Contrasting results of tests of peripheral vestibular function in patients with bilateral large vestibular aqueduct syndrome

Comparison of vestibular function in hereditary hearing loss patients with GJB2, CDH23, and SLC26A4 variants

To investigate the association between hereditary hearing loss and vestibular function, we compared vestibular function and symptoms among patients with GJB2, SLC26A4, and CDH23 variants. Thirty-nine patients with sensory neural hearing loss (11 males and 28 females) with biallelic pathogenic variants in either GJB2, SLC26A4, or CDH23 were included in this study (13 GJB2, 15 SLC26A4, and 11 CDH23). The patients were examined using caloric testing and cervical and ocular vestibular-evoked myogenic potentials (cVEMP and oVEMP). We also compared vestibular function and symptoms between patients with these gene variants and 78 normal-hearing ears without vestibular symptoms as controls. The frequency of semicircular canal hypofunction in caloric testing was higher in patients with SLC26A4 variants (47%) than in those with GJB2 (0%) and CDH23 variants (27%). According to the cVEMP results, 69% of patients with GJB2 variants had saccular hypofunction, a significantly higher proportion than in those carrying other variants (SLC26A4, 20%; CDH23, 18%). In oVEMP, which reflects utricular function, no difference was observed in the frequency of hypofunction among the three genes (GJB2, 15%; SLC26A4, 40%; and CDH23, 36%). Hence, discernable trends indicate vestibular dysfunction associated with each gene.

Vestibular Loss in Children Affected by LVAS and IP2 Malformation and Operated with Cochlear Implant

This is a single center cohort study regarding the prevalence of vestibular loss in hearing impaired children affected by large vestibular aqueduct syndrome (LVAS) with incomplete cochlear partition malformation type II (IP2), fitted with cochlear implant (CI). Twenty-seven children received CI operations at 0.4-13 years on one or both ears and tested for vestibular loss with head impulse test, video head impulse test, mini ice-water test and cervical VEMP. Vestibular loss was found in 19% of operated ears and in 13.9% of non-operated ears. The difference was not statistically significant and was not significantly modified by age at implantation, age at testing, sex, presence of SLC26A4 gene mutation or bilaterality. However, the presence of anatomic anomalies at the level of the vestibulum or semicircular canals was significantly associated with a higher incidence of vestibular loss in CI operated children but not in those non-operated. No other factors, such as the surgical access, the electrode type, the presence of Gusher perioperatively, or post-operative vertigo modified significantly the prevalence of vestibular loss. In conclusion, LVAS/IP2 appears to be the major determinant of vestibular loss in these children, with a less obvious impact of CI, excluding the cases with vestibulum/canal anomalies: this group might have a higher risk for vestibular loss after CI surgery.

Vestibular function in children with cochlear implant: Impact and evaluation

Over the last 30 years, cochlear implant (CI) has been dedicated to improving the rehabilitation of hearing impairments. However, CI has shown potential detrimental effects on vestibular function. For children, due to atypical symptoms and difficulty in cooperating with vestibular function tests, systematic and objective assessments of vestibular function with CI have been conducted sparsely. This review focuses on the impact of vestibular function in children with CI and summarized the evaluation of vestibular function in children. In addition, some recommended strategies are summarized and proposed.

High frequency hearing loss may act as a screening index evaluating otolith function in vertigo patients with normal semi-circular canal function

Objective

To investigate whether otolith dysfunction is related to hearing impairment in vertigo patients with normal semicircular canal function, and to clarify the types of hearing impairment that may be related to otolith organ damage.

Methods

The demographic data, pure tone threshold audiometry (PTA) results (air-conduction), data of bithermal and video-head impulse test (vHIT), and vestibular evoked myogenic potential (VEMP) results (reaction threshold, P1–N1 amplitude) of patients with vertigo in outpatient clinic from April 2017 to January 2020 were collected. The clinical records of 51 vertigo patients with normal semicircular canal function were included in this study. Low-frequency, speech-frequency, high-frequency, full-frequency PTA were defined as the average of PTA in different frequency bands, respectively (low: 0.125, 0.25, 0.5 kHz; speech: 0.5, 1, 2 kHz, high: 4, 8 kHz, full 0.125–8 kHz). The correlations between hearing impairment in different frequency bands and otolith function impairment were analyzed.

