Vestibular-Evoked Myogenic Potential in the Prediction of Recovery From Acute Low-Tone Sensorineural Hearing Loss

Prognosis of Acute Low-Tone Hearing Loss Without Vertigo: A Scoping Review

OBJECTIVE

Despite its relatively high prevalence, our understanding of the natural clinical course of acute low-tone hearing loss (ALHL) without vertigo remains incomplete. The purpose of this study is to summarize the findings of studies that evaluated recovery from hearing loss (HL), recurrence and/or fluctuation of HL, and progression to Meniere's Disease (MD) of patients presenting with ALHL without vertigo.

METHODS

A scoping review of the English literature was performed. On May 14, 2020 and July 6, 2022, MEDLINE, Embase, and Scopus were searched to identify articles related to the prognosis of ALHL. To be included, articles had to present outcomes that were clearly distinguishable for patients with ALHL without vertigo. Two reviewers evaluated articles for inclusion and extracted data. Disagreements were adjudicated by a third reviewer.

RESULTS

Forty-one studies were included. There was extensive heterogeneity between studies in regard to defining ALHL, treatment methods, and time of follow-up. Most of the cohorts (39 out of 40) reported partial or complete recovery of hearing in the majority (>50%) of patients, although reports of recurrence were relatively common. Progression to MD was infrequently reported. Shorter time from onset of symptoms to treatment predicted better hearing outcomes in 6 of 8 studies.

CONCLUSION

The literature suggests that although the majority of patients with ALHL experience hearing improvement, recurrence and/or fluctuation are common, and progression to MD occurs in a minority of patients. Additional trials utilizing standardized inclusion and outcome criteria are needed to determine the ideal treatment for ALHL.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2457-2469, 2023.

Impact of Endolymphatic Hydrops and Semicircular Canal Dysfunction on the Incomplete Recovery of Acute Low-Frequency Sensorineural Hearing Loss

OBJECTIVE

The reasons for short-term, incomplete recovery of some acute low-frequency sensorineural hearing loss (ALFHL) are unclear. We investigated the impact of endolymphatic hydrops and semicircular canal dysfunction on the incomplete recovery of ALFHL.

METHODS

The impact of electrocochleography (EcochG), caloric test, video head impulse test (vHIT), cervical vestibular-evoked myogenic potential (cVEMP), and ocular vestibular-evoked myogenic potential (oVEMP) results on the incomplete recovery of 86 patients with ALFHL was analyzed. The correlation between a high abnormal rate of vestibular-evoked myogenic potential (VEMP) and aural fullness, dizziness, and level of hearing loss was also examined.

RESULTS

Abnormal oVEMP with an odds ratio (OR) of 6.071 (P = .002) and EcochG with an OR of 5.919 (P = .005) were independent risk factors for incomplete recovery in ALFHL, but abnormal cVEMP, caloric test, and vHIT were not independent risk factors for ALFHL. There was no correlation between a high abnormal rate of VEMP and aural fullness, dizziness, or level of hearing loss in ALFHL.

CONCLUSION

Abnormal oVEMP and EcochG values rather than caloric test and vHIT were risk factors for incomplete recovery of ALFHL, which may be related to the difficulty of successfully treating utricular and cochlear hydrops. High abnormal rate of VEMP was not correlated with hearing loss level, aural fullness, or dizziness in ALFHL. Abnormal oVEMP and EcochG values can indicate poor short-term prognosis of ALFHL.

