Vestibular Evoked Myogenic Potential Responses Research Articles

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

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). 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. 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. 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.

Age effects on frequency amplitude ratio of cVEMP

BackgroundThe vestibular system can perceive sound at high intensity levels. The recording of vestibular evoked myogenic potentials (VEMPs) is one of the clinical techniques that capture the vestibular system when activated by sound. In healthy individuals, it has been demonstrated that VEMP thresholds are lower when using low-frequency stimuli, particularly 500 Hz tone burst. Aging affects frequency tuning, causing shift to higher frequencies.MethodsThis study was cross-sectional, which included 80 normal healthy individuals. Each participant in the study were subjected to cervical vestibular evoked myogenic potential (cVEMP) testing using air and bone conduction as a mode of stimulation. The following cVEMP parameters were assessed: cVEMP inter-frequency peak amplitude ratio (FAR): the ratio of peak-to-peak amplitude between 500 Hz and 1000 Hz in the same ear (1000 Hz/500 Hz FPA). Also, rectified FAR is a method of normalizing the amplitude of the VEMP response to the degree of muscle contraction as determined by EMG.ResultsThere were differences among the 5 age groups that were statistically different regarding FAR and rFAR of cVEMP when using air and bone conduction stimuli.ConclusionIn this study, we provided age norms for frequency amplitude ratio (FAR) (1000/500 Hz) of cVEMP using AC and BC stimuli. Participants above the 50 years age group showed significantly larger FAR and rectified FAR than the younger age groups in both the cVEMP. Air and bone conduction stimuli yielded similar FAR results and can be both used in testing.

Changes in vestibular and cochlear function following platinum-based chemotherapy: A preliminary report.

This study investigated the changes in vestibular and cochlear function in patients receiving platinum-based chemotherapy. A longitudinal study of 32 participants (10-70years) receiving chemotherapy participated in the study. Baseline and exit vestibular and hearing assessments that included video head impulse (VHIT) testing, cervical and ocular vestibular evoked myogenic potentials (VEMP), dynamic visual acuity (DVA) and pure-tone audiometry were performed at the patient's treatment venue. Half (50%) of the participants showed cochleotoxicity from baseline to exit testing, with left ears significantly more affected than right ears. There was no consistent relationship between hearing loss and vestibular dysfunction. DVA yielded normal results at baseline and exit testing in all participants. VEMP responses were absent in 28.1% of participants at baseline, reflecting the challenges of using VEMP for monitoring. VEMP and VHIT results showed a statistically significant (p < 0.05) decline in results from baseline to exit testing; however, participants did not report symptoms related to vestibular dysfunction. VHIT also showed left ears significantly (p < 0.05) more affected than right ears. VHIT proved to be a valuable measure of changes in vestibular function secondary to ototoxicity. Future investigations should determine vestibulotoxicity criteria and optimal protocols for vestibulotoxicity monitoring at the patient's treatment venue.

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

PurposeCurrent 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.MethodsWe 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.ResultsIn 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.ConclusionIn 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.

The effect of cochlear implants on vestibular-evoked myogenic potential responses in adults

Background Cochlear implants (CIs) as a golden solution for improving hearing for patients with profound hearing loss may although causes damage for peripheral vestibular system during insertion of electrode interpretatively leading to vestibular dysfunction. This can be assessed by several methods. One of the important methods is cervical vestibular evoked myogenic potential (cVEMP) which can assess the function of saccule. Aim of the work Study the effect of insertion of electrodes of CIs on the saccular function, by using cVEMP test which was performed before and after the operation. Also, cVEMP was measured in the CI-on and CI-off modes to determine if electrical stimulation of electrodes of CIs affects the saccular function or not. Materials and method Thirty adult CI candidates were recruited from the audiology unit of Hearing and Speech Institute. cVEMP was recorded preoperatively for each candidate and two months post operative. cVEMP testing was performed in the CI-on and CI-off modes. Results cVEMP response was recorded postoperatively for 19 out of 30 (63%) implanted ears. The amplitude of wave P and wave N in implanted ears with CI-off mode was decreased compared to preoperative results and this decrease is statistically significant. Also, amplitude of wave P and wave N in implanted ears with CI-on mode were increased compared to preoperative results and this increase is statistically significant. The interaural amplitude difference (IAD) ratio in postoperative CI-on mode was decreased compared to preoperative results and this decrease is not statistically significant. Conclusion cVEMP should be included in cochlear implant selection protocol with caloric testing as it is more sensitive for discovering vestibular disorders. Also, postoperative cVEMP testing in the CI-on and CI-off modes will offer accurate evaluation of saccule function after CI surgery.