Results

The mean thresholds of 51 patients (102 ears) in low-PTA, speech-PTA, high-PTA, full-PTA were 20.95 ± 6.01, 21.92 ± 6.90, 40.12 ± 17.47, 26.97 ± 8.53 dB nHL, respectively. Among 102 ears, 87 ears (85.3%) could elicit c-VEMP waveforms and 65 ears (63.7%) had o-VEMP waveforms. The mean threshold and P1–N1 amplitude of c-VEMP were 83.10 ± 6.96 dB nHL and 176.79 ± 103.10 uV, while those of o-VEMP were 87.92 ± 5.99 dB nHL and 21.45 ± 32.22 uV. The mean threshold in high-PTA was significantly linearly correlated with c-VEMP threshold (P = 0.01) and P1–N1 amplitude (P = 0.028). There were not significant linear correlations between the mean threshold in each frequency band of PTA and o-VEMP threshold (low-PTA: P = 0.266, speech-PTA: P = 0.33, high-PTA: P = 0.311) or P1–N1 amplitude (low-PTA: P = 0.414, speech-PTA: P = 0.069, high-PTA: P = 0.08).

Conclusions

There is a positive linear correlation between saccule dysfunction and high-frequency hearing impairment in vertigo patients with normal semi-circular canal function. High frequency hearing loss can be expected in patients who have saccular damage. It suggests that high frequency hearing loss in PTA may act as a screening index that otolith organ function should be comprehensively evaluated.

Clinical Implication of Caloric and Video Head Impulse Tests for Patients With Enlarged Vestibular Aqueduct Presenting With Vertigo

Background: By examining the clinical features and results of video head impulse test (vHIT) and caloric tests in patients with enlarged vestibular aqueduct (EVA) presenting with vertigo, we aimed to investigate the function of angular vestibulo-ocular reflex (VOR) and its clinical implications.

Methods: Nine patients with EVA manifesting with vertigo were enrolled. The medical history, audiological examination, imaging, and the results of the caloric test and the vHIT were analyzed.

Results: Of the nine patients with EVA (eight bilateral and one unilateral case), five were pediatric cases. All 17 ears exhibited sensorineural hearing loss (SNHL). Enlarged vestibular aqueduct patients can present with recurrent (seven cases) or single (two cases) vertigo attack, trauma-induced (two cases), or spontaneous (seven cases) vertigo. Diminished caloric responses were observed in 77.8% (7/9) of the patients (four cases unilaterally and three bilaterally), while unilateral abnormal vHIT results in 11.1% (1/9) patients. Abnormal caloric and normal horizontal vHIT responses were found in 66.7% (6/9) of EVA patients.

Conclusions: Vestibular manifestations in EVA are diverse. Enlarged vestibular aqueduct patients with vertigo can present with a reduced caloric response and normal horizontal vHIT, and this pattern of angular VOR impairment was also found in other hydropic ear diseases.

Objective vestibular function changes in children following cochlear implantation

BACKGROUND:

To date, systematically objective evaluations of vestibular function in children with cochlear implantation (CI) have been conducted sparsely, especially in children with large vestibular aqueduct syndrome (LVAS).

OBJECTIVE:

Our goal was to investigate the function of all five vestibular end-organs pre- and post-cochlear implantation in children with LVAS and normal CT.

METHODS:

In this retrospective cohort study, 34 children (age 4–17 years) with bilateral profound sensorineural hearing loss (SNHL) undergoing unilateral CI were included. Participants included 18 (52.9%) children with LVAS. Objective modalities to evaluate vestibular function included the caloric test, cervical vestibular-evoked myogenic potentials (cVEMP), ocular vestibular-evoked myogenic potentials (oVEMP), and video head impulse test (vHIT). All measurements were performed before surgery and 9 months after surgery.

RESULTS:

Mean age at CI was 8.1±3.7 years. Caloric testing showed hypofunction in 38.2% of cases before implantation and in 50% after (p > 0.05). We found a significant increase of overall abnormality rate in cVEMP and oVEMP from pre- to post-CI (p < 0.05). In all three semicircular canals tested by vHIT, there were no statistically significant mean gain changes (p > 0.05). Higher deterioration rates in cVEMP (53.3%) and oVEMP (52.0%) after surgery were observed (p < 0.05). In children with LVAS, cVEMP revealed a higher deterioration rate than superior semicircular canal (SSC) and posterior semicircular canal (PSC) (p < 0.05). In children with normal CT, the deterioration rates in VEMPs were both higher than those in vHIT (p < 0.05).

CONCLUSIONS:

In general, the otolith organs were the most affected peripheral vestibular sensors in children after cochlear implantation. The variations in otolith function influenced by CI were different between children with LVAS and normal CT. We recommend the use of this vestibular function test battery for children with cochlear implantation.

