Association between Vestibular Function and Hearing Outcome in Idiopathic Sudden Sensorineural Hearing Loss

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.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

Vestibular function assessment in sudden hearing loss

OBJECTIVES

To perform vestibular assessment using cervical and ocular vestibular evoked myogenic potential, video head impulse test and caloric testing in patients with sudden hearing loss. Moreover, to evaluate the correlation of dizziness with vestibular tests and the correlation of vestibular tests with hearing prognosis.

METHODS

This is an observational, longitudinal and prospective study, including participants diagnosed with sudden hearing loss. The participants underwent cervical and ocular vestibular evoked myogenic potential, video head impulse test and caloric testing. The audiometric assessment was performed at the beginning and at the end of the follow-up. A value of p≤0.05 was considered statistically significant.

RESULTS

Seventeen patients were included in the study sample, with a mean age of 45.4±11.1 years. Five participants (29.41%) had dizziness and 15 (88.23%) had tinnitus. All participants underwent vestibular evaluation through cervical and ocular vestibular evoked myogenic potential and video head impulse test, and 13 of them were evaluated through caloric testing. The cervical vestibular evoked myogenic potential was considered altered in five (29.41%) participants, while 11 (64.71%) showed alterations at the ocular vestibular evoked myogenic potential. The video head impulse test and the caloric testing were considered altered in seven (41.18%) and five (38.46%) participants, respectively. There was no statistically significant correlation between the clinical data and the results of vestibular tests or hearing recovery, nor between the results of vestibular tests and hearing recovery.

CONCLUSION

The assessment through vestibular evoked myogenic potential, video head impulse test and caloric testing showed vestibular involvement in some participants. However, it cannot be stated that the results of the vestibular tests are related to the hearing prognosis of sudden hearing loss.

Vestibular functions in patients with idiopathic sudden sensorineural hearing loss and its relation to prognosis

OBJECTIVE

Because of the anatomically close relationship between the cochlea and the vestibular organs, cochlear function disorders may be accompanied by vestibular disorders. This study aimed to evaluate vestibular functions in patients with idiopathic sudden sensorineural hearing loss using VEMP, caloric test, and VNG test battery and its relation to prognosis.

MATERIALS AND METHODS

For this study, 42 patients aged 18-55 years with idiopathic sudden sensorineural hearing loss and 30 volunteers who had no hearing and balance problems were included. Audiometry, cVEMP, oVEMP, caloric tests, and VNG tests were performed. Moreover, the effects of age, sex, time of admission, degree and configuration of hearing loss, accompanying vertigo, tinnitus, and ear fullness on improvement in hearing were evaluated.

RESULTS

Of the 42 patients in the study group, 26 (56.52%) were male, 20 (43.48%) were female, and the mean age was 41.54 ± 12.23 years. Of the 30 individuals in the control group, 19 (63.3%) were male, 11 (36.7%) were female, and the mean age was 39.53 ± 13.03 years. There was no significant difference in the incidence of sudden sensorineural hearing loss in terms of sex and age, and the prognosis was better for female patients. Early admission to treatment was a factor of good prognosis; profound hearing loss, bilateral hearing loss and vertigo were factors of poor prognosis. Prognosis was better in patients with rising type audiogram configuration, while the prognosis was worse in patients with flat, descending and total hearing loss. Tinnitus and ear fullness had no effect on the prognosis. No anomalies were observed in VNG findings. Moreover, abnormal caloric response was higher in patients with profound hearing loss and total hearing configuration. Shortening was observed in cVEMP / oVEMP P1 and N1 latency after treatment. Furthermore, there was an improvement in abnormal responses after treatment.

CONCLUSION

In this study, vestibular function was affected in patients with idiopathic sudden sensorineural hearing loss. The present study can help the development of a clinical strategy in the evaluation of the vestibular system in idiopathic SSNHL, patient follow-up, patient information, and the implementation of vestibular rehabilitation. Note that additional studies involving larger patients series are required.

