Relationship between video head impulse test, ocular and cervical vestibular evoked myogenic potentials, and compartmental magnetic resonance imaging classification in menière's disease

The effect of delay time after injecting gadobutrol on the diagnosis of endolymphatic hydrops

OBJECTIVES

The aim of this study was to reduce the time delay between gadolinium injection and 3D-FLAIR (three-dimensional fluid-attenuated inversion recovery) MRI by using a single dose of intravenous gadobutrol in Menière's disease patients.

METHODS

17 patients diagnosed with definite unilateral Meniere's disease underwent 3D-FLAIR MRI scans at 2, 4, and 6 h post-intravenous administration of a single-dose of gadobutrol. The signal intensity ratio of bilateral inner ear, cochlear and vestibular hydrops was measured at 2 h, 4 h and 6 h, while the differences in signal intensity ratio and endolymphatic hydrops were evaluated at three time points.

RESULTS

The cochlea, vestibule, and semicircular canal exhibit clear structural features with distinct perilymph-endolymph boundaries at 2 h, 4 h, and 6 h. The signal intensity ratio of the affected ear was significantly higher than that of the unaffected ear at 2 h, 4 h, and 6 h. The signal intensity ratio at 4 h and 6 h in both the affected and unaffected ears was significantly higher than that at 2 h, but there was no significant difference between 4 h and 6 h. Cochlear hydrops and vestibular hydrops show no significant differences at these time points, demonstrating excellent consistency.

CONCLUSIONS

We have demonstrated that 3D-FLAIR images acquired 2 h after intravenous administration of a single-dose gadobutrol are of high quality and equally effective as those obtained at the conventional 4-h time point for diagnosing endolymphatic hydrops in Menière's disease. In clinical practice, the delay time can be safely shortened to 2 h.

Assessing the optimal MRI descriptors to diagnose Ménière's disease and the added value of analysing the vestibular aqueduct

OBJECTIVES

To evaluate the diagnostic performance and reliability of MRI descriptors used for the detection of Ménière's disease (MD) on delayed post-gadolinium MRI. To determine which combination of descriptors should be optimally applied and whether analysis of the vestibular aqueduct (VA) contributes to the diagnosis.

MATERIALS AND METHODS

This retrospective single centre case-control study evaluated delayed post-gadolinium MRI of patients with Ménièriform symptoms examined consecutively between Dec 2017 and March 2023. Two observers evaluated 17 MRI descriptors of MD and quantified perilymphatic enhancement (PLE) in the cochlea. Definite MD ears according to the 2015 Barany Society criteria were compared to control ears. Cohen's kappa and diagnostic odds ratio (DORs) were calculated for each descriptor. Forward stepwise logistic regression determined which combination of MRI descriptors would best predict MD ears, and the area under the receiver operating characteristic curve for this model was measured.

RESULTS

A total of 227 patients (mean age 48.3 ± 14.6, 99 men) with 96 definite MD and 78 control ears were evaluated. The presence of saccular abnormality (absent, as large as or confluent with the utricle) performed best with a DOR of 292.6 (95% confidence interval (CI), 38.305-2235.058). All VA descriptors demonstrated excellent reliability and with DORs of 7.761 (95% CI, 3.517-17.125) to 18.1 (95% CI, 8.445-39.170). Combining these saccular abnormalities with asymmetric cochlear PLE and an incompletely visualised VA correctly classified 90.2% of cases (sensitivity 84.4%, specificity 97.4%, AUC 0.938).

CONCLUSION

Either absent, enlarged or confluent saccules are the best predictors of MD. Incomplete visualisation of the VA adds value to the diagnosis.

CLINICAL RELEVANCE STATEMENT

A number of different MRI descriptors have been proposed for the diagnosis of Ménière's disease, but by establishing the optimally performing MRI features and highlighting new useful descriptors, there is an opportunity to improve the diagnostic performance of Ménière's disease imaging.

KEY POINTS

• A comprehensive range of existing and novel vestibular aqueduct delayed post-gadolinium MRI descriptors were compared for their diagnostic performance in Ménière's disease. • Saccular abnormality (absent, confluent with or larger than the utricle) is a reliable descriptor and is the optimal individual MRI predictor of Ménière's disease. • The presence of this saccule descriptor or asymmetric perilymphatic enhancement and incomplete vestibular aqueduct visualisation will optimise the MRI diagnosis of Ménière's disease.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL RELEVANCE STATEMENT

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

KEY POINTS

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

The correlation of hearing prognosis and caloric test results in Meniere's disease: a follow up study

BACKGROUND

Hearing loss is important in the diagnosis and treatment of Meniere's disease (MD). However, little is known about the factors associated with hearing changes in MD.

AIMS/OBJECTIVES

This study aimed to investigate the correlation between hearing prognosis and caloric test (CT) results in MD.

MATERIAL AND METHODS

Ninety consecutive patients diagnosed with unilateral definite MD underwent pure tone audiometry (PTA) and CT at initial visits, and were re-tested PTA at the 6-month follow-up.

RESULTS

Fifty-three of ninety MD patients (58.89%) had abnormal CT results. The change of PTA (cPTA = initial PTA-last PTA) was negatively correlated with canal paresis (CP) values (overall association p = 0.032 and non-linear association p = 0.413). Multivariate linear model showed that as the CP value changed from 0 to 1, the cPTA decreased by -13.31 dB (95% CI: -24.03, -2.6) (p = 0.016). Stratified analysis found that the association was present in MD patients of Stage 1 and 2 (p < 0.05) but not in patients of Stage 3 and 4 (p > 0.05).

CONCLUSIONS AND SIGNIFICANCE

Elevated CP values may be linked to worse hearing outcomes in MD, especially in Stage 1 and 2 patients. Conducting a caloric test at the initial consultation may aid in assessing hearing regression in MD.

Role of conventional MD staging in modern era of hydrops MR imaging

Objective/Hypothesis

This study correlated stage of Meniere's disease (MD) with MR imaging of endolymphatic hydrops (EH) to assess the role of MD staging in modern era.

Study Design

Retrospective study.

Methods

Fifty-four MD patients (60 ears) underwent an inner ear test battery and were further confirmed by MR imaging. Sixty MD ears were divided into stages I-IV, and hydrops MR images at each stage were compared.

Results

Hydrops MRI demonstrated that EH at the cochlea with respective Grades 0/I/II were 3/7/1 ears for stage I, 0/5/3 ears for stage II, 1/6/26 ears for stage III and 0/2/6 ears for stage IV. Significant relationship was not identified between MD stage and grades of cochlear hydrops. Similarly, no significant relationship was shown between MD stage and grades of vestibular (saccular/utricular) hydrops. The optimal cutoff value of four-tone average for predicting severe type (Grade II-III) cochlear/vestibular EH was 48 dB, which was within the stage III. Hence, prevalence of severe type (Grade II) cochlear EH in stages III (79%) and IV (75%) was significantly higher than stages I (9%) and II (38%). Similarly, severe type saccular/utricular EH in stages III (64%) and IV (75%) also showed significantly higher than stages I (18%) and II (25%).

