Predictors of non-primary auditory and vestibular symptom persistence following surgical repair of superior canal dehiscence syndrome

Objective

Patients with superior canal dehiscence syndrome (SCDS) can present with a plethora of auditory and/or vestibular symptoms associated with a bony defect of the superior semicircular canal. While surgical repair is a reasonable option for patients with significant localizing symptoms, the degree of clinical improvement will vary among patients and poses challenges in outcome prediction. This study aims to assess the relationship between preoperative and postoperative symptoms and identify predictors of symptom persistence following repair.

Study design

Retrospective chart review.

Setting

Tertiary neurotology single-institution care center.

Main outcome measures

The primary outcome was to determine the proportion of resolved and persistent primary (most bothersome) and non-primary audiologic and vestibular symptoms following SCD repair. Secondary outcomes included comparison of patient, operative and radiologic characteristics between patients with resolved vs. persistent symptoms. Standardized patient questionnaires including 11 auditory and 8 vestibular symptoms were administered to patients at their preoperative and follow-up visits. Patient pre- vs. postoperative survey results, demographic and clinical characteristics, operative characteristics, audiometric data and cervical vestibular evoked myogenic potential (cVEMP) thresholds were compared via univariate χ2 and multivariate binary logistic regression analyses between those patients reporting full postoperative resolution of symptoms and persistence of one or more symptoms. Radiologic computed tomography (CT) measurements of superior canal dehiscence (SCD) defect size, location, and laterality were also compared between these two groups.

Results

Of 126 patients (132 ears) included in our study, 119 patients (90.2%) reported postoperative resolution (n = 82, 62.1%) or improvement (n = 37, 28.0%) of primary (most bothersome) symptoms, while 13 patients (9.8%) reported persistence of primary symptoms. The median (interquartile range) and range between surgery and questionnaire completion were 9 (4-28), 1-124 months, respectively. Analyzing all symptoms (primary and non-primary) 69 (52.3%) and 68 (51.1%) patients reported complete postoperative auditory and vestibular symptom resolution, respectively. The most likely persistent symptoms included imbalance (33/65/67, 50.8%), positional dizziness (7/20, 35.0%) and oscillopsia (44/15, 26.7%). Factors associated with persistent auditory symptoms included history of seizures (0% vs. 7.6%, p = 0.023), auditory chief complaint (50.0% vs. 70.5%), higher PTA (mean 19.6 vs. 25.1 dB, p = 0.043) and higher cervical vestibular evoked myogenic potential (cVEMP) thresholds at 1000 Hz (mean 66.5 vs. 71.4, p = 0.033). A migraine diagnosis (14.0% vs. 41.9% p < 0.010), bilateral radiologic SCD (17.5% vs. 38.1%, p = 0.034) and revision cases (0.0% vs. 14.0%, p = 0.002) were associated with persistent vestibular symptoms. Neither SCD defect size nor location were significantly associated with symptom persistence (P > 0.05).

Conclusions

Surgical repair for SCDS offers meaningful reduction in the majority of auditory and vestibular symptoms. However, the persistence of certain, mostly non-primary, symptoms and the identification of potential associated factors including migraines, PTA thresholds, cVEMP threshold, bilateral SCD, and revision cases emphasize the importance of individualized patient counseling and management strategies.

Vestibular assessment in children with sensorineural hearing loss: diagnostic accuracy and proposal for a diagnostic algorithm

Introduction

Vestibular assessment in children with sensorineural hearing loss (SNHL) is critical for early vestibular rehabilitation therapy to promote (motor) development or guide decision making towards cochlear implantation (timing of surgery and laterality). It can be challenging from a clinical viewpoint to decide which vestibular tests should be performed for a pediatric patient. The aim of this study was to evaluate the diagnostic accuracy of several clinically available vestibular tests in children with SNHL, and to provide recommendations for the implementation of vestibular testing of children in clinical practice, to screen for vestibular hypofunction (VH).

Methods

A two-center retrospective chart review was conducted. Eighty-six patients between the age of 0 and 18 years were included in this study with SNHL. Vestibular tests included video headimpulse test (VHIT), caloric test (performed at the age of four or higher), rotatory chair and cervical vestibular evoked myogenic potential (cVEMP). A combination of the clinical assessment and (combinations of) vestibular test outcomes determined the diagnosis. The diagnostic quality of tests and combination of tests was assessed by diagnostic accuracy, sensitivity and specificity.

Results

VH was diagnosed in 44% of the patients. The VHIT and caloric test showed the highest diagnostic accuracy compared to the rotatory chair and cVEMP. All combinations of VHIT, caloric test and cVEMP showed improvement of the diagnostic accuracy compared to the respective tests when performed singularly. All combinations of tests showed a relatively similar diagnostic accuracy, with the VHIT combined with the caloric test scoring the highest. Adding a third test did not substantially improve the diagnostic accuracy.

Discussion

Vestibular testing is feasible and VH is highly prevalent in children with SNHL. A proposed diagnostic algorithm recommends starting with VHIT, followed by cVEMP for children under the age of four, and caloric testing for older children if VH is not confirmed with the first test. Performing a third test is redundant as the diagnostic accuracy does not improve substantially. However, challenges remain, including the lack of a gold standard and the subjective nature of the diagnosis, highlighting the need for standardized testing and increased understanding of VH in this population.

Vestibular evoked myogenic potential (VEMP) test-retest reliability in adults

BACKGROUND

The technique of measuring ocular vestibular evoked myogenic potentials (oVEMP) in response to Mini-shaker vibration is relatively new, there is a limited normative data to define the presence or absence of a response in the literature.

OBJECTIVE

To determine the test-retest reliability of cervical and ocular VEMPs (cVEMP and oVEMP, respectively) to air-conducted sound (ACS) and bone-conducted vibration (BCV) stimulation and to determine normative ranges for the responses.

METHODS

Twenty normal-hearing individuals (40 ears) and 20 hearing impaired volunteers with normal balance function (40 ears) were examined in this study. ACS cVEMP and BCV oVEMP (using a Mini-shaker) were recorded from both groups to assess the test-retest reliability and to collect normative VEMP data for P1/N1 latencies and amplitudes from 20 normal hearing individuals. To test reliability, VEMP recordings were repeated within the same session.

RESULTS

The test-retest reliability for all the cVEMP parameters showed excellent reliability whereas oVEMP parameters showed between fair and excellent reliability depending on the parameter tested. Normative data for VEMP P1/N1 latencies and amplitudes were established.

CONCLUSIONS

Normative data and test-retest reliability for BCV oVEMP using the Mini-shaker at 100 Hz were established in our study for the first time in the literature. Responses appear reliable.

The Caloric Test Is More Consistent With the Presence of Endolymphatic Hydrops Than the Vestibular-Evoked Myogenic Potential Test in Meniere's Disease

Objective This study aimed to investigate the correlation between enhanced inner ear magnetic resonance imaging (MRI) findings and vestibular and cochlear function test results in patients with definite Meniere's disease and confirmed endolymphatic hydrops. Methods Among 70 consecutive patients diagnosed with definite Meniere's disease, 49 underwent contrast-enhanced 3-T inner ear MRI. The patients also underwent pure-tone audiometry, glycerol, caloric, and vestibular-evoked myogenic potential (VEMP) tests. Correlations between the pure-tone audiometry, glycerol test, caloric test, VEMP test, and MRI findings were evaluated using the chi-square test or Fisher's exact test, Student's t-test, one-way ANOVA, and Bonferroni's post-hoc test. Results Contrast-enhanced inner ear MRI revealed that 33 of 49 patients (67.3%) had endolymphatic hydrops. Among them, 19 patients had bilateral endolymphatic hydrops, and 14 had unilateral hydrops. The mean hearing threshold was higher in patients with endolymphatic hydrops than those without (p< 0.001). The proportion of patients with positive glycerol test results was higher among those with endolymphatic hydrops than in those without (p= 0.01). The rate of abnormal caloric response in patients with and without endolymphatic hydrops was not significantly different (p= 0.09). Furthermore, the rate of abnormal VEMP response in patients with and without endolymphatic hydrops was not significantly different (p= 0.70). On the affected side, in the caloric test, the ratio of the presence of vestibular and cochlear hydrops was similar (p= 1.00). On the affected side, in the VEMP test, the ratio of the presence of vestibular and cochlear hydrops was also similar (p= 0.80). The consistency of the caloric test in detecting cochlear hydrops was higher than that of the VEMP test (p= 0.04). The consistency of the caloric test in detecting vestibular hydrops tended to be higher (but not significantly) than that of the VEMP test (p= 0.11). Conclusion The cochlea and vestibule on the clinically affected side were more likely to have endolymphatic hydrops revealed by contrast-enhanced 3-T inner ear MRI than on the unaffected side. The sum of the three low frequencies (125, 250, and 500 Hz) of the pure-tone audiometry was higher in patients with endolymphatic hydrops than in those without endolymphatic hydrops. The caloric test was more consistent in detecting endolymphatic hydrops, especially cochlear hydrops, than the VEMP test in patients with definite Meniere's disease. The results of this study may contribute to the future diagnosis of Meniere's disease and improve the understanding of endolymphatic hydrops.

