A 3-hour time interval may not be sufficient for delayed enhancement magnetic resonance imaging with intravenous gadoteridol injection based on 3d-real IR sequence of the inner ear in Meniere's disease patient

BACKGROUND

Magnetic resonance imaging (MRI) can be applied to visualize endolymphatic hydrops (EH).

AIMS/OBJECTIVES

To explore whether a 3-h time interval was feasible for clinical practice.

MATERIALS AND METHODS

We prospectively enrolled 15 patients with unilateral Meniere's disease, each of whom underwent delayed enhancement MRI scan of the inner ear after intravenous gadoteridol injection at a 3-h interval. The ears of these patients were divided into two groups (group A: the affected ears; group B: the unaffected ears). Among the two groups, the signal intensity in perilymphatic area of the basal turn of cochlea, the results of visual evaluations in the vestibule, cochlea and semicircular canal and the detection results of EH were compared.

RESULTS

Regarding the signal intensity, a difference was found between group A and group B (p = .016). Besides, no difference was found between the visual evaluations in the vestibule, cochlea and semicircular canal of the two groups. Regarding the detection results of EH, group A (6 vestibules were undiagnosable; 8 cochleae were undiagnosable); group B (9 vestibules were undiagnosable; 10 cochleae were undiagnosable).

CONCLUSIONS AND SIGNIFICANCE

In the clinical application of gadoteridol for the inner ear, 3-h delayed MR imaging may not be sufficient.

MRI can help differentiate Ménière's disease from other menieriform diseases

It is difficult to distinguish other pathologies mimicking Ménière's disease (MD) clinically. This study aims to investigate the differences of imaging findings and features between MD and other menieriform diseases via intravenous gadolinium-enhanced magnetic resonance imaging (MRI). 426 patients with menieriform symptoms, including MD, vestibular migraine (VM), and vestibular schwannoma (VS), underwent 3D-FLAIR and 3D-T2WI MRI 6 h after the intravenous gadolinium injection. MR images were analyzed for inner ear morphology, perilymphatic enhancement (PE), EH and other abnormalities. EH was observed at a higher rate in MD patients (85.71%) than patients with other menieriform diseases (VM group = 14.75%, VS group = 37.50%). The prevalence of unilateral EH as well as both cochlear and vestibular EH showed significant differences between MD and VM groups. The prevalence of cochlear EH (I and II) and vestibular EH (II and III) was different between MD and VM groups. The prevalence of PE was higher in MD than VM group. The degrees of cochlear and vestibular hydrops were higher in the definite than probable MD group (P < 0.05). Using these imaging features, MRI can be used to help differentiate MD from other menieriform diseases.

Meniere's disease: Pathogenesis, treatments, and emerging approaches for an idiopathic bioenvironmental disorder

Meniere's disease (MD) is a severe inner ear condition known by debilitating symptoms, including spontaneous vertigo, fluctuating and progressive hearing loss, tinnitus, and aural fullness or pressure within the affected ear. Prosper Meniere first described the origins of MD in the 1860s, but its underlying mechanisms remain largely elusive today. Nevertheless, researchers have identified a key histopathological feature called Endolymphatic Hydrops (ELH), which refers to the excessive buildup of endolymph fluid in the membranous labyrinth of the inner ear. The exact root of ELH is not fully understood. Still, it is believed to involve several biological and bioenvironmental etiological factors such as genetics, autoimmunity, infection, trauma, allergy, and new theories, such as saccular otoconia blocking the endolymphatic duct and sac. Regarding treatment, there are no reliable and definitive cures for MD. Most therapies focus on managing symptoms and improving the overall quality of patients' life. To make significant advancements in addressing MD, it is crucial to gain a fundamental understanding of the disease process, laying the groundwork for more effective therapeutic approaches. This paper provides a comprehensive review of the pathophysiology of MD with a focus on old and recent theories. Current treatment strategies and future translational approaches (with low-level evidence but promising results) related to MD are also discussed, including patents, drug delivery, and nanotechnology, that may provide future benefits to patients suffering from MD.

Ménière's disease and allergy: Epidemiology, pathogenesis, and therapy

The etiology of Ménière's disease (MD) remains controversial. Allergies are potential extrinsic factors that, in conjunction with underlying intrinsic factors, may cause MD. The link between allergies and MD was first described in 1923. For nearly a century, studies have demonstrated a possible link between allergies and MD, even though a causal relationship has not been definitively determined. Previous reviews have mainly focused on clinical epidemiology studies of patients. In this review, we shed light on the association between allergies and MD not only in terms of its epidemiology, but also from an immunology, pathophysiology, and immunotherapy perspective in both patients and animal models. Patients with MD tend to have a high risk of comorbid allergies or an allergy history, showing positive allergy immunology characteristics. Other MD-related diseases, such as migraine, may also interact with allergies. Allergy mediators such as IgE may worsen the symptoms of MD. Deposits of IgE in the vestibular end organs indicate the ability of the inner ear to participate in immune reactions. Allergic challenges can induce vertigo in animals and humans. Anti-allergy therapy plays a positive role in patients with MD and animal models of endolymphatic hydrops.

Characterizing a Joint Reflection-Distortion OAE Profile in Humans With Endolymphatic Hydrops

OBJECTIVES

Endolymphatic hydrops (EH), a hallmark of Meniere disease, is an inner-ear disorder where the membranes bounding the scala media are distended outward due to an abnormally increased volume of endolymph. In this study, we characterize the joint-otoacoustic emission (OAE) profile, a results profile including both distortion- and reflection-class emissions from the same ear, in individuals with EH and speculate on its potential utility in clinical assessment and monitoring.

DESIGN

Subjects were 16 adults with diagnosed EH and 18 adults with normal hearing (N) matched for age. Both the cubic distortion product (DP) OAE, a distortion-type emission, and the stimulus-frequency (SF) OAE, a reflection-type emission, were measured and analyzed as a joint OAE profile. OAE level, level growth (input/output functions), and phase-gradient delays were measured at frequencies corresponding to the apical half of the human cochlea and compared between groups.

RESULTS

Normal hearers and individuals with EH shared some common OAE patterns, such as the reflection emissions being generally higher in level than distortion emissions and showing more linear growth than the more strongly compressed distortion emissions. However, significant differences were noted between the EH and N groups as well. OAE source strength (a metric based on OAE amplitude re: stimulus level) was significantly reduced, as was OAE level, at low frequencies in the EH group. These reductions were more marked for distortion than reflection emissions. Furthermore, two significant changes in the configuration of OAE input/output functions were observed in ears with EH: a steepened growth slope for reflection emissions and an elevated compression knee for distortion emissions. SFOAE phase-gradient delays at 40 dB forward-pressure level were slightly shorter in the group with EH compared with the normal group.

CONCLUSIONS

The underlying pathology associated with EH impacts the generation of both emission types, reflection and distortion, as shown by significant group differences in OAE level, growth, and delay. However, hydrops impacts reflection and distortion emissions differently. Most notably, DPOAEs were more reduced by EH than were SFOAEs, suggesting that pathologies associated with the hydropic state do not act identically on the generation of nonlinear distortion at the hair bundle and intracochlear reflection emissions near the peak of the traveling wave. This differential effect underscores the value of applying a joint OAE approach to access both intracochlear generation processes concurrently.

Delayed post gadolinium MRI descriptors for Meniere's disease: a systematic review and meta-analysis

OBJECTIVES

Delayed post-gadolinium magnetic resonance imaging (MRI) detects changes of endolymphatic hydrops (EH) within the inner ear in Meniere's disease (MD). A systematic review with meta-analysis was conducted to summarise the diagnostic performance of MRI descriptors across the range of MD clinical classifications.

MATERIALS AND METHODS

Case-controlled studies documenting the diagnostic performance of MRI descriptors in distinguishing MD ears from asymptomatic ears or ears with other audio-vestibular conditions were identified (MEDLINE, EMBASE, Web of Science, Scopus databases: updated 17/2/2022). Methodological quality was evaluated with Quality Assessment of Diagnostic Accuracy Studies version 2. Results were pooled using a bivariate random-effects model for evaluation of sensitivity, specificity and diagnostic odds ratio (DOR). Meta-regression evaluated sources of heterogeneity, and subgroup analysis for individual clinical classifications was performed.