Conclusion

Although conventional MD staging fails to correlate with the grades of EH on hydrops MRI, late-stage MD may indicate heightened EH severity in the cochlea and vestibule.

Level of Evidence

4.

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.

Iterative Denoising Accelerated 3D FLAIR Sequence for Hydrops MR Imaging at 3T

BACKGROUND AND PURPOSE

3D FLAIR sequences have become the criterion standard for identifying endolymphatic hydrops, but scan time remains an important limitation to their widespread use. Our purpose was to evaluate the diagnostic performance and image quality of an accelerated 3D FLAIR sequence combined with an iterative denoising algorithm.

MATERIALS AND METHODS

This was a retrospective study performed on 30 patients with clinical suspicion of endolymphatic hydrops who underwent 3T MR imaging 4 hours after gadolinium injection using two 3D FLAIR sequences. The first (conventional FLAIR) was accelerated with a conventional turbo factor of 187. The second was accelerated with an increased turbo factor of 263, resulting in a 33% scan time reduction (5 minutes 36 seconds versus 8 minutes 15 seconds, respectively). A sequence was reconstructed in-line immediately after the accelerated 3D FLAIR acquisition from the same raw data with iterative denoising (accelerated-FLAIR iterative denoising). The signal intensity ratio image quality score and endolymphatic hydrops diagnosis were evaluated.

RESULTS

The mean signal intensity ratio for symptomatic and asymptomatic ears of accelerated-FLAIR iterative denoising was significantly higher than the mean SNR of conventional FLAIR (29.5 versus 19 and 25.9 versus 16.3, P < .001). Compared with the conventional FLAIR sequence, the image-quality score was higher with accelerated-FLAIR iterative denoising (mean image-quality score, 3.8 [SD, 0.4] versus 3.3 [SD, 0.6] for accelerated-FLAIR iterative denoising and conventional FLAIR, respectively, P = .003). There was no significant difference in the diagnosis of endolymphatic hydrops between the 2 sequences. Interreader agreement was good-to-excellent.

CONCLUSIONS

The iterative denoising algorithm applied to an accelerated 3D FLAIR sequence for exploration of endolymphatic hydrops enabled significantly reducing the scan time without compromising image quality and diagnostic performance.

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.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

Reliability of Endolymphatic Hydrops Qualitative Assessment in Magnetic Resonance Imaging

The study aimed to compare the consistency of MRI interpretation of endolymphatic hydrops qualitative assessment of inner ear structures performed by independent observers. MRI with a delayed post-contrast 3D-FLAIR sequence was performed to visualize EH in patients suspected of having or diagnosed with MD. The scans were analyzed independently by three observers. In total, 220 ears were evaluated and, of these, 75 had definite MD, five probable MD, 67 with other Menieriform symptoms, and 73 were asymptomatic. Significant differences in cochlear endolymphatic hydrops (CoEH) grading between all observers were observed. On the Barath scale of vestibular endolymphatic hydrops (VEH), differences were found between the radiologists and otorhinolaryngologist in grading. No differences were noted in VEH on the Bernaerts scale and increased perilymphatic enhancement. Our study showed that evaluation of vestibular endolymphatic hydrops is repeatable between observers and easy to learn. It proved that Bernaerts' modification increased the sensitivity of EH diagnosis. Both parameters, CoEH and VEH, may serve as a differentiation method of EH from normal ears. The distinction between normal and hydropic ears is much easier to perform than EH grading. Therefore, it may be used to diagnose MD rather than EH staging.

Limitation of updated MR images on the vestibular hydrops in Meniere’s disease

PURPOSE

This study adopted the cervical and ocular vestibular-evoked myogenic potential (cVEMP and oVEMP) tests in Meniere's disease (MD) patients to correlate them with vestibular endolymphatic hydrops (EH) on MR images.

METHODS

A total of 25 patients with unilateral definite MD identified by positive cochlear hydrops on MR images were enrolled. All patients underwent audiometry, cVEMP test and oVEMP test, followed by MR imaging for confirmation.

RESULTS

A significantly declining sequence of abnormality rates in MD patients was identified from the audiometry (92%), cVEMP test (52%) to the oVEMP test (40%), which was consistent with a significantly decreasing order of prevalence of EH on MR images running from the cochlea (100%), saccule (56%) to the utricle (52%). The cVEMP test for detecting the saccular hydrops revealed a sensitivity of 62%, while the oVEMP test for assessing the utricular hydrops showed a sensitivity of 70%. However, correlating VEMP results with vestibular hydrops did not show any significant relationship. In addition, mean hearing level (MHL) at four frequencies (500, 1000, 2000, and 3000 Hz) of Grade I cochlear hydrops (51 ± 19 dB) did not significantly differ from Grade II cochlear hydrops (53 ± 19 dB).

CONCLUSION

Limitations of the updated MR imaging for visualizing the hydrops comprised: (1) failure to correlate vestibular hydrops with VEMP results, and (2) failure to correlate grade of cochlear hydrops with MHL. The reason is probably because updated MR imaging fails to identify distorted contour of the cochlea/utricle/saccule. Further advanced technique using ultrahigh resolution of fine structures in the inner ear compartments is essential to promote a wider use of MR imaging.

Magnetic resonance imaging of endolymphatic hydrops in Ménière's disease: A comparison of the diagnostic value of multiple scoring methods

Objectives

To compare three methods of scoring endolymphatic hydrops in patients with Ménière's disease in order to assess the correlation between endolymphatic hydrops and auditory characteristics.

Methods

A retrospective study of 97 patients with unilateral definite Ménière's disease (DMD) who underwent contrast-enhanced three-dimensional fluid attenuated inversion recovery (3D FLAIR) MRI. Each patient was scored by the Inner Ear Structural Assignment Method (IESAM), the Saccule to utricle area ratio (SURI), and the Four Stage Vestibular Hydrops Grading (FSVH), according to their corresponding axial images. Cohen's Kappa and intra-class correlation coefficient were used for consistency testing, combined with binary logistic regression analysis, to compare the sensitivity and specificity of the three methods. The degree of hydrops in different stages of MD was compared. The correlation between endolymphatic hydrops in the inner ear sub-units and hearing thresholds was further analyzed.

Results

The intra- and inter-reader reliability for the scoring of endolymphatic hydrops were excellent. The IESAM had a high diagnostic value for identifying definite Ménière's disease (sensitivity: 86.6%, specificity: 97.9%). The hearing thresholds were correlated with the degree of endolymphatic hydrops. Stages 3 and 4 were more significant for the severity of hydrops than stage 1. Within the subgroups of the Ménière's disease patients, compared with the non-hydrops group and the pure vestibular hydrops (V group), the cochlear combined vestibular hydrops group (CV group) had significantly higher auditory thresholds. The amplitude ratio of electrocochleogram was significantly higher in the affected ear than in the healthy ear.

Conclusion

The IESAM is a more sensitive and specific diagnostic scoring method for the diagnosis of DMD. Diagnostic imaging may improve the detection of inner ear hydrops which is correlated with severity of hearing loss. A comprehensive evaluation of the inner ear sub-unit structures maybe necessary.