Vestibular Function in Pendred Syndrome: Intact High Frequency VOR and Saccular Hypersensitivity

OBJECTIVE

Although Pendred syndrome involves anatomical abnormalities in the vestibular system and patient-perceived dizziness, the literature on vestibular function is scarce. The objective was to evaluate objective vestibular function in patients with PS using the video head impulse test (VHIT) and the cervical vestibular evoked myogenic potential (cVEMP) test, assessing the high frequency vestibulo-ocular reflex (VOR) and the saccular function, respectively.

METHODS

Twenty-six subjects (52 ears) with Pendred Syndrome and severe-to-profound hearing loss (cochlear implant candidacy) were studied retrospectively. Main outcome measures were VHIT VOR gain, refixation saccades, cVEMP stimulus thresholds and amplitudes.

RESULTS

In total, 4 of 52 ears (8%) had pathological VHIT outcomes (2 ears with low VHIT gain and 2 ears with saccades). The mean VHIT gain value was 0.96 (range 0.63-2.02). No patients had complete VOR loss. CVEMP responses were present in 76% of tested ears and absent in 24%. The mean cVEMP amplitude value was 192 μV. Absence of cVEMP response was associated with the presence of VHIT saccades (p = 0.038) and advanced age (rs = -0.34; p < 0.05). cVEMP amplitude was correlated with VHIT gain (rs = 0.46; p < 0.001).

CONCLUSION

Despite dysmorphic vestibular anatomy and severe loss of hearing, the VHIT VOR function is normal in patients with Pendred Syndrome. However, saccular function appears to be abnormally sensitive, as documented by low cVEMP thresholds and high amplitudes, which agrees with a "third window" effect secondary to the large vestibular aqueduct.

Systematic Review on Vestibular Symptoms in Patients With Enlarged Vestibular Aqueducts

OBJECTIVE

Enlarged vestibular aqueduct (EVA) is a congenital condition that can lead to various outcomes in pediatric patients including hearing loss and vestibular dysfunction. Our goal was to critically appraise the literature on the proportion of patients with EVA who report vestibular dysfunction, determine relevant risk factors for the development of these symptoms, and describe vestibular tests and interventions used to improve outcomes.

METHODS

A systematic review was performed in accordance with the PRISMA guidelines. We queried the EMBASE, Ovid Medline, and Cochrane Library databases for relevant literature. Studies were included if they had n > 10, reported vestibular symptoms or vestibular function testing in patients with EVA, and were published in English. Nonhuman studies, systematic reviews, and review articles were excluded.

RESULTS

Of 808 identified studies, 20 met inclusion criteria. Subjective vestibular symptoms included dizziness, episodic vertigo, and imbalance. Seventeen studies reported subjective vestibular symptoms, ranging from 2% to 71% of patients between studies. Seventeen studies performed some form of vestibular function test, including physical exam maneuvers (Dix-Hallpike), caloric testing, electronystagmography, and vestibular evoked myogenic potentials. Of those who had vestibular function testing, 7% to 92% had an abnormal result. Two studies identified head trauma as a risk factor. One study successfully treated patients with BPPV using the Epley maneuver, but other vestibular symptoms were not targeted with treatment.

CONCLUSION

The degree to which vestibular symptoms impact patients with EVA varies significantly. Performing vestibular function testing may help identify asymptomatic patients with vestibular dysfunction. Future studies should target improving treatment of vestibular symptoms in EVA patients. Laryngoscope, 2021.

Genetic architecture and phenotypic landscape of SLC26A4-related hearing loss

Mutations of coding regions and splice sites of SLC26A4 cause Pendred syndrome and nonsyndromic recessive hearing loss DFNB4. SLC26A4 encodes pendrin, a transmembrane exchanger of anions and bases. The mutant SLC26A4 phenotype is characterized by inner ear malformations, including an enlarged vestibular aqueduct (EVA), incomplete cochlear partition type II and modiolar hypoplasia, progressive and fluctuating hearing loss, and vestibular dysfunction. A thyroid iodine organification defect can lead to multinodular goiter and distinguishes Pendred syndrome from DFNB4. Pendred syndrome and DFNB4 are each inherited as an autosomal recessive trait caused by biallelic mutations of SLC26A4 (M2). However, there are some EVA patients with only one detectable mutant allele (M1) of SLC26A4. In most European-Caucasian M1 patients, there is a haplotype that consists of 12 variants upstream of SLC26A4, called CEVA (Caucasian EVA), which acts as a pathogenic recessive allele in trans to mutations affecting the coding regions or splice sites of SLC26A4. This combination of an M1 genotype with the CEVA haplotype is associated with a less severe phenotype than the M2 genotype. The phenotype in EVA patients with no mutant alleles of SLC26A4 (M0) has a very low recurrence probability and is likely to be caused by other factors.

