Multi-frequency VEMPs improve detection of present otolith responses in bilateral vestibulopathy

Objective

To investigate whether multi-frequency Vestibular Evoked Myogenic Potential (VEMP) testing at 500, 750, 1,000, and 2,000 Hz, would improve the detection of present dynamic otolith responses in patients with bilateral vestibulopathy (BV).

Methods

Prospective study in a tertiary referral center. BV patients underwent multi-frequency VEMP testing. Cervical VEMPs and ocular VEMPs were recorded with the Neuro-Audio system (v2010, Neurosoft, Ivanovo, Russia). The stimuli included air-conducted tone bursts of 500, 750, 1,000, and 2,000 Hz, at a stimulation rate of 13 Hz. Outcome measures included the percentage of present and absent VEMP responses, and VEMP thresholds. Outcomes were compared between frequencies and type of VEMPs (cVEMPs, oVEMPs). VEMP outcomes obtained with the 500 Hz stimulus, were also compared to normative values obtained in healthy subjects.

Results

Forty-nine BV patients completed VEMP testing: 47 patients completed cVEMP testing and 48 patients completed oVEMP testing. Six to 15 % more present VEMP responses were obtained with multifrequency testing, compared to only testing at 500 Hz. The 2,000 Hz stimulus elicited significantly fewer present cVEMP responses (right and left ears) and oVEMP responses (right ears) compared to the other frequencies (p ≤ 0.044). Using multi-frequency testing, 78% of BV patients demonstrated at least one present VEMP response in at least one ear. In 46% a present VEMP response was found bilaterally. BV patients demonstrated a significantly higher percentage of absent VEMP responses and significantly higher VEMP thresholds than healthy subjects, when corrected for age (p ≤ 0.002). Based on these results, a pragmatic VEMP testing paradigm is proposed, taking into account multi-frequency VEMP testing.

Conclusion

Multi-frequency VEMP testing improves the detection rate of present otolith responses in BV patients. Therefore, multi-frequency VEMPs should be considered when evaluation of (residual) otolith function is indicated.

Reported thresholds of self-motion perception are influenced by testing paradigm

Background/objective

Different testing paradigms have been proposed to investigate perceptual self-motion thresholds. They can differ regarding the amount of possible motions that patients have to choose from. Objective of this study was to compare the two-option paradigm and twelve-option paradigm, to investigate whether reducing the choice options significantly influences the reported thresholds of self-motion perception of healthy subjects.

Methods

Thirty-three volunteers with no prior vestibular complaints were included and sequentially tested with both paradigms at a random sequence. Perceptual self-motion thresholds were measured using a hydraulic motion platform in the absence of external visual and auditory cues. The platform delivered twelve different movements: six translations and six rotations. Each subject had to report the correct type and direction of movements. Thresholds were determined by a double confirmation of the lowest threshold, in combination with a double rejection of the one-step lower stimulus. Perceptual self-motion thresholds of both paradigms were compared using the mixed model analysis.

Results

The twelve-option paradigm showed significantly higher reported thresholds for yaw rotations and translations left, right and down (p < 0.001), compared to the two-option paradigm. No statistical difference was found for rolls and translations up. No significant gender effect, learning effect and carry-over effect were present in any of the applied motion directions.

Conclusion

Reported thresholds of self-motion perception of healthy subjects are influenced by the testing paradigm. The twelve-option paradigm showed significantly higher thresholds than the two-option paradigm. Results obtained with each testing paradigm should, therefore, be compared to paradigm-specific normative data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-022-11032-y.

The DizzyQuest: relation between self-reported hearing loss, tinnitus and objective hearing thresholds in patients with Meniere's disease

Background

Combining a mobile application-based vestibular diary called the DizzyQuest and an iPad-based hearing test enables evaluation of the relationship between experienced neuro-otological symptoms and hearing thresholds in daily life setting. The aim was to investigate the relationship between self-reported hearing symptoms and hearing thresholds in patients with Meniere’s disease (MD), using the DizzyQuest and the iPad-based hearing test simultaneously.

Methods

The DizzyQuest was administered for 3 weeks in 21 patients. Using the experience-sampling-method (ESM), it assessed hearing loss and tinnitus severity for both ears separately. Each day after the DizzyQuest, an iPad-based hearing test was used to measure hearing thresholds. A mixed model regression analysis was performed to investigate relationships between hearing thresholds and self-reported hearing loss and tinnitus severity.