RESULTS

The meta-analysis included 66 unique studies and 3073 ears with MD (mean age 40.2-67.2 years), evaluating 11 MRI descriptors. The combination of increased perilymphatic enhancement (PLE) and EH (3 studies, 122 MD ears) achieved the highest sensitivity (87% (95% CI: 79.92%)) whilst maintaining high specificity (91% (95% CI: 85.95%)). The diagnostic performance of "high grade cochlear EH" and "any EH" descriptors did not significantly differ between monosymptomatic cochlear MD and the latest reference standard for definite MD (p = 0.3; p = 0.09). Potential sources of bias were case-controlled design, unblinded observers and variable reference standard, whilst differing MRI techniques introduced heterogeneity.

CONCLUSIONS

The combination of increased PLE and EH optimised sensitivity and specificity for MD, whilst some MRI descriptors also performed well in diagnosing monosymptomatic cochlear MD.

KEY POINTS

• A meta-analysis of delayed post-gadolinium magnetic resonance imaging (MRI) for the diagnosis of Meniere's disease is reported for the first time and comprised 66 studies (3073 ears). • Increased enhancement of the perilymphatic space of the inner ear is shown to be a key MRI feature for the diagnosis of Meniere's disease. • MRI diagnosis of Meniere's disease can be usefully applied across a range of clinical classifications including patients with cochlear symptoms alone.

Long-term effects of middle ear pressure therapy with the EFET01 device in patients with Ménière's disease and delayed endolymphatic hydrops in Japan

BACKGROUND

Long-term efficacy of middle ear pressure therapy (MEPT) with the EFET01 device in patients in Japan with definitive Ménière's disease (MD) and delayed endolymphatic hydrops (DEH) was evaluated.

OBJECTIVE

To examine the effects of reducing vertigo attacks and improving hearing of MD and DEH patients by using MEPT with the EFET01 device for two years after treatment.

MATERIAL AND METHODS

A retrospective study was conducted of 32 MD patients and 2 DEH patients treated by MEPT with the EFET01 device from December 2018 to April 2021. According to Japan Society for Equilibrium Research (JSER) guidelines, patients were investigated for the frequency of vertigo attacks and change in hearing levels during a period of 6 months before to 18-24 months after start of treatment.

RESULTS

The frequency of vertigo attacks significantly decreased in both MD and DEH patients, and hearing level has remained stable in the majority of our patients after treatment.

CONCLUSION

Our study clarified that MEPT with the EFET01 device was effective in controlling vertigo symptoms of MD and DEH. It should be considered a safe option for patients failing medical treatment.

SIGNIFICANCE

The efficacy of MEPT with the EFET01 was shown over a 2-year follow-up period.

[Analysis of wideband acoustic immittance measurements in patients with unilateral Ménière's disease]

Objective:To investigate the characteristics of wideband acoustic immittance（WAI） measurements in patients with unilateral Ménière's disease（MD） and evaluate the clinical value of WAI in diagnosis of MD. Methods:WAI was performed in 30 patients with unilateral MD（30 ears for symptomatic and 30 ears for asymptomatic） and in 26 healthy individuals（52 ears）（control group）. The WAI measurements, including the frequency first appearing two peaks in energy absorbance（EA） tympanogram, resonance frequency（RF）, the peak value of absorbance（PVA）, the integral area of absorbance（IAA）, EA curve at peak pressure, were analyzed. Results:①The occurrence of two peaks in EA tympanogram in both the MD symptomatic and asymptomatic ear was observed in 27 ears（84.4%）, and 38 ears（70.4%） in the control group, with no significant difference in the frequency of first appearing in two peaks onset between the groups（all P>0.05）. ②The RF of the MD symptomatic ears was significantly lower than that of the asymptomatic ears（t=-3.544, P=0.001） and that of the control subjects（t=2.084, P=0.041）; there was no difference of RF between the MD asymptomatic ears and the control group（P>0.05）. ③The PVA were significantly lower in both MD symptomatic（t=4.240, P<0.01） and asymptomatic ears（t=4.202, P=0.001） than in controls. ④The IAA in MD symptomatic（t=3.295, P=0.001） and asymptomatic ears（t=3.193, P=0.003） was significantly lower than in the control group. ⑤Comparison of the EA curve at peak pressure of the three groups: the EAs of MD symptomatic ears were lower than those of the control group at the range of 1 059-2 911 Hz（all P<0.05）; the EAs of MD symptomatic ears were lower than those of MD asymptomatic ears within 1 000 Hz and 1 834-2 119 Hz（all P<0.05）; the EAs of MD asymptomatic ears were lower than those of the control group at the range of 515-2 748 Hz（all P<0.05）. Conclusion:Symptomatic ears in unilateral MD patients show alterations in some WAI measurements compared to asymptomatic ears and/or controls, suggesting that middle ear mechanical fuction of the affected side may be modified due to the endolymphatic hydrops. The clinical significance of WAI needs to be further explored in the context of evaluating MD.

Endolymphatic hydrops imaging and correlation with clinical characteristics, audiovestibular function and mental impairment in patients with Meniere's disease

PURPOSE

MR imaging was used to visualize the vestibular and cochlear endolymphatic hydrops in patients with Meniere's disease (MD). The relationship between the degree of hydrops and clinical characteristics, audiovestibular function, anxiety and depression state in MD patients.

METHODS

70 patients with definitely or probably unilateral Meniere's disease received bilateral intratympanic gadolinium administration and MR scanning. The degree of bilateral vestibular and cochlea hydrops were analyzed and evaluated by three-dimensional real inversion recovery (3D-real IR) sequence, and the correlation between the grades of endolymphatic hydrops (EH) and disease course, vertigo grading assessment, the duration of vertigo, hearing loss level, caloric test, vestibular myogenic evoked potential (VEMP), electrocochleogram (EcoG), vertigo disability scale (physical, emotional, functional), anxiety and depression scale were studied.

RESULTS

It was found that the vestibule and cochlea EH of the affected and the contralateral ear had different degrees of hydrops and there was no statistical difference between the left and right vestibules. The degree of vestibule EH (V-EH) was significantly positively correlated with the degree of cochlear EH (C-EH). C-EH and hearing loss level were positively correlated with EcoG. There was positive correlation between vestibular EH and hearing loss level, VEMP, caloric test, disease course or vertigo duration. There was a negative relationship between Dizziness Handicap Inventory (Emotion) (DHI(E)) and VEMP. Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) scores were positive correlated with DHI(E) and DHI total scores in MD patients.

CONCLUSION

Endolymph-enhancing MRI was used as an important imaging method for the diagnosis of labyrinthine hydrops in Meniere's disease. There were certain correlation between EH and the degree of vertigo attack, hearing loss level, vestibular function, and further changes in anxiety and depression emotion.

[A case report of middle ear cholesteatoma complicated with labyrinthine fistulaand delayed endolymphatic hydrops]

Delayed endolymphatic hydrops （DEH） is a rare disease that causes vertigo and is often misdiagnosed as other vertigo diseases. This article reports on a patient with vertigo who was easily misdiagnosed. The patient was a middle ear cholesteatoma complicated by labyrinthine fistula （LF）; however, his vertigo was episodic vertigo, which could not be explained solely by LF causing labyrinthitis. The possibility of endolymphatic hydrops was suspected, which was confirmed by inner ear magnetic resonance gadolinium imaging. This is the first reported case of middle ear cholesteatoma complicated by LF and DEH. The patient underwent surgical resection of the cholesteatoma and three semicircular canal obstructions at the same time. During two years postoperative follow-up, the patient did not experience a recurrence of vertigo. When diagnosing vertigo diseases, a careful history of vertigo is of utmost importance.

Vestibular migraine or Meniere's disease: a diagnostic dilemma

Meniere's disease (MD) represents one of the vertigo disorders characterized by triad symptoms (recurrent vertigo, fluctuating hearing loss, tinnitus or ear fullness). The diagnosis of MD relies on the accurate and detailed taking of medical history, and the differentiation between MD and vestibular migraine (VM) is of critical importance from the perspective of the treatment efficacy. VM is a highly prevalent vertigo condition and its typical symptoms (headache, vestibular symptoms, cochlear symptoms) mimic those of MD. Furthermore, the misdiagnosis in MD and VM could lead to VM patients mistakenly receiving the traumatic treatment protocol designed for MD, and sustaining unnecessary damage to the inner ear. Fortunately, thanks to the advances in examination technologies, the barriers to their differentiation are being gradually removed. These advances enhance the diagnostic accuracy of vertigo diseases, especially VM and MD. This review focused on the differentiation of VM and MD, with an attempt to synthesize existing data on the relevant battery of differentiation diagnosis (covering core symptoms, auxiliary tests [audiometry, vestibular tests, endolymphatic hydrops tests]) and longitudinal follow-up. Since the two illnesses are overlapped in all aspects, no single test is sufficiently specific on its own, however, patterns containing all or at least some features boost specificity.