Intratympanic gentamicin injection for refractory ménière's disease (MD) has potential effect in preventing contralateral MD occurrence

BACKGROUND

Ménière's disease (MD), characterized by episodic vertigo attacks and fluctuating progressive hearing loss, is treated by low-dose intratympanic gentamicin (ITG) injections. Whether ITG causes hearing loss is controversial, and knowledge about its effects on the contralateral hearing and vestibular function is lacking.

AIMS/OBJECTIVES

We aimed to evaluate the effect of ITG on bilateral auditory and otolith organ function in patients with unilateral refractory MD.

MATERIAL AND METHODS

The data of 30 patients was collected, including history, and pure tone audiometry and vestibular-evoked myogenic potentials (VEMPs) results before and one month after ITG treatment. Changes in vertigo were assessed at a two-year follow-up.

RESULTS

One month after ITG injection, auditory thresholds between 125 Hz and 8 kHz on the injection side remained unchanged but have improved on the contralateral side at 125 Hz, 250 Hz, 1 kHz. The cervical and ocular VEMP solicitation rates on the injection side were lower than before the injection. Two years after treatment, vertigo was improved in 88.5% and complete controlled in 76.7% patients respectively.

CONCLUSIONS AND SIGNIFICANCE

The intractable vertigo of MD can be effectively controlled by ITG injection. This can improve the low and medium frequency hearing level in the contralateral ear, suggesting that it might help prevent contralateral MD occurrence.

Influence of Cochlear Implantation on Vestibular Function in Children With an Enlarged Vestibular Aqueduct

Background: Cochlear implantation (CI) is becoming increasingly used in the rehabilitation of hearing-impaired patients. Children with an enlarged vestibular aqueduct (EVA) need CI for severe or profound hearing loss, with excellent outcomes in hearing rehabilitation. However, vestibular function influenced by CI in children with EVA has not been clarified. We compared the characteristics of vestibular function in implanted children with EVA and those with a normal cochlea.

Methods: In this retrospective case-control study, 16 children with large vestibular aqueduct syndrome (LVAS) and 16 children with a normal cochlea were recruited as the Study and Control Group, respectively. All children (mean age, 10.3 ± 4.4 years) had bilateral profound sensorineural hearing loss (SNHL) and normal pre-operative vestibular functions and underwent unilateral CI. Otolith and canal functions were assessed before CI and 12 months thereafter. Cervical vestibular-evoked myogenic potential (cVEMP), ocular vestibular-evoked myogenic potential (oVEMP), and video head impulse test (vHIT) were evaluated.

Results: Full insertion of the electrode array was achieved in all the cases. Preoperatively, no significant differences in parameters in cVEMP between the Study and Control Group were revealed (p > 0.05). In pre-operative oVEMP, shorter N1 latencies (p = 0.012), shorter P1 latencies (p = 0.01), and higher amplitudes (p = 0.001) were found in the Study than in the Control Group. The Study Group had shorter P1 latency in cVEMP (p = 0.033), and had lower amplitude in oVEMP after implantation (p = 0.03). Statistically significant differences were not found in VOR gains of all three semicircular canals before and after surgery (p > 0.05). VEMP results revealed that the Control Group had significantly lower deterioration rates after CI (p < 0.05). The surgical approach and electrode array had no statistically significant influence on the VEMP results (p > 0.05).

Conclusion: oVEMP parameters differed between children with EVA and children with a normal cochlea before surgery. Systematic evaluations before and after CI showed that otolith function was affected, but all three semicircular canals functions were essentially undamaged after implantation. In contrast to subjects with a normal cochlea, children with EVA are more likely to preserve their saccular and utricular functions after CI surgery. Possible mechanisms include less pressure-related damage, a reduced effect in terms of the air-bone gap (ABG), or more sensitivity to acoustic stimulation.

Objective Vestibular Test Battery and Patient Reported Outcomes in Cochlear Implant Recipients

OBJECTIVE

Cochlear implantation (CI) may have undesired effects on the vestibular apparatus. However, the literature holds no consensus on vestibular affection and the testing tools applied to test for vestibular dysfunction after cochlear implantation are inconsistent. We aimed to investigate the impact of CI on vestibular function by an extensive test battery including patient-reported outcomes.

STUDY DESIGN

Prospective observational study.

SETTING

University hospital.

PATIENTS

Forty adult unilateral first-time CI recipients.