Correlation of clinical parameters with endolymphatic hydrops on MRI in Meniere's disease

A clinical diagnosis of Ménière's disease (MD) is made based on medical history and audiometry findings. The 1995 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guidelines requires histopathological confirmation of endolymphatic hydrops (EH) for a diagnosis of “certain” MD. Symptoms such as dizziness and ear fullness are important diagnostic features; however, the descriptions provided by patients are frequently vague and non-specific. A recently developed magnetic resonance imaging (MRI) protocol to document EH is, therefore, useful for the evaluation of inner ear status in patients with MD. In this study, patients with MD were assessed using MRI and the HYDROPS (HYbriD of Reversed image Of Positive endolymph signal and native image of positive perilymph Signal) protocol to investigate the effectiveness of MRI for visualization of the endolymphatic space in the diagnosis of MD by correlating clinical laboratory parameters with the grade of EH. Of the 123 patients with MD recruited in this study, 80 had definite MD, 11 had probable MD, and 32 had possible MD based on the 1995 AAO-HNS guidelines. The EH grade based on HYDROPS MRI was determined independently by two otorhinolaryngologists and compared with several clinical parameters, including the diagnostic scale of MD (1995 AAO-HNS guidelines), pure tone average (PTA), low tone average (LTA), canal paresis (CP) on the caloric test, and disease duration. Cochlear hydrops and vestibular hydrops were detected in 58 and 80% of 80 definite MD ears, in 33 and 58% of 12 probable MD ears, and in 5 and 27% of 37 possible MD ears, respectively. The proportion of higher hydrops grades increased significantly with grade according to the MD diagnostic scale (p < 0.0001). Both PTA and LTA were significantly higher in patients with hydrops grade 2 than hydrops grade 0 in both the cochlea and the vestibule. CP was significantly higher in patients with grade 2 than grade 0 vestibular hydrops. Disease duration was not associated with hydrops grade. Radiological evaluation of MD using the HYDROPS protocol is useful for evaluation of the extent and severity of EH in the diagnosis of MD based on its pathophysiological mechanism.

Optimized 3D-FLAIR sequences to shorten the delay between intravenous administration of gadolinium and MRI acquisition in patients with Menière's disease

OBJECTIVES

The aim of this study was to shorten the 4-h delay between the intravenous administration of gadolinium and MRI acquisition for hydrops evaluation using an optimized 3D-FLAIR sequence in patients with Menière's disease.

METHODS

This was a single-center prospective study including 29 patients (58 ears), recruited between November 2020 and February 2021. All patients underwent a 3-T MRI with an optimized 3D-FLAIR sequence without contrast then at 1 h, 2 h, and 4 h after intravenous administration of gadobutrol. The signal intensity ratio was quantitatively assessed with the region of interest method. We also evaluated the volume of endolymphatic structures (saccule, utricle) then the presence of endolymphatic hydrops and blood-labyrinthine barrier impairment at each acquisition time.

RESULTS

For all ears, the signal intensity ratio was significantly non-inferior at 2 h compared to 4 h, with a mean geometric signal intensity ratio at 0.83 (95% CI: 0.76 to 0.90, one-sided p < .001 for non-inferiority at -30% margin). Mean volume equivalence of saccule and utricle between 2 and 4 h was proven at a ± 0.20 standardized deviation equivalence margin. Intra-rater agreements (Cohen's kappa) were all greater than 0.90 for all endolymphatic hydrops location and blood-labyrinthine-barrier impairment between the 2- and 4-h assessments.

CONCLUSIONS

We demonstrated that using an optimized 3D-FLAIR sequence we could shorten the acquisition from 4 to 2 h with a high reliability for the diagnosis of endolymphatic hydrops and blood-labyrinthine-barrier impairment.

CLINICAL TRIAL REGISTRATION

Clinical trial no: 38RC15.173 KEY POINTS: • Magnetic resonance imaging with delayed 3D-FLAIR sequences allows the diagnosis of endolymphatic hydrops in patients with definite Menière's disease. • An optimized 3D-FLAIR sequence with a long TR of 16000 ms and a constant flip angle allows for reducing the delay between intravenous injection of gadobutrol and MRI acquisition from 4 to 2 h to diagnose endolymphatic hydrops. • Reducing this delay between intravenous injection and MRI acquisition could have implications for clinical practice for both patients and imaging departments.

Dexamethasone does not affect endolymphatic hydrops (EH) in patients with Meniere’s disease within 24 h, and intratympanic administration of gadolinium plus dexamethasone simplifies high-quality imaging of EH using a novel protocol of 7 minutes

Background

Intratympanic administration of gadolinium chelate allows for a better visualization of endolymphatic hydrops (EH) using MRI than intravenous injection and was recently further improved to facilitate high-quality imaging of EH in 7 min. The aim of the present study was to simplify the intratympanic administration protocol by mixing gadolinium chelate with therapeutic dexamethasone and to evaluate the effects of this mixture on the visualization of EH in MRI.

Materials and methods

In an in vitro study, the potential impact of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) on the stability of dexamethasone was evaluated by analyzing dynamic changes in dexamethasone with high-performance liquid chromatography (HPLC) after mixing with Gd-DTPA. Ten patients with definite Meniere's disease (MD) were recruited to study the potential interference of dexamethasone on MRI visualization of EH, and 49 patients with MD were recruited to evaluate the effect of intratympanic injection of Gd-DTPA mixed with dexamethasone on MRI of EH using a 3T MR machine and a novel heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery reconstructed using a magnitude plus zero-filled interpolation (hT₂FLAIR-MZFI) sequence.

Results

The retention times and peak area of dexamethasone in HPLC were not modified by the addition of Gd-DTPA. EH grading in the cochlea and vestibule was not influenced in any ear by intratympanic injection of dexamethasone. Excellent inner ear images were obtained from all patients, and EHs with various grades were displayed. There were significant correlations between diagnosis and cochlear EH (p < 0.01, Spearman's Rho), between diagnosis and vestibular EH (p < 0.01, Spearman's Rho), and between cochlear and vestibular EH (p < 0.01, Spearman's Rho). The distribution of Gd-DTPA plus dexamethasone negatively correlated with the grade of vestibular EH. Injury of the endolymph-perilymph barrier was detected in one cochlea and three vestibules of 59 inner ears with MD.

Conclusions

Intratympanic administration of Gd-DTPA plus dexamethasone yielded high-quality MRI images of EH in patients with MD using a novel 7-min protocol and simplified the clinical application. Intratympanic administration of Gd-DTPA plus dexamethasone might be used to test its therapeutic effect in future work.

Level of evidence

3.

