testing during whole-body roll tilt., Significance: OVEMPs are easier to administer, less demanding on patients, and in general are more effective at identifying chronic unilateral vestibular loss than visual vertical measurements., (Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Objective: To evaluate a novel test for dynamic visual acuity (DVA) that uses an adaptive algorithm for changing the size of Landolt rings presented during active or passive head impulses, and to compare the results with search-coil head impulse testing., Design: Prospective study in healthy individuals and patients with peripheral vestibular deficits., Setting: Tertiary academic center., Participants: One hundred neuro-otologically healthy individuals (age range, 19-80 years) and 15 patients with bilateral (n = 5) or unilateral (n = 10) peripheral vestibular loss (age range, 27-72 years)., Interventions: Testing of static visual acuity (SVA), DVA during active and passive horizontal head rotations (optotype presentation at head velocities >100 degrees/s and >150 degrees/s), and quantitative horizontal head impulse testing with scleral search coils., Main Outcome Measure: Difference between SVA and DVA, that is, visual acuity loss (VA loss), gain of the high-acceleration vestibulo-ocular reflex., Results: Passive head impulses and higher velocities were more effective than active impulses and lower velocities. Using passive head impulses and velocities higher than 150 degrees/s, the DVA test discriminated significantly (P < .001) among patients with bilateral vestibulopathy, those with unilateral vestibulopathy, and normal individuals. The DVA test sensitivity was 100%, specificity was 94%, and accuracy was 95%, with search-coil head impulse testing used as a reference. In healthy individuals, VA loss increased significantly with age (P < .001; R(2) = 0.04)., Conclusion: Dynamic visual acuity testing with Landolt rings that are adaptively changed in size enables detection of peripheral vestibular dysfunction in a fast and simple way.