Usefulness of vestibular evoked myogenic potentials in diagnosis of peripheral vestibular disorders

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Vestibular evoked myogenic potentials (VEMP) are electromyographic responses to high-intensity acoustic stimuli to test vestibular system, otolith function and integrity of inferior vestibular nerve. These are easy to perform and non-invasive. In this study, we aimed at clinical application of VEMP to evaluate common peripheral vestibular disorders.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Prospective observational study carried in ENT department during January 2015-November 2016 over 40 patients in age group between 30-70 years with history of vertigo who underwent regular neuro-otological examination and VEMP.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Of these, 25 diagnosed with BPPV, 11 with Meniere’s disease, and four with vestibular neuritis. Eight patients showed delayed VEMP responses. 28 (70%) patients had normal VEMP, 12 (30%) had abnormal VEMP responses. Out of 25 patients suffering from benign paroxysmal positional vertigo (BPPV) posterior semi-circular canal was involved in 20 (80%) patients and lateral semi-circular canal in 5 (20%) patients.&lt;strong&gt; &lt;/strong&gt;Abnormal VEMP was found in 5 (20%) patients involving posterior semi-circular canal and in 1 (20%) patient involving lateral semi-circular canal. In patients with Meniere’s disease stage I, Meniere’s disease was observed in 7 (63.6%), stage II in 2 (18.1%), and stage IV disease in 1 (9.09%) patient. In these patients, abnormal VEMP was found in 3 (42.8%) of 7 stage I, 1 (50%) of 2 stage II and 1 (100%) of stage IV patients.&lt;strong&gt; &lt;/strong&gt;One (20%) patient had abnormal VEMP responses during study.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;VEMP are short-latency EMG that evaluates saccule and inferior vestibular nerve in peripheral vestibular nervous system. VEMP should be considered as complementary test along with conventional vestibular function tests in patients with peripheral vertigo.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;

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.

The resilience of the inner ear—vestibular and audiometric impact of transmastoid semicircular canal plugging

BackgroundCertain cases of superior semicircular canal dehiscence or benign paroxysmal positional vertigo can be treated by plugging of the affected semicircular canal. However, the extent of the impact on vestibular function and hearing during postoperative follow-up is not known.ObjectiveTo evaluate the evolution of vestibular function and hearing after plugging of a semicircular canal.MethodsSix patients underwent testing before and 1 week, 2 months, and 6 months after plugging of the superior or posterior semicircular canal. Testing included caloric irrigation test, video Head Impulse Test (vHIT), cervical and ocular Vestibular Evoked Myogenic Potentials (VEMPs) and audiometry.ResultsInitially, ipsilateral caloric response decreased in all patients and vHIT vestibulo-ocular reflex (VOR) gain of each ipsilateral semicircular canal decreased in 4/6 patients. In 4/6 patients, postoperative caloric response recovered to > 60% of the preoperative value. In 5/6 patients, vHIT VOR gain was restored to > 85% of the preoperative value for both ipsilateral non-plugged semicircular canals. In the plugged semicircular canal, this gain decreased in 4/5 patients and recovered to > 50% of the preoperative value. Four patients preserved cervical and ocular VEMP responses. Bone conduction hearing deteriorated in 3/6 patients, but recovered within 6 months postoperatively, although one patient had a persistent loss of 15 dB at 8 kHz.ConclusionPlugging of a semicircular canal can affect both vestibular function and hearing. After initial deterioration, most patients show recovery during follow-up. However, a vestibular function loss or high-frequency hearing loss can persist. This stresses the importance of adequate counseling of patients considering plugging of a semicircular canal.