Results

Fifteen patients were included. Overall, pure-tone averages (PTAs) were not correlated with self-reported hearing loss severity and tinnitus. Individual differences in PTA results between both ears did not significantly influence the difference in self-reported hearing loss severity between both ears. Self-reported hearing loss and tinnitus scores were significantly higher in ears that corresponded with audiometric criteria of MD (p < 0.001). Self-reported tinnitus severity significantly increased with self-reported hearing loss severity in affected (p = 0.011) and unaffected ears (p < 0.001).

Conclusion

Combining the DizzyQuest and iPad-based hearing test, facilitated assessment of self-reported hearing loss and tinnitus severity and their relationship with hearing thresholds, in a daily life setting. This study illustrated the importance of investigating neuro-otological symptoms at an individual level, using multiple measurements. ESM strategies like the DizzyQuest should therefore be considered in neuro-otological research.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10909-8.

Curriculum for vestibular medicine (vestmed) proposed by the barany society

This document presents the initiative of the Bárány Society to improve diagnosis and care of patients presenting with vestibular symptoms worldwide.

The Vestibular Medicine (VestMed) concept embraces a wide approach to the potential causes of vestibular symptoms, acknowledging that vertigo, dizziness, and unsteadiness are non-specific symptoms that may arise from a broad spectrum of disorders, spanning from the inner ear to the brainstem, cerebellum and supratentorial cerebral networks, to many disorders beyond these structures.

The Bárány Society Vestibular Medicine Curriculum (BS-VestMed-Cur) is based on the concept that VestMed is practiced by different physician specialties and non-physician allied health professionals. Each profession has its characteristic disciplinary role and profile, but all work in overlapping areas. Each discipline requires good awareness of the variety of disorders that can present with vestibular symptoms, their underlying mechanisms and etiologies, diagnostic criteria and treatment options. Similarly, all disciplines require an understanding of their own limitations, the contribution to patient care from other professionals and when to involve other members of the VestMed community. Therefore, the BS-VestMed-Cur is the same for all health professionals involved, the overlaps and differences of the various relevant professions being defined by different levels of detail and depth of knowledge and skills.

The BS-VestMed-Cur defines a Basic and an Expert Level Curriculum. The Basic Level Curriculum covers the VestMed topics in less detail and depth, yet still conveys the concept of the wide net approach. It is designed for health professionals as an introduction to, and first step toward, VestMed expertise. The Expert Level Curriculum defines a Focused and Broad Expert. It covers the VestMed spectrum in high detail and requires a high level of understanding. In the Basic and Expert Level Curricula, the range of topics is the same and runs from anatomy, physiology and physics of the vestibular system, to vestibular symptoms, history taking, bedside examination, ancillary testing, the various vestibular disorders, their treatment and professional attitudes. Additionally, research topics relevant to clinical practice are included in the Expert Level Curriculum. For Focused Expert proficiency, the Basic Level Curriculum is required to ensure a broad overview and additionally requires an expansion of knowledge and skills in one or a few specific topics related to the focused expertise, e.g. inner ear surgery. Broad Expert proficiency targets professionals who deal with all sorts of patients presenting with vestibular symptoms (e.g. otorhinolaryngologists, neurologists, audiovestibular physicians, physical therapists), requiring a high level of VestMed expertise across the whole spectrum. For the Broad Expert, the Expert Level Curriculum is required in which the minimum attainment targets for all the topics go beyond the Basic Level Curriculum. The minimum requirements regarding knowledge and skills vary between Broad Experts, since they are tuned to the activity profile and underlying specialty of the expert.

  The BS-VestMed-Cur aims to provide a basis for current and future teaching and training programs for physicians and non-physicians. The Basic Level Curriculum could also serve as a resource for inspiration for teaching VestMed to students, postgraduate generalists such as primary care physicians and undergraduate health professionals, or anybody wishing to enter VestMed.

  VestMed is considered a set of competences related to an area of practice of established physician specialties and non-physician health professions rather than a separate clinical specialty. This curriculum does not aim to define a new single clinical specialty.

  The BS-VestMed-Cur should also integrate with, facilitate and encourage translational research in the vestibular field.

