Short-term audiologic effect of intratympanic gadolinium contrast agent application in patients with Ménière's disease

Consensus on MR Imaging of Endolymphatic Hydrops in Patients With Suspected Hydropic Ear Disease (Meniere)

Endolymphatic hydrops (EH) is considered the histological hallmark of Meniere's disease. Visualization of EH has been achieved by special sequences of inner ear magnetic resonance imaging (MRI) with a gadolinium-based contrast agent via intravenous or intratympanic administration. Although it has been applied for more than 10 years since 2007, a unified view on this technique has not yet been achieved. This paper presents an expert consensus on MRI of endolymphatic hydrops in the following aspects: indications and contra-indications for patient selection, methods of contrast-agent administration (intravenous or intratympanic), MRI sequence selection, the specific scanning parameter settings, and standard image evaluation methods and their advantages and disadvantages. For each part of this consensus, a comment is attached to elucidate the reasons for the recommendation.

The Additional Value of Endolymphatic Hydrops Imaging With Intratympanic Contrast for Diagnostic Work-Up-Experience From a Neurotology Center in Austria

Objective: To illustrate the merit of hydrops imaging during clinical workup of dizziness and balance disorders. Background: Ever since the first description of in-vivo endolymphatic hydrops imaging in 2007, this diagnostic tool has been implemented in an increasing number of centers. The more experience in its clinical application is gathered, the more it is possible to critically assess its potential value for the diagnostic workup. This article intends to provide information about the experience of handling and utilization of endolymphatic hydrops imaging in one of the first centers in Austria. Methods: Retrospective analysis and review of clinical cases. Results: Based on our experience of endolymphatic hydrops imaging (EHI), which was established in cooperation between our departments of radiology and otorhinolaryngology in 2017, we have exclusively used intratympanic application of a contrast agent prior to magnetic resonance imaging, as this approach provides high quality imaging results. In 42.6% of cases, EHI could lead to the diagnosis of MD or HED. Since precise vestibular examination is still necessary, EHI is not a tool to replace the clinical examination but rather to add significantly to the interpretation of the results. Conclusion: Endolymphatic hydrops imaging represents a valuable, safe and well-applicable tool for evaluating cases with inconclusive clinical results. However, its potential additional diagnostic benefits rely on a correct indication based on prior thorough vestibular investigations.

Magnetic resonance imaging and Ménière's disease-unavoidable alliance

Ménière's disease (MD) is a clinical syndrome characterized by recurrent episodes of spontaneous vertigo, unilateral fluctuating sensorineural hearing loss, tinnitus, and aural fullness. Endolymphatic hydrops is recognized as the pathophysiological substrate of the disease, having been demonstrated in anatomical pathological studies and more recently by magnetic resonance imaging (MRI). The current criteria of the disease, however, remain symptom based and do not include the demonstration of endolymphatic hydrops. The authors review MRI techniques and diagnostic criteria of endolymphatic hydrops and the role of MRI in MD is discussed.

Clinical high-resolution imaging and grading of endolymphatic hydrops in Hydropic Ear Disease at 1.5 T using the two-slice grading for vestibular endolymphatic hydrops in less than 10 min

BACKGROUND

Hydropic Ear Disease (Menière) is one of the most common inner ear disorders and one of the most common causes of vertigo attacks. The underlying pathology is a distension of the endolymphatic space of the inner ear, termed endolymphatic hydrops. However, the unequivocal morphologic confirmation of ELH has been restricted to post-mortem histologic analysis until 2007, when the first clinical MR imaging report demonstrated ELH in living patients with Menière's disease at 3 T combined with intratympanic application of contrast. Imaging techniques have since then evolved further. However, a high magnetic field strength of 3 T has consistently been mandatory for reliable clinical imaging of ELH. This limitation has significantly prevented ELH imaging from being widely available across different health care systems around the world. With the aim of filling this gap, in the present study, we aim to describe the feasibility of ELH imaging at 1.5 T in clinical practice and to develop a dedicated grading system for cochlear and vestibular ELH for MR imaging at 1.5 T.

METHODS

In this retrospective study, we examined 30 patients with suspected hydropic ear disease undergoing diagnostic MR imaging. Contrast agent was diluted eightfold in saline solution and unilaterally applied by intratympanic injection as described previously. MRI scanning was performed using a 16-channel head coil on a 1.5 T Achieva Philips Medical Systems Scanner using a 3D FLAIR sequence. For the cochlea, a 3-stage grading was developed. For the vestibulum, a 4-stage grading based on two axial slices was developed by analysing both the superior and the inferior part of the vestibulum. The presence of hydropic herniation of the endolymphatic space into the posterior crus of the horizontal semicircular canal was evaluated.

