Quantification of endolymphatic hydrops and its correlation with Meniere's disease clinical features

Association Between Vestibular Aqueduct Morphology and Meniere's Disease

OBJECTIVE

To investigate the relationship between vestibular aqueduct (VA) morphology and Meniere's disease (MD) using ultrahigh-resolution computed tomography (U-HRCT).

METHODS

Retrospective data were collected from 34 patients (40 ears) diagnosed with MD in our hospital who underwent temporal bone U-HRCT with isotropic 0.05-mm resolution, magnetic resonance with gadolinium-enhanced, and pure-tone audiometry; 34 age- and sex-matched controls (68 ears) who underwent U-HRCT were also included. VA patency was qualitatively classified as locally not shown (grade 1), locally faintly shown (grade 2), or clearly shown throughout (grade 3). The width of the outer orifice and VA length and angle were quantitatively measured. Differences in VA morphology between the MD and control groups were analyzed. The correlations between VA morphology and the degrees of hearing loss and endolymphatic hydrops (EH) were also analyzed.

RESULTS

VA was classified as grades 1-3 in 11, 17, and 12 ears in the MD group and 5, 26, and 37 ears in the control group, respectively. The patency differed significantly between the groups (p < 0.01). The width of the outer orifice and length of VA were significantly smaller in the MD group than those in the control group (p < 0.05). Both VA patency and length were correlated with the degree of EH in the cochlea and the vestibule (p < 0.05). No difference was found between VA morphology and the degree of hearing loss (p > 0.05).

CONCLUSION

The morphological characteristics of VA were found to be associated with the occurrence of MD and the degree of EH.

LEVEL OF EVIDENCE

4 Laryngoscope, 2024.

Correlation of endolymphatic hydrops and perilymphatic enhancement with the clinical features of Ménière's disease

OBJECTIVES

To use three-dimensional real inversion recovery (3D-real IR) MRI to investigate correlations between endolymphatic hydrops (EH) grades or the degree of perilymphatic enhancement (PE) and clinical features of Ménière's disease (MD), as previous findings have been inconsistent.

METHODS

A total of 273 consecutive patients with definite unilateral MD were retrospectively enrolled from September 2020 to October 2021. All patients underwent 3D-real IR and 3D-T2WI 6 h after intravenous gadolinium injection. MD-related symptom duration and vertigo frequency were recorded. EH grades were evaluated, the signal intensity ratio (SIR) was measured, and correlations between clinical features and EH, PE were assessed respectively.

RESULTS

The study included 123 males and 150 females, with a mean age of 53.0 years. A longer duration of vertigo was associated with higher cochlear EH grades, whereas the opposite was true for the duration of aural fullness. A longer time since vertigo onset was associated with higher vestibular EH grades; the opposite was true for the duration of individual vertigo attacks. The multiple regression analysis revealed that age, tinnitus duration, and vestibular EH were risk factors for SIR. Furthermore, the low-frequency hearing threshold (HT) was a risk factor for cochlear and vestibular EH, and the SIR.

CONCLUSION

The EH grade and SIR (an indicator for the quantitative evaluation of PE) were correlated with clinical features and HT of MD; thus, imaging can be a valuable tool in planning individualised treatment.

CLINICAL RELEVANCE STATEMENT

This study revealed that the grade of endolymphatic hydrops and degree of perilymphatic enhancement positively correlates with the length of time since onset of clinical symptoms and hearing thresholds in patients with Ménière's disease, facilitating the tailored treatment.

KEY POINTS

• Relationships between 3-dimensional real inversion recovery features and clinical symptoms in Ménière's disease are unknown. • Symptom duration and hearing thresholds correlated with endolymphatic hydrops grades and degree of perilymphatic enhancement. • MRI features correlate with MD severity; thus, imaging is valuable for planning tailored treatment.

Low-Frequency Air-Bone Gap and Pulsatile Tinnitus Due to a Dural Arteriovenous Fistula: Considerations upon Possible Pathomechanisms and Literature Review

Low-frequency air-bone gap (ABG) associated with pulsatile tinnitus (PT) and normal impedance audiometry represents a common finding in patients with third window syndromes. Other inner disorders, including Meniere's disease (MD), perilymphatic fistula and intralabyrinthine schwannoma, might sometimes result in a similar scenario. On the other hand, PT is frequently associated with dural arteriovenous fistula (DAVF), while conductive hearing loss (CHL) is extremely rare in this clinical setting. A 47-year-old patient was referred to our center with progressive left-sided PT alongside ipsilateral fullness and hearing loss. She also experienced headache and dizziness. Otoscopy and video-oculographic examination were unremarkable. Conversely, a detailed instrumental audio-vestibular assessment revealed low-frequency CHL with normal impedance audiometry, slight left-sided caloric weakness, slightly impaired vestibular-evoked myogenic potentials on the left and normal results on the video-head impulse test, consistent with an MD-like instrumental profile. Gadolinium-enhanced brain MRI revealed an early enhancement of the left transverse sinus, consistent with a left DAVF between the left occipital artery and the transverse sinus, which was then confirmed by angiography. A trans-arterial embolization with Onyx glue was performed, resulting in a complete recession of the symptoms. Post-operatively, the low-frequency ABG disappeared, supporting the possible role of venous intracranial hypertension and abnormal pressure of inner ear fluids in the onset of symptoms and offering new insights into the pathomechanism of inner ear CHL.