Central Representation of Cervical Vestibular Evoked Myogenic Potentials

Sensitivity of vestibular system to sounds (SVSS) can be measureable by cervical vestibular evoked myogenic potentials (cVEMPs). The aim of this study is to investigate central representation of vestibular system sensitivity to sound. The research was conducted in 2022-2023 by searching English language databases. The criterion for selecting documents was their overlap with the aim of this work. The animals studies were not included. The saccule is stimulated by sounds, that are transmitted through air and bone conduction. Utricle and semicircular canals are activated only by the vibrations. The afferent nerve fibers of the vestibular system project to the temporal, frontal, parietal, primary visual cortex, insula and the cingulate cortex. There is a relationship between normal results of the cVEMPs and these parameters. Improved phonemes recognition scores and word recognition scores in white noise, the efficiency of auditory training, incraed amplitude of the auditory brainstem responses to 500 HZ tone burst. Learning the first words is not only based on the hearing and other senses participate. The auditory object is a three-dimensional imaging in people's minds, when they hear a word. The words expressed by a speaker create different auditory objects in people's minds. Each of these auditory objects has its own color, shape, aroma and characteristics. For the formation of the auditory objects, all senses and whole areas of the brain contribute. Like other senses, central representation of vestibular system sensitivity to sound are also involved in the formation of auditory objects.

Vestibular assessment in sudden sensorineural hearing loss: Role in the prediction of hearing outcome and in the early detection of vascular and hydropic pathomechanisms

Introduction

Predicting hearing outcome in sudden sensorineural hearing loss (SSNHL) is challenging, as well as detecting the underlying pathomechanisms. SSNHL could be associated with vestibular damage since cochleo-vestibular structures share the same vascularization, along with being in close anatomical proximity. Whereas viral inflammations and autoimmune/vascular disorders most likely represent the involved aetiologies, early-stage Menière's disease (MD) can also present with SSNHL. Since an early treatment could beneficially influence hearing outcome, understanding the possible etiology plays a pivotal role in orienting the most appropriate treatment. We aimed to evaluate the extent of vestibular damage in patients presenting with SSNHL with or without vertigo, investigate the prognostic role of vestibular dysfunctions on hearing recovery and detect specific lesion patterns related to the underlying pathomechanisms.

Methods

We prospectively evaluated 86 patients with SSNHL. Audio-vestibular investigation included pure-tone/speech/impedance audiometry, cervical/ocular-VEMPs, vHIT and video-Frenzel examination. White matter lesions (WML) were evaluated on brain-MRI. Patients were followed-up and divided into "SSNHL-no-vertigo," "SSNHL+vertigo" and "MD" subgroups.

Results

Hearing was more impaired in "SSNHL+vertigo" patients who exhibited either down-sloping or flat-type audiograms, and was less impaired in "MD" where low frequencies were mostly impaired (p < 0.001). Otolith receptors were more frequently involved than semicircular canals (SCs). Although the "SSNHL-no-vertigo" subgroup exhibited the lowest vestibular impairment (p < 0.001), 52% of patients developed otolith dysfunctions and 72% developed nystagmus. Only "MD" subjects showed anterior SC impairment and upbeating spontaneous/positional nystagmus. They more frequently exhibited cervical-VEMPs frequency tuning (p = 0.036) and ipsilesional spontaneous nystagmus (p < 0.001). "SSNHL+vertigo" subjects presented with more frequently impaired cervical-VEMPs and posterior SC and with higher number of impaired receptors (p < 0.001). They mainly exhibited contralesional spontaneous and vibration-induced nystagmus (p < 0.05) and only they showed the highest WML score and "vascular" lesion patterns (p < 0.001). Concerning the outcomes, hearing was better in "MD" and worse in "SSNHL+vertigo" (p < 0.001). Hearing recovery was mostly affected by cervical-VEMPs impairment and the number of involved receptors (p < 0.05). Patients with "vascular" lesion patterns presented with the highest HL degree and WML score (p ≤ 0.001), while none of them exhibited a complete hearing recovery (p = 0.026).

Conclusions

Our data suggest that vestibular evaluation in SSNHL can provide useful information on hearing recovery and underlying aetiologies.

Optimal First-Line Therapy for Acute Low-Tone Sensorineural Hearing loss

Background and Objectives

We aimed to analyze treatment outcomes following different initial management approaches and confirm treatment regimens for acute low-tone sensorineural hearing loss (ALHL) that would yield the best results.