Vestibular‐Evoked Myogenic Potential Outcomes Associated with Pediatric Sports‐Related Concussion

To 1) characterize vestibular-evoked myogenic potential responses in children and young adults with sports-related concussion (SRC) histories as compared with a normal healthy control group, and 2) correlate VEMP characteristics to SRC/sport history outcomes. Prospective cohort study. Seventy-six children and young adults with and without a history of SRC received cervical and ocular VEMP testing using a 500 Hz tone burst air conduction stimuli. VEMP response parameters (response rates, peak latencies, and peak-to-peak amplitudes) were assessed. Other clinical vestibular measures were performed. In the SRC group, sport history outcomes including number of SRC sustained over a lifetime, years of playing contact sports, and length of time playing contact sports were collected via in-person questionnaire. Children and young adults with SRC had significantly reduced oVEMP responses and peak-to-peak amplitudes and greater amplitude response asymmetries between left and right ear. There was no effect of group on cVEMP findings. A greater frequency of SRCs sustained throughout a lifetime, a greater number of contact sports played, and a longer duration of playing a contact sport correlated with significantly poorer VEMP response characteristics. Our results suggest that SRC and repeated subclinical head impact events have an effect on oVEMP outcomes. SRC may affect the utricle, superior vestibular nerve, and/or brainstem-mediated vestibular-ocular-reflex pathway. The prevalence of post-concussion-related dizziness is becoming increasingly common in a pediatric-otology clinic, thus performing VEMP testing in youth post-SRC provides an objective, noninvasive, and cost-effective method for monitoring the effects of sports-related impact on the vestibular system and related neural pathways. 3 Laryngoscope, 132:436-442, 2022.

Comparison of cervical and ocular vestibular-evoked myogenic potential responses between tone burst versus chirp stimulation.

To compare the effectiveness of chirp and tone burst stimuli in oVEMP and cVEMP testing for healthy adults METHODS: This study was conducted in 56 healthy volunteers (112 ears). Ocular and cervical VEMP (oVEMP, cVEMP) tests were performed for each participant using tone burst and chirp stimuli. VEMP response rates, latency of each peak (p1-n1, n1-p1), peak to peak amplitude (p1-n1 amplitude and n1-p1 amplitude), and rectified amplitudes were measured and compared between these two different stimuli. VEMP response rates with chirp stimuli are higher than the tone burst stimuli for both cVEMP and oVEMP tests (The difference was statistically significant for oVEMP, p = 0.001). Chirp stimuli have higher p1n1 amplitude and rectified amplitude and shorter p1and n1 latency then tone burst stimuli for cVEMP (p = 0.015, p = 0.007, p < 0.001, p < 0.001, respectively). Chirp stimuli also have higher n1p1 amplitude and shorter n1and p1 latency then tone burst stimuli for oVEMP (p = 0.006, p < 0.001, p < 0.001, respectively). The present findings show that the chirp stimulus triggers earlier VEMP responses with higher amplitudes than the tone burst stimulus during cVEMP and oVEMP testing. VEMP response rate with chirp stimulus is also higher than the tone burst. Therefore chirp stimulus can be used in VEMP testing as effectively as, if not more than, tone burst stimulus in clinical practice.

Evaluation of the Vestibulocochlear System in Patients with Pseudoexfoliation Syndrome

