Frequency–Amplitude Ratio of Ocular Vestibular-Evoked Myogenic Potentials for Detecting Meniere’s Disease: A Preliminary Investigation

Effects of Age on the Frequency Amplitude Ratio of Cervical and Ocular Vestibular Evoked Myogenic Potentials

PURPOSE

An increase in the 1000/500 Hz frequency amplitude ratio (FAR) of the cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP, respectively) may serve as a potential biomarker for diagnosing Meniere's disease (MD). However, the aging process can also result in an increased FAR for VEMPs. In older patients, distinguishing whether changes in VEMP FAR are due to MD or aging processes becomes difficult. We aimed to investigate the effects of age on VEMP FARs and establish a FAR-normative range for different age groups.

METHOD

cVEMP and oVEMP were recorded from a total of 106 participants grouped as young, middle-aged, and older adults using air-conducted tone bursts at 500, 750, and 1000 Hz at 125 dB pSPL. The FAR was calculated for the cVEMP and oVEMP for the following frequencies: FAR1 = 1000/500, FAR2 = 1000/750, and FAR3 = 750/500.

RESULTS

A significant age-related effect was observed on the cVEMP FAR. Although the oVEMP FAR showed an increasing trend with age, it was not statistically significant. Age-based normative FAR values are provided.

CONCLUSIONS

Drawing from the normative FAR from this study, there is evidence that the existing MD diagnostic criteria would misidentify a considerable number of older adults. Therefore, to reduce false positives, we recommend a more stringent cVEMP and oVEMP FAR criterion in older adults.

Utility of Inter-Frequency Amplitude Ratio of Vestibular-Evoked Myogenic Potentials in Identifying Meniere's Disease: A Systematic Review and Meta-Analysis

OBJECTIVES

A recently devised parameter of vestibular-evoked myogenic potential (VEMP) based on the principles of frequency tuning is the inter-frequency amplitude ratio (IFAR). It refers to the ratio of the amplitude of 1000 Hz tone burst evoked VEMP to 500 Hz evoked tone burst. A pathology like Meniere's disease changes the frequency response and alters the frequency tuning of the otolith organs. Because IFAR is based on the principle of frequency tuning of VEMP, it is likely to help identify Meniere's disease. Few studies in the last decade have investigated the utility of IFAR in identifying Meniere's disease. However, a systematic review and a meta-analysis on IFAR in Meniere's disease are lacking. The present study investigates whether the IFAR of VEMP helps identify Meniere's disease and differentiates it from healthy ears and other vestibular pathologies.

DESIGN

The present study is a systematic review and a meta-analysis. The studies investigating the IFAR of cervical and ocular VEMPs in Meniere's disease, healthy controls, and other vestibular pathologies were searched across research databases such as PubMed, Science Direct, and Scopus. The search strategy was developed using the PICO (population, intervention, comparison, and outcomes) format, and Medical Subject Headings (MeSH) terms and Boolean operators were employed. The systematic review was performed using the Rayyan software, whereas the Review Manager software was used to carry out the meta-analysis. A total of 16,605 articles were retrieved from the databases. After the duplicate removal, 2472 articles remained. These were eliminated using title screening, abstract screening, and full-length inspections. A total of nine articles were found eligible for quality assessment and meta-analysis, and the New Castle-Ottawa Scale was used for quality assessment. After the data extraction, 24 six articles were found to have the desired data format for the meta-analysis.

RESULTS

The results showed significantly higher IFAR in the affected ears of individuals in the Meniere's disease group than in the control group's unaffected ears. There was no significant difference between the unaffected ears of individuals in the Meniere's disease group and the ears of the control group. The only study on Meniere's disease and benign paroxysmal positional vertigo found significantly larger ocular VEMP IFAR in ears with Meniere's disease than in benign paroxysmal positional vertigo.