Evaluation of the relationship between endolymphatic hydrops and hearing loss in Meniere's disease based on three-dimensional real inversion recovery sequence

OBJECTIVES

The degree of endolymphatic hydrops in Meniere's disease may be related to hearing loss. However, the results of prior studies have been inconsistent. We aimed to investigate the relationship between endolymphatic hydrops and hearing loss characteristics in Meniere's disease.

METHODS

This study included 54 patients (62 ears) with Meniere's disease. Patients underwent three-dimensional real inversion recovery sequences for magnetic resonance imaging and pure-tone audiometry. Endolymphatic hydrops were assessed according to Gurkov's criteria (2011). Correlations between different degrees of endolymphatic hydrops and pure-tone audiometry, as well as staging, were analysed.

RESULTS

Pure tone audiometry and staging were higher for vestibular endolymphatic hydrops complicated by cochlear ones than isolated cochlear or vestibular hydrops (both p < 0.05). There was no significant correlation between vestibular endolymphatic hydrops and pure-tonal audiometry or staging (all p > 0.05). The degree of hydrops in the middle turn was correlated with the mid-frequency hearing threshold (p < 0.05). The degree of cochlear hydrops was correlated with the audiometry, low-frequency hearing thresholds, mid-frequency hearing thresholds and staging (p < 0.01).

CONCLUSION

The types and sites of endolymphatic hydrops based on a 3D-real inversion recovery sequence can be used to indicate the degree of hearing loss in patients with Meniere's disease.

LEVEL OF EVIDENCE

Level III.

OCT imaging of endolymphatic hydrops in mice: association with hearing loss

BACKGROUND

The etiology of Ménière's disease (MD) is still not completely clear, but it is believed to be associated with endolymphatic hydrops (EH), which is characterized by auditory functional disorders. Vasopressin injection in C57BL/6J mice can induce EH and serve as a model for MD. Optical Coherence Tomography (OCT) has shown its advantages as a non-invasive imaging method for observing EH.AimInvestigating the relationship between hearing loss and EH to assist clinical hearing assessments and indicate the severity of hydrops.

METHODS

C57BL/6J mice received 50 μg/100g/day vasopressin injections to induce EH. Auditory function was assessed using auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE). OCT was used to visualize the cochlea.

RESULT

OCT observed accumulation of fluid within the scala media in the cochlear apex. ABR showed significant hearing loss after 4 weeks. DPOAE revealed low-frequency hearing loss at 2 weeks and widespread damage across frequencies at 4 weeks.

CONCLUSION

The development of hearing loss in mouse models of MD is consistent with EH manifestations.SignificanceThis study demonstrates the possibility of indirectly evaluating the extent of EH through auditory assessment and emphasizes the significant value of OCT for imaging cochlear structures.

Comparison between audio-vestibular findings and contrast-enhanced MRI of inner ear in patients with unilateral Ménière’s disease

Objective

The diagnosis of Ménière’s disease (MD), characterized by idiopathic endolymphatic hydrops (ELH), remains a clinical priority. Many ancillary methods, including the auditory and vestibular assessments, have been developed to identify ELH. The newly emerging delayed magnetic resonance imaging (MRI) of the inner ear after intratympanic gadolinium (Gd) has been used for identifying ELH in vivo. We aimed to investigate the concordance of audio-vestibular and radiological findings in patients with unilateral MD.

Methods

In this retrospective study, 70 patients with unilateral definite MD underwent three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences following intratympanic application of Gd. Audio-vestibular evaluations were performed, including pure tone audiometry, electrocochleogram (ECochG), glycerol test, caloric test, cervical and ocular vestibular evoked myogenic potentials (VEMPs), and video head impulse test (vHIT). The relationship between imaging signs of ELH and audio-vestibular results was investigated.

Results

The incidence of radiological ELH was higher than that of neurotological results, including the glycerol test, caloric test, VEMPs, and vHIT. Poor or slight agreement was observed between audio-vestibular findings and radiological ELH in cochlear and/or vestibular (kappa values &lt;0.4). However, the pure tone average (PTA) in the affected side significantly correlated with the extent of both cochlear (r = 0.26795, p = 0.0249) and vestibular (r = 0.2728, p = 0.0223) hydrops. Furthermore, the degree of vestibular hydrops was also positively correlated with course duration (r = 0.2592, p = 0.0303) and glycerol test results (r = 0.3944, p = 0.0061) in the affected side.