Bilateral vestibulopathy and age: experimental considerations for testing dynamic visual acuity on a treadmill

INTRODUCTION

Bilateral vestibulopathy (BVP) can affect visual acuity in dynamic conditions, like walking. This can be assessed by testing Dynamic Visual Acuity (DVA) on a treadmill at different walking speeds. Apart from BVP, age itself might influence DVA and the ability to complete the test. The objective of this study was to investigate whether DVA tested while walking, and the drop-out rate (the inability to complete all walking speeds of the test) are significantly influenced by age in BVP-patients and healthy subjects.

METHODS

Forty-four BVP-patients (20 male, mean age 59 years) and 63 healthy subjects (27 male, mean age 46 years) performed the DVA test on a treadmill at 0 (static condition), 2, 4 and 6 km/h (dynamic conditions). The dynamic visual acuity loss was calculated as the difference between visual acuity in the static condition and visual acuity in each walking condition. The dependency of the drop-out rate and dynamic visual acuity loss on BVP and age was investigated at all walking speeds, as well as the dependency of dynamic visual acuity loss on speed.

RESULTS

Age and BVP significantly increased the drop-out rate (p ≤ 0.038). A significantly higher dynamic visual acuity loss was found at all speeds in BVP-patients compared to healthy subjects (p < 0.001). Age showed no effect on dynamic visual acuity loss in both groups. In BVP-patients, increasing walking speeds resulted in higher dynamic visual acuity loss (p ≤ 0.036).

CONCLUSION

DVA tested while walking on a treadmill, is one of the few "close to reality" functional outcome measures of vestibular function in the vertical plane. It is able to demonstrate significant loss of DVA in bilateral vestibulopathy patients. However, since bilateral vestibulopathy and age significantly increase the drop-out rate at faster walking speeds, it is recommended to use age-matched controls. Furthermore, it could be considered to use an individual "preferred" walking speed and to limit maximum walking speed in older subjects when testing DVA on a treadmill.

Bilateral vestibulopathy: beyond imbalance and oscillopsia

Objective

To optimize the current diagnostic and treatment procedures for patients with bilateral vestibulopathy (BV), this study aimed to determine the complete spectrum of symptoms associated with BV.

Method

A prospective mixed-method study design was used. Qualitative data were collected by performing semi-structured interviews about symptoms, context, and behavior. The interviews were recorded and transcribed until no new information was obtained. Transcriptions were analyzed in consensus by two independent researchers. In comparison to the qualitative results, quantitative data were collected using the Dizziness Handicap Inventory (DHI), Hospital Anxiety and Depression Scale (HADS) and a health-related quality of life questionnaire (EQ-5D-5L).

Results

Eighteen interviews were transcribed. Reported symptoms were divided into fourteen physical symptoms, four cognitive symptoms, and six emotions. Symptoms increased in many situations, such as darkness (100%), uneven ground (61%), cycling (94%) or driving a car (56%). These symptoms associated with BV often resulted in behavioral changes: activities were performed more slowly, with greater attention, or were avoided. The DHI showed a mean score of severe handicap (54.67). The HADS questionnaire showed on average normal results (anxiety = 7.67, depression = 6.22). The EQ-5D-5L demonstrated a mean index value of 0.680, which is lower compared to the Dutch age-adjusted reference 0.839 (60–70 years).

Conclusion

BV frequently leads to physical, cognitive, and emotional complaints, which often results in a diminished quality of life. Importantly, this wide range of symptoms is currently underrated in literature and should be taken into consideration during the development of candidacy criteria and/or outcome measures for therapeutic interventions such as the vestibular implant.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10243-5) contains supplementary material, which is available to authorized users.

Introducing the DizzyQuest: an app-based diary for vestibular disorders

Background

Most questionnaires currently used for assessing symptomatology of vestibular disorders are retrospective, inducing recall bias and lowering ecological validity. An app-based diary, administered multiple times in daily life, could increase the accuracy and ecological validity of symptom measurement. The objective of this study was to introduce a new experience sampling method (ESM) based vestibular diary app (DizzyQuest), evaluate response rates, and to provide examples of DizzyQuest outcome measures which can be used in future research.

Methods

Sixty-three patients diagnosed with a vestibular disorder were included. The DizzyQuest consisted of four questionnaires. The morning- and evening-questionnaires were administered once each day, the within-day-questionnaire 10 times a day using a semi-random time schedule, and the attack questionnaire could be completed after the occurrence of a vertigo or dizziness attack. Data were collected for 4 weeks. Response rates and loss-to-follow-up were determined. Reported symptoms in the within-day-questionnaire were compared within and between patients and subgroups of patients with different vestibular disorders.