Objectives:Patients with pseudoexfoliation syndrome (PES) can also have sensorineural hearing loss as well as balance problems. Our aim was to evaluate vestibulocochlear system involvement in PES patients.Materials and Methods:The study included 16 subjects with PES (study group) with a mean age of 66.12±5.64 years and 17 healthy subjects (control group) with a mean age of 61.70±8.46 years. Both groups underwent ophthalmological, neuro-otological, audiological, and vestibular evaluation. Pure-tone audiometry and tympanometry were performed as audiological tests and bithermal caloric test and vestibular-evoked myogenic potential (VEMP) testing were used as vestibular tests. The Romberg, tandem Romberg, and Unterberger tests were also performed.Results:In the PES group, bithermal caloric tests revealed right canal paresis in 6 patients, left canal paresis in 3 patients, and bilateral stimulation loss in 2 patients, despite no clinical evidence of balance loss. Paresis was not detected in any of the control subjects. Unilateral VEMP responses could not be obtained in 3 patients in the PES group. The ocular PES patients whose VEMP waves were obtained differed significantly from the control group (p<0.05). In office tests for vestibular evaluation, pathologic findings were found in 7 of 16 patients in the study group and only 4 subjects in the control group. Audiological evaluation with pure-tone thresholds revealed sensorineural decline at 4000 and 8000 Hertz in the PES patients. A statistically significant difference was found between the study group and the control group (p<0.05).Conclusion:Patients with PES showed elevation in pure-tone thresholds and a decrease in superior and inferior vestibular nerve function, demonstrating that the vestibular system as well as the auditory system are affected in PES.

Differences in Vestibular-Evoked Myogenic Potential Responses by Using Cochlear Implant and Otolith Organ Direct Stimulation.

Objective: Several studies have demonstrated the possibility to obtain vestibular potentials elicited with electrical stimulation from cochlear and vestibular implants. The objective of this study is to analyze the vestibular-evoked myogenic potentials (VEMPs) obtained from patients implanted with cochlear and vestibulo-cochlear implant.Material and Methods: We compared two groups: in the first group, four cochlear implant (CI) recipients with present acoustic cVEMPs before CI surgery were included. In the second group, three patients with bilaterally absent cVEMPs and bilateral vestibular dysfunction were selected. The latter group received a unilateral cochleo-vestibular implant. We analyze the electrically elicited cVEMPs in all patients after stimulation with cochlear and vestibular electrode array stimulation.Results: We present the results obtained post-operatively in both groups. All patients (100%) with direct electrical vestibular stimulation via the vestibular electrode array had present cVEMPs. The P1 and N1 latencies were 11.33–13.6 ms and 18.3–21 ms, respectively. In CI patients, electrical cVEMPs were present only in one of the four subjects (25%) with cochlear implant (“cross”) stimulation, and P1 and N1 latencies were 9.67 and 16.33, respectively. In these patients, the responses present shorter latencies than those observed acoustically.Conclusions: Electrically evoked cVEMPs can be present after cochlear and vestibular stimulation and suggest stimulation of vestibular elements, although clinical effect must be further studied.

Age Effects of Bone Conduction Vibration Vestibular-evoked Myogenic Potentials (VEMPs) Using B81 and Impulse Hammer Stimuli.

Recently developed, the Radioear B81 bone oscillator allows for higher bone conduction vibration output; however, normative data are lacking regarding its use in vestibular-evoked myogenic potential (VEMP) testing. The purpose of this study was to examine the effect of age on cervical and ocular VEMP (c- and oVEMP) responses using the B81 and to compare with air conduction stimuli (ACS) and impulse hammer (IH) VEMP response characteristics. c- and oVEMP were completed with ACS, B81, and IH stimuli in healthy participants (age range = 10 to 87 years, n = 85). Regardless of stimulus type, c- and oVEMP amplitudes and response rates decreased with age. For cVEMP response rates, ACS performed better or equal to B81, which was superior to the IH. For cVEMP corrected amplitude, ACS had significantly higher amplitudes compared with B81 and IH. There was no difference in cVEMP corrected amplitude between B81 and IH. For oVEMP, response rates were comparable between stimuli with the largest disparity in response rates occurring in the oldest groups where IH outperformed both ACS and B81. For oVEMP amplitude, IH had significantly higher amplitudes compared with B81 and ACS. There was no difference in oVEMP amplitude between B81 and ACS. Age significantly affected c- and oVEMP amplitudes regardless of stimulus type (ACS, B81, IH). All stimuli are appropriate for eliciting c- and oVEMP in the young individuals. While ACS resulted in higher cVEMP corrected amplitudes, either ACS or B81 are appropriate for older individuals. However, for oVEMPs, higher response rates and larger amplitudes were noted for IH followed by B81 and ACS. Overall, the B81 performed well across the lifespan for c- and oVEMPs and may be a reasonable bone conduction vibration option for patients with absent ACS VEMPs, but at this time is not recommended as a replacement to ACS.