A bibliometric and visualization study of Meniere's disease: Current status and global hotspots and emerging trends

BACKGROUND

Meniere's disease (MD) is a clinical condition characterized by endolymphatic hydrops. Persistent symptoms negatively affect patients mood, and the underlying etiology remains unclear. It is necessary to comprehensively understand the relevant publications, review the history and current status of research, and analyze hotspots and frontiers of research on MD.

METHODS

We retrieved literature on Meniere's disease from 2003 to 2022 from the Web of Science database and extracted the data. Data visualization and analysis was conducted using Cite Space, VOS viewer, an online web tool, and Microsoft Office Power Point 2019.

RESULTS

In total, 2847 publications were analyzed. The number of annual publications was relatively stable, with an accelerated upward trend over the past 5 years. The country with the most publications was USA (751, 26.38%), while the University of Munich contributed more publications than any other institution (117, 4.11%). The article titled "Diagnostic criteria for Meniere's disease" by Lopez-Escamez J et al in 2015 was the most cited and co-cited publication, and also had the top co-cited references with the strongest citation bursts. Naganawa S was the author with the most publications (85, 2.99%). The top 3 journals and co-cited journals were Otology Neurotology, Acta Oto Laryngologica, and Laryngoscope. Recently, the key theme words were "sensorineural hearing loss," "therapy," "intratympanic injection method," "vestibular-evoked myogenic potentials," "vestibular migraine," "magnetic resonance imaging," and "meniere's disease."

CONCLUSIONS

The US has the largest number of publications and research institutions, many European countries have high-quality journals, and Japan has the highest number of scholars. The international opinion on Meniere's disease is relatively uniform. The stepped-therapy for MD is scientific and clear. Intratympanic injection of steroids and intratympanic injection of gentamicin are commonly used, but steroids are considered safer. Saccular dysfunction may be more common in patients with MD than in those with utricular dysfunctions. It is worth paying attention to study the relationship between MD and vestibular migraine through headache. Progress in magnetic resonance imaging technology is still required for the imaging diagnosis of MD.

Frequency-specific Electrocochleography and Traveling Wave Time as a Clinical Test for Menière's Disease

INTRODUCTION

Menière's disease is a clinical entity with no definitive objective testing. It has been hypothesized that underlying endolymphatic hydrops stiffens the basilar membrane leading to increased speed of the acoustic stimulus, therefore traveling wave velocity has been proposed as an objective test to aid in the diagnosis. The objective of this study is to compare electrocochleography frequency-specific action potential latency, basilar membrane traveling wave time, and summation to action potential (SP/AP) ratio in Menière's and non-Menière's patients.

METHODS

Tympanic electrocochleography was performed with frequency-specific action potential latency time and SP/AP ratio recorded. Patient demographics, symptoms, audiogram data, AAO-HNS classification of Menière's disease, management interventions, and follow-up were recorded. Statistical analysis was performed to compare outcome measures across patient groups, demographics, and clinical data.

RESULTS

Ninety-one patients (182 ears) were included. There was a significant difference between a "definite" Menière's diagnosis and an "unlikely" or "probable" diagnosis by an average of 13 dB HL for the pure-tone thresholds at 250 Hz on the affected side (p = 0.006). There was no significant difference in pure-tone thresholds at any other frequency, AP latency at any frequency, or AP/SP ratio between the different Menière's classification groups.

CONCLUSIONS

Our study fails to show significance of the traveling wave velocity as an objective test for Menière's disease. A significant correlation was found with low-frequency hearing loss between AAO-HNS Menière's classification groups.

Diagnostic and therapeutic strategies for Meniere's disease of the Japan Society for Equilibrium Research

OBJECTIVE

We provided diagnostic and therapeutic strategies for Meniere's disease in accordance with Japanese Clinical Practice Guideline of Meniere's disease and delayed endolymphatic hydrops 2nd ed. Tokyo: Kanehara Shuppan; 2020 edited by the Japan Society for Equilibrium Research.

METHODS

The Committee for Clinical Practice Guidelines was entrusted with a review of the scientific literature on the above topic. Clinical Questions (CQs) concerning the treatment for Meniere's disease were produced, and the literature according to each of them including CQ was searched. The recommendations are based on the literature review and the expert opinion of a subcommittee.

RESULTS

Diagnosis criteria of Meniere's disease are classified into Meniere's disease with typical cochlear and vestibular symptoms, and atypical Meniere's disease with either cochlear symptoms or vestibular symptoms. Treatment of Meniere's disease was composed of lifestyle changes, medications such as anti-vertigo drugs and diuretics, middle ear positive pressure treatment, and selective destruction of the vestibule.

CONCLUSION

Meniere's disease is diagnosed based on clinical histories and examination findings after processes of differential diagnosis. Treatment option of the disease should be selected in order of invasiveness, according to the severity of the disease and the response to each treatment.

Electrocochleography in the Evaluation of Patients with Ménière's Disease/Endolymphatic Hydrops

Electrocochleography (ECochG) has evolved as an important tool in the diagnosis/assessment/monitoring of Ménière's disease/endolymphatic hydrops (MD/ELH). This manuscript provides an update on the use of ECochG for these purposes. The material presented includes descriptions of the components of the electrocochleogram; ECochG recording approaches and parameters; how to prepare for an exam, including subject/patient considerations; construction and placement of a tympanic membrane recording electrode; and interpretation the electrocochleogram. Various approaches aimed at improving ECochG's sensitivity and specificity to MD/ELH also are described. These approaches go beyond simple measurement of the now-conventional summating potential (SP)/action potential (AP) magnitude ratio to include the SP magnitude to tonebursts, the SP/AP area ratio, and the AP latency difference to clicks of opposing polarity.

The round window sign: a sensitive sign to detect perilymphatic fistulae on delayed postcontrast 3D-FLAIR sequence

OBJECTIVES

The aim of this study is to assess the diagnostic performance of a new MR sign, named the round window sign (RWS), to diagnose perilymphatic fistula (PLF) in a population of patients with chronic cochleo-vestibular symptoms, classified as definite or probable Menière's disease (MD).

METHODS

A total of 164 patients (mean age 52 ± 35 years) with chronic cochleo-vestibular symptoms underwent MRI, between 4 and 5 h after intravenous gadoteric acid injection (Dotarem®, 0.1 mmol/kg). MRI exploration was carried out on a 3-T Achieva® TX scanner. We analyzed the presence of the RWS, defined as a nodular FLAIR high signal in the round window (RW) and the presence of associated saccular hydrops. When this RWS was present, a temporal bone CT scan was performed and the RW was analyzed.

RESULTS

Of the 164 patients with definite MD (85 patients) or probable MD (79 patients), we found the RWS in 18 (11%), and 17/18 were classified into the group of probable MD. All these 18 patients showed other MR sequences considered as normal, including heavily weighted T2 imaging. Among these 18 patients, the temporal bone CT examination presented a filling of the RW in 13 patients (72%) and no filling of the RW in 5 patients (28%). Seven patients were surgically managed confirming in vivo the PLF diagnosis. The RWS was associated with the presence of a saccular hydrops in 4 cases.

CONCLUSION

Delayed postcontrast 3D-FLAIR may reveal perilymphatic fistulae in patients with probable Menière's disease using the round window sign.

KEY POINTS

• MRI with delayed acquisition can detect perilymphatic fistulae with perfect sensitivity, based on the presence of the round window sign. • This visual sign is only visible on a 3D-FLAIR sequence. • 3D-FLAIR sequence with delayed acquisition is more sensitive than temporal bone CT scan examination in detecting PLF.

Early Detection of Endolymphatic Hydrops using the Auditory Nerve Overlapped Waveform (ANOW)

Endolymphatic hydrops is associated with low-frequency sensorineural hearing loss, with a large body of research dedicated to examining its putative causal role in low-frequency hearing loss. Investigations have been thwarted by the fact that hearing loss is measured in intact ears, but gold standard assessments of endolymphatic hydrops are made postmortem only; and that no objective low-frequency hearing measure has existed. Yet the association of endolymphatic hydrops with low-frequency hearing loss is so strong that it has been established as one of the important defining features for Ménière's disease, rendering it critical to detect endolymphatic hydrops early, regardless of whether it serves a causal role or is the result of other disease mechanisms. We surgically induced endolymphatic hydrops in guinea pigs and employed our recently developed objective neural measure of low-frequency hearing, the Auditory Nerve Overlapped Waveform (ANOW). Hearing loss and endolymphatic hydrops were assessed at various time points after surgery. The ANOW detected low-frequency hearing loss as early as the first day after surgery, well before endolymphatic hydrops was found histologically. The ANOW detected low-frequency hearing loss with perfect sensitivity and specificity in all ears after endolymphatic hydrops developed, where there was a strong linear relationship between degree of endolymphatic hydrops and severity of low-frequency hearing loss. Further, histological data demonstrated that endolymphatic hydrops is seen first in the high-frequency cochlear base, though the ANOW demonstrated that dysfunction begins in the low-frequency apical cochlear half. The results lay the groundwork for future investigations of the causal role of endolymphatic hydrops in low-frequency hearing loss.