Subjects and Methods

We retrospectively analyzed the medical records of 106 patients with ALHL who visited a university hospital’s otology clinic from March 2013 to June 2019. Pure-tone averages at the initial visit and at 2 and 4 weeks after the initial visit were evaluated.

Results

Forty-nine patients were enrolled in this study; of them, 41 (83.7%) exhibited complete recovery (CR) at 2 weeks and 43 (87.8%) exhibited CR at 1 month after the initial visit. Regression analysis revealed that CR at 2 weeks after the initial visit was associated with diuretic use [Exp(B): 10.309, 95% confidence interval (CI): 1.007-100]. An initial daily low-dose steroid use was marginally significant [Exp(B): 1.042, 95% CI: 0.997-1.092; p=0.066]. Isolated diuretic use [Exp(B): 25.641, 95% CI: 1.121-90.909; p=0.039] was an independent, good prognostic factor at 1 month after the initial visit. However, other treatment regimens did not affect the final results.

Conclusions

A combination of initial daily administration of ≤30 mg prednisolone plus diuretics was sufficient as the first-line treatment for ALHL. High-dose steroids and salvage intratympanic steroid injections can be applied as a second choice; however, the predicted outcome would not be good in that case.

Ocular and cervical vestibular-evoked myogenic potentials in idiopathic sudden sensorineural hearing loss (ISSHL) without vertigo: VEMPs in ISSHL

PURPOSE

Idiopathic sudden sensorineural hearing loss (ISSHL) is a hearing impairment greater than 30 dB at three consecutive frequencies developing in less than 3 days. The aim of this study was to evaluate VEMPs and caloric testing in patients affected by ISSHL without vertigo.

METHODS

We retrospectively evaluated 35 subjects affected by ISSHL. The audio-vestibular investigation consisted of pure-tone and speech audiometry, impedance, bithermal caloric testing, oVEMPs and cVEMPs.

RESULTS

VEMPS were abnormal in 21 patients (60%): cVEMPs in 12 (34.2%) and oVEMPs in 19 (54.2%). 10 patients (28.5%) presented with both c-and oVEMPs altered. Subjects without vestibular involvement showed a significant lower PTA in the affected ear both at admission and at discharge. Recovery rate was significantly higher in group without vestibular involvement.

CONCLUSION

The evaluation of the vestibular system can be useful for predicting the auditory recovery in patients without vertigo also.

Intermediate Latency-Evoked Potentials of Multimodal Cortical Vestibular Areas: Galvanic Stimulation

Introduction

Human multimodal vestibular cortical regions are bilaterally anterior insulae and posterior opercula, where characteristic vestibular-related cortical potentials were previously reported under acoustic otolith stimulation. Galvanic vestibular stimulation likely influences semicircular canals preferentially. Galvanic stimulation was compared to previously established data under acoustic stimulation.

Methods

14 healthy right-handed subjects, who were also included in the previous acoustic potential study, showed normal acoustic and galvanic vestibular-evoked myogenic potentials. They received 2,000 galvanic binaural bipolar stimuli for each side during EEG recording.

Results

Vestibular cortical potentials were found in all 14 subjects and in the pooled data of all subjects (“grand average”) bilaterally. Anterior insula and posterior operculum were activated exclusively under galvanic stimulation at 25, 35, 50, and 80 ms; frontal regions at 30 and 45 ms. Potentials at 70 ms in frontal regions and at 110 ms at all of the involved regions could also be recorded; these events were also found using acoustic stimulation in our previous study.

Conclusion

Galvanic semicircular canal stimulation evokes specific potentials in addition to those also found with acoustic otolith stimulation in identically located regions of the vestibular cortex. Vestibular cortical regions activate differently by galvanic and acoustic input at the peripheral sensory level.

Significance

Differential effects in vestibular cortical-evoked potentials may see clinical use in specific vertigo disorders.