CONCLUSIONS

This systematic review and meta-analysis found IFAR efficient in differentiating Meniere's disease from healthy controls. We also found an enhanced IFAR as a potential marker for Meniere's disease. However, more investigations are needed to confirm the utility of an enhanced IFAR value in the exclusive identification of Meniere's disease.

[An analyzation on the characterization of frequency tuning of vestibular evoked myogenic potential in patients with unilateral vestibular hypofunction]

Objective: To explore the value of adding 1 kHz cervical vestibular evoked myogenic potential（cVEMP） and ocular vestibular evoked myogenic potential（oVEMP） in the auxiliary diagnosis of unilateral vestibular hypofunction. Methods:A retrospective analysis of 84 patients with unilateral vestibular hypofunction receiving two or more vestibular function tests was conducted,29 cases of unilateral Ménière's disease, 27 cases of benign paroxysmal positional vertigo （BPPV）, 8 cases of idiopathic sudden sensorineural hearing loss （ISSHL） with vertigo, and 20 cases of ISSHL without vertigo were included. SPSS 25.0 software was used for statistical analysis to observe the difference of frequency amplitude ratio （FAR） at 500 Hz/1 kHz of cVEMP and oVEMP between the experimental and control groups. Results:①The cVEMP elicitation rates were 95.24% （80/84） and 98.81% （83/84） for 500 Hz and 1 kHz, respectively; and the oVEMP elicitation rates were 78.57% （66/84） and 91.67% （77/84） for 500 Hz and 1 kHz, respectively. ②Except for the lateral difference of FAR in oVEMP of the posterior semicircular canal BPPV group and cVEMP of the horizontal semicircular canal BPPV group （P<0.05）, no significant lateral difference was observed in the other disease groups （P>0.05）. Conclusion:In patients with unilateral vestibular hypofunction, cVEMP and oVEMP showed different frequency tuning changes in different semicircular canal BPPV groups. Additionally, 1 kHz cVEMP and oVEMP as regular stimulation frequencies in clinical test, which has certain clinical reference significance for determining the diagnosis and prognosis of BPPV on the weak ear and in different semicircular canal involvement.

Effects of aging on ocular vestibular-evoked myogenic potential using ER-3A insert earphone and B81 bone vibrator

Purpose

Aging is a process associated with degeneration and dysfunction of peripheral vestibular system or apparatus. This study aimed to investigate the influence of aging on ocular vestibular-evoked myogenic potential (oVEMP) response rates and recording parameters using the B81 bone vibrator and compare them with air conduction stimuli (ACS) oVEMP response characteristics.

Methods

In 60 healthy participants aged 10–71 years (mean age 39.9; 29 male participants), the oVEMP response was elicited using a B81 bone vibrator and an ER-3A insert earphone. The effects of age and stimulus on oVEMP response rates and recording parameters were evaluated.

Results

Response rates and amplitudes declined with aging using either ACS or bone-conducted vibration (BCV) stimulation, particularly in individuals over 60 years of age, whereas thresholds increased and N1 latencies were prolonged. BCV showed fewer risks of absent oVEMP response than ACS (p = 0.002). BCV acquired higher amplitudes (p &lt; 0.001), lower thresholds, and shorter N1 and P1 latencies (all p &lt; 0.001) than ACS.

Conclusions

The absence of an oVEMP response may be attributed to aging rather than a concurrent vestibular disorder. B81-BCV likely produces higher mechanical drives to the vestibular hair cells at safer and non-traumatic levels compared with ACS and therefore may be more likely to evoke a response in the elderly cohort, whose vestibular function and mechanical sensitivity have declined. Thus, B81-BCV stimulation is more effective and safer to elicit oVEMPs, and it should be recommended when ACS fails in the clinic, particularly in the elderly population.

Simultaneous Multifrequency (SiMFy) Stimulus: A Novel and Reliable Stimulus for Frequency Tuning of Ocular Vestibular-Evoked Myogenic Potentials

BACKGROUND

Frequency tuning of ocular vestibular evoked myogenic potential (oVEMP) refers to the frequency of tone burst that produces the largest amplitude oVEMP. There is an ever-growing pool of published studies that found the frequency tuning of oVEMP distinctly different in Ménière's disease than the age-matched controls and benign paroxysmal positional vertigo. However, recording oVEMP in response to many frequencies makes an already lengthy vestibular test battery even more cumbersome and time-consuming.

