Otolithic organ function in patients with profound sensorineural hearing loss

Assessment of Otolith Function with Subjective Visual Vertical Test in Sensorineural Hearing Loss: An Analytical Cross - Sectional Study

The inner ear is responsible for balance and auditory function. Sensorineural hearing loss (SNHL) affects auditory function across various age groups. Vestibular apparatus, particularly the otolith organ can also be affected in cases of SNHL because of the close proximity of the otolith organs with the cochlea inside the bony labyrinth. The otolith organs can be assessed with Subjective Visual vertical test (SVV), which is a simple, rapid, non-invasive test with high sensitivity and specificity. Present study was conducted with the objective to compare the SVV parameters between normal and SNHL patients and to correlate between the degree of tilt in SVV with severity of SNHL. A convenient sample size of 60 was taken of which 30 were control and 30 were SNHL patients. PTA and SVV were performed on both groups and results were analysed in IBM SPSS version 26. Age stratified analysis between the control group and SNHL group for the age group 20-40 years and for > 40 years revealed a significant statistical difference in the average static SVV (P = 0.019 and P = 0.009 for age group 20-40 years and > 40 years respectively) and dynamic anti clockwise SVV (P = 0.024 and P = 0.031 for age group 20-40 years, and > 40 years respectively) between the control group and the SNHL group. Correlational analysis also shows a moderate correlation between the bone conduction threshold and the various SVV parameters. Statistical difference of SVV parameters between the two groups suggests a possible early involvement of the otolith organ in SNHL. As such the utility of SVV as an early marker for otolith dysfunction needs to be further explored. It may be worthwhile to follow up the patients of SNHL longitudinally and assess the otolith function with SVV at periodic intervals to identify any progression.

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.

Development of a new method for assessing otolith function in mice using three-dimensional binocular analysis of the otolith-ocular reflex

In the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively. In the current study, we tested whether lateral-eyed mice exhibit both of these otolith-ocular reflexes. In addition, we propose a new index for assessing the otolith-ocular reflex in mice. During lateral translational movement, mice did not show appropriate horizontal eye movement, but exhibited unnecessary vertical torsion-like eye movement that compensated for the angle between the body axis and gravito-inertial acceleration (GIA; i.e., the sum of gravity and inertial force due to movement) by interpreting GIA as gravity. Using the new index (amplitude of vertical component of eye movement)/(angle between body axis and GIA), the mouse otolith-ocular reflex can be assessed without determining whether the otolith-ocular reflex is induced during translational movement or during tilting movement.

Contribution of Audiogram Classification in Evaluating Vestibular Dysfunction in Sudden Sensorineural Hearing Loss With Vertigo

Object: We aimed to identify the relationship between vertigo symptoms and the involvement of vestibular dysfunction in sudden sensorineural hearing loss (SSNHL) and the contribution of audiogram classification.

Methods: A total of 50 patients with unilateral SSNHL were retrospectively divided into the vertigo group and non-vertigo group depending on the presence of vertigo. The involved vestibular end organs (VEOs) were verified by a battery of vestibular function tests including video head impulse test (vHIT), cervical vestibular-evoked myogenic potential (cVEMP), and ocular VEMP (oVEMP). The correlations of audiogram configurations, initial pure-tone average (PTA), number of involved VEOs, prognosis (complete recovery rate), and vestibular functions were analyzed between the two groups. Additionally, the vestibular functions in a subgroup of profound SSNHL patients were further compared within groups with or without vertigo.

Results: Significant differences in the initial audiogram configurations (p = 0.033) and the abnormal rates of the posterior semicircular canal (PSC) (p = 0.035) and oVEMP (p = 0.046) were found between the two groups. The number of involved VEOs was related to the initial PTA in the vertigo group (p = 0.002, r = 0.541) and non-vertigo group (p = 0.042, r = 0.446). The prognosis was related to the abnormal rate of cVEMP and the number of involved VEOs in both vertigo group (p = 0.008, r = 0.482; p = 0.039, r = 0.385, respectively) and non-vertigo group (p = 0.016, r = 0.520; p = 0.022, r = 0.495, respectively), and it was especially related to the audiogram configurations in the vertigo group (p < 0.001, r = 0.692). However, after classification by audiogram configurations, there was no statistical difference in the abnormal rates of all vestibular function tests or the number of involved VEOs between the profound SSNHL patients with or without vertigo.