Vestibular evoked myogenic and auditory brainstem evoked potentials in a female migraine population

Background and purpose

The purpose of the present study was to evaluate ocular vestibular evoked myogenic potential (oVEMP), cervical vestibular evoked myogenic potential (cVEMP), and brainstem auditory evoked potential (BAEP) response characteristics and to understand the pathophy­siology of vestibular dysfunction in female migraineurs with vertigo symptoms. We also aimed to assess the electrophysiological di­­agnostic significance of the VEMP respon­ses in vestibular migraine (VM). 

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Methods

23 patients with migraine without aura (MoA), 23 patients with VM, and 20 sex-and age-matched healthy controls, a total of 66 female participants were enrolled in this study. The outcome parameters were asymmetry ratios (ARs), amplitudes of oVEMP, cVEMP, N1P1, P13N23, and the respective latencies (mean ± SD). From the BAEP graphs, absolute and interpeak interval latencies of waves were analyzed. 

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Results

30.4% of the MoA group and 21.7% of the VM group had uni- or bilaterally absent cVEMP responses which were statistically significant only in the MoA group (p=0.035) in comparison to control group. Both groups displayed statistically insignificant absent or asymmetrical responses for oVEMP (13.1%). Cervical VEMP P13 and N23 latency, peak-to-peak amplitude, interaural latencies, and amplitude ARs did not show any significant difference between MoA and VM patients and healthy controls. No significant difference was detected among the three groups in the oVEMP and BAEP parameters.

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Conclusion

Although absent cVEMP responses were more common in MoA and VM patients than in healthy individuals, the VEMP and BAEP test results should not be used in the differential diagnosis of VM and MoA. 

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[A comparative study of detection methods for assessing superior and inferior vestibular nerve damages in patients with vestibular neuritis]

Objective:This study aims to compare the examination results of the vestibular evoked myogenic potential（VEMP） and video head impulse testing（vHIT） in patients with vestibular neuritis（VN）, thus exploring the methods to distinguish superior and inferior vestibular nerve damages in VN patients, and their feasibility. Methods:A total of 25 patients with unilateral VN treated in the Otology Department of the First Hospital of Qinhuangdao from May 2018 to July 2021 were recruited. They were respectively tested for ocular VEMP（oVEMP）, cervical VEMP（cVEMP） and vHIT, and the examination results were analyzed. Results:Examination results of oVEMP showed that 96%（24/25） patients had one-ear abnormalities with the amplitude decline or no waveform introduced, and 4%（1/25） patient had no waveform introduced of both ears. The overall abnormal rate examined by oVEMP was 100%（26/26）. Examination results of cVEMP showed that 36%（9/25） patients had one-ear abnormalities with the amplitude decline or no waveform introduced, and 4%（1/25） patients had no waveform introduced of both ears. The overall abnormal rate examined by cVEMP was 40%（10/25）, and 60%（15/25） patients had normal waveforms of both ears. Examination results of vHIT showed that 100%（25/25） patients had semicircular canal gain decline of one side, 92%（23/25） had anterior Semicircular canal decline of one side, and 36%（9/25） had posterior semicircular canal decline of one side. VEMP and vHIT results were compared. Examination results of VEMP showed that 60%（15/25） VN patients had superior vestibular nerve damage, and 40%（10/25） had both superior and inferior vestibular nerve damages. Examination results of vHIT showed that 64%（16/25） VN patients had superior vestibular nerve damage, and 36%（9/25） had both superior and inferior vestibular nerve damages. There was no significant difference in the ratio of VN patients with superior and inferior vestibular nerve damages examined by VEMP or vHIT（χ²=0.085, P>0.05）. The matching ratio of VEMP and vHIT results was 80%（20/25）, and the non-matching ratio was 20%（5/25）. Conclusion:Consistent results obtained from both VEMP and vHIT can preliminarily identify the type of vestibular nerve damage. If their results are not consistent, it is recommended not to identify the scope of the vestibular nerve damage.

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.

The functional status of vestibular otolith and conductive pathway in patients with unilateral idiopathic sudden sensorineural hearing loss

Background

The cause of idiopathic sudden sensorineural hearing loss (ISSNHL) remains unknown. It has been found that the functional status of the vestibular otolith is relevant to its prognosis; however, the evaluation of the vestibular otolith (intra-labyrinth) and superior and inferior vestibular nerve pathways (retro-labyrinth) in ISSNHL patients is not well-documented.

Objective

This study aimed to investigate the functional status of the vestibular otolith and conductive pathway in patients with unilateral ISSNHL and analyze the correlations between vestibular evoked myogenic potentials (VEMPs) and hearing improvement after treatment.

Methods

A total of 50 patients with unilateral ISSNHL underwent a battery of audio-vestibular evaluations, including pure tone audiometry, middle ear function, air-conducted sound-cervical VEMP (ACS-cVEMP), ACS-ocular VEMP (ACS-oVEMP), galvanic vestibular stimulation-cervical VEMP (GVS-cVEMP), and GVS-ocular VEMP (GVS-oVEMP). The results of auditory and VEMPs were retrospectively analyzed.

Results

The abnormal rates of ACS-cVEMP, ACS-oVEMP, GVS-cVEMP, and GVS-oVEMP in affected ears were 30, 52, 8, and 16%, respectively. In affected ears, the abnormal rate of ACS-oVEMP was significantly higher than that of ACS-cVEMP (p = 0.025), while it was similar between GVS-cVEMP and GVS-oVEMP (p = 0.218). Compared with GVS-cVEMP, affected ears presented with a significantly higher abnormal rate of ACS-cVEMP (p = 0.005), and the abnormal rate of ACS-oVEMP was significantly higher than that of GVS-oVEMP (p < 0.001). No significant difference existed in latency and amplitude between affected and unaffected ears in ACS-VEMPs or GVS-VEMPs (p > 0.05). The abnormal rate of VEMPs in the poor recovery group was significantly higher than that of the good recovery group (p = 0.040). The abnormality percentages of ACS-oVEMP and GVS-oVEMP in the poor recovery group were significantly higher than that of the good recovery group (p = 0.004 and 0.039, respectively). The good hearing recovery rates were 76.47% in the normal VEMPs group, 58.33% in the intra-labyrinth lesion group, and 22.22% in the retro-labyrinth lesion group. Hearing recovery worsened as a greater number of abnormal VEMPs was presented.

Conclusion

Besides Corti's organ, the impairment of otolithic organs was prominent in patients with ISSNHL. The normal VEMPs group had the highest rate of good recovery, followed by the intra-labyrinth lesion group and the retro-labyrinth lesion group presented with the lowest recovery rate. Abnormalities in ACS-oVEMP and/or GVS-oVEMP were indicators of a poor prognosis.

Effect of Real-Ear Adjusted Stimuli on Vestibular Evoked Myogenic Potential Variability in Children and Young Adults

OBJECTIVES

There is large variability in cervical and ocular vestibular evoked myogenic potential (c- and oVEMP) amplitudes. One potential source of variability is differences in ear canal shape and size. Real ear-to-coupler difference (RECD) values are used to measure the acoustic environment of an individual's ear canal. RECD may be a useful measure to calibrate air conducted VEMP stimuli, which are elicited at high intensities and may put patients at risk of unsafe sound exposure. A recommendation for avoiding unsafe exposure is to use a 125 dB SPL stimulus for individuals with an equivalent ear canal volume (ECV) ≥ 0.9 mL and a 120 dB SPL stimulus for individuals with a smaller ECV. The purpose of this project was to determine if using a stimulus calibrated in the ear using RECD values significantly reduces intra-subject and inter-subject VEMP amplitude variability. We hypothesized that using a RECD-calibrated stimulus would significantly reduce inter-subject amplitude variability but not significantly reduce intra-subject variability. We further hypothesized that an RECD-adjusted VEMP stimulus would better protect against delivering unsafe sound exposure compared to the method of using ECV alone.

DESIGN

Eleven children (4 to 9 years), 10 adolescents (10 to 18 years), and 10 young adults (20 to 40 years) with normal hearing, tympanometry, vestibular and neurological function participated. On all subjects, RECD was measured twice per ear to account for test-retest reliability. cVEMP and oVEMP were then recorded bilaterally with a 500 Hz tone burst at a traditional and an adjusted VEMP intensity level. The traditional intensity level was 125 dB SPL for individuals with ≥ 0.9 mL ECV and 120 dB SPL for individuals with ≤ 0.8 mL ECV. The adjusted intensity level was calculated by subtracting the average 500 Hz RECD measured values from the 500 Hz normative RECD value. This value was applied as a correction factor to a 125 dB SPL stimulus. Peak to peak amplitudes were recorded and used to calculate asymmetry ratios.

RESULTS

Young children had significantly smaller ECVs compared to adolescents and young adults. Young children had larger RECDs; however, this was not significant in post hoc analyses. The method of calibration had no significant effect on intra-subject variability for cVEMP [ F (1, 27)= 0.996, p = 0.327] or oVEMP [ F (1, 25)= 1.679, p = 0.206]. The method of calibration also had no significant effect on inter-subject amplitude variability for cVEMP [ F (1, 120)= 0.721, p = 0.397] or oVEMP [ F (1, 120)= 0.447, p = 0.505]. Both methods of calibration adequately protected against unsafe exposure levels. However, there were subjects with ECVs ≥ 0.9 mL who approached unsafe exposure levels from the ECV-calibrated stimulus, suggesting there may be rare cases in which a 125 dB SPL stimulus is unsafe, even for patients with larger ECVs.