PURPOSE

The aim of this study was to develop a novel time-saving stimulus that produces reliable results.

RESEARCH DESIGN

Prospective study.

STUDY SAMPLE

The study included 25 young, healthy adults.

DATA COLLECTION

The tone-bursts of 2000, 1500, 1000, 750, 500, and 250 Hz were generated and sequenced in this order to prepare a stimulus for simultaneous multifrequency (SiMFy) oVEMP. The response parameters of SiMFy and conventional oVEMP methods were compared.

RESULTS

No significant difference in peak-to-peak amplitude and frequency tuning existed between conventional and SiMFy oVEMP (p > 0.05). SiMFy had better test-retest reliability and was less time-consuming than the conventional oVEMP.

CONCLUSIONS

SiMFy is a time-saving and reliable stimulus for obtaining frequency tuning of oVEMP with no compromise on the outcomes. It can be immediately applied in most commercially available evoked potential systems with a facility for loading an external stimulus.

Simultaneous Multifrequency (SiMFy) Stimulus: A Novel and Reliable Stimulus for Frequency Tuning of Ocular Vestibular-Evoked Myogenic Potentials

Background Frequency tuning of ocular vestibular evoked myogenic potential (oVEMP) refers to the frequency of tone burst that produces the largest amplitude oVEMP. There is an ever-growing pool of published studies that found the frequency tuning of oVEMP distinctly different in Ménière's disease than the age-matched controls and benign paroxysmal positional vertigo. However, recording oVEMP in response to many frequencies makes an already lengthy vestibular test battery even more cumbersome and time-consuming.

Purpose The aim of this study was to develop a novel time-saving stimulus that produces reliable results.

Research Design Prospective study.

Study Sample The study included 25 young, healthy adults.

Data Collection The tone-bursts of 2000, 1500, 1000, 750, 500, and 250 Hz were generated and sequenced in this order to prepare a stimulus for simultaneous multifrequency (SiMFy) oVEMP. The response parameters of SiMFy and conventional oVEMP methods were compared.

Results No significant difference in peak-to-peak amplitude and frequency tuning existed between conventional and SiMFy oVEMP (p > 0.05). SiMFy had better test–retest reliability and was less time-consuming than the conventional oVEMP.

Conclusions SiMFy is a time-saving and reliable stimulus for obtaining frequency tuning of oVEMP with no compromise on the outcomes. It can be immediately applied in most commercially available evoked potential systems with a facility for loading an external stimulus.

Endolymphatic hydrops in the unaffected ear of patients with unilateral Ménière's disease

PURPOSE

Current studies show that frequency tuning modification is a good marker for the detection of endolymphatic hydrops (EH) employing magnetic resonance imaging (MRI) in patients with Ménière's disease (MD). The purpose of the present study is to analyze the auditory and vestibular function with audiometric and vestibular-evoked myogenic potentials (VEMP) responses, respectively, in both the affected and unaffected ears of patients with unilateral MD using MRI as diagnostic support for the degree of EH.

METHODS

We retrospectively reviewed the medical records of 76 consecutive patients with unilateral definite MD (age 55 (28-75); 39 women, 37 men). MRI was used through intravenous gadolinium administration, audiometry, and VEMPs. Functional tests were performed up to a week after the MRI. All were followed up one year after imaging utilizing clinical, auditory, and vestibular testing to rule out bilateral involvement.

RESULTS

In the unaffected ear, the mean pure-tone average is normal even in cases with hydrops and, for a similar severity of hydrops is significantly lower than in the affected ear. Significant differences for the amplitude of the response at 0.5 kHz, at 1 kHz between the affected and unaffected ears were found to be lower in the affected ears. The relative amplitude ratio (1 Kz-0.5 kHz) was significantly lower in the affected ear and in the case of the oVEMP response depends on the degree of EH. The response in the unaffected ear was not modified by the presence or the degree of hydrops.