Relationship Between Galvanic Vestibular-evoked Myogenic Potentials and the Prognosis of Unilateral Severe to Profound Idiopathic Sudden Sensorineural Hearing Loss With Vertigo

OBJECTIVE

Idiopathic sudden sensorineural hearing loss (ISSNHL) may not only impair cochlear function but also damage vestibular structures, including the saccule, utricle, semicircular canals, and vestibular afferents. Poor recovery often occurs in patient with serious ISSNHL and accompanying vertigo. To define the severity of the disease and to predict prognosis, galvanic vestibular-evoked myogenic potentials (VEMPs) are added to the inner ear test battery.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Thirty patients with unilateral severe to profound ISSNHL and accompanying vertigo were enrolled in this retrospective study.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURES

All subjects underwent pure tone audiometry, cervical and ocular VEMPs, and caloric tests before the initiation of treatment. The treatment outcome, rates of abnormal responses in the tests, and the characteristic parameters of VEMPs such as latencies and amplitudes, were analyzed.

RESULTS

In affected ears, the rates of abnormal acoustic cVEMPs, vibratory oVEMPs, galvanic cVEMPs, and galvanic oVEMPs were 60, 47, 37, and 20%, respectively. The improvement in the hearing of the affected ear was specified as good recovery or poor recovery. The normal galvanic VEMP group had a significant higher rate of good recovery than abnormal galvanic VEMP group (87% versus 27%; p = 0.003).

CONCLUSIONS

Patients with unilateral severe to profound ISSNHL and accompanying vertigo who have normal galvanic VEMPs have a higher likelihood of hearing recovery than those who have abnormal galvanic VEMPs.

Topography of the lesion in idiopathic sudden sensorineural hearing loss

INTRODUCTION

Etiology of ISSNHL includes cessation of vascular perfusion, viral infection and cochlear membrane injury. Precise location of injury should be defined for a target-oriented treatment. Vestibular complaints in ISSNHL are hypothesized as involvement of vestibule. Vestibular complaints can be either due to involvement of inner ear or neural tract at any level.

OBJECTIVES

In the present study we aimed to demonstrate involvement of vestibular organs in the absence of vestibular symptoms. It was aimed to evaluate superior and inferior vestibular neural pathways.

METHODS

c-vemp and o-vemp were applied to patients suffering ISSNHL without vertigo. Pure tone averages, audiogram configurations, degree of hearing loss were analyzed. Latencies of P1 and N1 waves, amplitudes of P1-N1 waves were evaluated. Asymmetrical vemp wave patterns were compared between two ears regarding difference of PTA.

RESULTS

Latencies of c-vemp waves were longer and amplitudes were smaller. o-vemp parameters were similar on both sides. Positive correlation was observed between c-vemp latencies and degree hearing loss.

CONCLUSION

Inferior vestibular nerve pathway is affected in the absence of vertigo in ISSNHL with spared superior vestibular nerve pathway. Damage in IVN pathway correlates with degree of ISSNHL.

Vestibular evoked myogenic potentials in the prognosis of sudden hearing loss ‒ a systematic review

INTRODUCTION

Sudden hearing loss is an otorhinolaryngological emergency that often leads to severe damage to the auditory and vestibular function. The vestibular evoked myogenic potential is a test that allows a noninvasive evaluation of the otolithic system function and vestibulospinal and vestibulo-ocular pathways.

OBJECTIVE

To evaluate the importance of vestibular evoked myogenic potential in determining the prognosis of patients with sudden hearing loss.

METHODS

A search for articles published up to December 2018 was performed in the PubMed, Cochrane, VHL and LILACS databases using MeSH descriptors. Retrospective and prospective articles were included containing cervical or ocular vestibular evoked myogenic potential in sudden hearing loss patients and information on associated vertigo and/or dizziness.

RESULTS

Sixteen of 62 initially selected articles met the inclusion criteria and were analyzed. Regarding the methodology of the evaluated studies, 8 studies were prospective, six were retrospective, one contained part of the data from a retrospective analysis and another part from a prospective analysis, and one study was cross-sectional. A total of 872 patients were evaluated (50.22% males and 49.77% females) with a mean age of 51.26 years. Four hundred and twenty-six patients (50.35%) had vertigo and/or dizziness associated with sudden hearing loss. The cervical vestibular evoked myogenic potential was performed in all studies, but only seven assessed the ocular vestibular evoked myogenic potential. The cervical vestibular evoked myogenic potential showed alterations in 38.65% of 846 evaluated ears, whereas ocular vestibular evoked myogenic potential showed alterations in 47.88% of 368 evaluated ears. The hearing recovery rate was analyzed by 8 articles, with 63.4% of 410 evaluated ears showing hearing recovery.