INTERVENTION

Vestibular function was evaluated pre- and post-implantation with the video head impulse test (VHIT), the caloric test and cervical vestibular evoked myogenic potentials (cVEMPs), and the patient-reported dizziness handicap inventory (DHI).

RESULTS

Mean VHIT gain decreased from preoperative 0.92 to 0.84 postoperative (p = 0.018); mean caloric unilateral weakness increased from 20.5% preoperative to 42.9% postoperative (p < 0.0001); cVEMP responses were present on 10 operated ears preoperative and five ears postoperative, and compared with non-implanted ears, cVEMP responses on implanted ears were impaired (p = 0.023). 50% of patients reported early postoperative dizziness, but the mean DHI score remained unchanged (p = 0.94). The DHI scores correlated poorly with the objective outcomes (rs = 0.19 and rs = -0.22).

CONCLUSION

Vestibular function is significantly affected after cochlear implantation, but vestibular hypofunction varies with the test used. Although early dizziness after implantation is common, later DHI scores are not significantly higher than before the implantation, indicating that central compensation plays a major role for these patients.

Video head impulse test saccades and loss of cervical vestibular evoked myogenic potentials are late vestibular footprints of cochlear implantation

BACKGROUND

Cochlear implantation may be complicated by concurrent injury to the vestibular apparatus, potentially resulting in disabling vertigo and balance problems. Information on vestibular function before implantation as measured by the video head impulse test (VHIT) and cervical vestibular evoked myogenic potentials (cVEMPs) is scarce and literature on long-term effects is non-existing.

OBJECTIVE

We aimed to evaluate how vestibular function was affected by cochlear implantation (CI), as measured by VHIT and cVEMPs in the late phase after implantation.

METHODS

Retrospective repeated measurement study.

PATIENTS

Among the 436 patients elected for CI surgery during 2013 to 2018, 45 patients met the inclusion criteria (CI recipients with a vestibular assessment prior to the first CI and a repeated vestibular assessment after the CI operation).

INTERVENTION

VHIT and cVEMPs before and after cochlear implantation. Main outcome measures were vestibular function as evaluated by VHIT gain, saccades and cVEMPs.

RESULTS

The mean time between first and second vestibular screening was 19 months. The mean VHIT gain on implanted ears was 0.79 before the operation and showed no change at follow-up (p = 0.65). Likewise, the number of abnormal VHIT gain values was equal before and after the operation (p = 0.31). Preoperatively, saccades were present on 12 ears (14%) compared with 25 ears (29%) postoperatively (p = 0.013) and were associated with significantly lower VHIT gain values. Preoperatively, positive cVEMPs were found in 20 CI ears (49%) and 24 contralateral ears (62%). 10 CI ears lost cVEMP postoperatively compared with 2 ears on the contralateral side (p = 0.0047).

CONCLUSIONS

Even though VHIT gain has been reported to be affected in the immediate post-implantation period, the findings in this study show that VHIT gain is normalized in the long-term. However, cochlear implantation is associated with the occurrence of VHIT saccades in the long-term and these are associated with lower VHIT gain values. In addition, cVEMP responses are significantly reduced long-term on implanted ears, which agrees with other studies with shorter follow-up.

Air and bone-conducted vestibular evoked myogenic potentials in children with large vestibular aqueduct syndrome

BACKGROUND

There are few studies focused on vestibular symptoms and function of the children with LVAS.

OBJECTIVES

This study aimed to find the characteristics of air and bone-conducted VEMPs among children with LVAS, and to investigate the relationship between VEMPs and vestibular symptoms.

MATERIAL AND METHODS

A total of 44 children with LVAS and 10 healthy children were recruited as the case group and control group. Air and bone-conducted VEMP were performed to the participants.

RESULTS

For air-conducted measurement, there was elevated amplitude of cVEMP in case group than control group. There was no significant difference at oVEMP parameters between the case group and control group. For bone-conducted measurement, significantly longer P1 latency and shorter P1-N1 latency of cVEMP were observed among the case group; there were a series of changes in oVEMP parameters among the case group. Logistic regression model revealed that air-conducted oVEMP asymmetric ratio was valuable to predict vestibular symptoms' development among the kids with LVAS.

CONCLUSION

Asymmetric ratio of oVEMP could be used as one predictor of developing vestibular symptoms of the children with LVAS. Applying bone-conducted VEMP as one alternative parameter of vestibular syndrome is novel and will certainly remain an area of continued investigation.