The Short- and Long-Term Outcome of Intratympanic Steroid Therapy as a Salvage Treatment for Acute Low-Tone Sensorineural Hearing Loss without Episodes of Vertigo

OBJECTIVES

To evaluate the hearing outcomes of intratympanic steroid (ITS) treatment for patients with acute low-tone sensorineural hearing loss (ALHL) after failure of initial therapy and to investigate the recurrence and progression to definite Ménière's disease (MD) during a long-term follow-up.

METHODS

We retrospectively reviewed the medical records of 90 patients with refractory ALHL who were followed up for at least 1 year between January 2000 and April 2014. Patients who responded poorly to initial medical treatment received intratympanic dexamethasone injections (ITS group) or isosorbide administration for 4 weeks (diuretic group) as salvage treatment options according to their choice of management. The control group did not receive ITS or the diuretic, due to their refusal of both medical treatments. The hearing outcomes were evaluated 1 month, 1 year and 5 years after the completion of the second-line therapy, and the rates of recurrence and progression to MD were measured during a follow-up period of at least 1 year.

RESULTS

Twenty-seven patients in the ITS group, 39 patients in the diuretic group and 24 patients in the control group were enrolled. Of these, 12 patients in the ITS group, 15 patients in the diuretic group and 12 patients in the control group were followed up for over 5 years. We found that the recovery rates and the audiometric functional values after 1 month and 1 year in the ITS group were significantly higher than those in the diuretic and control groups. However, there were no significant differences in the recovery rates or the audiometric functional values after 5 years, or in the rates of recurrence and progression to MD between the groups.

CONCLUSIONS

Salvage ITS therapy can provide a relatively good short-term hearing outcome for ALHL patients who have persistent hearing loss despite conventional treatment. However, both recurrence and progression to MD after treatment were observed in some patients during the long-term follow-up.

International guidelines for the clinical application of cervical vestibular evoked myogenic potentials: an expert consensus report

BACKGROUND

Cervical vestibular evoked myogenic potentials (cVEMPs) are electromyogram responses evoked by high-level acoustic stimuli recorded from the tonically contracting sternocleidomastoid (SCM) muscle, and have been accepted as a measure of saccular and inferior vestibular nerve function. As more laboratories are publishing cVEMP data, there is a wider range of recording methods and interpretation, which may be confusing and limit comparisons across laboratories.

OBJECTIVE

To recommend minimum requirements and guidelines for the recording and interpretation of cVEMPs in the clinic and for diagnostic purposes.

MATERIAL AND METHODS

We have avoided proposing a single methodology, as clinical use of cVEMPs is evolving and questions still exist about its underlying physiology and its measurement. The development of guidelines by a panel of international experts may provide direction for accurate recording and interpretation.

RESULTS

cVEMPs can be evoked using air-conducted (AC) sound or bone conducted (BC) vibration. The technical demands of galvanic stimulation have limited its application. For AC stimulation, the most effective frequencies are between 400 and 800 Hz below safe peak intensity levels (e.g. 140 dB peak SPL). The highpass filter should be between 5 and 30 Hz, the lowpass filter between 1000 and 3000 Hz, and the amplifier gain between 2500 and 5000. The number of sweeps averaged should be between 100 and 250 per run. Raw amplitude correction by the level of background SCM activity narrows the range of normal values. There are few publications in children with consistent results.

CONCLUSION

The present recommendations outline basic terminology and standard methods. Because research is ongoing, new methodologies may be included in future guidelines.

Feasibility of simultaneous recording of cervical and ocular vestibular-evoked myogenic potentials via galvanic vestibular stimulation

CONCLUSION

Simultaneous galvanic vestibular stimulation (GVS)-cervical vestibular-evoked myogenic potential (cVEMP) and GVS-ocular (oVEMP) tests yielded similar information to that obtained in individual tests.

OBJECTIVE

This study compared the characteristic parameters of cVEMPs and oVEMPs via GVS between individual and simultaneous recording patterns in healthy and elderly subjects. Consequently, the effectiveness of simultaneous GVS-cVEMP and GVS-oVEMP tests was assessed.