CONCLUSIONS

The calibration method made no significant difference in intra- or inter-subject variability, indicating that the acoustic environment of the outer ear is not significantly contributing to VEMP amplitude variability. The RECD-adjusted stimulus is effective in protecting against unsafe exposure levels for two trials of both c- and oVEMPs. There may be instances where more than two trials of each test are required, which increases the effective stimulation level. Clinicians should be cautious when delivering VEMPs and not unnecessarily expose patients to unsafe levels of sound.

Hearing impairment in patients with alopecia areata

Background Alopecia areata is an autoimmune disease that damages hair follicles and follicular melanocytes can be involved in the autoimmune process. Therefore, similar to vitiligo, there may be a relationship between sensorineural hearing loss and alopecia areata. Aims/objectives This study aimed to investigate potential hearing impairments in patients with alopecia areata. Methods A total of 42 subjects with alopecia areata and 42 healthy individuals enrolled in this cross-sectional study. The hearing was evaluated by vestibular evoked myogenic potential, otoacoustic emission and pure tone audiometry tests in the patients and control subjects. Results A normal otoacoustic emission was reported in 59.5% and 100% of subjects with alopecia areata and the controls, respectively (P = 0.02). Higher speech recognition thresholds (P = 0.02) and speech discrimination scores were reported more in subjects with alopecia areata than in controls (P < 0.001); however, the most comfortable level of speech was not significantly different between the groups (P = 0.06). The greatest increase in the hearing threshold was recorded at a frequency of 8000 Hz, while at frequencies of 500 and 1000 Hz, the patients and controls did not significantly differ (P > 0.05). About 6 (14.3%) and 2 (4.8%) of patients with unilateral and bilateral involvement, respectively, demonstrated no vestibular evoked myogenic potential response in the alopecia areata group. The patients and controls did not significantly differ in terms of amplitudes of the vestibular evoked myogenic potential test (P = 0.097). Limitation Small sample size and qualitative measurement of otoacoustic emission were limitations of our study. Conclusion Hearing loss was more common in alopecia areata patients than in healthy individuals. Follicular melanocytes may be involved in the alopecia areata inflammatory process, and destroying melanocytes may impact hearing function in the inner ear. However, there was no significant relationship between the duration and severity of alopecia areata and hearing loss.

Functional and Molecular Markers for Hearing Loss and Vertigo Attacks in Meniere's Disease

Meniere's disease (MD) is one of the most complicated diseases in the otologic clinic. The complexity of MD is partially due to the multifactorial etiological mechanisms and the heterogenous symptoms, including episodic vertigo, hearing loss, aural fullness and tinnitus. As a result, the diagnosis of MD and differentiating MD from other diseases with similar symptoms, such as vestibular migraine (VM), is challenging. In addition, it is difficult to predict the progression of hearing loss and the frequency of vertigo attacks. Detailed studies have revealed that functional markers, such as pure tone audiometry (PTA), electrocochleography (ECochG), vestibular evoked myogenic potential (VEMP), caloric test, video head impulse test (vHIT) and magnetic resonance imaging (MRI) could help to evaluate MD with different hearing levels and frequency of vertigo attacks. Investigations of molecular markers such as autoimmunity, inflammation, protein signatures, vasopressin and circadian clock genes in MD are still underway. This review will summarize these functional and molecular markers, address how these markers are associated with hearing loss and vertigo attacks in MD, and analyze the results of the markers between MD and VM.

New model of superior semicircular canal dehiscence with reversible diagnostic findings characteristic of patients with the disorder

Background

Third window syndrome is a vestibular-cochlear disorder in humans in which a third mobile window of the otic capsule creates changes to the flow of sound pressure energy through the perilymph/endolymph. The nature and location of this third mobile window can occur at many different sites (or multiple sites); however, the most common third mobile window is superior semicircular canal dehiscence (SSCD). There are two essential objective diagnostic characteristics needed to validate a model of SSCD: the creation of a pseudoconductive hearing loss and cVEMP increased amplitude and decreased threshold.

Methods

Adult Mongolian gerbils (n = 36) received surgical fenestration of the superior semicircular canal of the left inner ear. ABR and c+VEMP testing were carried out prior to surgery and over acute (small 1 mm SSCD, 1-10 days) or prolonged (large 2 mm SSCD, 28 days) recovery. Because recovery of function occurred quickly, condenser brightfield stereomicroscopic examination of the dehiscence site was carried out for the small SSCD animals post-hoc and compared to both ABRs and c+VEMPs. Micro-CT analysis was also completed with representative samples of control, day 3 and 10 post-SSCD animals.

Results

The SSCD created a significant worsening of hearing thresholds of the left ear; especially in the lower frequency domain (1-4 kHz). Left (EXP)/right (CTL) ear comparisons via ABR show significant worsening thresholds at the same frequency representations, which is a proxy for the human pseudoconductive hearing loss seen in SSCD. For the c+VEMP measurements, increased amplitude of the sound-induced response (N1 2.5 ms and P1 3.2 ms) was observed in animals that received larger fenestrations. As the bone regrew, the c+VEMP and ABR responses returned toward preoperative values. For small SSCD animals, micro-CT data show that progressive osteoneogenesis results in resurfacing of the SSCD without bony obliteration.

Conclusion

The large (2 mm) SSCD used in our gerbil model results in similar electrophysiologic findings observed in patients with SSCD. The changes observed also reverse and return to baseline as the SSCD heals by bone resurfacing (with the lumen intact). Hence, this model does not require a second surgical procedure to plug the SSCD.

Diagnosis of Patients Presenting with Vertigo, Headache, and Epileptic Seizure: Evaluating Vestibular Patients by Using Cervical Vestibular Evoked Myogenic Potential and Auditory Middle Latency Responses in the Clinical Setting

Migraine and vertigo are common complaints seen in clinical practice, and in a few such cases, we also find epileptic manifestations, including migraine-triggered seizures. Currently, patients presenting with vertigo and headache are diagnosed according to established diagnostic criteria for Meniere's disease, vestibular migraine, or vestibular migraine/Meniere's disease overlapping syndrome. In addition to using those diagnostic criteria and the patient's history, cervical vestibular evoked myogenic potential and auditory middle latency responses are useful tools to better understand the physiological background of these patients and also to confirm the diagnosis. Here we report 2 cases: 1 of vestibular migraine/ Meniere's disease overlapping syndrome and 1 of vestibular migraine with epileptic manifestations. Each patient showed potentiation (lack of habituation) in auditory middle latency response, and each showed endolymphatic hydrops in cervical vestibular evoked myogenic potential. The potentiation in auditory middle latency response might be attributable to neuronal hyperexcitability in those patients with migraine or epilepsy, and neurogenic inflammation caused by migraine episodes might affect inner ear function.

A Preliminary Study on the Characteristics and Standard Diagnosis and Treatment of Vestibular Dysfunction in Children

OBJECTIVE

To understand the pathogenesis of vestibular dysfunction in children and to provide a reference for the diagnosis and treatment of vestibular dysfunction in children.

METHODS

A retrospective analysis was conducted on 80 children who visited our hospital from June 2011 to July 2020, aged between 4 and 17 years, with a duration of 1 day to 3 years. They were admitted to the hospital for treatment upon vestibular function-related examinations confirmed that there was peripheral vestibular function impairment.

RESULTS

Children aged 6-12 years old who are diagnosed are significantly more than other two age groups (4-6) and (12-17) (X2 = 101.738, P < .001). There was a significant statistical difference (X2 = 91.195, P < .001) in comparison of abnormal rates of vestibular function-related examinations. The Mann test had the highest abnormal rate and the lowest Cervical Vestibular Evoked Myogenic Potential (cVEMP) abnormality rate. Comparison of abnormal consistency rates for quantitative and qualitative examination of vestibular function, the abnormal rates (double temperature test and Mann test) were significantly better than other abnormal consistency rates, and there were statistical differences (X2 = 7.485, P = .024 < .05). Among the children with vestibular dysfunction, the etiology was most common in 58 cases (72.50%) of benign paroxysmal vertigo, 4 cases of vestibular migraine (5.00%), 8 cases (10.00%) of vestibular neuronitis, of which 22 cases (27.50%) were combined with other diseases, and the most common was 15 cases (18.75%) of sinusitis.

CONCLUSION

A limited number of studies were conducted on vestibular dysfunction in children. The current retrospective analysis suggests that age, gender, and side of ear pain have no significant effects, while children aged 6-12 are more likely to suffer from vestibular dysfunction. On children's vestibular dysfunction, more etiology is unclear, and special attention should be paid to differential diagnosis when giving treatment and the child's medical history should be examined in detail and appropriate vestibular function tests should be selected in order to provide timely, effective, and accurate treatment for the child.

Vestibular evoked myogenic potential may predict the hearing recovery in patients with unilateral idiopathic sudden sensorineural hearing loss

OBJECTIVE

This study investigates the association between vestibular function and prognosis in patients with unilateral idiopathic sudden sensorineural hearing loss (UISSNHL).

DESIGN

A retrospective analysis of 64 patients with UISSNHL was performed. Pure tone audiometry and vestibular function tests for otoliths and semicircular canals were performed to assess the influence of vestibular functional status on the outcome of patients with UISSNHL.