The Relationship Between Rotary Chair and Video Head Impulse Testing in Children and Young Adults With Cochlear Implants

Purpose Conflicts among video head impulse testing (vHIT) and rotary chair have occurred; therefore, the purpose of this study was to determine the relationship between rotary chair and vHIT outcome parameters to understand when these two tests disagree and determine if one or both test outcomes are needed in children. Method Data from 141 child and young adult subjects (73 males, 68 females, M _age = 15 years, range: 6-35) were retrospectively reviewed. Of those, 56 had a cochlear implant and 85 were normal controls. All subjects completed rotary chair and vHIT, which were categorized as (a) normal vestibular function, (b) unilateral vestibular loss, or (c) bilateral vestibular loss. vHIT tracings were analyzed to determine if gain and corrective saccade velocity, frequency, or latency were helpful parameters for determining vestibular loss. Results Of the 141 subjects, the misclassification rate was 13/141 (9%). All normal control subjects were classified as having normal rotary chair and normal vHIT. In subjects with a cochlear implant (n = 56), the misclassification rate was 13/56 (23%). There were four misclassification patterns. Using rotary chair as the gold standard, receiver operating characteristic analysis revealed optimal cut-points for vHIT gain (< 0.84), corrective saccade frequency (≥ 50%), amplitude (≥ 75°/s), and latency (≤ 320 ms). Using these vHIT cut-points improved the agreement between rotary chair and vHIT, resulting in an overall misclassification rate of 10/141 (7%) and 9/56 (16%) in subjects with a cochlear implant. Conclusions When testing children, caloric testing is often not an option due to tolerability or time. However, discordant results occur between rotary chair and vHIT. These data suggest vHIT is a sufficient first-tier assessment. If abnormal, rotary chair is not necessary. If normal, rotary chair can be helpful for uncovering other indicators of vestibular loss. When interpreting vHIT, including gain and all corrective saccade outcomes may improve sensitivity.

Bone-Conducted oVEMP Latency Delays Assist in the Differential Diagnosis of Large Air-Conducted oVEMP Amplitudes

Background: A sensitive test for Superior Semicircular Canal Dehiscence (SCD) is the air-conducted, ocular vestibular evoked myogenic potential (AC oVEMP). However, not all patients with large AC oVEMPs have SCD. This retrospective study sought to identify alternate diagnoses also producing enlarged AC oVEMPs and investigated bone-conducted (BC) oVEMP outcome measures that would help differentiate between these, and cases of SCD.

Methods: We reviewed the clinical records and BC oVEMP results of 65 patients (86 ears) presenting with dizziness or balance problems who underwent CT imaging to investigate enlarged 105 dB nHL click AC oVEMP amplitudes. All patients were tested with BC oVEMPs using two different stimuli (1 ms square-wave pulse and 8 ms 125 Hz sine wave). Logistic regression and odds ratios were used to determine the efficacy of BC oVEMP amplitudes and latencies in differentiating between enlarged AC oVEMP amplitudes due to dehiscence from those with an alternate diagnosis.

Results: Fifty-three ears (61.6%) with enlarged AC oVEMP amplitudes were identified as having frank dehiscence on imaging; 33 (38.4%) had alternate diagnoses that included thinning of the bone covering (near dehiscence, n = 13), vestibular migraine (n = 12 ears of 10 patients), enlarged vestibular aqueduct syndrome (n = 2) and other causes of recurrent episodic vertigo (n = 6). BC oVEMP amplitudes of dehiscent and non-dehiscent ears were not significantly different (p > 0.05); distributions of both groups overlapped with the range of healthy controls. There were significant differences in BC oVEMP latencies between dehiscent and non-dehiscent ears for both stimuli (p < 0.001). A prolonged n1 125 Hz latency (>11.5 ms) was the best predictor of dehiscence (odd ratio = 27.8; 95% CI:7.0-111.4); abnormal n1 latencies were identified in 79.2% of ears with dehiscence compared with 9.1% of ears without dehiscence.

Conclusions: A two-step protocol of click AC oVEMP amplitudes and 125 Hz BC oVEMP latency measures optimizes the specificity of VEMP testing in SCD.

Vestibular prognosis in idiopathic sudden sensorineural hearing loss with vestibular dysfunction treated with oral or intratympanic glucocorticoids: a protocol for randomized controlled trial

Background

Idiopathic sudden sensorineural hearing loss (ISSNHL) is a rapid-onset sensorineural hearing impairment with unclear etiology and unsatisfying treatment effects. Vestibular dysfunction has been considered as a poor indicator in the clinical manifestations and prognosis of ISSNHL, which occurred in approximately 28–57% cases. Glucocorticoids, administered through oral or intratympanic way, are currently regularly and standardly applied for ISSNHL to improve the hearing outcome. However, the vestibular prognosis of ISSNHL after routine treatments remains seldom explored. This study aims to compare the effectiveness of oral and intratympanic glucocorticoids in ISSNHL with vestibular dysfunction in terms of the pattern and trajectory of possible process of vestibular function recovery.