Hydropic Ear Disease: Correlation Between Audiovestibular Symptoms, Endolymphatic Hydrops and Blood-Labyrinth Barrier Impairment

Research Objective: To investigate the correlation between clinical features and MRI-confirmed endolymphatic hydrops (EH) and blood-labyrinth barrier (BLB) impairment. Study Design: Retrospective cross-sectional study. Setting: Vertigo referral center (Haga Teaching Hospital, The Hague, the Netherlands). Methods: We retrospectively analyzed all patients that underwent 4 h-delayed Gd-enhanced 3D FLAIR MRI at our institution from February 2017 to March 2019. Perilymphatic enhancement and the degree of cochlear and vestibular hydrops were assessed. The signal intensity ratio (SIR) was calculated by region of interest analysis. Correlations between MRI findings and clinical features were evaluated. Results: Two hundred and fifteen patients with MRI-proven endolymphatic hydrops (EH) were included (179 unilateral, 36 bilateral) with a mean age of 55.9 yrs and median disease duration of 4.3 yrs. Hydrops grade is significantly correlated with disease duration (P < 0.001), the severity of low- and high-frequency hearing loss (both P < 0.001), and the incidence of drop attacks (P = 0.001). Visually increased perilymphatic enhancement was present in 157 (87.7%) subjects with unilateral EH. SIR increases in correlation with hydrops grade (P < 0.001), but is not significantly correlated with the low or high Fletcher index (P = 0.344 and P = 0.178 respectively). No significant differences were found between the degree of EH or BLB impairment and vertigo, tinnitus or aural fullness. Conclusion: The degree of EH positively correlates with disease duration, hearing loss and the incidence of drop attacks. The BLB is impaired in association with EH grade, but without clear contribution to the severity of audiovestibular symptoms.

Increased signal intensity with delayed post contrast 3D-FLAIR MRI sequence using constant flip angle and long repetition time for inner ear evaluation

PURPOSE

The purpose of this study was to compare the degree of perilymphatic enhancement between 4 hour post-contrast constant flip angle three-dimensional fluid attenuated inversion recovery (3D-FLAIR) images obtained with short repetition time (TR) and those obtained with long TR.

MATERIALS AND METHODS

This single-center, prospective study included patients who underwent MRI of the inner ear with heavily T2-weighted sequence, 3D-FLAIR sequence with a "short" TR of 10,000 ms (s3D-FLAIR) and with a "long" TR of 16,000 ms (l3D-FLAIR). Signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) obtained with s3D-FLAIR and l3D-FLAIR were quantitatively assessed using region of interest (ROI) method and compared. The morphology of the endolymphatic space on both sequences was also evaluated.

RESULTS

From March 2020 to July 2020, 20 consecutive patients were enrolled (9 women and 11 men; mean age, 52.1 ± 14.5 [SD] years; age range: 29-75 years). On l3D-FLAIR images, mean SIR (21.1 ± 8.8 [SD]; range: 7.6-46.1) was significantly greater than that on s3D-FLAIR images (15.7 ± 6.7 [SD]; range: 5.9-33.4) (P < 0.01). On l3D-FLAIR images, mean CNR (17 ± 8.5 [SD]; range: 2-40) was significantly greater than that on s3D-FLAIR images (12 ± 6.3 [SD]; range: 3.2-29.8) (P < 0.01). Kappa value for inter-rater agreement for endolymphatic hydrops, vestibular atelectasis and perilymphatic fistula were 0.93 (95% CI: 0.74-1), 1 (95% CI: 0.85-1) and 1 (95% CI: 0.85-1) respectively.

CONCLUSION

This study demonstrates that the sensitivity of 3D-FLAIR sequences to low concentration gadolinium in the perilymphatic space is improved by elongation of the TR, with SIR and CNR increased by +34.4% and +41.3% respectively.

MRI characteristics of intralabyrinthine schwannoma on post-contrast 4 h-delayed 3D-FLAIR imaging

PURPOSE

The purpose of this study was to describe the MRI characteristics of intralabyrinthine schwannoma (ILS) on post contrast three-dimensional (3D) fluid-attenuation-inversion-recovery (FLAIR) images obtained four hours after intravenous administration of a gadolinium-based contrast agent (4h-3D-FLAIR).

MATERIALS AND METHODS

This IRB-approved retrospective multi-center study included patients presenting with typical ILS from January 2016 to October 2020. All medical charts were systematically collected. All MRI examinations, including 4h-3D-FLAIR images, were reviewed by two board-certified neuroradiologists. Main outcome measures were location, signal intensity and associated anomalies of ILS.

RESULTS

Twenty-seven out of 8730 patients (0.31%) referred for the investigation of a cochleovestibular disorder had a final diagnosis of ILS. There were 13 men and 14 women with a mean age of 52 ± 17 (SD) years (age range: 20-86 years). The most common clinical presentation was unilateral progressive sensorineural hearing loss (16/27; 59%). All ILS were unilateral and 15 (15/27; 55%) were intracochlear. All ILS presented as a hypointense filling defect within the labyrinth on T2-weighted images that enhanced on post-contrast T1-weighted images. On 4h-3D-FLAIR images, all ILS presented as a hypointense filling defect, associated with diffuse perilymphatic hyperintensity. Two patients (2/27; 7%) presented with ipsilateral endolymphatic hydrops.

CONCLUSION

ILS displays consistent features on post-contrast 4h-3D-FLAIR images. ILS should not be confused with endolymphatic hydrops and requires a systematic analysis of the corresponding T2-weighted images.

Advanced Imaging of the Vestibular Endolymphatic Space in Ménière's Disease

The diagnosis of "definite" Méniére's disease (MD) relies upon its clinical manifestations. MD has been related with Endolymphatic Hydrops (EH), an enlargement of the endolymphatic spaces (ES) (cochlear duct, posterior labyrinth, or both). Recent advances in Magnetic Resonance (MR) imaging justify its increasing role in the diagnostic workup: EH can be consistently recognized in living human subjects by means of 3-dimensional Fluid-Attenuated Inversion-Recovery sequences (3D-FLAIR) acquired 4 h post-injection of intra-venous (i.v.) Gadolinium-based contrast medium, or 24 h after an intratympanic (i.t.) injection. Different criteria to assess EH include: the comparison of the area of the vestibular ES with the whole vestibule on an axial section; the saccule-to-utricle ratio ("SURI"); and the bulging of the vestibular organs toward the inferior 1/3 of the vestibule, in contact with the stapedial platina ("VESCO"). An absolute link between MD and EH has been questioned, since not all patients with hydrops manifest MD symptoms. In this literature review, we report the technical refinements of the imaging methods proposed with either i.t. or i.v. delivery routes, and we browse the outcomes of MR imaging of the ES in both MD and non-MD patients. Finally, we summarize the following imaging findings observed by different researchers: blood-labyrinthine-barrier (BLB) breakdown, the extent and grading of EH, its correlation with clinical symptoms, otoneurological tests, and stage and progression of the disease.

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

OBJECTIVE

We aimed to quantitatively evaluate the degree of endolymphatic hydrops and its correlation with the clinical features of Meniere's disease.

METHODS

We retrospectively collected data from patients with Meniere's disease who underwent gadolinium-enhanced magnetic resonance imaging (MRI) at our department from January 2018 to December 2019. Mimics software was used to perform three-dimensional modelling of the labyrinth, and volume information was obtained to calculate the endolymphatic hydrops index (EHI). A correlation analysis was conducted with data from pure tone audiometry, electrocochleography (EchoG), vestibular myogenic-evoked potential (VEMP) testing, caloric testing and video head impulse testing (vHIT). A two-dimensional method was also employed to calculate the hydrops ratio (HR) of cochlea and vestibule. The test-retest reliability of EHI/HR from different operators was evaluated.