RESULTS

Patients with abnormal cervical vestibular evoked myogenic potential (cVEMP) or ocular vestibular evoked myogenic potential (oVEMP) responded less favorably to treatment. In the ineffective group, cVEMP was normal in four patients (6.3%) and oVEMPs in three (4.7%). Meanwhile, cVEMP was abnormal in 32 patients (50.0%) and oVEMP in 33 (51.6%). Better hearing recovery occurred in those with normal cVEMP (33.76 ± 15.07 dB HL improvement) or oVEMP (32.55 ± 19.56 dB HL improvement), but this was not the case in those with normal caloric tests. Patients with abnormalities in both cVEMP and oVEMP were less responsive to treatment and had worse hearing recovery than those with normal results in only one of the two tests.

CONCLUSION

Abnormal oVEMP and/or cVEMP results indicate poor auditory outcomes in patients with UISSNHL. Patients with impaired otolith organ function are likely to have a larger and more severe pathological change in their inner ear.

[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.

The value of vestibular evoked myogenic potential and electrocochleography in unexplained aural fullness

BACKGROUND

Unexplained aural fullness, after excluding external or middle ear diseases and vertigo, is not easily diagnosed.

AIM

The aim of this study is to determine the vestibular evoked myogenic potential (VEMP) and electrocochleography (ECochG) abnormal rates in patients with unexplained aural fullness, and analyzed the relationship between unexplained aural fullness and endolymphatic hydrops (EH).

MATERIAL AND METHODS

The VEMP and EcochG abnormal rates in 54 patients with unexplained aural fullness and 21 healthy volunteers, and the VEMP and EcochG abnormal rates in the four hearing loss groups were compared. The distribution of abnormal of VEMP and EcochG in age, sex or hearing loss groups were investigated.

RESULTS

The VEMP abnormal rate in patients was greater than that in healthy volunteers (p = .000). The abnormal rate of VEMP was greater than the EcochG in patients (p = .003). The VEMP abnormal rate was greater than the EcochG in patient with low-tone or high-tone hearing loss (p = .008).

CONCLUSION AND SIGNIFICANCE

Abnormal of VEMP in a significant proportion of patients with unexplained aural fullness maybe indicative of EH, and EH was more likely to involve the utricle or saccule in patients with low- or high-tone hearing loss.

Using Functional Outcomes to Predict Vestibular Loss in Children

OBJECTIVE

The purpose of this study was to determine: (1) the relationship between vestibular loss severity and functional performance, (2) which functional performance outcomes best predict vestibular loss, and (3) which vestibular rate sensors (canals vs. otoliths) provide the most weighting during different functional measures.

STUDY DESIGN

Prospective.

SETTING

Tertiary referral center.

PATIENTS

Fifty-seven children with normal hearing (mean age: 12.3 years, 32 males) and 55 children with cochlear implants (mean age 12.8 years, 29 males).

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURES

Video head impulse test, cervical vestibular evoked myogenic potential (cVEMP), ocular VEMP (oVEMP), single leg stance, Standing Balance Test, active and passive dynamic visual acuity, and the balance subtest of the Bruininks-Oseretsky Test of Motor Proficiency (BOT-2).

RESULTS

Performance worsened as vestibular loss severity worsened for all functional outcomes except the standing balance test conditions 1 and 2. The best outcomes for classifying children with vestibular loss were the single leg stance (cut-off criterion: 5 seconds; sensitivity and specificity of 88% and 86%) and the BOT-2 balance subtest (cut-off criterion of 27.5 points; sensitivity and specificity of 88% and 88%). Average horizontal canal vHIT gain was a significant predictor of all functional outcomes while neither corrected cVEMP amplitude nor oVEMP amplitude predicted performance.

CONCLUSION

Functional performance declines as vestibular loss severity worsens. Single leg stance is fast and efficient for predicting vestibular loss in school age children. Average horizontal canal vHIT best predicts functional performance; if using a tiered approach, horizontal canal vHIT should be completed first.

Effect of cochlear implantation on vestibular function in children: A scoping review

OBJECTIVE

To provide a scoping review of the available literature for determining objectively the effect of cochlear implantation on vestibular function in children.

METHODS

A literature search was performed and the following criteria were applied: vestibular tests that were performed on subjects within the range of 0-18 years old before and after cochlear implantation. The papers conducted at least one of the following tests: (video) head impulse test, caloric test, cervical and ocular vestibular evoked myogenic potentials or rotatory chair test. Included papers underwent quality assessment and this was graded by risk of bias and directness of evidence.

RESULTS

Fourteen articles met the selection criteria. The included studies showed that cochlear implantation leads to a decrease in vestibular function in a proportion of the patient population. This loss of vestibular function can be permanent, but (partial) restoration over the course of months to years is possible. The pooling of data determined that the articles varied on multiple factors, such as time of testing pre- and post-operatively, age of implantation, etiologies of hearing loss, used surgical techniques, type of implants and the applied protocols to determine altered responses within vestibular tests. The overall quality of the included literature was deemed as high risk of bias and medium to low level of directness of evidence. Therefore, the data was considered not feasible for systematic analysis.

CONCLUSION

This review implicates that vestibular function is either unaffected or shows short-term or permanent deterioration after cochlear implantation in children. However, the heterogeneity of the available literature indicates the importance of standardized testing to improve our knowledge of the effect of cochlear implantation on the vestibular function and subsequent developmental consequences for the concerned children.

[Application of vestibular function examination battery in the staging of vestibular function in Meniere's disease]

Objective:To investigate the staging of vestibular organ damage in Meniere's disease, based on the vestibular function examination battery. Methods:Thirty-nine patients, clinically diagnosed as unilateral Meniere's disease, underwent audiologic test and vestibular function examination battery, including ocular vestibular evoked myogenic potential（oVEMP）, cervical vestibular evoke myogenic potential（cVEMP）, and caloric tests. Based on the results of the vestibular function examination battery, the vestibular function was divided into 4 stages. StageⅠ: oVEMP, cVEMP, and caloric tests were normal; stage Ⅱ: any one test of the three examinations was abnormal; stage Ⅲ: two of the three examinations were abnormal; Stage Ⅳ: All the three examinations were abnormal. Results:According to the vestibular function staging strategy in this study, patients in stage Ⅰ, Ⅱ, Ⅲ, Ⅳ were 7.7%（3/39）, 30.8%（12/39）, 33.3%（13/39）, 28.2%（11/39） respectively in the 39 Meniere's disease patients. However, according to the current clinical staging strategy of Meniere's disease, patients of stage1, 2, 3, 4 were 20.5%（8/39）, 43.6%（17/39）, 28.2%（11/39）, and 7.7%（3/39） respectively. 37.5%（3/8） patients in stage 1 and 64.7%（11/17） patients in stage 2 had two or more abnormal vestibular organs. While all the patients in stage 4 had abnormal semicircular canals, utricle, and saccule. The stage of vestibular function was correlated with the distribution of current clinical staging strategy of Meniere's disease（P<0.05）. Conclusion:The combination of oVEMP, cVEMP and caloric tests can divide the vestibular function into four stages, which can be used as a supplement to the traditional vestibular evaluation and clinical staging based on audiology in Meniere's disease.

Effects on cervical vestibular-evoked myogenic potentials of four clinically used head and neck measurement positions in healthy subjects

BACKGROUND

The most reliable head and neck position for cervical vestibular-evoked myogenic potentials (cVEMPs) measurements yet to be determined.

AIMS/OBJECTIVES

To assess how four body positions used during clinical recordings of cVEMPs affect cVEMP parameters.

MATERIAL AND METHOD

cVEMPs of 10 healthy subjects (26-50 years old) were recorded in four body positions: A. sitting/head rotated; B. supine/head rotated; C. semi-recumbent/head rotated and elevated; D. supine/head elevated.

RESULTS

Mean background sternocleidomastoid muscle (SCM) electrical activity was significantly higher in positions C and D than in positions A and B. The latencies of p13 and n23 differed significantly among the four positions. Raw p13-n23 complex amplitude was significantly greater in positions C and D than in A and B. These differences were reduced when amplitudes were corrected by SCM activity. For positions A and B, one and two subjects, respectively, had an abnormal raw asymmetry ratio (AR). After correction, all subjects had normal ARs in all positions.

CONCLUSIONS AND SIGNIFICANCE

Body positions in which the head is elevated produce a quicker and larger cVEMP response compared to positions in which the head is not elevated. The difference in ARs among positions can be ignored as long as the correction is made.

[Methods and advances in clinical application of vestibular evoked myogenic potentials in children]

Vestibular dysfunction, which may lead to delayed motor development and reduced quality of life, is an overlooked entity among children and adolescents. Vestibular evoked myogenic potential （VEMPs） is a common, safe diagnostic tool in adults for vestibular disorders. However, there is no related data for children and adolescents. We aimed to collect and assess normative VEMP data for adolescents. In this article , we analyzed the results of VEMPs in children in recent years, and summarized the common detection methods of VEMPs in children, the detection rate and variability characteristics of VEMPs in children of different ages, and the current status of clinical application of VEMPs in children.

Bone Conduction Stimulated VEMP Using the B250 Transducer

Objective

Bone conduction (BC) stimulation is rarely used for clinical testing of vestibular evoked myogenic potentials (VEMPs) due to the limitations of conventional stimulation alternatives. The aim of this study is to compare VEMP using the new B250 transducer with the Minishaker and air conduction (AC) stimulation.