Methods/design

A randomized, outcome-assessor- and analyst-blinded, controlled, clinical trial (RCT) will be carried out. Seventy-two patients with ISSNHL complaining of vestibular dysfunction appearing as vertigo or imbalance will be recruited and randomized into either oral or intratympanic glucocorticoid therapy group with a 1:1 allocation ratio. The primary outcomes will be vestibular function outcomes assessed by sensory organization test, caloric test, video head impulse test, cervical vestibular evoked myogenic potential, and ocular vestibular evoked myogenic potential; the secondary outcomes include self-reported vestibular dysfunction symptoms; dizziness-related handicap, visual analogue scale for vertigo and tinnitus; and pure tone audiometry. Assessments of primary outcomes will be performed at baseline and at 4 and 8 weeks post-randomization, while assessments of secondary outcomes will be performed at baseline and 1, 2, 4, and 8 weeks post-randomization.

Discussion

Previous intervention studies of ISSNHL included only hearing outcomes, with little attention paid on the prognosis of vestibular dysfunction. This trial will be the first RCT study focusing on the progress and prognosis of vestibular dysfunction in ISSNHL. The efficacy of two commonly used therapies of glucocorticoids will be compared in both auditory and vestibular function fields, rather than in the hearing outcome alone.

Trial registration

ClinicalTrials.gov NCT03974867. Registered on 23 July 2019

Vestibular-evoked myogenic potentials in patients with large vestibular aqueduct syndrome

Background: The vestibular function in patients of large vestibular aqueduct syndrome (LVAS) has not been clarified yet.Aims/objectives: To investigate the characteristic of otolithic organ in LVAS patients, we accessed their ocular and cervical vestibular evoked myogenic potentials (oVEMPs and cVEMPs).Material and methods: This study was carried out between 29 bilateral LVAS patients and 35 healthy controls. Parameters of VEMPs were analyzed.Result: In children patients, response rate for oVEMP was 93.47% and 86.95% for cVEMP. No statistical significance was found compared to their controls. In adult patients, response rate for oVEMP was 83.33% and 75% for cVEMP, which were statistically lower than their controls. In comparison to parameters of VEMPs, no statistical significance were found in children group. Amplitude of oVEMP was significantly higher and that of cVEMP was lower in LVAS adults. N1 latencies were significantly longer and P1 latencies were shorter in adult patients than in controls of cVEMP. Thresholds and N1-P1 intervals of VEMP were found no statistical significance in adult group.Conclusions and significance: We discovered a severer otolithic dysfunction in adults than in children patients. We recommend cVEMP a more effective and sensitive method than oVEMP in assessment of LAVS adult patients.

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.

Effects of vestibular rehabilitation, with or without betahistine, on managing residual dizziness after successful repositioning manoeuvres in patients with benign paroxysmal positional vertigo: a protocol for a randomised controlled trial

INTRODUCTION

Benign paroxysmal positional vertigo (BPPV) is recognised as the leading cause of peripheral vertigo in adults. The canalith repositioning procedure (CRP) can be used for effective treatment of BPPV. However, some patients experience residual dizziness (RD) even after successful CRP, resulting in a significant negative impact on their daily function and quality of life. Exercise-based vestibular rehabilitation (VR) has been proven as an effective method for managing dizziness and has been applied in patients with various vestibular disorders. However, the efficacy of VR to specifically target RD post-BPPV is unknown. This study aims to investigate the efficacy of VR, compared with betahistine or VR plus betahistine treatment, in the treatment of patients experiencing RD after successful CRP.

METHODS AND ANALYSIS

A randomised single-blinded controlled trial will be carried out to determine the efficacy of VR compared with betahistine or VR plus betahistine treatment in mitigating RD and improving balance function. Patients with BPPV who experience RD after successful CRP will be recruited. Participants will be randomised into one of three groups to receive VR, betahistine or VR plus betahistine. There will be 61 participants in each group. The primary outcomes will be changes in the patient's daily function as measured by the Vestibular Activities and Participation questionnaire and balance ability assessed by computerised dynamic posturography. The secondary outcomes will be dizziness-related handicap, otolith function and duration of RD symptoms. Outcome measures will be noted at baseline and at 2, 4 and 8 weeks post-randomisation. This study has the potential to reduce unnecessary anti-vertigo drug prescriptions and may lead to a general consensus regarding the use of VR as a first-line treatment for RD in patients with BPPV.