RESULTS

A total of 23 affected ears were examined, and the EHI was significantly correlated with Meniere's disease stage, low-frequency hearing threshold, EchoG summating potential/action potential ratio (-SP/AP) and VEMP binaural asymmetry ratio, but no significant correlation was observed between EHI and the caloric test or vHIT. The Intraclass correlation coefficient (ICC) of EHI data calculated by two otologists was 0.946 (p < .001). And the ICC of cochlea and vestibule HR were 0.844 and 0.832 (p < .001).

CONCLUSION

Mimics software can be used to quantitatively evaluate the degree of endolymphatic hydrops and have shown higher test-retest reliability than traditional two-dimensional evaluation method. Endolymphatic hydrops correlates with clinical data, such as Meniere's disease stage, low-frequency hearing threshold, EchoG and VEMP asymmetry ratio.

Imaging of endolymphatic hydrops: A comprehensive update in primary and secondary hydropic ear disease

BACKGROUND

Since the first description by Hallpike and Cairns, the excess of endolymphatic fluid, also known as endolymphatic hydrops (EH), has been established as being the main biomarker in patients with Menière's disease. Recently, the concept of primary (PHED) and secondary hydropic ear disease (SHED) has been introduced. PHED corresponded to Menière's disease while SHED was defined as the presence of EH in patients with pre-existing inner ear disease.

OBJECTIVE

In this article, we would like to summarize the methodology of hydrops exploration using MRI and the previously published radiological findings in patients with PHED and SHED.

RESULTS

Before the emergence of delayed inner ear MRI, the presence of EH was assumed based on clinical symptoms. However, because of the recent technical developments, inner ear MRI became an important tool in clinical settings for identifying EH in vivo, in patients with PHED and SHED. The presence of EH on MRI is related with the degree of sensorineural hearing loss whether in patients with PHED or SHED. By contrast, in PHED or SHED patients without sensorineural hearing loss, MRI showed no sign of EH.

CONCLUSIONS

Thanks to the recent technical developments, inner ear MRI became an important tool in clinical settings for identifying EH in vivo, in patients with PHED and SHED.

Magnetic resonance imaging of endolymphatic hydrops in patients with unilateral Meniere's disease: a comparison between with and without herniation into the posterior and lateral semi-circular canals

BACKGROUND

The presence of endolymphatic hydrops (ELH) in patients with Meniere's disease (MD) is considered a pathological hallmark.

AIMS/OBJECTIVES

We aimed to conduct a quantitative volumetric measurement of inner ear ELH in patients with unilateral MD (uMD). The values of uMD with and without herniation into the posterior semi-circular canal (h-PSC) and the lateral semi-circular canal (h-LSC) were compared using 3 D magnetic resonance imaging.

MATERIAL AND METHODS

This study included 130 individuals (47 controls and 83 patients with uMD). We measured the total fluid space (TFS) and endolymphatic space (ELS) volumes. We also evaluated the ELS/TFS volume ratios (%).

RESULTS

The ELS/TFS volume ratios in the inner ear, cochlea, and vestibule were significantly different between the affected and contralateral sides in patients with h-PSC. Moreover, the ELS/TFS volume ratios of the inner ear, vestibule, and semi-circular canals in the affected ear were significantly higher in patients with h-PSC than in those without h-PSC. The vestibular ELS/TFS volume ratio in the affected ear was significantly higher in patients with h-LSC than in those without h-LSC.

CONCLUSIONS AND SIGNIFICANCE

H-LSC is present in extended vestibular ELH. However, this is a result of ELH progression in the inner ear.

Novel Magnetic Resonance Imaging-Based Method for Accurate Diagnosis of Meniere's Disease

Background: Pathologically, Meniere's disease symptoms are considered to be associated with endolymphatic hydrops. Examinations revealing endolymphatic hydrops can be useful for accurate Meniere's disease diagnosis. We previously reported a quantitative method for evaluating endolymphatic hydrops, i.e., by measuring the volume of the endolymphatic space using three-dimensional magnetic resonance imaging (MRI) of the inner ear. This study aimed to confirm the usefulness of our methods for diagnosing Meniere's disease. Here, we extracted new explanatory factors for diagnosing Meniere's disease by comparing the volume of the endolymphatic space between healthy volunteers and patients with Meniere's disease. Additionally, we validated our method by comparing its diagnostic accuracy with that of the conventional method.

Methods and Findings: This is a prospective diagnostic accuracy study performed at vertigo/dizziness centre of our university hospital, a tertiary hospital. Eighty-six patients with definite unilateral Meniere's disease and 47 healthy volunteers (25 and 33 males, and 22 and 53 females in the control and patient groups, respectively) were enrolled. All participants underwent 3-Tesla MRI 4 h after intravenous injection of gadolinium to reveal the endolymphatic space. The volume of the endolymphatic space was measured and a model for Meniere's disease diagnosis was constructed and compared with models using conventional criteria to confirm the effectiveness of the methods used. The area under the receiver operating characteristic curve of the method proposed in this study was excellent (0.924), and significantly higher than that derived using the conventional criteria (0.877). The four indices, sensitivity, specificity, positive predictive value, and negative predictive value, were given at the threshold; all of these indices achieved higher scores for the 3D model compared to the 2D model. Cross-validation of the models revealed that the improvement was due to the incorporation of the semi-circular canals.

Conclusions: Our method showed high diagnostic accuracy for Meniere's disease. Additionally, we revealed the importance of observing the semi-circular canals for Meniere's disease diagnosis. The proposed method can contribute toward providing effective symptomatic relief in Meniere's disease.

Vestibular Endolymphatic Hydrops Visualized by Magnetic Resonance Imaging and Its Correlation With Vestibular Functional Test in Patients With Unilateral Meniere's Disease

Background: Currently, 3 Tesla-MRI following intratympanic gadolinium injection has made it possible to assess the existence and the severity of hydrops in each compartment of the endolymphatic spaces in vivo. However, the relationship between vestibular endolymphatic hydrops (EH) visualized by MRI and vestibular functional tests, especially the correlation between caloric test, video-head impulse test, and semicircular canal hydrops, has not been well-investigated. Objective: The purpose of this study is to investigate the relationship between the severity of EH in each compartment of otoliths and semicircular canal and the results of vestibular functional tests. Methods: In this retrospective study, we performed three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences following intratympanic gadolinium injection in 69 unilateral patients with definite Menière's disease. Vestibular and lateral semicircular canal hydrops was graded on MRI using a four grade criterion. All patients underwent pure-tone audiometry, cervical vestibular evoked myogenic potential (cVEMP), ocular vestibular evoked myogenic potential (oVEMP), caloric test and video head impulse test (vHIT). The latency, amplitude and asymmetry ratio of VEMP, canal paresis (CP) and vestibulo-ocular reflex (VOR) gain of lateral semicircular canal of vHIT were collected. The correlation analysis were performed between the parameters of function test and EH. Results: Vestibular EH showed correlations with the duration of disease (r = 0.360) and pure tone average (r = 0.326). AR of cVEMP showed correlations with Vestibular EH (r = 0.407). CP (r = 0.367) and VOR gain of lateral semicircular canal at 60 ms (r = 0.311) showed correlations with lateral semicircular canal hydrops. Conclusion: EH in different compartments is readily visualized by using 3D-FLAIR MRI techniques. The degree of vestibular EH correlated with AR of cVEMP and EH in the semicircular canal ampullar affects the caloric and vHIT response in patients with unilateral Meniere's disease.