Results

Fifty-one patients completed the study period. Average response rates were significantly higher than the desired response rate of > 50% (p < 0.001). The attack-questionnaire was used 159 times. A variety of neuro-otological symptoms and different disease profiles were demonstrated between patients and subgroups of patients with different vestibular disorders.

Conclusion

The DizzyQuest is able to capture vestibular symptoms within their psychosocial context in daily life, with little recall bias and high ecological validity. The DizzyQuest reached the desired response rates and showed different disease profiles between subgroups of patients with different vestibular disorders. This is the first time ESM was used to assess daily symptoms and quality of life in vestibular disorders, showing that it might be a useful tool in this population.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10092-2) contains supplementary material, which is available to authorized users.

The Functional Head Impulse Test to Assess Oscillopsia in Bilateral Vestibulopathy

Introduction: Bilateral vestibulopathy (BV) is a chronic condition in which vestibular function is severely impaired or absent on both ears. Oscillopsia is one of the main symptoms of BV. Oscillopsia can be quantified objectively by functional vestibular tests, and subjectively by questionnaires. Recently, a new technique for testing functionally effective gaze stabilization was developed: the functional Head Impulse Test (fHIT). This study compared the fHIT with the Dynamic Visual Acuity assessed on a treadmill (DVA_treadmill) and Oscillopsia Severity Questionnaire (OSQ) in the context of objectifying the experience of oscillopsia in patients with BV.

Methods: Inclusion criteria comprised: (1) summated slow phase velocity of nystagmus of <20°/s during bithermal caloric tests, (2) torsion swing tests gain of <30% and/or phase <168°, and (3) complaints of oscillopsia and/or imbalance. During the fHIT (Beon Solutions srl, Italy) patients were seated in front of a computer screen. During a passive horizontal head impulse a Landolt C optotype was shortly displayed. Patients reported the seen optotype by pressing the corresponding button on a keyboard. The percentage correct answers was registered for leftwards and rightwards head impulses separately. During DVA_treadmill patients were positioned on a treadmill in front of a computer screen that showed Sloan optotypes. Patients were tested in static condition and in dynamic conditions (while walking on the treadmill at 2, 4, and 6 km/h). The decline in LogMAR between static and dynamic conditions was registered for each speed. Every patient completed the Oscillopsia Severity Questionnaire (OSQ).

Results: In total 23 patients were included. This study showed a moderate correlation between OSQ outcomes and the fHIT [rightwards head rotations (r_s = −0.559; p = 0.006) leftwards head rotations (r_s = −0.396; p = 0.061)]. No correlation was found between OSQ outcomes and DVA_treadmill, or between DVA_treadmill and fHIT. All patients completed the fHIT, 52% of the patients completed the DVA_treadmill on all speeds.

Conclusion: The fHIT seems to be a feasible test to quantify oscillopsia in BV since, unlike DVA_treadmill, it correlates with the experienced oscillopsia measured by the OSQ, and more BV patients are able to complete the fHIT than DVA_treadmill.

The Video Head Impulse Test and the Influence of Daily Use of Spectacles to Correct a Refractive Error

Objective

To determine the influence of daily use of spectacles to correct a refractive error, on the vestibulo-ocular reflex (VOR) gain measured with the video head impulse test (vHIT).

Study design

This prospective study enrolled subjects between 18 and 80 years old with and without a refractive error. Subjects were classified into three groups: (1) contact lenses, (2) spectacles, and (3) control group without visual impairment. Exclusion criteria comprised ophthalmic pathology, history of vestibular disorders, and alternated use of spectacles and contact lenses in daily life. Corrective spectacles were removed seconds before testing. One examiner performed all vHIT’s under standardized circumstances using the EyeSeeCam system. This system calculated the horizontal VOR gain for rightward and leftward head rotations separately.

Results

No statistically significant difference was found in VOR gain between the control group (n = 16), spectacles group (n = 48), and contact lenses group (n = 15) (p = 0.111). Both the spectacles group and contact lenses group showed no statistically significant correlation between VOR gain and amount of refractive error, for rightwards (p = 0.071) and leftwards (p = 0.716) head rotations. There was no statistical significant difference in VOR gain between testing monocularly or binocularly (p = 0.132) and between testing with or without wearing contact lenses (p = 0.800).

Conclusion

In this study, VOR gain was not influenced by wearing corrective spectacles or contact lenses on a daily basis. Based on this study, no corrective measures are necessary when performing the vHIT on subjects with a refractive error, regardless of the way of correction.