Methods

Thirty normal subjects between 20 and 37 years old and equal gender distribution were recruited, 15 for ocular VEMP and 15 for cervical VEMP. Four stimulation conditions were compared: B250 on the mastoid (F_M); Minishaker and B250 on the forehead (F_Z); and AC stimulation using an insert earphone.

Results

It was found that B250 at F_M required a statistically significant lower hearing level than with AC stimulation, in average 41 dB and 35 dB lower for ocular VEMP and cervical VEMP, respectively, but gave longer n10 (1.1 ms) and n23 (1.6 ms). No statistical difference was found between B250 at F_M and Minishaker at F_Z.

Conclusion

VEMP stimulated with B250 at F_M gave similar response as the Minishaker at F_Z and for a much lower hearing level than AC stimulation using insert earphones.

MRI With Intratympanic Gadolinium: Comparison Between Otoneurological and Radiological Investigation in Menière's Disease

Objectives/hypothesis: To compare findings obtained using both magnetic resonance imaging plus intratympanic gadolinium and audiovestibular testing for Menière's disease.

Study design: Retrospective cohort study.

Methods: Patients with definite unilateral Menière's disease (n = 35) diagnosed according to 2015 Barany Criteria were included. Three-dimensional real inversion recovery (3D-real-IR) MRI was executed 24 h after intratympanic gadolinium injection to assess the presence and degree of endolymphatic hydrops. Pure tone audiometry, bithermal caloric test, head impulse test, ocular, and cervical VEMPs using air-conducted sound were performed to evaluate the level of hearing and vestibular loss. The results were compared to verify precision of the method in providing correct diagnoses.

Results: Different degrees of endolymphatic hydrops were observed in the MRI of the cochlea and vestibule in the affected ears of Menière's disease patients, even though it was impossible to radiologically distinguish the two otolithic structures separately. The correlation between the degree of linked alterations between instrumental and MRI testing was statistically significant. In particular, an 83% correspondence with audiometry, a 63% correspondence for cVEMPs and 60% correspondence for cVEMPs were seen. While for HIT the accordance was 70 and 80% for caloric bithermal test.

Conclusions: MRI using intratympanic gadolinium as a contrast medium has proved to be a reliable and harmless method, even though there is an objective difficulty in disclosing macular structures. The study revealed that there is no complete agreement between instrumental values and MRI due to the definition of the image and fluctuation of symptoms. The present work highlights the greater (but not absolute) sensitivity of otoneurological tests while MRI, although not yet essential for diagnosis, is certainly important for understanding the disease and its pathogenic mechanisms.

Parameters of Off-Vertical Axis Rotation in Unilateral and Bilateral Vestibulopathy and Their Correlation with Vestibular Evoked Myogenic Potentials

Off-vertical axis rotation (OVAR) is a laboratory test to assess the otolith function. This study aimed to analyze the parameters of OVAR in patients with unilateral vestibular hypofunction (UVH) and bilateral vestibulopathy (BVP), and to correlate the parameters of OVAR with those of VEMPs. Ten healthy volunteers, 41 UVH, and 13 BVP patients performed OVAR. Bias component (BIC) and modulation component (MOC) of UVH and BVP patients were compared with those of healthy controls. BIC and MOC were correlated with amplitude and interaural difference (IAD) of cervical VEMP (cVEMP) and ocular VEMP (oVEMP). In UVH patients, the direction of BICs to affected side rotation were reversed and the absolute value of BICs were decreased when they were compared to healthy controls. In BVP patients, BICs were markedly attenuated. MOCs were not changed in UVH and BVP patients. There was no statistically significant correlation between VEMPs and OVAR.

[Study of ocular vestibular evoked myogenic potentials in benign paroxysmal positional vertigo associated with Meniere's disease]

Objective:The aim of this study is to explore the characteristics of ocular muscle vestibular evoked myogenic potential （oVEMP） in patients with Meniere's disease and benign paroxysmal positional vertigo （BPPV-MD）, and to explore the clinical characteristics of oVEMP frequency amplitude ratio （FAR）. Methods:Forty-one patients with unilateral MD diagnosed in the outpatient clinic from January 2016 to April 2019 were selected, of which 15 patients with BPPV-MD were set as BPPV-MD group, and 26 patients with unilateral MD were set as MD group. During the same period, 30 healthy volunteers matched in age and gender were selected as the control group. All the individuals underwent oVEMP and cVEMP recording for 500 Hz and 1000 Hz tone burst. The oVEMP and cVEMP response rate, N1 and P1 waves latency, N1-P1 wave amplitude and 1000/500 Hz FAR of the affected and contralateral ears of the three groups were compared and analyzed by SPSS 20.0 software. The receiver operating characteristics curves were obtained for finding out the criterion point, sensitivity, and specificity of 1000/500 Hz FAR for the diagnosis of BPPV-MD. Results:In response to 500 Hz tone burst, oVEMP response rates in the affected lateral ears of BPPV-MD group, MD group and right ears of control group were 46.67%, 46.15% and 76.67%, respectively; the rates for the 1000 Hz-oVEMP of the three groups were 53.33%, 46.15% and 63.33%, respectively. By the 500 Hz air-conducted tone-burst stimulus, the oVEMP N1 and P1 latency of the affected ears in the BPPV-MD group was longer than that in the MD group and the control group（P<0.05）. By the stimulus of 1000 Hz tone burst, the oVEMP N1 and P1 latency of the affected ears in BPPV-MD group and MD group was longer than that in control group（P<0.05）. At 500 Hz, the oVEMP amplitude of the affected ears in BPPV-MD group and MD group was lower than that in the right ears of the control group（P<0.05）. There was no statistically significant difference in the N1-P1 amplitudes of oVEMP in the three groups under the stimulation of 1000 Hz tone burst（P>0.05）. The FAR for 1000/500 Hz of the affected ears in BPPV-MD group and MD group was higher than that in control group（P<0.05）, but there was no significant difference between BPPV-MD group and MD group（P>0.05）. Conclusion:When FAR is greater than 0.84, which indicates that the pathophysiologic factor is accumulation of excessive amounts of endolymph; when FAR is greater than 1.79, which suggests that the otolitic membrane of the elliptic cyst is damaged by the hydrops of the labyrinthus. The FAR of BPPV-MD can be used as one of the indicators to evaluate the function of the utricle.

Is There Any Effect of Subjective Tinnitus on Vestibular Evoked Myogenic Potentials

Idiopathic subjective tinnitus has a complex pathophysiology in which not only cochlear and central classical auditory pathways but also nonclassical auditory pathways of different parts of the brain are involved. Vestibuloocular and vestibulocollic pathways are the central projections of utricle and saccule used in the vestibular evoked myogenic potential (VEMP) test. Aim of this study was to investigate the effects of idiopathic subjective tinnitus on vestibuloocular and vestibulocollic pathways via VEMP. We prospectively analyzed 30 unilateral idiopathic subjective tinnitus patient's cervical, ocular VEMP tests, tinnitus handicap index scores, symptom duration and compared with contralateral ear and 35 healthy volunteers. The latencies and amplitudes of P1 and N1 waves were recorded and pathologic wave criteria was calculated according to healthy volunteer's data. In cervical VEMP there were significant longer latencies of P1 and N1 waves with respect to contralateral ear and control group. In ocular VEMP test, N1 and P1 latencies and amplitudes were not significantly different. The percentages of pathologic wave of the tinnitus side were not significantly higher in both cervical VEMP and ocular VEMP tests with respect to contralateral side. Tinnitus handicap index scores and symptom duration had no relationship with latency and amplitude of VEMP tests. Although cervical VEMP P1 and N1 latencies were significantly longer, subjective tinnitus did not result in pathological alterations in the VEMP test. Presence of subjective tinnitus is not an influencing factor in the VEMP interpretation.

Quantifying the effects of electrode placement and montage on measures of cVEMP amplitude and muscle contraction

BACKGROUND

The cervical vestibular evoked myogenic potential (cVEMP) can be affected by the recording parameters used to quantify the response.

OBJECTIVE

We investigated the effects of electrode placement and montage on the variability and symmetry of sternocleidomastoid (SCM) contraction strength and cVEMP amplitude.

METHODS

We used inter-side asymmetries in electrode placement to mimic small clinical errors in twenty normal subjects. cVEMPs were recorded at three active electrode sites and referred to the distal SCM tendon (referential montages: upper, conventional and lower). Additional bipolar montages were constructed offline to measure SCM contraction strength using closely-spaced electrode pairs (bipolar montages: superior, lower and outer).

RESULTS

The conventional montage generally produced the largest cVEMP amplitudes (P < 0.001). SCM contraction strength was larger for referential montages than bipolar ones (P < 0.001). Inter-side electrode position errors produced large variations in cVEMP and SCM contraction strength asymmetries in some subjects, producing erroneous abnormal test results.

CONCLUSION

Recording locations affect cVEMP amplitude and SCM contraction strength. In most cases, small changes in electrode position had only minor effects but, in a minority of subjects, the different montages produced large changes in cVEMP and contraction amplitudes and asymmetry, potentially affecting test outcomes.

Influence of Cochlear Implantation on Balance Function in Pediatrics

BACKGROUND AND OBJECTIVE

Patients with profound Sensorineural Hearing Loss (SNHL) are susceptible to vestibular disturbances following Cochlear Implant (CI) surgery. This study aimed to evaluate vestibular dysfunctions following unilateral CI in the congenitally deaf children.