MRI With Gadolinium as a Measure of Blood-Labyrinth Barrier Integrity in Patients With Inner Ear Symptoms: A Scoping Review

Objective: Capillaries within the inner ear form a semi-permeable barrier called the blood-labyrinth barrier that is less permeable than capillary barriers elsewhere within the human body. Dysfunction of the blood-labyrinth barrier has been proposed as a mechanism for several audio-vestibular disorders. There has been interest in using magnetic resonance imaging (MRI) with intravenous gadolinium-based contrast agents (GBCA) as a marker for the integrity of the blood labyrinth barrier in research and clinical settings. This scoping review evaluates the evidence for using intravenous gadolinium-enhanced MRI to assess the permeability of the blood-labyrinth barrier in healthy and diseased ears.

Methods: A systematic search was conducted of three databases: PubMed, EMBASE, CINAHL PLUS. Studies were included that used GBCA to study the inner ear and permeability of the blood-labyrinth barrier. Data was collected on MRI protocols used and inner ear enhancement patterns of healthy and diseased ears in both human and animal studies.

Results: The search yielded 14 studies in animals and 53 studies in humans. In healthy animal and human inner ears, contrast-enhanced MRI demonstrated gradual increase in inner ear signal intensity over time that was limited to the perilymph. Signal intensity peaked at 100 min in rodents and 4 h in humans. Compared to controls, patients with idiopathic sudden sensorineural hearing loss and otosclerosis had increased signal intensity both before and shortly after GBCA injection. In patients with Ménière's disease and vestibular schwannoma, studies reported increased signal at 4 h, compared to controls. Quality assessment of included studies determined that all the studies lacked sample size justification and many lacked adequate control groups or blinded assessors of MRI.

Conclusions: The included studies provided convincing evidence that gadolinium crosses the blood-labyrinth barrier in healthy ears and more rapidly in some diseased ears. The timing of increased signal differs by disease. There was a lack of evidence that these findings indicate general permeability of the blood-labyrinth barrier. Future studies with consistent and rigorous methods are needed to investigate the relationship between gadolinium uptake and assessments of inner ear function and to better determine whether signal enhancement indicates permeability for molecules other than gadolinium.

Which Inner Ear Disorders Lie Behind a Selective Posterior Semicircular Canal Hypofunction on Video Head Impulse Test?

OBJECTIVE

To assess all different patterns of associated abnormalities on audiometry, bithermal caloric test (BCT) and cervical/ocular vestibular-evoked myogenic potentials (VEMPs) to air/bone-conduction in patients with selective posterior semicircular canal (PSC) hypofunction and to correlate them with underlying disorders.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral center.

PATIENTS

51 patients (23 men, 28 women, mean age 57.5 yr) with isolated PSC deficit (one bilateral).

INTERVENTIONS

Correlation with instrumental data and underlying diagnoses.

MAIN OUTCOME MEASURES

Video-oculographic findings, objective measurements on audiometry, BCT, VEMPs and video-head impulse test (vHIT).

RESULTS

Ongoing or previous acute vestibular loss (AVL) was diagnosed in 13 patients (25.5%, 3 inferior vestibular neuritis, 10 AVL with sudden sensorineural hearing loss [SSNHL]), Meniere's disease (MD) in 12 (23.5%), cerebellopontine angle (CPA) lesion in 9 (17.6%), various causes in 7 (13.7%), benign paroxysmal positional vertigo (BPPV) involving the non-ampullary arm of PSC in 5 cases (9.8%) whereas unknown pathology in 5 (9.8%). Involvement of at least one additional receptor besides PSC was seen in 89.8% of cases. Cochlear involvement was diagnosed in 74.5% with pure-tone average significantly greater in patients with AVL+SSNHL (p < 0.05). Overall involvement of labyrinthine receptors or afferents was highest in patients with AVL+SSNHL (p < 0.01), MD and CPA lesions (p < 0.05).

CONCLUSIONS

Isolated loss of PSC function on vHIT is mostly accompanied by additional labyrinthine deficits that could only be identified through an accurate instrumental evaluation. Assessment of all receptors and afferents should be always pursued to identify the lesion site and better understand the underlying pathophysiological mechanisms.

Correlation between magnetic resonance imaging classification of endolymphatic hydrops and clinical manifestations and audiovestibular test results in patients with definite Ménière's disease

OBJECTIVES

The purpose was to evaluate magnetic resonance imaging (MRI) classification of endolymphatic hydrops with clinical features, audiological and vestibular tests in patients with definite unilateral Ménière's disease (MD).

METHODS

Thirty-eight patients were enrolled in this study. The severity of the main clinical symptoms, audiovestibular tests, and MRI, performed 4 hours after intravenous injection of gadobutrol to visualize inner ear compartments, were evaluated. Endolymphatic space dilatation was assessed using Barath and Bernaerts grading systems, and the correlation between the grade of the hydrops and clinical features was evaluated.

RESULTS

Using the Barath system, cochlear hydrops was visualized in 81.6% of affected ears, while vestibular was 63.2%. Sensitivity increased to 94.7% using Bernaerts' modification. Vestibular hydrops involving the utricle was present only among patients with cochlear and saccular endolymphatic space dilatation. There was a significant relationship between the hearing level and the vestibular hydrops degree in the Bernaerts scale. The grade of the hydrops correlated neither with the duration of MD nor with the severity of main clinical symptoms. Our study proved MRI to be a sensitive diagnostic tool in MD. The endolymphatic hydrops' grade correlates with the hearing level, which confirms endolymphatic space dilatation's role in hearing loss.

CONCLUSIONS

In our study, two similar MRI grading systems were used; however, several differences were found compared to one another. The Bernaerts scale was more sensitive than the Barath scale, and several relationships between the radiological and clinical data were found. Therefore, several MRI evaluating scales and correlating them with the clinical features are needed. The increased perilymphatic enhancement of the cochlea and an extra low-grade vestibular hydrops distinguished in the Bernaerts scale may increase MD diagnosis sensitivity. Magnetic resonance findings in MD support the clinical diagnosis and may help to understand MD pathophysiology better. This study adds to the knowledge and diagnostics in MD for healthcare to improve patients' treatment.

Detecting Intralabyrinthine Pressure Increase by Postural Manipulation with Wideband Tympanometry and Distortion Product Otoacoustic Emissions

Objective

Intracranial pressure increase is known to affect inner ear pressure through the cochlear and vestibular aqueducts. This finding forms a good model for inner ear pressure studies. Standard techniques used to detect this pressure increase are neither reliable nor easily repeatable or cheap. Studies with immitancemetry and otoacoustic emissions have been giving hopeful results. This study aims to confirm the results in the literature with wideband tympanometry and add a new parameter of otoacoustic emissions to inner ear pressure testing.