CONCLUSIONS

The studies suggest that the assessment of the vestibular system using vestibular evoked myogenic potential seems to be important in the prognosis of sudden hearing loss. For better follow-up of patients with sudden hearing loss, the emphasis should not be limited to the cochlea, but also include the diagnosis and treatment of vestibular abnormalities, regardless of the presence of vertigo.

Nystagmus Findings and Hearing Recovery in Idiopathic Sudden Sensorineural Hearing Loss Without Dizziness

OBJECTIVES

To investigate the incidence of nystagmus in patients with sudden sensorineural hearing loss (SSNHL) without dizziness, and to evaluate the correlation of the presence of nystagmus with hearing recovery in those patients.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral academic medical center.

PATIENTS

Thirty-eight patients with SSNHL who did not complained of dizziness were enrolled.

MAIN OUTCOME MEASURE

The presence of nystagmus was evaluated by recording eye movements, and if present, nystagmus was classified as direction-fixed or positional nystagmus. Vestibular function tests were performed, including caloric test.

RESULTS

Of 33 idiopathic SSNHL patients without dizziness, nystagmus was observed in 22 patients (67%), of which 14 patients exhibited direction-fixed nystagmus, and 8 patients exhibited direction-changing nystagmus. Among the 14 patients with direction-fixed nystagmus, 9 displayed the paretic type, and 5 displayed the irritative type. Direction-changing nystagmus (n = 8) was defined as that in which the direction of nystagmus was changed in a supine head-roll test, and the geotropic type and apogeotropic type were observed in two and six patients, respectively. The mean initial pure tone threshold was 58.2 ± 28.1 dB and 57.3 ± 20.0 dB in SSNHL patients with and without nystagmus, respectively, which was not significantly different (p = 0.925). When hearing improvement was compared according to the presence of nystagmus, 39% (8 of 21) of patients with nystagmus were found to belong in the good prognosis group, and 72% (8 of 11) of patients without nystagmus were found to belong in the good prognosis group, which showed marginal statistical significance (p = 0.063).

CONCLUSION

Nystagmus was observed in two-thirds of idiopathic SSNHL patients without dizziness, and the pattern of nystagmus was either direction fixed or direction changing. Because hearing recovery was worse in patients with nystagmus than those without it, the diagnosis of nystagmus, even in SSNHL patients without dizziness, may be important in evaluating the hearing prognosis.

Vestibular Dysfunctions in Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-analysis

Background

Sudden sensorineural hearing loss (SSHL) not only involves cochlear function but might also be accompanied by vestibular disturbances. The assessment of vestibular function could be of great relevance in SSHL.

Objective

To investigate the prevalence of vestibulocochlear lesions in SSHL and the correlation of specific vestibular organs with hearing prognosis.

Data sources

A complete literature search of eligible studies in the PubMed and EMBASE databases was performed.

Study selection

For our aim, studies that focused on vestibular examination in the case of SSHL were retrieved, including caloric tests, cervical vestibular-evoked myogenic potential (cVEMP) tests, or ocular vestibular-evoked myogenic potential (oVEMP) tests.

Results

Of the 18 studies included, a caloric test was performed in 16 studies, cVEMP in 13 studies, and oVEMP in 5 studies, and together the studies included a total population of 1,468 subjects. The scores on the Agency for Healthcare Research and Quality (AHRQ) questionnaire ranged from 6 to 11. These results indicated that the most commonly damaged vestibular organ in SSHL was the utricle and superior vestibular pathway (U + S) followed by the lateral semicircular canal and superior vestibular pathway (LSC + S), the saccule and inferior vestibular pathway (S + I), and the cochlea only (C only). The meta-analysis indicated that SSHL patients with vertigo have a statistically increased risk of vestibular organ lesions compared with those without vertigo, including the LSC + S subgroup (OR = 4.89, 95% CI = 1.20-19.93, I² = 80%, p = 0.03) and the S + I subgroup (OR = 3.58, 95% CI = 1.61-7.95, I² = 0%, p = 0.002). The pooled possibility of hearing recovery within the LSC + S lesion group was less than half that of the non-LSC + S lesion group (OR = 0.24, 95% CI = 0.11-0.52, I² = 68%, p = 0.0003).

Conclusion

This study shows the relevance of vestibular damage concomitant with SSHL and that SSHL patients with vertigo are at an increased risk of vestibular organ lesions compared with patients without vertigo. LSC + S lesions thus appear to be a critical variable that influence the possibility of hearing improvement in SSHL.