Elevated ocular VEMP responses in the absence of a superior semicircular canal dehiscence.

Vestibular evoked myogenic potentials (VEMPs) have an accepted role in the diagnosis of the superior semicircular canal dehiscence (SSCD) syndrome. The current impression is that ocular VEMPs (oVEMPs) are more sensitive than cervical VEMPs (cVEMPs) for detecting a SSCD and that oVEMP testing in response to air conducted sound provides an excellent screening test without risk of radiation exposure from computerized tomography (CT). To report on patients with elevated oVEMP amplitudes but without evidence for a SSCD on multiplanar CT imaging. Retrospective chart review of all patients referred for vestibular function testing to our department. Patients with oVEMP peak-to-peak amplitudes ≥17μν without evidence for a SSCD on imaging were evaluated. 26 patients had oVEMP peak-to-peak amplitudes ≥17μν with no evidence of a SSCD on imaging. The most common diagnosis was Meniere's disease in those identified. oVEMPs can provide false positive results for diagnosis of a SSCD and an elevated oVEMP amplitude in itself is insufficient for diagnosis of a SSCD.

Tap-hammer elicited vestibular-evoked myogenic potentials system: its design and preliminary application

Objective: The aim of this study was to design and perform "Tap-hammer"system that can be used to elicit vestibular evoked myogenic potentials (VEMP) in normal adults and to report the preliminary results of this system. Methods: A triggered Tap-hammer was designed, made and connected with an electric recording system, to form as a system for Tap-VEMP recording. Twenty healthy adult volunteers (7 males and 13 females, aged 20 to 37 years, 40 ears in total) were recruited for air-conducted sound VEMP (ACS-VEMP) and Tap-VEMP examinations. Waveforms and parameters of both VEMPs were recorded and analyzed. SPSS 22.0 software was used for statistical analysis. Results: The response rates of ACS-, Tap-ocular VEMP (oVEMP) and ACS-, Tap-cervical VEMP (cVEMP) were both 100% (40/40). The mean±SD n1 latency, p1 latency, n1-p1 interval, amplitude, and asymmetry ratio (AR%) of Tap-oVEMP were (9.80±2.51)ms, (13.90±3.26)ms, (4.09±1.43)ms, (16.43±9.61)μV, (22.68±17.35)% respectively. The mean±SD p1 latency, n1 latency, p1-n1 interval, amplitude, and asymmetry ratio (AR%) of Tap-cVEMP were (13.26±2.07)ms, (21.84±2.89)ms, (8.58±2.10)ms, (457.65±274.94)μV, (20.42±13.46)% respectively. Both n1 latency and p1 latency of Tap-VEMPs were shorter than those in ACS-VEMPs (P<0.05). No statistical difference could be found between the two stimulation methods in the parameters of n1-p1 interval, amplitude, and asymmetry ratio(P>0.05). Conclusion: The Tap-hammer system can elicit VEMP responses in healthy young people. This system can be used as an alternative stimulation method for bone conduction VEMP.

Effect of Cochlear Implantation on Vestibular Evoked Myogenic Potentials and Wideband Acoustic Immittance.