METHODS

This was a cross-sectional study conducted on 24 children (mean age: 10.56 ± 5.49 years old) who underwent unilateral CI and 24 age-matched controls (mean age: 11.13 ± 6.21 years old). Vestibular functions were assessed by Vestibular Evoked Myogenic Potential (VEMP) and Computerized Dynamic Posturography (CDP). The VEMP test was performed for otolith's function (especially saccule) evaluation. Sensory Organization Test (SOT) protocol of CDP was also utilized to differentiate the role of various sensory systems contributing to postural stability. In addition, total equilibrium score was calculated. The variables were comparatively assessed between the two groups.

RESULTS

The mean p13-n23 amplitude in the CI users was significantly lower than the controls (p<0.05). However, the two groups showed no significant difference in cVEMP latency values (p>0.05). The SOT analysis revealed that 45.83% (11/24) of the CI subjects had some kind of sensory abnormalities: 7 cases (29.17%) vestibular, 2 cases (8.33%) visual, 2 cases (8.33%) vestibular and somatosensory involvements. Furthermore, total equilibrium score was significantly reduced in implanted group than the controls (p<0.001). At least, 70.59% (12/24) CI patients showed abnormal values in the CDP or cVEMP examinations.

CONCLUSION

This study shows functional vestibular impairments in children who underwent CI. These patients showed significantly increased postural instability which was more evident in dynamic conditions. These findings provide the basis for better pre-operative counseling and postoperative vestibular rehabilitation to CI recipients.

Ocular Vestibular-Evoked Myogenic Potential Amplitudes Elicited at 4 kHz Optimize Detection of Superior Semicircular Canal Dehiscence

Introduction: High-resolution temporal bone computed tomography (CT) is considered the gold standard for diagnosing superior semicircular canal dehiscence (SCD). However, CT has been shown over-detect SCD and provide results that may not align with patient-reported symptoms. Ocular vestibular-evoked myogenic potentials (oVEMPs)—most commonly conducted at 500 Hz stimulation—are increasingly used to support the diagnosis and management of SCD. Previous research reported that stimulation at higher frequencies such as 4 kHz can have near-perfect sensitivity and specificity in detecting radiographic SCD. With a larger cohort, we seek to understand the sensitivity and specificity of 4 kHz oVEMPs for detecting clinically significant SCD, as well as subgroups of radiographic, symptomatic, and surgical SCD. We also investigate whether assessing the 4 kHz oVEMP n10-p15 amplitude rather than the binary n10 response alone would optimize the detection of SCD.

Methods: We conducted a cross-sectional study of patients who have undergone oVEMP testing at 4 kHz. Using the diagnostic criteria proposed by Ward et al., patients were determined to have SCD if dehiscence was confirmed on temporal bone CT by two reviewers, patient-reported characteristic symptoms, and if they had at least one positive vestibular or audiometric test suggestive of SCD. Receiver operating characteristic (ROC) analysis was conducted to identify the optimal 4 kHz oVEMP amplitude cut-off. Comparison of 4 kHz oVEMP amplitude across radiographic, symptomatic, and surgical SCD subgroups was conducted using the Mann-Whitney U test.

Results: Nine hundred two patients (n, ears = 1,804) underwent 4 kHz oVEMP testing. After evaluating 150 temporal bone CTs, we identified 49 patients (n, ears = 61) who had radiographic SCD. Of those, 33 patients (n, ears = 37) were determined to have clinically significant SCD. For this study cohort, 4 kHz oVEMP responses had a sensitivity of 86.5% and a specificity of 87.8%. ROC analysis demonstrated that accounting for the inter-amplitude of 4 kHz oVEMP was more accurate in detecting SCD than the presence of n10 response alone (AUC 91 vs. 87%). Additionally, using an amplitude cut-off of 15uV reduces false positive results and improves specificity to 96.8%. Assessing 4 kHz oVEMP response across SCD subgroups demonstrated that surgical and symptomatic SCD cases had significantly higher amplitudes, while radiographic SCD cases without characteristic symptoms had similar amplitudes compared to cases without evidence of SCD.

Conclusion: Our results suggest that accounting for 4 kHz oVEMP amplitude can improve detection of SCD compared to the binary presence of n10 response. The 4 kHz oVEMP amplitude cut-off that maximizes sensitivity and specificity for our cohort is 15 uV. Our results also suggest that 4 kHz oVEMP amplitudes align better with symptomatic SCD cases compared to cases in which there is radiographic SCD but no characteristic symptoms.

Vestibular Evoked Myogenic Potential (VEMP) Testing for Diagnosis of Superior Semicircular Canal Dehiscence

Superior semicircular canal dehiscence is a bony defect of the superior semicircular canal, which can lead to a variety of auditory and vestibular symptoms. The diagnosis of superior semicircular canal dehiscence (SCD) can be challenging, time consuming, and costly. The clinical presentation of SCD patients resembles that of other otologic disease, necessitating objective diagnostics. Although temporal bone CT imaging provides excellent sensitivity for SCD detection, it lacks specificity. Because the treatment of SCD is surgical, it is crucial to use a highly specific test to confirm the diagnosis and avoid false positives and subsequent unnecessary surgery. This review provides an update on recent improvements in vestibular evoked myogenic potential (VEMP) testing for SCD diagnosis. Combining audiometric and conventional cervical VEMP results improves SCD diagnostic accuracy. High frequency VEMP testing is superior to all other methods described to date. It is highly specific for the detection of SCD and may be used to guide decision-making regarding the need for subsequent CT imaging. This algorithmic sequential use of testing can substantially reduce radiation exposure as well as cost associated with SCD diagnosis.

The Effect of Cochlear Implantation on Vestibular Evoked Myogenic Potential in Children

Objectives/Hypothesis

We conducted this study to assess the effects of unilateral cochlear implantation (CI) on otolith function by observing the changes in ocular vestibular evoked myogenic potential (oVEMP) and cervical vestibular evoked myogenic potential (cVEMP) in children.

Study Design: Prospective case series.

Methods

The oVEMP and cVEMP elicited by air‐conducted sound in 35 children were analyzed preoperatively and at 5 days, 1 month, and 2 months after surgery.

Results

Before CI, the response rates of oVEMPs and cVEMPs were 81.4% and 91.4%, respectively. In the implanted side, oVEMPs and cVEMPs were reduced by 37.1% and 68.6%, respectively, 5 days after CI. One month after CI, oVEMPs and cVEMPs were 34.6% and 72%, respectively, with the device switched off, and 50% and 73.1%, respectively, with the device switched on. Two months after CI, the oVEMPs and cVEMPs were 36% and 80%, respectively, when the implant was turned off, and 70.8% and 75%, respectively, when the implant was turned on.

Conclusions

The study confirmed the value of VEMP testing in the clinical setting and that absent VEMPs could indicate impairment of otolith function after CI.

Level of Evidence

4 Laryngoscope, 2020

Vestibular evoked myogenic potential (VEMP) results in migraine and migrainous vertigo

Background: The pathophysiology of vertigo is not fully known; thus, it is difficult to diagnose vestibular migraine (VM) in some migraine patients with vertigo symptoms.Aims/objectives: We aimed to evaluate the diagnostic value of cervical vestibular evoked myogenic potential (cVEMP) in patients with VM.Materials and Methods: Thirty-two patients diagnosed with migraine and 31 patients with VM were prospectively included in this study. The cVEMP responses were obtained, and P1-N1 latency, interpeak amplitude, amplitude asymmetry ratio were calculated. The patients' demographics, results of physical and audiometric examinations, and VEMP records as well as absence of responses were evaluated and compared between groups.Results: The incidence of ears with absence VEMP responses was found to be numerically higher in the migraine group than in the VM group (p = .106). Additionally, there were no statistically significant differences detected between the groups in terms of the p13 or n23 latency, interpeak amplitude, and amplitude asymmetry ratio measured in both right and left ears (p > .05).Conclusions: The increased rate of absent VEMPs was associated with the hypoperfusion of the sacculo-collic reflex pathway in migraine patients. In addition, it was concluded that VEMP reflex responses appear to be insufficient to differentiate between VM and migraine diagnoses.

Vestibular evoked myogenic potential responses in Parkinson's disease

Background and purpose

- Our objectives were to determine the differences in the vestibular evoked myogenic potential (VEMP) responses in patients diagnosed with early staged idiopathic Parkinson's disease (PD) compared to the normal population and evaluate the vestibular system disorder causing balance-posture disorders. Second aim of this study was to investigate caloric test responses particularly in early staged PD compared to normal popu-lation.

Methods

Thirty patients (14 females and 16 males; mean age, 60.6 ± 13.1 years) diagnosed with idiopathic PD and 28 healthy subjects (20 males and 8 females; mean age, 59.1 ± 6.4 years) were included. The patient and control groups were subdivided according to their age, gender and the patient group was subdivided according to onset time of the Parkinson symptoms, Hoehn-Yahr staging. The subgroups were compared for VEMP and caloric test responses.

Results

There were no significant differences between the study and control groups for right and left VEMP measurements. Patients over 60 years and under 60 years did not show significant differences in terms of right and left mean VEMP measurements. However, P1 amplitude was significantly lower in patients over 60 years old (P = .004). Gender, disease duration, BERG balance scale and Hoehn-Yahr stage had no effect on the VEMP amplitudes. There was no significant correlation with the side of Parkinsonian symptoms to the side of canal paresis (P = .566) and the side on which no VEMP response was obtained in caloric test.