Methods

Wideband tympanometry (WBT) and distortion product otoacoustic emissions (DPOAE) tests were applied to 40 healthy participants in sitting, supine, and Trendelenburg positions. DPOAE were measured under ambient or peak pressure. Resonance frequency, tympanic peak pressure, 1000, 1500, 2000, 3000, 4000, and 6000 Hz frequencies in DPOAE were measured.

Results

The increase in the tympanic peak pressure and the decrease in resonance frequency (RF) due to position change were found statistically significant (p<0.01). Signal noise ratio (SNR) decrease at 1 kHz frequency and SNR increase at 2, 3, 6 kHz in the normal protocol, SNR decrease at 1 kHz in the pressurized protocol were found statistically significant (p<0.01).

Conclusion

RF in WBT and 1 kHz DPOAE SNR parameters were found useful in supporting the diagnosis in pathologies that increase intracranial pressure and inner ear pressure. Future research may ease their widespread use in clinical practice as they are non-invasive and rapidly applicable.

Benign recurrent vestibulopathy: MRI and vestibular tests results in a series of 128 cases

PURPOSE

Benign recurrent vestibulopathy is a recent entity, close to probable Meniere's disease and vestibular-migraine. So far, no study has systematically investigated the presence of endolymphatic hydrops of the lateral semicircular canal in benign recurrent vestibulopathy using magnetic resonance imaging. The aim of this study was to determine magnetic resonance imaging data and vestibular test results in patients with benign recurrent vestibulopathy.

METHODS

128 patients with benign recurrent vestibulopathy included since 2010 were retrospectively analyzed. Patients had magnetic resonance imaging with a delayed acquisition, audiogram, head shaking test, caloric-test, skull-vibration-induced-nystagmus-test, video-head- impulse-test, and vestibular evoked myogenic potential. Endolymphatic hydrops presence was classified into four categories: cochlear, saccular, lateral semicircular canal and association with saccule.

RESULTS

In benign reccurent vestibulopathy, 23% of cases showed an endolymphatic hydrops on magnetic resonance imaging, more frequently located in the lateral semicircular canal (59%) and related to the disease duration. The most often impaired tests were caloric-test (49%) with fluctuations of hypofunction in 67% and skull-vibration-induced-nystagmus-test (61%). No correlation between the caloric-test and the presence and location of the endolymphatic hydrops was observed.

CONCLUSION

In our series of benign reccurent vestibulopathy, a rare endolymphatic hydrops was most often observed for the lateral semicircular canal and correlated with the seniority of the pathology. Hydrops identified at the magnetic resonance imaging was not correlated with the caloric-test results. Skull-vibration-induced-nystagmus-test and caloric-test were the most often modified vestibular tests.

Methods for Testing the Subjective Visual Vertical during the Chronic Phase of Menière's Disease

The subjective visual vertical (SVV) evaluates the function of the utricle, which, in patients with Menière’s disease (MD), can be affected by endolymphatic hydrops. This study aimed to determine the SVV in MD patients during the chronic phase of illness compared to healthy participants. The second aim was to compare the SVV measurement tools: the analog bucket test, digital bucket test, and C-SVV© goggles. The SVV scores differed significantly between MD patients and the control group for the analog bucket test (p < 0.001) and the C-SVV^® goggles (p = 0.028), but no significance was shown when using the digital bucket test (p = 0.062). When comparing the analog bucket test and the C-SVV^® goggles applying the calculated threshold (1.125° in analog bucket test, 2.5° in C-SVV^® goggles), the bucket test showed higher accuracy (bucket test 73.84%, C-SVV^® goggles 69.23%). When examining the influence of betahistine on SVV scores, there were no statistically significant differences in both the analog bucket test and C-SVV© goggles. We conclude that SVV test can be used as an additional tool to evaluate utricle function during the chronic phase of MD and that the analog bucket test produces the most reliable results. The intake of betahistine does not influence the perception of SVV.

The relationship between cochleovestibular function tests and endolymphatic hydrops grading on MRI in patients with Menière's disease

PURPOSE

In this retrospective study the relationship between cochleovestibular function and a magnetic resonance imaging (MRI-) based classification system of endolymphatic hydrops was investigated.

METHODS

Seventy-eight patients with unilateral definite Menière's disease who underwent MRI were included. The parameters of Pure Tone Audiometry (PTA), caloric irrigation test, cervical vestibular evoked myogenic potentials, and video Head Impulse Test were compared between the grades of endolymphatic hydrops (EH) and perilymphatic enhancement (PE) on MRI.

RESULTS

The low-frequency PTA was significantly different between cochlear EH grades I and II (p = 0.036; Grade I: mean (Standard Deviation, SD) = 51 decibel Hearing Level (dB HL) (18 dB HL); Grade II: mean (SD) = 60 dB HL (16 dB HL)), and vestibular EH grades 0 and III (p = 0.018; Grade 0: mean (SD) = 43 dB HL (21 dB HL); Grade III: mean = 60 dB HL (10 dB HL)). The ipsilateral caloric sum of ears with vestibular EH grade I (n = 6) was increased with regards to vestibular EH grades 0 (p = 0.001), II (p < 0.001), and III (p < 0.001) (Grade 0: mean (SD) = 24°/s (15°/s); Grade I: mean (SD) = 47°/s (11°/s); Grade II: mean (SD) = 21°/s (13°/s); Grade III: mean (SD) = 16°/s (8°/s)).

CONCLUSION

According to these results we can conclude that only the highest grades of cochlear and vestibular EH seem to be associated with decreased cochleovestibular functioning.

Magnetic resonance imaging of the inner ear in the diagnostics of Ménière's disease

Ménière's disease is characterized by sudden episodes of vertigo accompanied by tinnitus and/or feeling of fullness in the ear as well as fluctuating sensorineural hearing loss. Despite numerous studies, the etiology of this disease remains unknown. However, the enlargement of the inner ear's endolymphatic spaces, referred to as endolymphatic hydrops, is considered the underlying condition. Thanks to recent advances in magnetic resonance (MR) technology, it is now possible to obtain in vivo imaging of endolymphatic hydrops in patients presenting with Ménière's disease symptoms. Visualization of the inner ear fluid compartments is achieved after gadolinium contrast is administered into the tympanic cavity or via the intravenous route. Evaluation of endolymphatic hydrops is possible as the contrast agent selectively penetrates the perilymph, and endolymph is visualized as contrast defects. The currently used radiological hydrops grading systems include qualitative, semi-quantitative, and volumetric scales. The methods are subject to ongoing modifications to increase their sensitivity and specificity. Numerous studies describe correlations between clinical symptoms and audiological and otoneurological examination results with the endolymphatic hydrops grade. MRI is also applicable in patients' diagnostics with an incomplete or atypical course of the Ménière's disease. In the course of the treatment, follow-up MRI scans enable assessing individual treatment modalities' efficacy in terms of the severity of lesions and the further course of the disease within the inner ear.