ETHICS AND DISSEMINATION

This trial received ethical approval from the Institutional Review Board of Eye and ENT Hospital of Fudan University (reference number 2017046). The study results will be disseminated via peer-reviewed journals and conferences.

TRIAL REGISTRATION NUMBER

NCT03624283; Pre-results.

Quantitative evaluation of endolymphatic hydrops with MRI through intravenous gadolinium administration and VEMP in unilateral definite Meniere's disease

PURPOSE

To help clinicians to further understand the significance of vestibular-evoked myogenic potential (VEMP) examinations to diagnose MD and the quantitative relationship between VEMP and MRI in assessing the location and degree of endolymphatic hydrops (EH) in definite Meniere's disease (MD) patients.

METHODS

Fifty-six patients with unilateral definite MD participated in this study, which used MRIs through intravenous gadolinium administration (IV-Gd), audiometry, caloric tests and VEMP tests. The VEMP results of 26 healthy volunteers were used as a normal reference value.

RESULTS

The participants were found through MRI to have differing degrees of vestibular and cochlear EH. Quantitative comparison of MRI and VEMP results found that the response rates of oVEMP decreased with cochlear EH increasing; the asymmetry ratio (AR) of oVEMP can be used to find whether cochlear EH or not, and the P1-N1 amplitude was lower in the extreme cochlear EH group (P < 0.01). The AR of cVEMP was larger in severe vestibular EH group than that of the mild or no vestibular EH group (P < 0.01). The correlation between the degree of cochlear EH and the mean PTA threshold was statistically significant (P < 0.05). The duration of MD correlated positively with vestibular EH (P < 0.05). The abnormal rate of caloric tests was higher in severe vestibular EH group than that of the mild or no vestibular EH group (P < 0.05).

CONCLUSIONS

The advantages of MRIs by IV-Gd administration were obvious in assessing the location and degree of EH. oVEMP and PTA can be indirectly used to evaluate the extent of cochlear EH, cVEMP and caloric tests can be used to assess the extent of vestibular EH on the condition of absent MRIs.

The prediction of the tumor size of a vestibular schwannoma by clinical performance and vestibular function tests

PURPOSE

To investigate the relationship between vestibular schwannoma (VS) size and the dysfunction and compensation of the vestibular system.

METHODS

One hundred fifty-two patients with unilateral VS were investigated using multiple auditory-vestibular function tests such as audiometry, sensory organization test (SOT), caloric test, cervical vestibular-evoked myogenic potential (cVEMP) test, and ocular VEMP (oVEMP) test.

RESULTS

In this study, 89% of patients with unilateral VS had mild to severe hearing loss on the involved side. All patients showed higher threshold values or no response in the cVEMP and oVEMP tests, which both exhibited a lower response rate on the affected side than on the unaffected side. Patients with a tumor size ≥ 30 mm had significantly lower equilibrium scores for condition 5 and condition 6 of the SOT, which were associated with vestibular dysfunction, higher rates of canal paresis in the caloric test, and lower response rates in the cVEMP and oVEMP tests on the affected sides, compared with the results of patients with a tumor size ≤ 14 mm and patients with a tumor size of 15-29 mm.

CONCLUSIONS

A diameter > 30 mm may be the critical threshold at which vestibular function is affected and vestibular compensation is interfered with by a VS tumor. Functional performance of the vestibular system can help clinicians predict the size of a tumor and provide a basis for the development of treatment protocols.

Vestibular-Evoked Myogenic Potentials in Bilateral Vestibulopathy

Bilateral vestibulopathy (BVP) is a chronic condition in which patients have a reduction or absence of vestibular function in both ears. BVP is characterized by bilateral reduction of horizontal canal responses; however, there is increasing evidence that otolith function can also be affected. Cervical and ocular vestibular-evoked myogenic potentials (cVEMPs/oVEMPs) are relatively new tests of otolith function that can be used to test the saccule and utricle of both ears independently. Studies to date show that cVEMPs and oVEMPs are often small or absent in BVP but are in the normal range in a significant proportion of patients. The variability in otolith function is partly due to the heterogeneous nature of BVP but is also due to false negative and positive responses that occur because of the large range of normal VEMP amplitudes. Due to their variability, VEMPs are not part of the diagnosis of BVP; however, they are helpful complementary tests that can provide information about the extent of disease within the labyrinth. This article is a review of the use of VEMPs in BVP, summarizing the available data on VEMP abnormalities in patients and discussing the limitations of VEMPs in diagnosing bilateral loss of otolith function.