3D-real IR MRI of Meniere's disease with partial endolymphatic hydrops

OBJECTIVES

A three-dimensional inversion-recovery sequence with real reconstruction (3D-real IR) sequence 4 h after intravenous gadolinium injection (IV) has been used to visualize the endolymphatic hydrops (ELH) in Meniere's disease (MD). This study was designed to explore the pathology of MD with partial ELH.

METHODS

We collected 338 patients with definite MD, all of whom underwent the IV method. Patients who were found to have partial ELH (vestibular or cochlear) were enrolled. The hearing thresholds of the enrolled patients were analyzed, the regions of interest of the cochlear perilymph and the cerebellum white matter were determined, and the signal intensity ratio in the former to the latter (CC ratio) for both sides in the patients was subsequently evaluated.

RESULTS

Of the 338 collected patients with definite MD, 19 patients (5.6%) had unilateral vestibular ELH (N = 18) or cochlear ELH (N = 1), and 4 patients (1.2%) with bilateral ELH had contralateral cochlear ELH. The CC ratio of the affected side (1.44 ± 0.46) was higher than that of the unaffected side (1.15 ± 0.33, P < 0.05) in the 19 patients with unilateral ELH. Conversely, there was no difference between the ratio of the contralateral side (1.18 ± 0.16) and the unaffected side (P > 0.05) in the 4 patients with bilateral ELH.

CONCLUSIONS

Partial vestibular ELH was more common than partial cochlear ELH in MD. Moreover, vestibular ELH, rather than cochlear ELH, may correlate with the elevated contrast effect in the affected side, which may better reflect the pathologic mechanism of MD.

Clinical manifestations of hydropic ear disease (Menière's)

INTRODUCTION

Hydropic ear disease, initially described by and named after Prosper Menière, is one of the most frequent vertigo disorders and one of the most frequent inner ear disorders. It is the syndrome of endolymphatic hydrops which until 2007 could be diagnostically confirmed only by post-mortem histology. In the past, various attempts to formulate clinical diagnostic criteria have been undertaken but were hampered by the inability to ascertain the diagnosis in living patients. With the milestone achievement of endolymphatic hydrops imaging, today the pathology can be ascertained. In this study, we have performed a detailed analysis of the clinical features of hydropic ear disease for the first time by examining a large cohort of patients with morphologically confirmed endolymphatic hydrops using a detailed physician-administered neurotologic face-to-face interview.

RESULTS

During a hydropic vertigo attack, the patients report nausea, vomiting, sweating, urge to defecate, urge to urinate, phosphenes, headache, photophobia, phonophobia and even transient loss of consciousness. A third of the patients does not experience auditory symptoms during the vertigo attacks. Vertigo attacks last less than 20 min in more than one-fourth of the patients. Audiometric hearing loss has its greatest diagnostic value at the frequencies of 1 kHz and below. Cochleovestibular symptom onset simultaneity is associated with a high frequency of drop-attacks. Migraine and autoimmune disorders are not associated with hydropic ear disease.

CONCLUSION

This study marks the beginning of the clinical characterization of hydropic ear disease. The findings have important implications for the future formulation of clinical diagnostic criteria.

Vestibular Schwannoma and Ipsilateral Endolymphatic Hydrops: An Unusual Association

Vestibular schwannoma and endolymphatic hydrops are two conditions that may present with similar audio-vestibular symptoms. The association of the two in the same patient represents an unusual finding that may lead clinicians to errors and delays in diagnosis and clinical management of affected subjects. We discuss the case of a patient with an intrameatal vestibular schwannoma reporting symptoms suggestive for ipsilateral endolymphatic hydrops. The patient presented with fluctuating hearing loss, tinnitus, and acute rotatory vertigo episodes, and underwent a full audiological evaluation and imaging of the brain with contrast-enhanced Magnetic Resonance Imaging. Clinical audio-vestibular and radiological examination confirmed the presence of coexisting vestibular schwannoma and endolymphatic hydrops. Hydrops was treated pharmacologically; vestibular schwannoma was monitored over time with a wait and scan protocol through conventional MRI. The association of vestibular schwannoma and endolymphatic hydrops is rare, but represents a possible finding in clinical practice. It is therefore recommended investigating the presence of inner ear disorders in patients with vestibular schwannoma and, similarly, to exclude the presence of this condition in patients with symptoms typical of inner ear disorders.

Treatment of ear and bone disease in the Phex mouse mutant with dietary supplementation

HYPOTHESIS

Phosphorus and vitamin D (calcitriol) supplementation in the Phex mouse, a murine model for endolymphatic hydrops (ELH), will improve otic capsule mineralization and secondarily ameliorate the postnatal development of ELH and sensorineural hearing loss (SNHL).

BACKGROUND

Male Phex mice have X-linked hypophosphatemic rickets (XLH), which includes osteomalacia of the otic capsule. The treatment for XLH is supplementation with phosphorus and calcitriol. The effect of this treatment has never been studied on otic capsule bone and it is unclear if improving the otic capsule bone could impact the mice's postnatal development of ELH and SNHL.

METHODS

Four cohorts were studied: 1) wild-type control, 2) Phex control, 3) Phex prevention, and 4) Phex rescue. The control groups were not given any dietary supplementation. The Phex prevention group was supplemented with phosphorus added to its drinking water and intraperitoneal calcitriol from postnatal day (P) 7-P40. The Phex rescue group was also supplemented with phosphorus and calcium but only from P20 to P40. At P40, all mice underwent auditory brainstem response (ABR) testing, serum analysis, and temporal bone histologic analysis. Primary outcome was otic capsule mineralization. Secondary outcomes were degree of SNHL and presence ELH.

RESULTS

Both treatment groups had markedly improved otic capsule mineralization with less osteoid deposition. The improved otic capsule mineralized did not prevent the development of ELH or SNHL.

CONCLUSION

Supplementation with phosphorus and calcitriol improves otic capsule bone morphology in the Phex male mouse but does not alter development of ELH or SNHL.

In Vivo Visualization of Endolymphatic Hydrops in Guinea Pigs: Magnetic Resonance Imaging Evaluation at 4.7 Tesla

In order to find out whether it is possible to visualize experimental endolymphatic hydrops in the cochlea with magnetic resonance imaging (MRI) at 4.7 T, we used 11 guinea pigs. Five normal guinea pigs were used as controls. Early manifestation of endolymphatic hydrops was evaluated in endolymphatic sac (ES)-intact animals (n = 6), and advanced manifestation in ES-damaged animals (n = 5) by means of MRI with gadolinium-diethylenetriaminepentaacetate-bismethylamide (Gd-DTPA-BMA) contrast agent. Hearing was tested with electrocochleography. The surface area of 3 partitions of the cochlea was used to quantify endolymphatic hydrops. The fine structure of the 3 partitions of the cochlea was visualized with MRI in all animals, as Gd-DTPA-BMA appeared mainly in the scala tympani and scala vestibuli. As early as 5 days after endolymphatic sac surgery, endolymphatic hydrops started to appear as visualized by MRI and also verified with histology. Severe damage to the inner ear barrier with Gd-DTPA-BMA leakage into the scala media was detected with MRI in 1 ES-damaged animal that had a 60-dB hearing loss. To conclude, endolymphatic hydrops can be visualized with high-resolution MRI by means of Gd-DTPA-BMA, and it is possible to quantify the extent of endolymphatic hydrops. Damage to the inner ear barrier or possible rupture of membranes can be shown with the assistance of Gd-DTPA-BMA.