RESULTS

In all 30 patients, the perilymphatic fluid spaces of the inner ear showed clear and high signal intensity, while the endolymphatic space was not enhanced. In all patients, the vestibular endolymphatic space could be clearly delineated and differentiated from the perilymphatic space. Analysis of the cochlear endolymphatic space revealed no evidence of ELH in 7 patients, a grade 1 cochlear ELH in 11 patients and a grade 2 cochlear ELH in 12 patients. Analysis of the vestibular endoylmphatic space revealed no evidence of ELH in 8 patients, a grade 1 vestibular ELH in 5 patients, a grade 2 vestibular ELH in 9 patients and a grade 3 vestibular ELH in 8 patients. Three patients showed a clear hydropic herniation of the vestibular endolymphatic space into the posterior non-ampullated crus of the horizontal SCC.

CONCLUSION

In summary, the findings presented in this study offer an easy, reliable and universally available technique of ELH imaging for diagnostic management of patients with suspected Hydropic Ear Disease.

State of the Art Imaging in Menière’s Disease. Tips and Tricks for Protocol and Interpretation

Purpose of Review

Menière’s disease (MD) is a burdensome and not well understood inner ear disorder that has received increasing attention of scientists over the past decade. Until 2007, a certain diagnosis of endolymphatic hydrops (EH) required post-mortem histology. Today, dedicated high-resolution magnetic resonance imaging (MRI) protocols enable detection of disease-related changes in the membranous labyrinth in vivo. In this review, we summarize the current status of MR imaging for MD.

Recent Findings

The mainstays of hydrops imaging are inversion recovery sequences using delayed acquisition after intravenous or intratympanic contrast administration. Based on these techniques, several methods have been developed to detect and classify EH. In addition, novel imaging features of MD, such as blood-labyrinth barrier impairment, have recently been observed.

Summary

Delayed contrast enhanced MRI has emerged as a reliable technique to demonstrate EH in vivo, with promising application in the diagnosis and follow-up of MD patients. Therefore, familiarity with current techniques and diagnostic imaging criteria is increasingly important.

Menière's disease patients improve specific posturographic parameters following diagnostic intratympanic injection

PURPOSE

Evaluation of specific computerized posturographic parameters in patients with Menière's disease (MD) following the intratympanic injection of gadolinium, a contrast agent, used in radiological diagnosing.

MATERIALS AND METHODS

We have observed 12 adult patients with unilateral Menière's Disease subjected to inner ear magnetic resonance imaging (MRI) examination after intratympanic gadolinium injection (ITG). The diagnoses have been performed according to the guidelines of the American Academy of otolaryngology. Before and after 24 h the ITG, all patients were subjected to the clinical evaluation and computerized posturography (CP), in 4 conditions depending on open/closed eyes and with/without foam cushion under feet.

RESULTS

After ITG, in the affected ear the MRI confirmed the endolymphatic hydrops revealing a thin or even disappeared perilymphatic space. The statokinesigram showed improvement of stability only with closed eyes on a foam cushion. The CP performed 24 h after the contrast intratympanic injection showed a significant reduction of Path Length and Confidence Ellipse Area, due to an improvement of vestibular function on static balance. This improvement could be directly dependent to intratympanic pressure modification mediated by volume of contrast liquid, by "columella effect".

CONCLUSIONS

This study demonstrates the absence of vestibular damage in patients undergoing intratympanic gadolinium infiltration and confirms the relationship between intratympanic pressure and vestibular stability modifications providing positive evidences for an applicative use of CP as a functional assessment to better address diagnosis and follow-up in MD patients treated with intratympanic injections.

MRI detection of endolymphatic hydrops in Meniere's disease in 8 minutes using MIIRMR and a 20-channel coil after targeted gadolinium delivery

Background

Endolymphatic hydrops (EH) become visible in vertigo patients, particularly in those with Meniere's disease (MD), in vivo using gadolinium-enhanced MRI. However, the image quality is not satisfying after intravenous injection of gadolinium chelate (GdC), and occasional failure in GdC uptake has been noticed after traditional intratympanic injection. In the present report, targeted delivery of GdC and using a cost-effective MRI system to obtain high quality images of EH in only 8 min will be introduced.