CONCLUSION

In the unaffected ear, hydrops is not associated with hearing deterioration. For a similar degree of hydrops, hearing loss is significantly greater in the affected ear. The endolymphatic hydrops in the vestibule induces a frequency bias in the VEMP response only in the affected ear and not in the unaffected ear. Because of these findings we consider that hydrops does not represent an active disorder in the unaffected ear.

Similarities and Differences Between Vestibular and Cochlear Systems - A Review of Clinical and Physiological Evidence

The evoked response to repeated brief stimuli, such as clicks or short tone bursts, is used for clinical evaluation of the function of both the auditory and vestibular systems. One auditory response is a neural potential - the Auditory Brainstem Response (ABR) - recorded by surface electrodes on the head. The clinical analogue for testing the otolithic response to abrupt sounds and vibration is the myogenic potential recorded from tensed muscles - the vestibular evoked myogenic potential (VEMP). VEMPs have provided clinicians with a long sought-after tool - a simple, clinically realistic indicator of the function of each of the 4 otolithic sensory regions. We review the basic neural evidence for VEMPs and discuss the similarities and differences between otolithic and cochlear receptors and afferents. VEMPs are probably initiated by sound or vibration selectively activating afferent neurons with irregular resting discharge originating from the unique type I receptors at a specialized region of the otolithic maculae (the striola). We review how changes in VEMP responses indicate the functional state of peripheral vestibular function and the likely transduction mechanisms allowing otolithic receptors and afferents to trigger such very short latency responses. In section "ELECTROPHYSIOLOGY" we show how cochlear and vestibular receptors and afferents have many similar electrophysiological characteristics [e.g., both generate microphonics, summating potentials, and compound action potentials (the vestibular evoked potential, VsEP)]. Recent electrophysiological evidence shows that the hydrodynamic changes in the labyrinth caused by increased fluid volume (endolymphatic hydrops), change the responses of utricular receptors and afferents in a way which mimics the changes in vestibular function attributed to endolymphatic hydrops in human patients. In section "MECHANICS OF OTOLITHS IN VEMPS TESTING" we show how the major VEMP results (latency and frequency response) follow from modeling the physical characteristics of the macula (dimensions, stiffness etc.). In particular, the structure and mechanical operation of the utricular macula explains the very fast response of the type I receptors and irregular afferents which is the very basis of VEMPs and these structural changes of the macula in Menière's Disease (MD) predict the upward shift of VEMP tuning in these patients.

Altered mapping of sound frequency to cochlear place in ears with endolymphatic hydrops provide insight into the pitch anomaly of diplacusis

A fundamental property of mammalian hearing is the conversion of sound pressure into a frequency-specific place of maximum vibration along the cochlear length, thereby creating a tonotopic map. The tonotopic map makes possible systematic frequency tuning across auditory-nerve fibers, which enables the brain to use pitch to separate sounds from different environmental sources and process the speech and music that connects us to people and the world. Sometimes a tone has a different pitch in the left and right ears, a perceptual anomaly known as diplacusis. Diplacusis has been attributed to a change in the cochlear frequency-place map, but the hypothesized abnormal cochlear map has never been demonstrated. Here we assess cochlear frequency-place maps in guinea-pig ears with experimentally-induced endolymphatic hydrops, a hallmark of Ménière’s disease. Our findings are consistent with the hypothesis that diplacusis is due to an altered cochlear map. Map changes can lead to altered pitch, but the size of the pitch change is also affected by neural synchrony. Our data show that the cochlear frequency-place map is not fixed but can be altered by endolymphatic hydrops. Map changes should be considered in assessing hearing pathologies and treatments.