METHODS

A total of 24 healthy and 16 elderly subjects were enrolled in this study. All participants underwent individual cVEMP, individual oVEMP, and simultaneous cVEMP and oVEMP testing via GVS mode in a random order. The response rates and characteristic parameters of cVEMPs and oVEMPs between individual and simultaneous tests, including latencies, intervals, and amplitudes, were measured.

RESULTS

The VEMP parameters, including latencies, intervals, and amplitudes, all demonstrated no significant differences between individual and simultaneous tests (p > 0.05, paired t test), either in healthy or elderly subjects. Pearson's correlation analyses also revealed significant positive correlations in all parameters between these two tests (p < 0.05).

Vestibular hearing and neural synchronization

Objectives. Vestibular hearing as an auditory sensitivity of the saccule in the human ear is revealed by cervical vestibular evoked myogenic potentials (cVEMPs). The range of the vestibular hearing lies in the low frequency. Also, the amplitude of an auditory brainstem response component depends on the amount of synchronized neural activity, and the auditory nerve fibers' responses have the best synchronization with the low frequency. Thus, the aim of this study was to investigate correlation between vestibular hearing using cVEMPs and neural synchronization via slow wave Auditory Brainstem Responses (sABR). Study Design. This case-control survey was consisted of twenty-two dizzy patients, compared to twenty healthy controls. Methods. Intervention comprised of Pure Tone Audiometry (PTA), Impedance acoustic metry (IA), Videonystagmography (VNG), fast wave ABR (fABR), sABR, and cVEMPs. Results. The affected ears of the dizzy patients had the abnormal findings of cVEMPs (insecure vestibular hearing) and the abnormal findings of sABR (decreased neural synchronization). Comparison of the cVEMPs at affected ears versus unaffected ears and the normal persons revealed significant differences (P < 0.05). Conclusion. Safe vestibular hearing was effective in the improvement of the neural synchronization.

Vestibular hearing and speech processing

Vestibular hearing in human is evoked as a result of the auditory sensitivity of the saccule to low-frequency high-intensity tone. The objective was to investigate the relationship between vestibular hearing using cervical vestibular-evoked myogenic potentials (cVEMPs) and speech processing via word recognition scores in white noise (WRSs in wn). Intervention comprised of audiologic examinations, cVEMPs, and WRS in wn. All healthy subjects had detectable cVEMPs (safe vestibular hearing). WRSs in wn were obtained for them (66.9 ± 9.3% in the right ears and 67.5 ± 11.8% in the left ears). Dizzy patients in the affected ears, had the cVEMPs abnormalities (insecure vestibular hearing) and decreased the WRS in wn (51.4 ± 3.8% in the right ears and 52.2 ± 3.5% in the left ears). The comparison of the cVEMPs between the subjects revealed significant differences (P < 0.05). Therefore, the vestibular hearing can improve the speech processing in the competing noisy conditions.

[Recording cervical and ocular vestibular evoked myogenic potentials. Part 2: influencing factors, evaluation of findings and clinical significance]

VEMP measurements are subject to various influencing factors: patient age, threshold, sound intensity and frequency. Using air (AC) and bone conduction (BC) the vestibular receptors and afferents of the otolith organs can be activated to varying degrees. Recordings of cervical (cVEMP) and ocular VEMP (oVEMP) are clinically possible. AC-cVEMP are primarily an indicator of the sacculocollic reflex pathway. Together with findings on the vestibuloocular reflex (VOR) and complimentary otolith tests, VEMP enable otolith function analysis of each side separately. In addition, the distinction between combined or isolated canal and otolith dysfunction in terms of subtyping and patterns of damage in mono- and bilateral disorders, such as vestibular neuritis or bilateral vestibulopathy, is possible. Moreover, VEMP is relevant in terms of prognostic and therapeutic considerations as well as expert assessments.