Conclusion

VEMP responses were not different between PD and healthy subjects. VEMP P1 amplitude was decreased with age in PD group. Canal paresis and symptoms side were not statistically correlated in caloric test.

Are Meniere's disease patients with otolith organ impairment more likely to have balance dysfunction?

Background: Patients with Meniere's disease (MD) may present with peripheral vestibular end organ dysfunction and balance dysfunction. Objective: This study aimed to compare the results of vestibular evoked myogenic potential (VEMP) tests with those of the sensory organization test (SOT) in patients with MD to determine whether they are correlated. Material and methods: In total, 132 patients with unilateral MD were evaluated using an audiometric test, the SOT, a caloric test and VEMP tests. Results: Cervical VEMP and ocular VEMP tests were conducted in 132 patients with MD, and the response rates of the affected side were lower than those of the unaffected side. The composite score, C5^ES, and C6^ES of the SOT were significantly decreased in patients with no VEMP responses compared to those with VEMP responses. Conclusions and significance: MD patients with no VEMP responses are more likely to develop balance impairment than those with VEMP responses. MD patients with otolith organ impairment may therefore have balance disorders, and should exercise caution to prevent falls and subsequent injuries.

Otolith dysfunction in recurrent benign paroxysmal positional vertigo after mild traumatic brain injury

BACKGROUND

The pathogenesis of recurrence of traumatic benign paroxysmal positional vertigo (BPPV) is poorly understood by far.

OBJECTIVES

To evaluate the value of secondary otolith dysfunction using vestibular evoked myogenic potential (VEMP) test in the pathogenesis of recurrence of BPPV after mild traumatic brain injury (mTBI).

MATERIAL AND METHODS

We reviewed 42 patients with BPPV after mTBI. According to recurrence, patients were divided into two groups. Both cervical VEMP (cVEMP) and ocular VEMP (oVEMP) tests were performed on all of them.

RESULTS

We detected abnormal cVEMP responses in four (26.7%) patients in the recurrent BPPV group after mTBI and five (18.5%) patients in the non-recurrent BPPV group after mTBI, and there was no significant difference between both groups. We detected abnormal oVMEP responses in nine (60.0%) patients in the recurrent BPPV group after mTBI and six (22.2%) patients in the non-recurrent BPPV group after mTBI, and there was a significant difference between both groups.

CONCLUSIONS AND SIGNIFICANCE

Our study shows that oVEMP abnormalities in recurrent BPPV group after mTBI are significantly higher than those in non-recurrent BPPV group after mTBI. Therefore, we can conclude that secondary utricular dysfunction may be a potential pathogenesis of recurrence of traumatic BPPV.

[Evaluation of curative effect of VNG and VEMP in patients with severe sudden hearing loss]

Objective:To evaluate the relationship between vestibular function and curative effect in patients with severe sudden hearing loss.Method:The vestibular function of 79 patients with severe hearing loss was examined by video-nystagmography (VNG) and vestibular evoked myogenic potential (VEMP).Result:There were significant differences between the two test outcomes (P<0.01) in the severe group (27 cases). The effective rate of both VNG and VEMP normal group was 100%, the effective rate that both VNG and VEMP were abnormal was 41.7%. In the profound severe group (52 cases) there was also a significant difference between the two test results and the therapeutic effect (P<0.01). The effective rate of both VNG and VEMP normal group was 76.9%. The effective rate was 34.6% with both VNG and VEMP abnormal. There was no significant difference between hearing loss degree and curative effect.Conclusion:The VNG and VEMP examinations in patients with severe sudden hearing loss are valuable in evaluating the efficacy. Both VNG and VEMP were abnormal with the worst curative effect.

Vestibular Evoked Myographic Correlation

This work started from the hypothesis that the physiological processes giving rise to the vestibular evoked myogenic potential (VEMP) can be induced not only by transient sounds but also by a continuous stimulation with a stochastic signal. The hypothesis is based on the idea that the number of motor unit action potentials (MUAPs) decreases after a momentary amplitude increase of the effective stimulus, whereas a momentary amplitude decrease has the opposite effect. This concept was theoretically analyzed by assuming that the effective stimulus is closely related to the envelope of the stimulus actually presented. The analysis led to the prediction that the cross-correlation function of the effective stimulus and the measured electromyogram (EMG) has VEMP-like properties. Experiments confirmed this prediction, thus providing evidence of a novel electrophysiological response: the vestibular evoked myographic correlation (VEMCorr). The methodological approach corresponded to a conventional VEMP study, except that the stimulus (delivered with a hand-held minishaker) comprised not only a series of 500-Hz tone pulses (classical VEMP measurement, for comparison) but also sequences of narrow-band noise with a center frequency of 500 Hz (VEMCorr measurement). Each of the 12 test persons showed a clear VEMCorr. Moreover, VEMP and VEMCorr largely resembled each other, as predicted. Apparently they are two different expressions of a more general mechanism that leads to a roughly linear relationship between stimulus envelope and expectation of the EMG. Future applications of the VEMCorr could exploit that a continuous-stimulation paradigm allows for varying the center frequency of the stimulus without changing the relative bandwidth.

[Advance in research of delayed endolymphatic hydrops]

Delayed endolymphatic hydrops (DEH) is a disease entity first described by Kamei and named by Schuknecht, defined as profound sensorineural deafness at early stage and after several years started to appear clinical feature of endolymphatic hydrops such as vertigo, aural fullness like Meniere's disease or fluctuating hearing loss in the contralateral ear . DEH can be classified into ipsilateral type, contralateral type and bilateral type. Although DEH has low incident rate, there are many kinds of etiology and audiology and vestibular tests. Up to now, a lot of literatures about etiology, diagnose, clinical manifestation, relevant examination and therapy of DEH were published abroad. In this review, we will make a summary of research status of DEH.

Sound-Evoked Biceps Myogenic Potentials Reflect Asymmetric Vestibular Drive to Spastic Muscles in Chronic Hemiparetic Stroke Survivors

Aberrant vestibular nuclear function is proposed to be a principle driver of limb muscle spasticity after stroke. We sought to determine whether altered cortical modulation of descending vestibulospinal pathways post-stroke could impact the excitability of biceps brachii motoneurons. Twelve chronic hemispheric stroke survivors aged 46–68 years were enrolled. Sound evoked biceps myogenic potentials (SEBMPs) were recorded from the spastic and contralateral biceps muscles using surface EMG electrodes. We assessed the impact of descending vestibulospinal pathways on biceps muscle activity and evaluated the relationship between vestibular function and the severity of spasticity. Spastic SEBMP responses were recorded in 11/12 subjects. Almost 60% of stroke subjects showed evoked responses solely on the spastic side. These data strongly support the idea that vestibular drive is asymmetrically distributed to biceps motoneuron pools in hemiparetic spastic stroke survivors. This abnormal vestibular drive is very likely to be a factor mediating the striking differences in motoneuron excitability between the clinically affected and clinically spared sides. This study extends our previous observations on vestibular nuclear changes following hemispheric stroke and potentially sheds light on the underlying mechanisms of post-stroke spasticity.

Ageing-related changes in the cortical processing of otolith information in humans

Acoustic short tone bursts (STB) trigger ocular and cervical vestibular-evoked myogenic potentials (oVEMPs/cVEMPs) by activating irregular otolith afferents. Simultaneously, STBs introduce an artificial net acceleration signal of otolith origin into the vestibular network. VEMP parameters as diagnostic otolith processing markers have been shown to decline after the age of thirty. To delineate the differential effects of healthy ageing on the cortical vestibular subnetwork processing otolith information, we measured cVEMPs and the differential effects of unilateral STB in three age groups (20-40, 40-60 and 60+; n = 42) using functional neuroimaging. STB evoked responses in the main vestibular hubs in the parieto-opercular cortex. Whereas cVEMP amplitudes declined linearly with age, analysis of the BOLD response size depicted a u-shaped curve. Vestibular perception of the otolith stimulus on the other hand remained unchanged with age. Therefore, we propose that the comparably larger BOLD responses past the age of sixty could reflect a mechanism of central sensitisation for otolith perception to counterbalance the concurrent peripheral vestibular and somatosensory function decline.

Magnetic resonance imaging of intratympanic gadolinium helps differentiate vestibular migraine from Ménière disease

OBJECTIVES/HYPOTHESIS

To study the differential diagnosis of vestibular migraine (VM) and Ménière disease (MD) by using magnetic resonance imaging (MRI) of intratympanic gadolinium.

STUDY DESIGN

Prospective cohort study.

METHODS

Definite MD patients (n = 30) and definite or probable VM patients (n = 30) were included, and the two groups were age and sex matched. Three-dimensional real inversion recovery (3D-real-IR) MRI was performed 24 hours after bilateral intratympanic gadolinium to assess the presence and degree of endolymphatic hydrops (EH). Response rates, amplitudes, latency, and response threshold of cervical and ocular vestibular evoked myogenic potentials (c/oVEMPs) were tested by using air-conducted sound. Pure tone audiometry was used to evaluate the level of hearing loss.