Conclusion: The relationship between the involvement of vestibular dysfunction and vertigo symptoms in patients with SSNHL was significantly different before and after audiogram classification. When evaluating the vestibular dysfunction in SSNHL patients, more attention should be paid to the audiogram configuration.

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.

Sensorineural hearing loss (SNHL) as an adverse event following immunization (AEFI): Case definition & guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration case definition of the term "Sensorineural Hearing Loss" to be utilized in the evaluation of adverse events following immunization. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for Lassa Fever and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and define levels of diagnostic certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network.

The semicircular canal function tests contribute to identifying unilateral idiopathic sudden sensorineural hearing loss with vertigo

BACKGROUND

Few studies focused on the prognosis of unilateral idiopathic sudden sensorineural hearing loss (UISSNHL) with vertigo.

OBJECTIVES

To describe how the semicircular canal (SCC) function tests may prove helpful in the diagnosis of UISSNHL with vertigo.

MATERIAL AND METHODS

59 UISSNHL patients underwent audiometry, caloric test and video head impulse test (vHIT). The correlation between hearing loss and SCC dysfunction was analyzed.

RESULTS

The results showed significant differences of hearing loss grades (p = 0.004) and hearing loss configurations (p = 0.009) between UISSNHL patients with and without vertigo. In vHIT, the gains of horizontal canal (HC) and posterior canal (PC) were more frequently impaired compared with that of anterior canal (AC). The abnormal rate of caloric test was the highest, followed by the abnormal rates of HC and PC gain. A significant difference of abnormal rate of HC gain was only found between the mild and moderate UISSNHL patients with and without vertigo (p = 0.029).

CONCLUSION

Abnormal SCC function happens frequently in patients with profound hearing loss. Ipsilesional abnormal vHIT (especially the HC gain) in the presence of abnormal caloric test is a pattern of findings observed in mild and moderate UISSNHL patients with vertigo.

Short Communication: The Belly-Tendon Derivation Yields Superior Ocular Vestibular Evoked Myogenic Potential Amplitudes in a Normal Pediatric Sample

Purpose The purpose of the investigation was to determine whether the "belly-tendon" electrode derivation produced ocular vestibular evoked myogenic potentials (oVEMPs) in children that were superior to those recorded with the infraorbital-chin electrode derivation. Method This was a prospective observational study using a sample of convenience at a tertiary care medical center. Subjects were 13 children between the ages of 5 and 12 years. We compared the latency of the N1 wave and the N1-P1 peak-to-peak amplitude for the belly-tendon electrode derivation to the infraorbital-chin electrode derivation. Results The belly-tendon electrode derivation was associated with superior N1-P1 amplitudes compared to the infraorbital-chin electrode derivation. However, the large amplitude was also associated with greater variability compared to the infraorbital-chin derivation. There were no significant electrode derivation-based differences in N1 latency. Additionally, there was no predictable relationship between age and oVEMP amplitude. Conclusion As shown previously in adults, the belly-tendon electrode derivation produces significantly larger oVEMP amplitudes compared to the infraorbital-chin electrode derivation.

Assessment of Vestibular Function in Adults with Prelingual Hearing Loss Using c/oVEMP Tests

OBJECTIVES

The aim of the present study was to compare the vestibular system integrity of individuals with normal hearing with that of prelingual hearing impaired individuals. It is well known that ocular vestibular evoked myogenic potentials (oVEMPs) reflect utricular function, whereas cervical vestibular evoked myogenic potentials (cVEMPs) reflect saccular function. Therefore, oVEMP and cVEMP tests were applied to evaluate the vestibular system integrity of hearing impaired individuals participating in the research.

MATERIALS AND METHODS

The study group consisted of sensorineural prelingual hearing-loss volunteers aged from 18 to 60 years, whereas the control group consisted of age- and gender-matched healthy volunteers. cVEMP and oVEMP tests were performed to evaluate the integrity of the vestibular system, and the results were compared with those of the control group.