Identification of early-stage Meniere's disease as a cause of unilateral tinnitus

Introduction

Meniere's disease (MD) is characterized by episodic symptoms, including vertigo, hearing loss, and tinnitus.

Objectives

in this study, cases of unilateral tinnitus were investigated for MD.

Method

Twenty-two patients who presented with chronic unilateral tinnitus on puretone audiograms showing an average threshold better than 25 dB HL and thresholds in the lower frequencies worse than those in the higher frequencies by more than 10 dB were suspected to have early-stage MD and underwent electrocochleography (ECochG). Patients showing ECochG findings conclusive for MD were compared to a control group of patients presenting with chronic unilateral tinnitus on pure-tone audiograms showing an average threshold better than 25 dB and thresholds in the higher frequencies worse than those in the lower frequencies by more than 10 dB.

Results

Eighteen of the 22 patients included in this study showed elevated summating potential amplitude to action potential amplitude ratios in ECochG (suggestive of endolymphatic hydrops due to MD) and were followed up for 2 months; 14 of them experienced at least two attacks of vertigo or unsteadiness. In contrast, only one patient in the control group reported two or more attacks of vertigo or unsteadiness in the 2 month observation period. The incidence of this finding in the two groups was significantly different.

Conclusion

Patients with early-stage MD can present with only unilateral tinnitus. Thus, the addition of "pure-tone audiograms showing lower-frequency thresholds worse than higher-frequency thresholds" to the probable MD category in the globally.agreed diagnostic criteria for MD, may be useful.

Effect of advancing age on inter-frequency amplitude ratio of ocular vestibular evoked myogenic potentials

OBJECTIVE

The inter-frequency amplitude ratio (IFAR) is the ratio of the amplitude of 1000-Hz tone-burst evoked ocular vestibular evoked myogenic potential (oVEMP) to the 500 Hz tone-burst evoked oVEMP. Since IFAR is an amplitude-based parameter, and the amplitudes of oVEMP for different frequencies are differentially affected by ageing, IFAR could potentially be affected by the ageing process. Therefore, we aimed to examine the effects of ageing on the IFAR of oVEMPs.

DESIGN

Multiple static groups comparison.

STUDY SAMPLE

We recorded oVEMPs for 500 Hz and 1000 Hz tone-bursts from 270 healthy individuals, each included in one of the six age groups.

RESULTS

The IFAR was significantly larger in the ≥60 years age group than the age groups up to 49 years. Furthermore, the IFAR in the 50-59 years age group was significantly larger than all the other age groups up to 39 years. There was a significant positive correlation between age and IFARs (p < 0.01).

CONCLUSIONS

IFAR, a sensitive tool in the test battery for the diagnosis of Meniere's disease, is affected even in healthy individuals due to ageing; hence its cautious interpretation is recommended when evaluating adults >50 years of age who are suspected of having Meniere's disease.

[Labyrinth hydrops and its diagnosis]

The article deals with the basic theories of maze and labyrinth hydrops, which are often used in clinical practice for its diagnosis according to the world literature. Tonal threshold, suprathreshold audiometry, broadband thympanometry, ultrasound tests, test for determination of lateralization of loud sounds, dehydration test, extra-timbanical electrocochleography, method of registration of evoked vestibular myogenic potentials, study of vestibular function (video pulse test, caloric sample), CT of temporal bones with gadolinium, MRI, and other methods are considered. None of these study methods gives an accurate confirmation of the presence of maze hydrops. Only taking into account the history, complaints of the patient, clinical manifestations of the disease and a comprehensive evaluation of the results of all the above methods of study can we speak with confidence about hydropse.

Minimally Invasive Gastric Electrical Stimulation Using a Newly Developed Wireless Gastrostimulator: A Pilot Animal Study

Background/Aims

Gastric electrical stimulation (GES) is a feasible modality for the treatment of gastroparesis; however, the presently available device requires invasive surgical implantation for long-term stimulation and repeated surgical procedure after a period of time. This study is aimed at developing a wireless miniature GES device and testing its endoscopic insertion in animal models.