The objective of this study was to determine if absent air conduction stimuli vestibular evoked myogenic potential (VEMP) responses found in ears after cochlear implantation can be the result of alterations in peripheral auditory mechanics rather than vestibular loss. Peripheral mechanical changes were investigated by comparing the response rates of air and bone conduction VEMPs as well as by measuring and evaluating wideband acoustic immittance (WAI) responses in ears with cochlear implants and normal-hearing control ears. The hypothesis was that the presence of a cochlear implant can lead to an air-bone gap, causing absent air conduction stimuli VEMP responses, but present bone conduction vibration VEMP responses (indicating normal vestibular function), with changes in WAI as compared with ears with normal hearing. Further hypotheses were that subsets of ears with cochlear implants would (a) have present VEMP responses to both stimuli, indicating normal vestibular function and either normal or near-normal WAI, or (b) have absent VEMP responses to both stimuli, regardless of WAI, due to true vestibular loss. Twenty-seven ears with cochlear implants (age range 7 to 31) and 10 ears with normal hearing (age range 7 to 31) were included in the study. All ears completed otoscopy, audiometric testing, 226 Hz tympanometry, WAI measures (absorbance), air conduction stimuli cervical and ocular VEMP testing through insert earphones, and bone conduction vibration cervical and ocular VEMP testing with a mini-shaker. Comparisons of VEMP responses to air and bone conduction stimuli, as well as absorbance responses between ears with normal hearing and ears with cochlear implants, were completed. All ears with normal hearing demonstrated 100% present VEMP response rates for both stimuli. Ears with cochlear implants had higher response rates to bone conduction vibration compared with air conduction stimuli for both cervical and ocular VEMPs; however, this was only significant for ocular VEMPs. Ears with cochlear implants demonstrated reduced low-frequency absorbance (500 to 1200 Hz) as compared with ears with normal hearing. To further analyze absorbance, ears with cochlear implants were placed into subgroups based on their cervical and ocular VEMP response patterns. These groups were (1) present air conduction stimuli response, present bone conduction vibration response, (2) absent air conduction stimuli response, present bone conduction vibration response, and (3) absent air conduction stimuli response, absent bone conduction vibration response. For both cervical and ocular VEMPs, the group with absent air conduction stimuli responses and present bone conduction vibration responses demonstrated the largest decrease in low-frequency absorbance as compared with the ears with normal hearing. Bone conduction VEMP response rates were increased compared with air-conduction VEMP response rates in ears with cochlear implants. Ears with cochlear implants also demonstrate changes in low-frequency absorbance consistent with a stiffer system. This effect was largest for ears that had absent air conduction but present bone conduction VEMPs. These findings suggest that this group, in particular, has a mechanical change that could lead to an air-bone gap, thus, abolishing the air conduction VEMP response due to an alteration in mechanics and not a true vestibular loss. Clinical considerations include using bone conduction vibration VEMPs and WAI for preoperative and postoperative testing in patients undergoing cochlear implantation.

Ocular and cervical vestibular evoked myogenic potentials elicited by air-conducted, low-frequency sound.

Sound is not only detected by the cochlea, but also, at high intensities, by the vestibular system. Acoustic activation of the vestibular system can manifest itself in vestibular evoked myogenic potentials (VEMPs). In a clinical setting, VEMPs are usually evoked with rather high-frequency sound (500 Hz and higher), despite the fact that only a fraction of saccular and utricular hair cells in the striolar region is available for high-frequency stimulation. As a growing proportion of the population complains about low-frequency environmental noise, including reports on vestibular symptoms, the activation of the vestibular system by low-frequency sound deserves better understanding. We recorded growth functions of oVEMPs and cVEMPs evoked with air-conducted sound at 120 Hz and below. We estimated VEMP thresholds and tested whether phase changes of the stimulus carrier result in changes of VEMP amplitude and latency. The VEMP response of the otholith organs to low-frequency sound is uniform and not tuned when corrected for middle ear attenuation by A-weighting the stimulus level. Different stimulus carrier phases result in phase-correlated changes of cVEMP latencies and amplitudes. VEMPs can be evoked with rather low-frequency sound, but high thresholds suggest that they are unlikely to be triggered by environmental sounds.

Predictive Value of Vestibular Evoked Myogenic Potentials in the Diagnosis of Menière's Disease and Vestibular Migraine.