Methods

39 MD patients were recruited in the study. First, 0.1 ml of 20-fold diluted gadolinium-diethylenetriamine acid (Gd-DTPA) was delivered onto the posterior upper part of the tympanic medial wall using a soft-tipped micro-irrigation catheter through an artificially perforated tympanic membrane. Inner ear MRI was performed 24 h after Gd-DTPA administration using a 3T MR machine and a 20-channel head/neck coil with an 8 min sequence of medium inversion time inversion recovery imaging with magnitude reconstruction (MIIRMR). The parameters were as follows: TR 16000 ms, TE 663 ms, inversion time 2700 ms, flip angle 180°, slices per slab 60.

Results

Efficient inner ear uptake of Gd-DTPA was detected 24 h after delivery and it created excellent contrast in the inner ear of all cases. High quality images demonstrating EH in the vestibule and cochlea were obtained.

Conclusion

Targeted delivery of minimum Gd-DTPA (0.1 ml, 20-fold dilution) onto the posterior upper portion of the tympanic medial wall and MRI with MIIRMR in a 3T machine and 20-channel head/neck coil are clinically practical to obtain high quality images displaying EH.

Menière and Friends: Imaging and Classification of Hydropic Ear Disease

BACKGROUND

Over 75 years ago, endolymphatic hydrops was discovered as the pathologic correlate of Menière's disease. However, this pathologic finding could be ascertained only in postmortem histologic studies. Due to this diagnostic dilemma and the variable manifestation of the various audiovestibular symptoms, diagnostic classification systems based on clinical findings have been used hitherto.

METHODS

A review of the literature of magnetic resonance (MR) imaging of hydropic ear disease.

RESULTS

Recent developments of high resolution MR imaging of the inner ear have now enabled us to visualize in vivo endolymphatic hydrops in patients with suspected Menière's disease. The existing knowledge from temporal bone histologic studies and from the emerging evidence on imaging based evaluation of patients with suspected Menière's disease indicate that endolymphatic hydrops not only is responsible for the full-blown clinical triad of simultaneous attacks of auditory and vestibular dysfunction, but also for other clinical presentations such as "vestibular" and "cochlear Menière's disease."

CONCLUSION

As a consequence, we propose the term "Hydropic Ear Disease" as a new terminology which is based on symptomatic and imaging characteristics of these clinical entities to clarify and simplify their diagnostic classification.

Ultra-high-field (9.4 T) MRI Analysis of Contrast Agent Transport Across the Blood-Perilymph Barrier and Intrastrial Fluid-Blood Barrier in the Mouse Inner Ear

HYPOTHESIS

Effective paramagnetic contrast agent for the penetration of the perilymphatic spaces of the scala tympani, scala vestibuli, and scala media of the mouse inner ear can be determined using intravenous injection of various gadolinium (Gd) complexes and ultra-high-field magnetic resonance imaging (MRI) at 9.4 Tesla.

BACKGROUND

A number of contrast agents have been explored in experimental high-field MRI to determine the most effective Gd complex for ideal signal-to-noise ratio and maximal visualization of the in vivo mammalian inner ear in analyzing the temporal and spatial parameters involved in drug penetration of the blood-perilymph barrier and intrastrial fluid-blood barrier in the mouse model using MRI.

METHODS

Gadoteric acid (Dotarem), Gadobutrol (Gadovist), Gadodiamide (Omniscan), Gadopent acid (Magnevist), and Mangafodipir (Teslascan) were administered intravenously using the tail vein of 60 Balb/C mice. High-resolution T1 images of drug penetration were acquired with a horizontal 9.4 T Agilent magnet after intravenously injection. Signal intensity was used as a metric of temporal and spatial parameters of drug delivery and penetration of the perilymphatic and endolymphatic spaces.

RESULTS

ANOVA analysis of the area under the curve of intensity enhancement in perilymph revealed a significant difference (p < 0.05) in the scalae uptake using different contrast agents (F (3,25) = 3.54, p = 0.029). The Gadoteric acid complex Dotarem was found to be the most effective Gd compound in terms of rapid, morphological enhancement for analysis of the temporal, and spatial distribution in the perilymphatic space of the inner ear.

CONCLUSION

Gadoteric acid (Dotarem) demonstrated efficacy as a contrast agent for enhanced visualization of the perilymphatic spaces of the inner ear labyrinthine in the mouse, including the scala tympani and scala vestibuli of the cochlea, and the semicircular canals of the vestibular apparatus. These findings may inform the clinical application of Gd compounds in patients with inner ear fluid disorders and vertigo.