Vestibular Evoked Myogenic Potentials and Distortion-Product Otoacoustic Emissions Combined with Glycerol Testing in Endolymphatic Hydrops: Their Value in Early Diagnosis

The present investigation was specifically designed to evaluate the ability of the glycerol test combined with pure tone audiometry, distortion-product otoacoustic emissions (DPOAEs), and vestibular evoked myogenic potentials (VEMPs) to diagnose endolymphatic hydrops early and to identify cases that may evolve toward Meniere's disease. This investigation consisted of 29 consecutive patients with mild dizziness or vertigo who received no treatment. Each patient underwent glycerol testing measured with conventional pure tone audiometry and with both DPOAEs and VEMPs. It is interesting to note that in 7 and 8 of the 29 cases, the VEMPs and DPOAEs, respectively, showed an improvement after glycerol administration that had not been shown on traditional audiometry. A further element worthy of consideration emerges from an analysis of the VEMP results compared to the DPOAE results that divided the patients into 4 groups. The first group had a postglycerol improvement with both methods, which would seem to suggest hydrops in both the anterior and posterior parts of the labyrinth. In the second and third groups, there was an improvement only either with VEMPs or DPOAEs, and this finding seems to indicate that only one endolymphatic compartment might be involved. In the last group, all patients had a positive glycerol test with positive DPOAEs on one side and with positive VEMPs on the other. Although endolymphatic hydrops can only be proven after death, a combination of VEMPs and DPOAEs with the glycerol test may permit early diagnosis of endolymphatic hydrops. These results clearly imply that these methods should be permanently included in the diagnostic protocol of patients with vestibular and audiological symptoms.

Perilymphatic Fistula and Meniere's Disease

There continues to be considerable confusion concerning the diagnosis and treatment of perilymphatic fistulas (PLFs) and Meniere's disease. This paper reports an 8-year experience with patients whose symptoms were compatible with Meniere's disease but who had some other element that raised the possibility of their having a PLF. This review is a retrospective report on 64 patients who had fluctuating hearing loss, vertigo, tinnitus, and aural fullness typical of Meniere's disease. However, they also had a positive fistula test and/or symptoms beginning immediately after head trauma. They all underwent at least a unilateral PLF repair, and some also underwent an endolymphatic sac–mastoid shunt operation. This report provides a literature review to help put this series' results into perspective. Of those 40 patients who underwent an initial PLF repair, 58% had a successful outcome. Of the 10 patients who underwent an initial PLF repair plus an endolymphatic sac–mastoid shunt, 70% had a successful outcome. Since it is often difficult to distinguish patients with PLFs and secondary endolymphatic hydrops (Meniere's syndrome) from patients with Meniere's disease (idiopathic endolymphatic hydrops), PLF repair is a reasonable first operation, reserving an endolymphatic sac–mastoid shunt operation as a secondary procedure if needed. The decision to consider a PLF repair is guided by a positive fistula test or an immediate onset of Meniere's disease symptom complex after head or ear trauma.

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.

[Preliminary application of video head impulse test in the diagnosis of vertigo]

OBJECTIVE

To investigate clinical application of head impulse test with video recording eye movements in the diagnosis of vertigo.

METHOD

The video head impulse test(vHIT) was used to measure the eye saccades and velocity gain in 95 patients with vertigo which were divided into two groups, peripheral vertigo (47 cases) and central vertigo(48 cases); the characteristics of eye saccades and velocity gain of six semicircular canals in different patients with vertigo were analyzed, and were compared between the two groups.

RESULT

The vHIT result in patients with peripheral vertigo: in 22 patients (23 affected ears) with Meniere's disease, 21 ears were abnormal (91. 3%); the vHIT results in 4 patients with vestibular schwannoma, 2 patients with vestibular neuritis, 5 patients with delayed endolymphatic hydrops, 6 patients with sudden hearing loss accompanied vertigo, and 8 patients with vestibular dysfunction, were abnormal with correct saccades and/or lower velocity gain of vHIT. The abnormal vHIT results were also found in 35 of 48 patients (72. 9%) with central vertigo, which including posterior cerebral circulation ischemia(7 patients), cerebral infarction/stroke(6 patients), and dizziness with vertigo(17 patients) and others(18 patients). Abnormal rate of vHIT in patients with peripheral vertigo was 95. 7% (45/47), which was significantly higher than that (72. 9%) in patients with central vertigo.

CONCLUSION

It is easy to perform the vHIT which without adverse reactions. We can record high-frequency characteristics of vestibular-ocular reflex among six semicircular canals through vHIT. The vHIT results which show the function of vestibular ocular reflex in different diseases with vertigo, can help discriminate peripheral vertigo from central vertigo, and it is a practical assessment method for vertigo.

Frequency preference in cervical vestibular evoked myogenic potential of idiopathic otolithic vertigo patients. Does it reflect otolithic endolymphatic hydrops?

CONCLUSION

Idiopathic otolithic vertigo (IOV) with relatively long duration of attacks might be caused by endolymphatic hydrops in the otolith organ.

OBJECTIVES

To clarify the pathophysiology underlying IOV, episodic tilting or translational sensation attacks by unknown causes, especially the possibility of endolymphatic hydrops in the otolith organ.

METHODS

Sixteen patients (6 men and 10 women) diagnosed with having IOV were enrolled. In these subjects, frequency preference in cervical vestibular evoked myogenic potential (cVEMP) was studied. The subjects underwent cVEMP testing using 500 Hz and 1000 Hz short tone bursts (STB) (125 dB SPL, air-conducted sound). The 500-1000 Hz cVEMP slope was calculated and assessed in comparison with data from healthy subjects in the preceding study.

RESULTS

Twelve of the 16 examined patients had a significant preference of 1000 Hz to 500 Hz, which was suggestive of endolymphatic hydrops in the saccule. Patients with frequency preference of 1000 Hz to 500 Hz showed a tendency for longer vertigo attacks than patients without preference of 1000 Hz.

Gadolinium contrast-enhanced MRI reveals cystic lateral semicircular canal contents

CONCLUSION

Contrast-enhanced magnetic resonance imaging (MRI) reveals variations in the endolymphatic morphology of the cystic lateral semicircular canal (CLSC) that correlate with inner ear function. This report is the first to suggest a relationship between the morphology and function of this common inner ear malformation in clinical cases.

OBJECTIVES

This study investigated the radiological and functional findings of a common inner ear malformation using computed tomography (CT), gadolinium contrast-enhanced magnetic resonance imaging (MRI), caloric testing, and cervical and ocular vestibular evoked myogenic potential (VEMP) testing.

METHOD

Four ears in three patients who were radiologically diagnosed with a CLSC and a normal cochlea on high-resolution CT and contrast-enhanced MRI were included. Semicircular canal and vestibular functions were analyzed using the caloric test and cervical and ocular VEMP testing.

RESULTS

Unilateral and bilateral cystic canals were found in two and one patients, respectively. In the first patient, the malformed vestibule and cystic space were separate on imaging, and perilymph filled the cystic space. The functional test results were normal. In the second patient, endolymph filled both cystic spaces, and the functional responses were poor. In the third patient, endolymph filled the cystic space, and the ear did not respond during functional testing.

Detection and grading of endolymphatic hydrops in Menière disease using MR imaging

BACKGROUND AND PURPOSE

Endolymphatic hydrops has been recognized as the underlying pathophysiology of Menière disease. We used 3T MR imaging to detect and grade endolymphatic hydrops in patients with Menière disease and to correlate MR imaging findings with the clinical severity.

MATERIALS AND METHODS

MR images of the inner ear acquired by a 3D inversion recovery sequence 4 hours after intravenous contrast administration were retrospectively analyzed by 2 neuroradiologists blinded to the clinical presentation. Endolymphatic hydrops was classified as none, grade I, or grade II. Interobserver agreement was analyzed, and the presence of endolymphatic hydrops was correlated with the clinical diagnosis and the clinical Menière disease score.

RESULTS

Of 53 patients, we identified endolymphatic hydrops in 90% on the clinically affected and in 22% on the clinically silent side. Interobserver agreement on detection and grading of endolymphatic hydrops was 0.97 for cochlear and 0.94 for vestibular hydrops. The average MR imaging grade of endolymphatic hydrops was 1.27 ± 0.66 for 55 clinically affected and 0.65 ± 0.58 for 10 clinically normal ears. The correlation between the presence of endolymphatic hydrops and Menière disease was 0.67. Endolymphatic hydrops was detected in 73% of ears with the clinical diagnosis of possible, 100% of probable, and 95% of definite Menière disease.

CONCLUSIONS

MR imaging supports endolymphatic hydrops as a pathophysiologic hallmark of Menière disease. High interobserver agreement on the detection and grading of endolymphatic hydrops and the correlation of MR imaging findings with the clinical score recommend MR imaging as a reliable in vivo technique in patients with Menière disease. The significance of MR imaging detection of endolymphatic hydrops in an additional 22% of asymptomatic ears requires further study.