[Labyrinth hydrops and its diagnosis]

The article deals with the basic theories of maze and labyrinth hydrops, which are often used in clinical practice for its diagnosis according to the world literature. Tonal threshold, suprathreshold audiometry, broadband thympanometry, ultrasound tests, test for determination of lateralization of loud sounds, dehydration test, extra-timbanical electrocochleography, method of registration of evoked vestibular myogenic potentials, study of vestibular function (video pulse test, caloric sample), CT of temporal bones with gadolinium, MRI, and other methods are considered. None of these study methods gives an accurate confirmation of the presence of maze hydrops. Only taking into account the history, complaints of the patient, clinical manifestations of the disease and a comprehensive evaluation of the results of all the above methods of study can we speak with confidence about hydropse.

Association of cervical vestibular-evoked myogenic potential tuning property test results with MRI findings of endolymphatic hydrops in Meniere's disease

PURPOSE

To examine the concordance between cervical vestibular-evoked myogenic potential (cVEMP) tuning property test results and MRI findings of endolymphatic hydrops (EH).

METHODS

Fourteen subjects (age 24-76 years) that had been diagnosed with unilateral definite Meniere's disease (MD) (N = 8) or unilateral probable MD (N = 6) were enrolled. All of the subjects underwent cVEMP tests (using 500 Hz and 1000 Hz tone bursts), pure-tone audiometry, and gadolinium-enhanced 3 T-MRI. To examine tuning properties of cVEMP, the 500-1000 Hz amplitude ratio was calculated as the SLOPE. The results of the cVEMP tuning property test results were compared with EH-related MRI findings.

RESULTS

EH positivity in both the cochlea and vestibule on MRI was observed in 7 of the 8 affected ears of definite MD and 3 of the 6 affected ears of probable MD, although it was only in one of the 14 unaffected ears. EH(+) or no response (NR) in cVEMP tuning property test was significantly associated with EH positivity on MRI, while EH(-) in the cVEMP tuning property test was significantly associated with EH-negativity on MRI (p = 0.0016 Fisher's exact test test).

CONCLUSION

EH(+) or NR in the cVEMP tuning property test correspond well to EH positivity in the MRI findings. The cVEMP tuning property test is useful for screening and following up EH.

Clinical characteristics in unilateral vestibular atelectasis

INTRODUCTION

Unilateral vestibular atelectasis (UVA), an entity first described by Merchant and Schuknecht in 1988, has rarely been reported in vivo as of yet. We specify here the clinical characteristics of 22 patients diagnosed with UVA.

MATERIALS AND METHODS

Patients with a radiological diagnosis of UVA who underwent delayed inner ear MRI were included between April 2017 and January 2020. Full clinical testing including ocular infrared video-oculography, oVEMPs, cVEMPs, vHIT, bithermal caloric testing and auditory testing was performed.

RESULTS

There were 13 men and 9 women, of mean age 58.6 ± 13.7 years. Onset was more frequently sudden (73%) than insidious (27%) though both clinical presentations were reported, and positional vertigo was described in 41% of cases. There were only two (9%) patients reporting Tullio's phenomenon. Vestibular testing showed that in 90% of cases, there was utricular dysfunction on oVEMP, while in 77% of cases, saccular function was preserved on cVEMP. vHIT showed high-velocity canal function impairment in all 22 patients: 8 patients (36%) had one impaired canal, 5 (23%) had two and 9 (41%) had all three canals affected. Caloric tests found complete unilateral areflexia, in 65% of tested cases, and partial deficiency in 35% of cases. Nine patients (40%) displayed asymmetrical hearing.

CONCLUSION

We described in this study the various clinical presentations of a disease rarely reported in vivo, UVA. Initial clinical presentation can appear similar to an acute vestibular deficit, a recurrent positional vertigo, or fluctuating dizziness.

Clinical and radiological characteristics of patients with collapse or fistula of the saccule as evaluated by inner ear MRI

Background: Delayed 3D-FLAIR sequences enable the distinction between the utricle and the saccule.Aims/objectives: We sought to evaluate the clinical and radiological findings in patients with no visible saccule (NVS) on 4-hour post-contrast MRI.Material and Methods: We retrospectively assessed the presence of NVS signs in 400 patients who underwent delayed inner ear MRI.Results: We reported on 28 patients with NVS. Among this group, on the NVS affected side: 14 had isolated sensorineural hearing loss (SNHL); 4 had fluctuating cochleo-vestibular disease; 3 had definite Menière's disease; 3 had Minor syndrome; 2 had delayed endolymphatic hydrops (EH); 2 had inner ear malformations; 1 had sudden cochleo-vestibular deficit following stapes surgery; 1 had a perilymphatic fistula and 1 had a contralateral fluctuating SNHL. Sixteen out of these 28 patients (57.1%) had cochlear hydrops on the same side as the NVS, while 10 patients (35.7%) had saccular hydrops on the contralateral side. Moreover, isolated blood labyrinth barrier (BLB) impairment on the NVS side was observed in 7 patients. Two patients (7.1%) had large vestibular aqueduct and NVS on the same side and one patient had perilymphatic fistula.Conclusions and significance: NVS seems to be multifactorial and could be linked to hydropic ear disease, third-mobile window pathologies and congenital malformation.

Comparison of Enhancement of the Vestibular Perilymph between Variable and Constant Flip Angle-Delayed 3D-FLAIR Sequences in Menière Disease

BACKGROUND AND PURPOSE

Endolymphatic hydrops in patients with Menière disease relies on delayed postcontrast 3D-FLAIR sequences. The purpose of this study was to compare the degree of perilymphatic enhancement and the detection rate of endolymphatic hydrops using constant and variable flip angles sequences.

MATERIALS AND METHODS

This was a retrospective study performed in 16 patients with Menière disease who underwent 3T MR imaging 4 hours after gadolinium injection using two 3D-FLAIR sequences with a constant flip angle at 140° for the first and a heavily-T2 variable flip angle for the second. The signal intensity ratio was measured using the ROI method. We graded endolymphatic hydrops and evaluated the cochlear blood-labyrinth barrier impairment.

RESULTS

Both for symptomatic and asymptomatic ears, the median signal intensity ratio was significantly higher with the constant flip angle than with the heavily-T2 variable flip angle (7.16 versus 1.54 and 7.00 versus 1.45, P < .001). Cochlear blood-labyrinth barrier impairment was observed in 4/18 symptomatic ears with the heavily-T2 variable flip angle versus 8/19 with constant flip angle sequences. With heavily-T2 variable flip angle sequences, endolymphatic hydrops was observed in 7-10/19 symptomatic ears versus 12/19 ears with constant flip angle sequences. We found a significant association between the clinical symptomatology and the presence of endolymphatic hydrops with constant flip angle but not with heavily-T2 variable flip angle sequences. Interreader agreement was always perfect with constant flip angle sequences while it was fair-to-moderate with heavily-T2 variable flip angle sequences.

CONCLUSIONS

3D-FLAIR constant flip angle sequences provide a higher signal intensity ratio and are superior to heavily-T2 variable flip angle sequences in reliably evaluating the cochlear blood-labyrinth barrier impairment and the endolymphatic space.