Methods

Endoscopic gastric implantation of the GES device was performed on 5 healthy weaner pigs under general anesthesia. We created an endoscopic submucosal pocket and inserted the gastro-electrical stimulator. In vivo gastric slow waves were recorded and measured during electrical stimulation. A multi-channel recorder, called an electrogastrogram, was used to record the gastric myoelectrical activity in the study.

Results

The gastric slow waves on the electrogastrogram were more consistent with GES on the gastric tissues compared to no stimulation. The frequency-to-amplitude ratio was also significantly altered after the electrical stimulation.

Conclusions

GES is feasible with our minimally invasive wireless device. This technique has the potential to increase utilization of GES as a treatment alternative.

Intersession Variations in Frequency Tuning of Ocular Vestibular Evoked Myogenic Potentials in Healthy Individuals

Objective Frequency tuning of ocular vestibular evoked myogenic potential (oVEMP), which is the stimulus frequency corresponding to the largest oVEMP amplitude, has been used to diagnose cases with Ménière's disease and differentiate them from cases with benign paroxysmal positional vertigo with a high degree of sensitivity and specificity. However, this measure of oVEMP is carved out of the peak-to-peak amplitude of oVEMP, and studies on test-retest reliability of amplitude of oVEMP have shown moderate-to-excellent reliability of amplitude. This would theoretically render the frequency tuning of oVEMP susceptible to variations across multiple recordings. This being the case, erroneous conclusions regarding the presence of Ménière's disease could be made if the frequency tuning varies between recordings. However, there is no published report regarding the test-retest reliability of frequency tuning measure of oVEMP even in healthy individuals, to the best of our knowledge. Therefore, this study aimed to study the test-retest reliability of frequency tuning of oVEMP in healthy individuals. Method The study included 20 healthy adults in the age range of 18-25 years. All participants underwent oVEMP recording in 4 different sessions, with each session consisting of oVEMP recording for octave and midoctave tone-burst frequencies from 250 to 2000 Hz. Results The results revealed no significant difference in frequency tuning of oVEMP among the sessions (p > .05). The intraclass correlation coefficient for frequency tuning data was found to be .857. Conclusion The frequency tuning of oVEMP has excellent test-retest reliability and therefore lends itself to applications requiring multiple sessions of recording.

A Novel Stimulation Paradigm for Obtaining Interfrequency Amplitude Ratio of Ocular Vestibular Evoked Myogenic Potentials

Purpose Interfrequency amplitude ratio (IFAR), the ratio of amplitude between ocular vestibular evoked myogenic potentials (oVEMPs) for tone bursts of 500 and 1000 Hz, aids in identification of Ménière's disease with high sensitivity and specificity. However, it requires recording of oVEMP for 2 frequencies, which doubles the time of recording. Use of simultaneous recording of responses for both frequencies could potentially bring down testing time. Simultaneous recording might be possible by modifying the oddball paradigm and using a ratio of 1:1 for the 2 frequencies. This might also reduce variation in oVEMP amplitude between frequencies due to changes in gaze angle between the recordings. However, it remains to be explored whether or not the use of modified oddball paradigm to record oVEMP (MoVEMP) will produce comparable responses to conventional sequential recording of oVEMP (CoVEMP) for obtaining IFAR. Hence, the study aimed to compare MoVEMP and CoVEMP on various measures of oVEMP. Method The study included 29 healthy adults in the age range of 18-30 years, 23 of which were used for validation and 6 for finding test-retest reliability. All participants underwent contralateral oVEMP recording using 500- and 1000-Hz tone bursts presented using MoVEMP and CoVEMP paradigms. Results Comparable outcomes on latencies, amplitude, and IFAR were obtained between CoVEMP and MoVEMP. Furthermore, MoVEMP took significantly lesser time per ear and also produced better test-retest reliability than CoVEMP. Conclusion MoVEMP is a quicker and more reliable clinical stimulation paradigm for obtaining IFAR than CoVEMP.