Evidence for bilateral endolymphatic hydrops in ipsilateral delayed endolymphatic hydrops: preliminary results from examination of five cases

CONCLUSION

After the administration of a standard dose of gadodiamide, an intravenous gadolinium-based contrast agent (GBCA), magnetic resonance imaging (MRI) evaluation of endolymphatic hydrops (EH) became possible in patients with ipsilateral delayed endolymphatic hydrops (DEH). We found that patients with ipsilateral DEH may also have bilateral EH.

OBJECTIVE

MRI evaluation contributes to understanding of the pathological conditions in patients with EH. However, double or triple the standard dose of GBCA is often required to obtain images of high quality. We attempted to examine EH bilaterally in patients with ipsilateral DEH after routine administration of an intravenous GBCA.

METHODS

GBCA (gadodiamide, 0.2 ml/kg) was administered intravenously to five patients with ipsilateral DEH. Three-dimensional fluid attenuated inversion recovery (3D-FLAIR) MRI was performed with a 3-T MRI scanner 4 h after GBCA administration.

RESULTS

In all five patients, EH was observed in the affected vestibules. Moreover, EH was observed bilaterally in four (80%) of five patients with ipsilateral DEH. The region of the deaf ear affected by EH was considerably larger compared with the normal ear in three patients. However, observed regions of EH were of approximately the same size in both ears in patients 4 and 5.

Secondary endolymphatic hydrops after sudden deafness

CONCLUSION

Patients with sudden deafness who had abnormal ocular vestibular-evoked myogenic potential (oVEMP)/cervical VEMP (cVEMP) responses but retained caloric function may subsequently develop secondary hydrops with a mean interval of 8 years.

OBJECTIVE

This study applied the inner ear test battery in patients who had sudden deafness previously to elucidate how secondary endolymphatic hydrops occurs years after sudden deafness.

METHODS

Twenty patients who had experienced recent vertiginous attacks several years after sudden deafness (group A) and 20 patients without rotational vertiginous episode for at least 5 years following sudden deafness (group B) were enrolled. All patients underwent an inner ear test battery comprising audiometry, caloric test, and oVEMP and cVEMP tests.

RESULTS

The mean interval from initial sudden deafness to vertiginous attack in group A was 8 years, with a mean hearing level of 66 ± 20 dB, which did not significantly differ from 61 ± 20 dB in group B. For the vestibular test results, the percentages of abnormal cVEMP, oVEMP, and caloric tests in group A were 65%, 70%, and 25%, respectively. Compared to the respective 70%, 60%, and 75% abnormalities in group B, only the caloric test differed significantly.

Changes in endolymphatic hydrops after sac surgery examined by Gd-enhanced MRI

CONCLUSION

Endolymphatic hydrops could be a reversible inner ear pathological condition. After sac surgery, hydrops was reduced and symptoms went into remission in some cases, although vertigo suppression was not always a result of the reduced hydrops.

OBJECTIVE

To examine the changes in endolymphatic hydrops detected by gadolinium (Gd) contrast-enhanced magnetic resonance imaging (MRI) before and 6 months after endolymphatic sac surgery in patients with unilateral Ménière's disease.

METHODS

Fluid-attenuated inversion recovery MRI was obtained 4 h after intravenous administration or 24 h after intratympanic administration of Gd contrast medium. An enlarged negative stain corresponding to the cochlear duct and endolymphatic space of the vestibule was assessed as hydrops.

RESULTS

Of seven patients with hydrops confirmed by MRI before surgery, both cochlear and vestibular hydrops became negative in two, cochlear hydrops became negative in one, both hydrops were present, but reduced, in one, and there was no change in three patients. The number of vertigo spells was reduced in all cases at 6-12 months after surgery. As for the three cases of negative hydrops, vertigo was completely suppressed. In two cases in which hearing level improved, hydrops became negative after surgery.

[Visualization of endolymphatic hydrops in 3D-FLAIR MRI after intratympanic Gd-DTPA administration in Meniere's disease patients]

OBJECTIVE

To study the feasibility of endolymphatic visualization and the diagnosis of Meniere's disease by applying intratympanic gadolinium administration through the tympanic membrance and three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI). To study the relationship between the endolymphatic hydrops visualized by MRI and audio-vestibular functional tests, such as pure tone audiometry (PTA), electrocochleography (EcoG), caloric test and vestibular evoked myogenic potential (VEMP).

METHODS

With a three Tesla magnetic resonance imaging (MRI) unit, 3D-FLAIR imaging was performed 24 hours after intratympanic gadolinium through the tympanic membrance in 32 patients with clinically diagnosed unilateral Meniere's Disease. We visualized the enhanced imaging of perilymphatic space in bilateral cochlea, vestibular and (or) canal, scoring scala tympani and scala vestibule of bilateral cochlear basal turn respectively and measuring the developing area of bilateral vestibule and the signal intensity ratio (SIR) between the vestibule and the brain stem subjectively. PTA, EcoG, caloric test and VEMP were performed. The relationship between the endolymphatic hydrops visualized by MRI and audio-vestibular functional tests were studied.

RESULTS

The gadolinium appeared in almost all parts of the perilymph in cochlea, vestibular and (or) canals in all 32 patients' inner ears, so the endolymphatic space was clearly shown on 3D-FLAIR imaging. The scala vestibuli score value between the affected side and the healthy side were statistically significant (Z = 4.309, P < 0.05) . The developing vestibular area between the affected side and the healthy side [(6.04 ± 2.89) mm(2), (8.28 ± 3.04)mm(2)] were statistically significant (t = 3.322, P < 0.05) . Abnormal vestibular evoked myogenic potentials were significantly correlated with the developing vestibular area of the affected side (F = 11.96, P < 0.05) . Abnormal electrocochleography were significantly correlated with scala vestibuli score value of cochlear basal turn in the affected side (Z = 3.17, P < 0.05) . No significant correlation was found between the scala vestibuli score value or the developing vestibular area and caloric test or PTA findings.

CONCLUSIONS

3D-FLAIR MRI with intratympanic gadolinium injection through the tympanic membrance can discriminate the border between the perilymph and the endolymph and show endolymphatic hydrops. This method may provide radiographic reference for the diagnosis of Meniere's disease. The results of VEMP and electrocochleography might have appropriate correlation with degree of vestibular and cochlear hydrops.

Magnetic resonance imaging of the inner ear after both intratympanic and intravenous gadolinium injections

CONCLUSION

Using magnetic resonance imaging (MRI), endolymphatic hydrops could be visualized on both sides after intratympanic (IT) injection of gadolinium contrast agents (Gd) in one symptomatic ear and subsequent intravenous (IV) Gd injection. The MRI revealed a difference of intracochlear Gd distribution between the IT injection side and the contralateral IV side.

OBJECTIVES

Although the IT method allows greater enhancement of the perilymph, many patients feel reluctance in receiving the IT injection in asymptomatic ears. We attempted to evaluate endolymphatic space size on both sides without the IT injection in asymptomatic ears.

METHODS

In 10 patients with Meniere's disease, MRI was performed 24 h after the IT Gd injection in one symptomatic ear and 4 h after the IV Gd injection. The signal intensity of Gd in the basal and apical turns of the cochlea was evaluated.

RESULTS

The signal intensity in the scala tympani of the basal turn of the cochlea was 1.70 ± 0.60 on the IT + IV side and 0.42 ± 0.10 on the contralateral (IV) side. Gd was distributed uniformly in the scala tympani in the cochlea on the IV side, whereas it was strongly localized in the basal turn on the IT + IV side.

Endolymphatic hydrops revealed by magnetic resonance imaging in patients with atypical Meniere's disease

CONCLUSION

Our study showed that patients with atypical Meniere's disease had endolymphatic hydrops (EH) in both the cochlea and the vestibule. Using an imaging method, we provide evidence that atypical Meniere's disease is a true variant of classic Meniere's disease.

OBJECTIVES

The aim of present study was to investigate images of the endolymphatic space in patients with atypical Meniere's disease (cochlear and vestibular Meniere's disease).

METHODS

Sixty-four patients divided into two groups were enrolled in this study. The first group included 36 patients who had fluctuating hearing loss without vertigo, as candidates for cochlear Meniere's disease (CMD). The second group included 28 patients who had recurrent vertigo without hearing loss, as candidates for vestibular Meniere's disease (VMD). The patients underwent 3 T magnetic resonance imaging (MRI) after injection of gadolinium enhancement medium intratympanically or intravenously. We evaluated EH using MRI.