RESULTS

The study included 20 (76.9%) women and 6 (23.1%) men in the study group; on the other hand, the control group consisted of 19 (73.1%) women and 7 (26.9%) men. There was a difference between the study group and the control group when oVEMP and cVEMP responses were compared, and the response percentage was higher in the control group. The response rates of oVEMP and cVEMP in patients with prelingual hearing loss were 44.2% and 59.6%, respectively. There was also a statistically significant difference between the groups for oVEMP amplitude and cVEMP P1 latency (p≤0.05).

CONCLUSION

These findings suggest that prelingual hearing loss is related to both utricular and saccular dysfunctions. However, oVEMPs were more often abnormal in prelingual deaf patients than cVEMPs, suggesting that utricular dysfunction may be more common than saccular dysfunction.

Application of Cervical Vestibular-Evoked Myogenic Potentials in Adults with Moderate to Profound Sensorineural Hearing Loss: A Preliminary Study

Introduction  The cochlea and the vestibular receptors are closely related in terms of anatomy and phylogeny. Patients with moderate to profound sensorineural hearing loss (MPSHL) should have their vestibular organ functions tested.

Objective  To evaluate the incidence of vestibular abnormalities in patients with MPSHL and to study the correlation between the etiology of hearing loss (HL) and a possible damage to the labyrinth.

Methods  A case-control retrospective study was performed. In the case group, 20 adults with MPSHL of known etiology were included. The control group was composed of 15 adults with normal hearing. The case group was divided into 4 subgroups based on the etiology (bacterial meningitis, virus, vascular disease, congenital). Cervical vestibular-evoked myogenic potentials (cVEMPs) were used to rate the saccular function and lower vestibular nerve.

Results  The study was performed in 70 ears, and it highlighted the presence of early biphasic P1-N1 complex in 29 (71.5%) out of 40 ears in the study group, and in all of the 30 ears in the control group ( p  = 0.001). Regarding the presence or absence of cVEMPs among the four subgroups of patients with MPSHL, the data were statistically significant ( p  < 0.001). The comparison between the latencies and amplitude of P1-N1 in case and control groups from other studies and in the four subgroups of cases in the present study did not detect statistically significant differences.

Conclusion  The present study demonstrates that patients with MPSHL have a high incidence of damage to the labyrinthine organs, and it increases the current knowledge about the etiopathogenesis of sensorineural HL, which is often of unknown nature.

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

OBJECTIVE

To analyze and summarize the effect of bilateral large vestibular aqueducts in peripheral vestibular organ function.

METHODS

Eighteen patients with bilateral large vestibular aqueduct syndrome (LVAS; Study Group) and 18 healthy volunteers (Control Group) were investigated using audiometry, caloric test, sensory organization test (SOT), and vestibular-evoked myogenic potential (VEMP) tests.

RESULTS

All 18 patients (36 ears) exhibited sensorineural hearing loss. For cervical VEMP (cVEMP), the Study Group showed lower thresholds (Study Group vs.

CONTROL GROUP

71.4vs. 75.3dBnHL; p=0.006), N1 latencies (24.1vs. 25.2ms; p=0.026) and shorter P1 (15.3vs. 16.6ms; p=0.003), and higher amplitudes (400.7vs. 247.2µV; p<0.001) than the Control Group. For ocular VEMP (oVEMP), the Study Group had lower thresholds (79.3vs. 81.8dBnHL; p=0.046) and higher amplitudes (40.6vs. 14.4µV; p<0.001) than the Control Group. Fourteen of 16 patients (87.5%) who completed caloric tests had abnormal results, and 10 of 18 patients (55.6%) exhibited abnormal results in SOTs.

CONCLUSIONS

The hyperfunction of vestibular test in otolithic organs and the hypofunction of vestibular test in semicircular canals, as well as the dysfunction in the balance test were demonstrated in patients with LVAS.

SIGNIFICANCE

Our findings can help clinicians gain a better understanding of the characteristics of vestibular organ function in patients with LVAS, which can facilitate optimal targeted treatment.