To explore the usefulness of vestibular evoked myogenic potentials (VEMPs) in the diagnosis of Menière's disease (MD) and vestibular migraine (VM). Retrospective cohort. Multidisciplinary neurotology clinic. Definite MD and definite VM patients between January, 2015 and May, 2017, as well as healthy volunteers. Cervical and ocular VEMP (cVEMP and oVEMP) testing. VEMP response, amplitude, and latency. Twenty five definite MD, 34 definite VM, and 13 control subjects were analyzed. MD affected ears had significantly lower cVEMP (p = 0.007) and oVEMP (p < 0.001) amplitudes than control ears. VM ears had significantly lower oVEMP (p = 0.001), but not cVEMP (p = 0.198) amplitudes than control ears. MD affected ears, but not VM ears, had significantly more absent cVEMP (25.9% versus 0%, p = 0.005) and oVEMP responses (40.7% versus 0%, p < 0.001) than control ears. oVEMP latency was significantly shorter for both MD affected (p < 0.001) and VM ears (p < 0.001) than control ears. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated using a neurotology clinic MD prevalence of 7.9% in dizzy patients. A present cVEMP or oVEMP both have more than 93% chance of ruling MD out in the tested ear, while a cVEMP amplitude more than 54.9 μV or oVEMP amplitude more than 5.1 μV both have more than 94% of ruling out MD in the tested ear. Despite some overlap in VEMP results between MD and VM, when the diagnosis is uncertain between the two disorders due to symptomatic overlap and nonspecific audiometric data, VEMPs can be helpful in guiding treatment toward one disease entity or the other until more evidence points to a definitive diagnosis.

Vestibular migraine: Our experiences at a tertiary care teaching hospital of Eastern India

Introduction: The etiopathology and management of vestibular migraine (VM) are a puzzling dilemma among the clinician. The migraine and vertigo are important symptoms of VM. Objective: Clinical and audio-vestibular evaluation of VM patients. Materials and Methods: It is a prospective study which was conducted between June 2016 and May 2019. Patients attending vertigo clinic were thoroughly reviewed. The patients of VM were selected on the basis of criteria fulfilling the International classification of headache disorders, 3rd edition (beta version). Neuro-otological examinations with videonystagmography (VNG) and vestibular evoked myogenic potentials (VEMPs) tests were done in all cases those diagnosed for VM. Results: There were 51 VM patients out of 168 dizzy patients during the study period. Aural fullness (45.09%) was the most common aural symptom, followed by tinnitus and hearing loss. Phonophobia (82.35%) was the most common migrainous symptom. The relation between headache and menstrual period among female patients was significant. VNG was showing abnormality in 11.76% of cases during caloric test with the highest abnormality in positional test. In VEMPs, 32 patients (62.74%) had abnormal cervical VEMPs response, whereas abnormal ocular VEMPs response seen 38 patients (74.50%). Conclusion: VM is a leading cause of vertigo in the clinical practice and high percentage of patients presented with abnormalities in VNG and VEMPs during vestibular symptoms. Proper history taking and neuro-otological examination and vestibular investigations help for the early diagnosis and treatment.

Vestibular evoked myogenic potentials (VEMP) captured in the forearm flexor muscles: a study of its feasibility and reference ranges

OBJECTIVE:To determine the central tendency measures and variability of vestibular evoked myogenic potential (VEMP) with regard to the latency and wave amplitude when potentials are captured from the flexor muscles of the forearm.METHODS:Ten adult volunteers with normal hearing underwent examination of their forearm flexor muscles (right and left sides; 20 samples in total) for VEMP acquisition. To this end, 200 tone burst stimuli at a 500 Hz frequency and 95 dBnHL intensity were promediated.RESULTS:No statistical differences were observed in VEMP responses acquired from the right and left forearm flexor muscles concerning P34 and N44 latencies (p=0.32 and 0.90, respectively). The mean latency obtained for the P34 wave component was 34.9 ms (±2.6), with a lower limit equal to 29.3 and an upper limit equal to 40.4 ms. The average latency of the N44 wave component was 43.6 ms (±2.1), with a lower limit of 39.1 ms and an upper limit of 48.1 ms. The results were consistent and had low variability, and showed an average asymmetry index of 15.4 (±10.7). These findings indicate that potentials may be investigated in different age groups and in specific clinical populations, such as pathologies that may alter the neuronal transmission of the inferior vestibular pathway, especially when a longer portion is observed.CONCLUSIONS:VEMP recording from forearm flexors is both feasible and stable, with latency reference ranges between 29.3 and 40.4 ms for P34, and 39.1 and 48.1 ms for N44.