RESULTS

Of 56 ears (36 patients) with CMD, 38 showed EH in the cochlea and 44 showed EH in the vestibule. Of 56 ears (28 patients) with VMD, 29 showed EH in the cochlea and 47 showed EH in the vestibule. The VMD group had a significant vestibular predominance in EH distribution whereas the CMD group showed no significant regional predominance of EH.

[Diagnostics of endolymphatic hydrops]

The objective of the present work was to analyse the methods for diagnostics of endolymphatic hydrops associated with Miniere's disease most frequently employed in clinical practice using both the data from the world scientific literature and our own 25-30 year experience based on the observation of more than 500 patients. Camertonal studies of hearing acuity estimated from the results of air conduction measurements and relevant acoumetric curves were considered. The main methods of research are discussed including such as tonal threshold audiometry, ultrasound testing, loud sound lateralization, dehydration test, extratympanic electrocochleography, otoacoustic emission, and functional computed stabilometry. It is concluded that none of the above methods is as reliable as to yield the comprehensive information being sought. All the data obtained by the application of these techniques need to be supplemented by the medical history data, the patients' complaints, clinical signs and symptoms of the disease if the definitive diagnosis of endolymphatic hydrops is to be made.

Study of cochlear hydrops analysis masking procedure in patients with Meniere's disease and otologically normal adults

BACKGROUND

The cochlear hydrops analysis masking procedure (CHAMP) is a new diagnostic technique for Meniere's disease (MD). But its value has not been well proven. This study aimed to evaluate the diagnostic value of CHAMP for MD.

METHODS

CHAMP test was taken in three populations using the Auditory Evoked Potential system delivered by Bio-logic Systems Corporation: (1) otologically normal subjects; (2) patients clinically diagnosed with definite MD; (3) patients clinically diagnosed with probable and possible MD.

RESULTS

According to the comparison between the normal and definite MD group, if the abnormal criterion of CHAMP was defined as latency delay less than 0.3 ms, then the corresponding sensitivity was only 52%. However, if the abnormal criterion was defined as latency delay between 0.6 and 3.8 ms, then a sensitivity of 93% and a specificity of 100% can be achieved. The complex amplitude ratio showed a significant overlap between normal and definite MD group. If the abnormal criterion was defined as a complex amplitude ratio less than 0.95, the corresponding specificity was only 50%. However, if the abnormal criterion was defined as less than 0.80, the corresponding sensitivity was 60%, and the specificity was 97%. If the abnormal criterion of CHAMP was defined as latency delay less than 0.6 ms or the complex amplitude ratio less than 0.80, CHAMP result can be obtained in all subjects with good sensitivity and specificity.

CONCLUSIONS

CHAMP can differentiate patients with Meniere's disease from otologically normal subjects with high sensitivity and specificity. The recommended criterion of abnormal CHAMP was a latency delay less than 0.6 ms or a complex amplitude ratio less than 0.80.

Analysis of auditory and vestibular function in patients with unilateral Meniere's disease

CONCLUSION

The percentage of the unilateral weakness of the caloric response also reflects the clinical progress of Meniere's disease (MD), including clinical hearing loss.

OBJECTIVE

To evaluate the relationship between hearing status and vestibular function in patients with MD.

METHODS

Seventy-nine patients with unilateral definite MD underwent bithermal air caloric testing, vestibular evoked myogenic potential (VEMP) testing, and pure tone audiometry (PTA). The stages of the disease, clinical hearing level of the diseased ears, and dPTA (the difference in hearing level between ears in each patient) were compared with the percentage of the unilateral weakness of the caloric response and the interaural amplitude difference (IAD) ratio of the VEMP response.

RESULTS

Twenty ears (25.3%) revealed normal caloric responses and 59 ears (74.7%) showed reduced caloric responses. Testing revealed that the VEMPs were normal in 49 ears (62%), while 30 ears (38%) had abnormal VEMPs. The percentage of the unilateral weakness of the caloric response was positively correlated with the clinical hearing level of the diseased ears (p = 0.006) and the dPTA (p = 0.013).

Endolymphatic space imaging in idiopathic sudden sensorineural hearing loss with vertigo

OBJECTIVES/HYPOTHESIS

To investigate endolymphatic space images in patients with idiopathic sudden sensorineural hearing loss (ISNHL) and vertigo using three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI).

STUDY DESIGN

This is a prospective study of an analysis using the imaging technology of 3D-FLAIR MRI for patients with ISNHL and vertigo.

METHODS

3D-FLAIR MRI was performed 24 hours after intratympanic injection of gadolinium-diethylenetriamine penta-acetic acid.

RESULTS

In four of seven cases of ISNHL with vertigo, endolymphatic hydrops were confirmed in the cochlea and/or the vestibule of the affected ears.

CONCLUSIONS

The results of the study imply that there may be some relationship between endolymphatic hydrops and ISNHL with vertigo.

Contrast enhancement of the inner ear in magnetic resonance images taken at 10 minutes or 4 hours after intravenous gadolinium injection

CONCLUSION

Contrast enhancement of the inner ear by three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI) taken 4 h after intravenous gadolinium (Gd) injection was better than when taken at 10 min. Using heavily T2-weighted 3D-FLAIR MRI, visualization of endolymphatic hydrops (EH) was possible in the vestibule and the cochlea after a standard intravenous dose of Gd.

OBJECTIVES

To define a suitable time point for imaging Gd uptake in the inner ear acquired with heavily T2-weighted 3D-FLAIR MRI after standard intravenous Gd administration.

METHODS

Using a 3 Tesla MRI unit, heavily T2-weighted 3D-FLAIR MRI images were taken twice at approximately 10 min (conventional timing) and 4 h after intravenous gadodiamide (0.1 mmol/kg) injection in 10 patients with inner ear diseases including Ménière's disease.

RESULTS

The 4 h delay increased Gd enhancement of the 3D-FLAIR MRI images of the perilymphatic space in both symptomatic and asymptomatic ears. The increase in Gd enhancement was greater in symptomatic than in asymptomatic ears. Using this heavily T2-weighted 3D-FLAIR technique, EH was observed in both the cochlea and vestibule in images taken 4 h after the intravenous Gd injection.

Meniere's disease: new concepts, new treatments

Our understanding of Meniere's disease is being revamped. For decades, the condition was thought to be caused by excessive fluid retention (hydrops) in the endolymphatic spaces of the inner ear, which led to tears or ruptures of the membranous structures that affect hearing and balance. More recently, research has shown that hydrops is not always associated with Meniere's and ought not to be considered the ultimate cause of its symptoms. New theories center on the fact that Meniere's disease may not have a single cause but may well be a common endpoint of a variety of anatomic or physiologic variables, including ischemic or even autoimmune injuries. This article describes the new thinking about Meniere's and explains why current treatment approaches, although they are based on outdated understanding, may still be valuable for alleviating symptoms in some patients.

Endolymphatic sac tumor with overexpression of V2 receptor mRNA and inner ear hydrops

CONCLUSION

We reported previously that hyperactivation of vasopressin type-2 receptor (V2R)-mediated signaling in the endolymphatic sac could affect endolymphatic fluid metabolism, resulting in the pathogenesis of endolymphatic hydrops. Taken together with the present endolymphatic sac tumor (ELST) study, it is suggested that disorder of V2R signaling in the endolymphatic sac for any reason could be involved in the pathogenesis of endolymphatic hydrops. Although it is due to tumor genesis in ELST, it is idiopathic in nature in Meniere's disease.

OBJECTIVE

We encountered two cases of ELST showing Meniere's disease-like symptoms. Both cases were suspected of having endolymphatic hydrops using neuro-otological examinations. To clarify the histopathological diagnosis of ELST and the molecular pathogenesis of endolymphatic hydrops, we performed histopathological and molecular biological examinations of the endolymphatic sac.

METHODS

ELSTs in two rare cases were removed completely through the transmastoidal approach. V2R mRNA expression was examined using real-time PCR.

RESULTS

The first case was diagnosed as inflammatory granulation adjacent to the endolymphatic sac, i.e. pseudo-ELST, and the second case was diagnosed as papillary adenoma of ELST. V2R mRNA expression was up-regulated in the endolymphatic sac of both cases as seen in Meniere's disease compared with controls.