An Exploratory Study to Detect Ménière's Disease in Conventional MRI Scans Using Radiomics

OBJECTIVE

The purpose of this exploratory study was to investigate whether a quantitative image analysis of the labyrinth in conventional magnetic resonance imaging (MRI) scans using a radiomics approach showed differences between patients with Ménière's disease (MD) and the control group.

MATERIALS AND METHODS

In this retrospective study, MRI scans of the affected labyrinths of 24 patients with MD were compared to the MRI scans of labyrinths of 29 patients with an idiopathic asymmetrical sensorineural hearing loss. The 1.5- and 3-T MRI scans had been previously made in a clinical setting between 2008 and 2015. 3D Slicer 4.4 was used to extract several substructures of the labyrinth. A quantitative analysis of the normalized radiomic image features was performed in Mathematica 10. The image features of the two groups were statistically compared.

RESULTS

For numerous image features, there was a statistically significant difference (p-value <0.05) between the MD group and the control group. The statistically significant differences in image features were localized in all the substructures of the labyrinth: 43 in the anterior semicircular canal, 10 in the vestibule, 22 in the cochlea, 12 in the posterior semicircular canal, 24 in the horizontal semicircular canal, 11 in the common crus, and 44 in the volume containing the reuniting duct. Furthermore, some figures contain vertical or horizontal bands (three or more statistically significant image features in the same image feature). Several bands were seen: 9 bands in the anterior semicircular canal, 1 band in the vestibule, 3 bands in the cochlea, 0 bands in the posterior semicircular canal, 5 bands in the horizontal semicircular canal, 3 bands in the common crus, and 10 bands in the volume containing the reuniting duct.

CONCLUSION

In this exploratory study, several differences were found in image features between the MD group and the control group by using a quantitative radiomics approach on high resolution T2-weighted MRI scans of the labyrinth. Further research should be aimed at validating these results and translating them in a potential clinical diagnostic method to detect MD in MRI scans.

Vestibular implants: Hope for improving the quality of life of patients with bilateral vestibular loss

The vestibular system plays an essential role in crucial tasks such as postural control, gaze stabilization, and spatial orientation. Currently, there is no effective treatment for a bilateral loss of the vestibular function (BVL). The quality of life of affected patients is significantly impaired. During the last decade, our group has explored the potential of using electrical stimulation to artificially restore the vestibular function. Our vestibular implant prototype consists of a custom modified cochlear implant featuring one to three vestibular electrodes implanted in the proximity of the ampullary branches of the vestibular nerve; in addition to the main cochlear array. Special surgical techniques for safe implantation of these devices have been developed. In addition, we have developed stimulation strategies to generate bidirectional eye movements as well as the necessary interfaces to capture the signal from a motion sensor (e.g., gyroscope) and use it to modulate the stimulation signals delivered to the vestibular nerves. To date, 24 vestibular electrodes have been implanted in 11 BVL patients. Using a virtual motion profile to modulate the "baseline" electrical stimulation, vestibular responses could be evoked with 21 electrodes. Eye movements with mean peak eye velocities of 32°/s and predominantly in the plane of the stimulated canal were successfully generated. These are within the range of normal compensatory eye movements during walking and were large enough to have a significant effect on the patients' visual acuity. These results indicate that electrical stimulation of the vestibular nerve has a significant functional impact; eye movements generated this way could be sufficient to restore gaze stabilization during essential everyday tasks such as walking. The innovative concept of the vestibular implant has the potential to restore the vestibular function and have a central role in improving the quality of life of BVL patients in the near future.

[The effect of elevated ozone levels in the ambient air on lung function of children engaged in sports]

In the summer of 1989, ozone levels in the ambient air were regularly found to be increased in The Netherlands. The question was studied whether this affected pulmonary function of children aged 7 to 12 years practising sports in the open air. Before and after sessions of training in the open air, the peak expiratory flow rate was determined using peak flow meters (mini-Wright). This was done on 37 different days with varying ozone concentrations. Measurements were carried out on four or more days in a total of 65 children. No correlation between ozone concentration during training and differences between pre- and post-training peak flows was found. No correlation was found either between the maximal ozone concentration on a given day and the peak flow at the end of training on that day. However, a negative correlation was found between the maximal ozone concentration on the day preceding the pulmonary function tests and the peak flow after the training.