Investigation of the ototoxicity of gadoteridol (ProHance) and gadodiamide (Omniscan) in mice

CONCLUSION

In the mouse, when a tympanic perforation is present, gadoteridol does not seem to cause ototoxicity. Gadodiamide may cause mild ototoxicity other than toxicity to the outer hair cells of the cochlea.

OBJECTIVES

Endolymphatic hydrops have been visualized through intra-tympanic injection of gadolinium-based contrast agents (GBCAs) and three-dimensional fluid-attenuated inversion recovery (3-D FLAIR) magnetic resonance imaging. However, reports on the safety of GBCAs are limited. This study aimed to assess ototoxicity of gadoteridol and gadodiamide.

METHOD

In a prospective, randomized, controlled trial, myringotomies in the left ear were performed in 20 male C57 BL/6 mice. After testing the baseline auditory brainstem response (ABR) (range = 8-32 kHz), the test solution (gadoteridol, gadodiamide, saline, or cisplatin) was injected into the left ear. ABR testing was repeated 14 days after test solution application. In morphological experiments, images of post-mortem surface preparations were assessed for cochlear hair cell status.

RESULTS

At 14 days following gadoteridol application, there was no significant change in ABR thresholds at 8, 16, or 32 kHz. Gadodiamide application caused a significant change in the ABR threshold at 8 kHz. Apparent cochlear hair cell loss was not observed in the surface preparation after gadoteridol or gadodiamide application.

What is Menière's disease? A contemporary re-evaluation of endolymphatic hydrops

Menière's disease is a chronic condition with a prevalence of 200-500 per 100,000 and characterized by episodic attacks of vertigo, fluctuating hearing loss, tinnitus, aural pressure and a progressive loss of audiovestibular functions. Over 150 years ago, Prosper Menière was the first to recognize the inner ear as the site of lesion for this clinical syndrome. Over 75 years ago, endolymphatic hydrops was discovered as the pathologic correlate of Menière's disease. However, this pathologic finding could be ascertained only in post-mortem histologic studies. Due to this diagnostic dilemma and the variable manifestation of the various audiovestibular symptoms, diagnostic classification systems based on clinical findings have been repeatedly modified and have not been uniformly used in scientific publications on Menière's disease. Furthermore, the higher level measures of impact on quality of life such as vitality and social participation have been neglected hitherto. Recent developments of high-resolution MR imaging of the inner ear have now enabled us to visualize in vivo endolymphatic hydrops in patients with suspected Menière's disease. In this review, we summarize the existing knowledge from temporal bone histologic studies and from the emerging evidence on imaging-based evaluation of patients with suspected Menière's disease. These indicate that endolymphatic hydrops is responsible not only for the full-blown clinical triad of simultaneous attacks of auditory and vestibular dysfunction, but also for other clinical presentations such as "vestibular" and "cochlear Menière's disease". As a consequence, we propose a new terminology which is based on symptomatic and imaging characteristics of these clinical entities to clarify and simplify their diagnostic classification.

Differences in perilymphatic space enhancement and adverse inflammatory reaction after intratympanic injection of two different gadolinium agents: A 9.4-T magnetic resonance imaging study

PURPOSE

To compare the inner ear enhancement after intratympanic injection of two widely used gadolinium (Gd) agents by 9.4 T micro-magnetic resonance imaging (MRI) and to investigate the effects of Gd on the inner ear.

METHODS

Twelve ears of six rats received intratympanic administration of 1/5 diluted Gd agents: gadoterate meglumine (Gd-DTPA) for the left ear and gadodiamide (Gd-DTPA-BMA) for the right ear. MRI was performed every 30 min from 1 to 4 h after administration. The normalized signal intensity was evaluated by quantitative analysis at each cochlear fluid compartment. Eight, six, and seven ears treated with Gd-DTPA, Gd-DPTA-BMA, and nothing as controls, respectively, were processed for histological evaluation after MRI. After hematoxylin & eosin staining, adverse inflammatory reactions were evaluated for turbid aggregation and lymphocytes.