Conclusion

In the diagnosis of MD, contrast-enhanced MRI of the inner ear is advantageous in detecting ELH over the conventional audio-vestibular evaluations, which estimates more than hydropic dilation of endolymphatic space.

Worldwide Meniere's disease research: A bibliometric analysis of the published literature between 2002 and 2021

Background

In recent years, there has been an increasing number of publications on Meniere's disease. However, there are no bibliometric research on Meniere's disease. The purpose of this study was to find the focus and trends of Meniere's disease research through bibliometric approach.

Methods

Publications related to Meniere's disease in the Web of Science Core Collection (WOSCC) from 2002 to 2021 were collected. The bibliometric approach was used to estimate the searched data. Research foci of the studies were identified using VOSviewer and CiteSpace software.

Results

A total of 1,987 articles meet the inclusion criteria and are included in the study. In the past 20 years, the number of Meniere's disease publications is gradually increasing, especially in the past 3 years. The country with the largest contribution to Meniere's disease research is the United States, followed by Europe and Japan. High-frequency keywords included Meniere's disease, endolymphaic hydrops, vertigo, meniere-disease, inner ear, dizziness, symptoms, hearing, diagnosis, and tentamicin. The analyses of keyword burst direction indicate that evoked myogenic potential, MRI, and committee are emerging research hotspots.

Conclusion

This study provides an objective, systematic, and comprehensive analysis of Meniere's disease-related literature. In addition, we find a dramatic increase in studies in this field over the past 3 years. Evoked myogenic potentials and MRI may become the research hotspots of Meniere's disease in future. This study will help otolaryngologists, neurologists, and audiologists to clarify the research direction and potential hotspots of Meniere's disease and further help clinicians improve patients' prognosis.

Prevalence of Endolymphatic Hydrops in Cochlear Implant Candidates with Idiopathic Profound Sensorineural Hearing Loss

OBJECTIVE

To determine the prevalence of endolymphatic hydrops (EH) in cochlear implant (CI) candidates with idiopathic profound sensorineural hearing loss (SNHL) and its influence on the preservation of audiovestibular function after cochlear implantation.

STUDY DESIGN

Prospective case series.

SETTING

Tertiary referral center.

PATIENTS

CI candidates with idiopathic progressive SNHL, but without classic EH-associated symptoms.

INTERVENTIONS

Delayed intravenous gadolinium-enhanced inner ear fluid-attenuated inversion recovery magnetic resonance imaging as well as pure-tone audiograms, video head impulse tests, and vestibular evoked myogenic potentials before and 4 weeks after cochlear implantation.

MAIN OUTCOME MEASURES

Prevalence of EH before cochlear implantation, audiovestibular function before and after surgery in hydropic and nonhydropic ears.

RESULTS

Thirty-two ears in 16 CI candidates were included. Nine ears (28%) with EH were detected. Although preoperative hearing thresholds, utricular function, and semicircular canal function were not different between the two groups, saccular function was reduced in hydropic ears. Ten subjects received a unilateral CI. Of these, 3 (30%) showed EH on the implanted side. There was no difference regarding postoperative hearing loss between the two groups, but the results point toward a higher vulnerability of hydropic ears with respect to loss of otolith function after cochlear implantation.

CONCLUSIONS

This is the first study showing that EH can be assumed in about one third of CI candidates with idiopathic profound SNHL, but no classic EH-associated symptoms. Preliminary results suggest that EH has no influence on the preservation of cochlear function but could be a risk factor for loss of otolith function after cochlear implantation.

[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 usefulness of inner ear magnetic resonance imaging in patient with Ménière’s disease: A narrative review

Ménière’s disease (MD) is a multifactorial disorder with typical symptoms of recurrent vertigo, tinnitus, fluctuating hearing loss, and sensations of ear fullness. This disease greatly reduces the quality of life for patients. Unfortunately, it is difficult to diagnose and predictthe prognosis using only diagnostic methods, including audiometry. Therefore, since the mid-2000s, various efforts have been made to directly identify endolymphatic hydrops (EH), a histologic hallmark of MD, through magnetic resonance imaging (MRI) of the inner ear. Various studies have revealed significant correlation among degree of EH on inner ear MRI, patient symptoms, and test results. Although there are some limitations, inner ear MRI is expected to be widely used for differential diagnosis of MD, recurrent low-frequency hearing loss, non-specific vertigo, and vestibular migraine. In addition, as an automated analysis system of EH using the convolutional neural network algorithm has been developed,the usefulness of inner ear MRI is increasing. This algorithm can generate results that are highly consistent with those generated by manual calculation and can do so more quickly. Although there are some limitations to be overcome, inner ear MRI is expected to be widely used for differential diagnosis of various EH-related diseases in the not-too-distantfuture.