RESULTS

Different degrees of EH were observed in the cochlea and vestibule in the affected ears of MD patients, but only suspicious cochlear hydrops and no vestibular hydrops was noted in the VM patients. The correlation between the degree of EH and low-frequency hearing loss was statistically significant. Only the response threshold for c/oVEMP differentiated the MD-affected side from VM. The latency and amplitude for c/oVEMP showed no significant difference between groups.

CONCLUSIONS

Characteristic pathological changes of MD include EH in the inner ear, and 3D-real-IR MRI helps differentiate VM from MD. VM and MD behaved similarly in vestibular dysfunction and their transduction pathway, but MD appeared to be more severe than VM. An association in their pathophysiology may play a part in these responses.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:2382-2388, 2017.

[Normal values of otolith function tests and age-related changes]

Objective:To explore the normal values of otolith function tests and agerelated changes in health volunteers.Method: One hundred and seventyone health volunteers were distributed to seven age groups, all subjects accepted otolith function tests, including fundus photography, static subjective visual vertical(SSVV), cervical vestibular evoked myogenic potential(cVEMP)and ocular vestibular evoked myogenic potential(oVEMP), the fundus photographs was used to measure the discfovea angle(DFA). DFA, SSVV and VEMPs were analyzed and compared among groups. Result: For DFA and SSVV,there were no significant differences either between different ages or between the two eyes in one individual（P>0.05）. For cVEMP, the detection rate declined with age over 60 years old（P<0.01）; the cVEMP threshold increased with every 20 years old(P<0.05); and the cVEMP amplitude decreased with every 10 years old(P<0.05),however, there was an exception that no significant difference was found between 41-50 years old and 51-60 years old groups（P=0.93）;the cVEMP P1 latency prolonged with age over 70 years old（P<0.01）.For oVEMP, the detection rate also declined with age over 60 years old（P<0.01）; the oVEMP threshold was lowest at the age less than 30 years old and the largest threshold was found at the age over 70 years old（P<0.01）; consistently, the oVEMP amplitude was found largest at the age less than 20 years old and lowest at the age over 60 years old(P<0.05).The P1 and N1 latencies were found significantly longer in the group of over 70 years old than other groups（P<0.01）.No significant difference was found between both sides in one individual for oVEMP threshold,amplitude or latency (P>0.05). Conclusion: In health volunteers,there were no obvious aged related changes in DFA and SSVV. However,the detection rate, threshold, amplitude and latency of cVEMP and oVEMP greatly changed with age.

Vestibulo-spinal and vestibulo-ocular reflexes are modulated when standing with increased postural threat

We investigated how vestibulo-spinal reflexes (VSRs) and vestibulo-ocular reflexes (VORs) measured through vestibular evoked myogenic potentials (VEMPs) and video head impulse test (vHIT) outcomes, respectively, are modulated during standing under conditions of increased postural threat. Twenty-five healthy young adults stood quietly at low (0.8 m from the ground) and high (3.2 m) surface height conditions in two experiments. For the first experiment (n = 25) VEMPs were recorded with surface EMG from inferior oblique (IO), sternocleidomastoid (SCM), trapezius (TRP), and soleus (SOL) muscles in response to 256 air-conducted short tone bursts (125 dB SPL, 500 Hz, 4 ms) delivered via headphones. A subset of subjects (n = 19) also received horizontal and vertical head thrusts (∼150°/s) at each height in a separate session, comparing eye and head velocities by using a vHIT system for calculating the functional VOR gains. VEMP amplitudes (IO, TRP, SOL) and horizontal and vertical vHIT gains all increased with high surface height conditions (P < 0.05). Changes in IO and SCM VEMP amplitudes as well as horizontal vHIT gains were correlated with changes in electrodermal activity (ρ = 0.44-0.59, P < 0.05). VEMP amplitude for the IO also positively correlated with fear (ρ = 0.43, P = 0.03). Threat-induced anxiety, fear, and arousal have significant effects on VSR and VOR gains that can be observed in both physiological and functional outcome measures. These findings provide support for a potential central modulation of the vestibular nucleus complex through excitatory inputs from neural centers involved in processing fear, anxiety, arousal, and vigilance.

Increased gain of vestibulospinal potentials evoked in neck and leg muscles when standing under height-induced postural threat

OBJECTIVE

To measure changes in amplitudes of vestibular evoked myogenic potentials (VEMPs) elicited from neck, upper and lower limb muscles during a quiet standing task with increased postural threat achieved by manipulating surface height.

METHODS

Twenty eight subjects were tested while standing on a platform raised to 0.8 m and 3.2 m from the ground. Surface electromyography was recorded from the ipsilateral sternocleidomastoid (SCM), biceps brachii (BB), flexor carpi radialis (FCR), soleus (SOL) and medial gastrocnemius (MG) muscles. Stimulation was with air-conducted short tone bursts (4 ms). After controlling for background muscle activity, VEMP amplitudes were compared between heights and correlated with changes in state anxiety, fear and arousal.

RESULTS

VEMP amplitude significantly increased in SCM (9%) and SOL (12.7%) with increased surface height (p<0.05). These modest increases in SCM VEMP amplitude were significantly correlated with anxiety (Rho=0.57, p=0.004) and confidence (Rho=-0.38, p=0.047) and those for SOL were significantly correlated with anxiety (Rho=0.33, p=0.049) and fear (Rho=0.36, p=0.037).

CONCLUSION

Postural threat significantly increased vestibulospinal reflex (VSR) gains. Results demonstrate that VEMPs can be used to test different VSR pathways simultaneously during stance. Since fear and anxiety are prevalent with vestibular disorders, they should be considered as potential contributing factors for clinical vestibular outcome measures.

Simultaneous, unilateral plugging of superior and posterior semicircular canal dehiscences to treat debilitating hyperacusis

OBJECTIVE

To describe a case of bilateral superior and posterior semicircular canal dehiscences, and the use of a unilateral transmastoid approach to address both right-sided defects simultaneously.

CASE REPORT

In a patient with right-sided hyperacusis, bilateral dehiscence of both the superior and the posterior semicircular canals was identified, located adjacent to the common crus, together with a right-sided, anterosuperiorly positioned sigmoid sinus and a high-riding jugular bulb. Results for audiography and cervical vestibular evoked myogenic potential testing were consistent with right-sided semicircular canal dehiscence. At surgery, a right-sided transmastoid approach provided access to plug both defects simultaneously, following posterior mobilisation of the sigmoid sinus. The patient's hyperacusis was completely resolved, with a 10-30 dB improvement in his right ear air conduction hearing, without decrement in bone conduction.

CONCLUSION

In properly selected patients, a transmastoid approach can be used to effectively manage superior semicircular canal dehiscence and posterior semicircular canal dehiscence simultaneously. Pre-operative computed tomography is recommended to evaluate the dehiscence sites and to identify complicating vascular anatomy.

Ocular vestibular evoked myogenic potentials in response to three test positions and two frequencies

OBJECTIVES/HYPOTHESIS

To determine how eye closure, test positions, and stimulus frequencies influence ocular vestibular evoked myogenic potentials.

STUDY DESIGN

This study used a within-subjects repeated measures design.

METHODS

Twenty asymptomatic subjects were each tested on ocular vestibular evoked myogenic potentials in three head/eye conditions at 500 Hz and 1,000 Hz using air-conducted sound: 1) sitting upright, head erect, eyes open, looking up; 2) lying supine, neck flexed 30°, eyes open, looking up; and 3) lying supine, neck flexed 30°, eyes closed, relaxed. The four dependent variables measured were n10, p16, amplitude, and threshold.

RESULTS

Supine/eyes open was comparable to sitting/eyes open and better than supine/eyes closed. Eyes closed resulted in lower amplitude, higher threshold, and prolonged latency. Significantly fewer subjects provided responses with eyes closed than with eyes open. No significant differences were found between both eyes open conditions. Both n10 and p16 were lower at 1,000 Hz than at 500 Hz. Amplitude and threshold were higher at 1,000 Hz than at 500 Hz.

CONCLUSIONS

Supine/eyes open is a reliable alternative to sitting/eyes open in patients who cannot maintain a seated position. Testing at 1,000 Hz provides a larger response with a faster onset that fatigues faster than at 500 Hz. The increased variability and decreased response in the eyes closed position suggest that the eyes closed position is not reliable.

LEVEL OF EVIDENCE

3b.

Vestibular function in families with inherited autosomal dominant hearing loss

The inner ear contains the developmentally related cochlea and peripheral vestibular labyrinth. Given the similar physiology between these two organs, hearing loss and vestibular dysfunction may be expected to occur simultaneously in individuals segregating mutations in inner ear genes. Twenty-two different genes have been discovered that when mutated lead to non-syndromic autosomal dominant hearing loss. A review of the literature indicates that families segregating mutations in 13 of these 22 genes have undergone formal clinical vestibular testing. Formal assessment revealed vestibular dysfunction in families with mutations in ten of these 13 genes. Remarkably, only families with mutations in the COCH and MYO7A genes self-report considerable vestibular challenges. Families segregating mutations in the other eight genes do not self-report significant balance problems and appear to compensate well in everyday life for vestibular deficits discovered during formal clinical vestibular assessment. An example of a family (referred to as the HL1 family) with progressive hearing loss and clinically-detected vestibular hypofunction that does not report vestibular symptoms is described in this review. Notably, one member of the HL1 family with clinically-detected vestibular hypofunction reached the summit of Mount Kilimanjaro.