Vasopressin in definite Meniere's disease with positive electrocochleographic findings

CONCLUSION

There was no evidence of a mean raised vasopressin level in 80 subjects suffering from definite Meniere's disease with positive electrocochleographic findings. There was no correlation with stress. The only group with a mildly raised level comprised those who had had a vertigo attack within a day. The most likely cause is nausea, which is the most potent trigger for vasopressin release.

OBJECTIVE

It has been claimed that patients with Meniere's disease have raised vasopressin levels. This has been linked with a long-standing notion that that there is a link between stress and Meniere's disease, so that an increase in vasopressin could trigger a vertigo attack.

METHODS

Serum vasopressin concentrations were measured in 80 patients with Meniere's disease whose diagnosis was based on conventional symptom criteria plus electrocochleographic evidence of endolymphatic hydrops.

RESULTS

The community mean for vasopressin is 2.2 pmol/L (SD = 2.4). For all 80 Meniere's patients the mean vasopressin concentration was 2.1 pmol/L (SD = 1.6), and 2.8 pmol/L (SD = 0.9) when the last attack was within a day.

Endolymphatic hydrops in Meniere's disease detected by MRI after intratympanic administration of gadolinium: comparison with sudden deafness

CONCLUSION

The detection rate of endolymphatic hydrops was significantly higher in patients with Meniere's disease compared with those with sudden deafness, indicating that 3 T magnetic resonance imaging (MRI) with intratympanic gadolinium injection was effective in diagnosing endolymphatic hydrops.

OBJECTIVES

To compare the detection rate of endolymphatic hydrops between patients with Meniere's disease and sudden deafness as controls by 3 T MRI after intratympanic gadolinium injection with conventional pulse sequence such as two-dimensional fluid-attenuated inversion recovery.

METHODS

Ten patients with unilateral Meniere's disease and eight with sudden deafness underwent inner ear MRI 24 h after intratympanic gadolinium injection.

RESULTS

The endolymphatic space was detected as a low signal intensity area, while the perilymphatic space showed high intensity by gadolinium enhancement. Due to faint enhancement, images could not be evaluated in 1 of 10 patients with Meniere's disease. However, the other nine patients together with two of the eight with sudden deafness were diagnosed as having hydrops. The difference in detection rates between the two diseases was statistically significant. Two hydrops-positive cases with sudden deafness were considered to be of the secondary type of hydrops, because images were taken after partial recovery from hearing loss several months after the onset of the disease.

Visualization of endolymphatic hydrops after administration of a standard dose of an intravenous gadolinium-based contrast agent

CONCLUSION

Even after the administration of a standard dose of an intravenous gadolinium-based contrast agent (GBCA), visualization of endolymphatic hydrops (ELH) became possible in patients with Meniere's disease. The next step would be to consistently visualize ELH in the upper part of the cochlea.

OBJECTIVE

To visualize ELH after routine administration of an intravenous GBCA.

METHODS

An intravenous GBCA (gadodiamide; 0.2 ml/kg) was administered to three patients with unilateral Meniere's disease and two healthy volunteers. Three-dimensional fluid attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI) was performed with a 3 T MRI scanner 4 h later.

RESULTS

In all three patients, ELH was observed in the affected vestibules. In contrast, the endolymphatic space of both vestibules was the same size in healthy volunteers. ELH of the cochlea was not observed in any of the subjects. Gadolinium enhancement was insufficient in the upper turns of both cochleae in patients 1 and 3.

[Study of characteristic of the cochlear hydrops analysis masking procedure in normal adults]

OBJECTIVE

To study the characteristic of the cochlear hydrops analysis masking procedure (CHAMP) in normal adults, and to evaluate the diagnostic values of its parameters for membranous labyrinth hydrops.

METHODS

Twenty otologically normal adults were recruited (male:female = 10:10), and their auditory brainstem responses (ABR) were obtained to six stimulus conditions using Bio-logic auditory evoked potential system: clicks presented alone (unmasked condition) and clicks presented with ipsilateral pink noise high-pass filtered at 8, 4, 2, 1, and 0.5 kHz respectively.

RESULTS

The wave V latency of ABR to the high-pass masking pink noise clicks were longer than ABR to clicks alone. The latency delays of wave V for clicks presented with ipsilateral pink noise high-pass filtered at 8, 4, 2, 1, and 0.5 kHz compared to clicks alone were (0.30 ± 0.18), (0.97 ± 0.43), (1.65 ± 0.64), (3.21 ± 0.56), (4.66 ± 0.37) ms respectively. The complex amplitude ratio between ABR to click + 0.5 kHz high-pass noise and click alone was 0.95 ± 0.11.

CONCLUSIONS

CHAMP is a promising diagnostic method for membranous labyrinth hydrops, and the latency delay of wave V might be used as the normal criterion. The specificity of the complex amplitude ratio need further evaluation in clinical work.

[Epidemiological characteristic of the patients presenting with cochleovestibular disorders associated with labyrinthine hydrops]

A total of 1,067 patients complaining of hearing impairment, dizziness, and tympanophony were admitted for the treatment to the Surdological Department of N.I. Pirogov City Clinical Hospital No 1 during the period from 2000 to 2010. As many as 326 (30.5%) patients were preliminarily diagnosed with Meniere's disease based on their medical histories, clinical condition, and the results of questionnaire studies. All of them were subjected to comprehensive audiologic and vestibulogic examination with the use of up-to-date techniques. The data thus obtained allowed to reveal labyrinthine hydrops in 275 (84%) patients. It is concluded that 101 (9.5%) patients presenting with the typical symptoms of Meniere's disease had labyrinthine hydrops.

A comparison of three methods of using transtympanic electrocochleography for the diagnosis of Meniere's disease: click summating potential measurements, tone burst summating potential amplitude measurements, and biasing of the summating potential using a low frequency tone

CONCLUSION

Stimulus biasing modulated the amplitude of the tone burst evoked summating potential (SP) in ears affected by Meniere's disease less than in normal ears. A reduced SP bias ratio added diagnostic accuracy for the diagnosis of Meniere's disease.

OBJECTIVES

To evaluate the effect of stimulus biasing on the human tone burst SP, and to determine if stimulus biasing could contribute to the electrocochleography as a means of confirming the diagnosis of Meniere's disease.

PATIENTS AND METHODS

Patients referred for transtympanic electrocochleography (TT ECochG) were assessed prospectively on clinical grounds according to the AAO-HNS criteria and a scale devised by one of the authors. A Meniere's group of ears and a non-Meniere's group of ears was determined. The ears opposite a Meniere's ear were not included in the analysis. The ratio of the click SP amplitude and the action potential (AP) amplitude (SP/AP ratio), the tone burst SP amplitude at 500 Hz,1 kHz, 2 kHz and 8 kHz, and the effect of stimulus biasing on the tone burst SP were measured.

RESULTS

A unipolar stimulus biasing ratio established for the modulation of the 1 kHz tone burst SP separated the Meniere's ears from the non-Meniere's ears with a sensitivity of 85% at a specificity of 80.6% and the difference between groups reached statistical significance (p=0.016). The 1 kHz SP amplitude measurements and the stimulus biasing measurements were superior to the click SP/AP ratio for identifying the Meniere's group. A combination of 1 kHz SP amplitude measurements and SP bias ratio separated the Meniere's ears from the non-Meniere's ears with an accuracy of 85%.

3 Tesla magnetic resonance imaging obtained 4 hours after intravenous gadolinium injection in patients with sudden deafness

CONCLUSION

3 Tesla (3T) magnetic resonance imaging (MRI) performed 4 h after intravenous gadolinium (Gd) injection provides sufficient anatomic resolution of the inner ear fluid spaces in sudden deafness. The signal intensity ratio (SIR) between the cochlea and cerebellum may be a good indicator of disruption of the blood-labyrinthine barrier.

OBJECTIVES

We evaluated the inner ear 4 h after intravenous Gd injection to determine whether 3T MRI enables the acquisition of images of the affected inner ear in sudden deafness.

METHODS

Ten patients underwent 3T MRI scanning 4 h after intravenous Gd injection. Three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) MRI was performed.

RESULTS

The SIR varied from 0.45 to 2.17 in 11 affected ears and from 0.43 to 1.48 in 9 unaffected ears. The difference of contrast (affected ear vs unaffected ear) could be detected in five of the nine patients with unilateral sudden deafness. The Gd distribution was recognized in the vestibule of 10 affected ears and in the cochlea of 5 affected ears, in which no significant hydrops was observed. In the remaining vestibules and cochleas of affected ears, the Gd enhancement was too faint to evaluate the endolymphatic hydrops.