RESULTS

The perilymphatic enhancement of Gd-DTPA was superior to that of Gd-DTPA-BMA regardless of cochlear turn, compartment, and time point. Inflammatory reactions were found in 4/8 (50.0%) and 4/6 (66.6%) ears administered Gd-DTPA and Gd-DTPA-BMA, respectively. Regardless of the contrast agent used, inflammatory reactions were most definite in the scala tympani of the basal turn, i.e., near the round window. Slightly greater inflammatory reactions were observed in ears injected with Gd-DTPA-BMA compared to Gd-DTPA although the difference was not statistically significant. No inflammatory reaction was observed in any of the seven controls. The auditory brainstem response threshold was 11.8 ± 2.5 dB SPL before IT Gd injection and it did not change for up to 5 days (15.4 ± 6.6 dB SPL) post-injection.

CONCLUSIONS

Gd-DTPA was superior to Gd-DTPA-BMA for visualization of the inner ear. Administration of diluted Gd agents intratympanically may induce considerable inflammatory reactions in the inner ear.

Endolymphatic hydrops in patients with vestibular migraine and auditory symptoms

Vertigo patients exhibiting features of vestibular migraine (VM) and Menière's disease (MD) present a difficult diagnostic challenge to the clinician, and the two entities are likely to overlap. The aim of the present study was to investigate the occurrence of endolymphatic hydrops in patients with VM and auditory symptoms. This was an observatory diagnostic study. At an academic interdisciplinary dizziness centre, nineteen consecutive patients with definite or probable VM and auditory symptoms were examined by locally enhanced inner ear MR imaging. MR images were evaluated for the presence of endolymphatic hydrops. Of the 19 included patients, four patients (21 %) demonstrated evidence of cochlear and vestibular endolymphatic hydrops on locally enhanced inner ear MR imaging (three with "definite VM", one with "probable VM"). Locally enhanced inner ear MR imaging may be useful in the diagnostic evaluation of patients with VM and auditory symptoms, as some of these patients have signs of endolymphatic hydrops. Whether these patients suffer from MD only and are misdiagnosed as VM or suffer from both, VM and MD or whether endolymphatic hydrops is a consequence of inner ear damage due to VM are clinically relevant questions that can be evaluated by application of this technique.

Hearing function after intratympanic application of gadolinium-based contrast agent: A long-term evaluation

OBJECTIVES/HYPOTHESIS

The aim of this study was to evaluate the long-term influence of intratympanic gadolinium-based contrast agent on hearing function in patients with possible Ménière's disease and normal auditory thresholds who were undergoing locally enhanced magnetic resonance imaging scans.

STUDY DESIGN

Prospective observational cohort study in a tertiary referral university hospital ear, nose, and throat department.

METHODS

Between 2009 and 2012, 17 patients with possible or probable Ménière's disease and a four-tone pure-tone average baseline of <25 dB were recruited for our study. Before undergoing intratympanic injection of gadolinium-based contrast agent, all patients underwent a complete audiological evaluation. The study population was then invited back after at least 6 months postinjection for a follow-up auditory evaluation. This consisted of comprehensive clinical and audiological tests on both sides and were evaluated according to the ototoxicity guidelines.

RESULTS

A long-term evaluation of our study group revealed no significant difference in the air-conduction pure-tone average. Furthermore, no statistical difference at individual frequencies compared to baseline was found. There was no evidence of ototoxicity in the injected ear.

CONCLUSIONS

Long-term hearing function assessment after intratympanic application of gadolinium-based agent showed no evidence of ototoxicity. The use of intratympanic gadolinium-based agent in the diagnosis of Ménièrés disease is currently a helpful tool, and seems to be a safe method, especially with regard to auditory function.

LEVEL OF EVIDENCE

4.

Effect of standard-dose Betahistine on endolymphatic hydrops: an MRI pilot study

This study aimed to assess whether standard-dose Betahistine (48 mg daily) exerts an effect upon the degree of endolymphatic hydrops in patients with Menière's disease using a retrospective case series in the setting of a tertiary neurotology referral centre. In six patients with definite unilateral Menière's disease, the degree of cochlear and vestibular endolymphatic hydrops was assessed before and after treatment with a standard dose of Betahistine (48 mg daily), using high-resolution 3 T MR imaging after intratympanic contrast medium application. The treatment duration was 3-7 months (mean 5 months), and the patients were followed-up for 6-29 months (mean 11 months). In the study cohort, the standard dose of Betahistine did not have an MR morphologically measurable beneficial effect on the degree of endolymphatic hydrops. The results indicated no effect of standard-dose Betahistine on endolymphatic hydrops found on high-resolution MR imaging. Possible explanations are: (1) insufficient dosage or duration of treatment with betahistine, (2) insufficient resolution of the MR imaging technique, and (3) insufficient length of follow-up. Further studies addressing these issues are warranted.