Does CISS MRI Reliably Depict the Endolymphatic Duct in Children with and without Vestibular Aqueduct Enlargement?

BACKGROUND AND PURPOSE: High-resolution CT is the mainstay for diagnosing an enlarged vestibular aqueduct (EVA), but MR imaging may be an appealing alternative, given its lack of ionizing radiation exposure. The purpose of this study was to determine how reliably MR imaging demonstrates the endolymphatic duct and endolymphatic duct enlargement in hearing-impaired children. MATERIALS AND METHODS: We performed a retrospective review of temporal bone high-resolution CT and MR imaging of hearing-impaired children evaluated between 2017 and 2020. Vestibular aqueduct diameter was measured on high-resolution CT. The vestibular aqueducts were categorized as being enlarged (EVA+) or nonenlarged (EVA-) using the Cincinnati criteria. The endolymphatic ducts were assessed on axial high-resolution CISS MR imaging. We categorized endolymphatic duct visibility into the following: type 1 (not visible), type 2 (faintly visible), and type 3 (easily visible). Mixed-effect logistic regression was used to identify associations between endolymphatic duct visibility and EVA. Interreader agreement for the endolymphatic duct among 3 independent readers was assessed using the Fleiss κ statistic. RESULTS: In 196 ears from 98 children, endolymphatic duct visibility on MR imaging was type 1 in 74.0%, type 2 in 14.8%, and type 3 in 11.2%; 20.4% of ears were EVA+ on high-resolution CT. There was a significant association between EVA+ status and endolymphatic duct visibility (P < .01). Endolymphatic duct visibility was type 1 in 87.1%, type 2 in 12.8%, and type 3 in 0% of EVA- ears and type 1 in 22.5%, type 2 in 22.5%, and type 3 in 55.0% of EVA+ ears. The predicted probability of a type 3 endolymphatic duct being EVA+ was 0.997. There was almost perfect agreement among the 3 readers for distinguishing type 3 from type 1 or 2 endolymphatic ducts. CONCLUSIONS: CISS MR imaging substantially underdiagnoses EVA; however, when a type 3 endolymphatic duct is evident, there is a >99% likelihood of an EVA.

Endolymphatic Duct and Sac Decompression: A New Life for an Old Technique.

BACKGROUND: Ménière's disease is an inner ear disorder causing recurrent vertigo, hearing loss, and tinnitus. Diagnosis is based on the variability of the symptoms over time and absence of radiological abnormalities. Medical therapy is effective only in a small percentage of patients. Surgical strategies remain controversial. In this article, we revisit a surgical technique neglected over the years: endolymphatic sac surgery. METHODS: Fifty-four patients affected by Ménière's disease underwent endolymphatic duct and sac decompression. According to the American Academy of Otolaryngology-Head and Neck Surgery criteria, vertigo control was evaluated with follow-up at 6 months, 1 year, and 2 years from the intervention. Hearing results were evaluated before the surgery and at 2 years of follow-up using the pure tone average. The results were compared with similar techniques of endolymphatic sac surgery described in the literature. RESULTS: According to the American Academy of Otolaryngology-Head and Neck Surgery criteria classification, 2 years after surgery, 87% patients achieved complete control of vertigo (class A). The hearing remained stable in 93.5% of patients. The results appear compatible with other publications data regarding endolymphatic sac surgeries. CONCLUSION: The duct and endolymphatic sac decompression allows the control of vertigo and preserves hearing from the pathological effects of Ménière's disease. The revised technique allows the functional restoration of endolymphatic homeostasis.

Quantitative assessment of inner ear variation in elasmobranchs.

Considerable diversity has been documented in most sensory systems of elasmobranchs (sharks, rays, and skates); however, relatively little is known about morphological variation in the auditory system of these fishes. Using magnetic resonance imaging (MRI), the inner ear structures of 26 elasmobranchs were assessed in situ. The inner ear end organs (saccule, lagena, utricle, and macula neglecta), semi-circular canals (horizontal, anterior, and posterior), and endolymphatic duct were compared using phylogenetically-informed, multivariate analyses. Inner ear variation can be characterised by three primary axes that are influenced by diet and habitat, where piscivorous elasmobranchs have larger inner ears compared to non-piscivorous species, and reef-associated species have larger inner ears than oceanic species. Importantly, this variation may reflect differences in auditory specialisation that could be tied to the functional requirements and environmental soundscapes of different species.

Endolymphatic Duct Blockage as a Surgical Treatment Option for Ménière's Disease.

Endolymphatic duct blockage is a relatively new treatment option for Ménière's disease, aiming to reduce vertigo attacks while sparing hearing and equilibrium. After a regular mastoidectomy, the posterior semicircular canal is identified, and Donaldson's line is determined. This is a line through the horizontal semicircular canal, crossing the posterior semicircular canal. The endolymphatic sac is usually found at this site under the posterior semicircular canal. The bone of the endolymphatic sac and the dura are thinned until the sac is skeletonized, after which the endolymphatic duct is identified. The duct is then blocked with a titanium clip. Using a computerized tomography (CT) scan, the position is confirmed. Follow-up visits take place 1 week, 6 weeks and 1 year after surgery. To this day, only one prospective trial assessing this method has been conducted, comparing this new method to endolymphatic sac decompression. Results of the duct blockage are promising, with 96.5% of the patients free of vertigo after 2 years. However, further research is required.

Meniere's Disease Patients with Distinct Sac Pathoanatomic Findings React Differently to Endolymphatic Duct Blockage.

OBJECTIVES: To explore the possible difference in response to endolymphatic duct blockage (EDB) treatment in patients with Meniere's disease (MD) with distinct pathoanatomic characteristics of the sac. METHODS: In a total of 24 patients with MD receiving EDB treatment, the dynamics of the vertigo attack, hearing, vestibular function, and endolymph hydrops (EH) before surgery and 40 months following surgery in patients with normoplastic extraosseous portion of endolymphatic sac (eES) were compared with that in patients with atrophic eES. RESULTS: A higher prevalence of complete vertigo control, better cochlear and vestibular function, and lower endolymph to vestibule-volume ratio were found in patients with normoplastic eES than in those with atrophic eES. Moreover, the reversal of EH was found in a total of six patients in normoplastic eES group, but no reversal of EH was detected in the atrophic eES group after surgery. CONCLUSIONS: A difference in response to EDB treatment was shown in the MD patients with normoplastic eES and those with atrophic eES; the reversal of EH was found in the normoplastic eES group, but not in the atrophic eES group after surgery, suggesting two distinct pathologies in the eESs may underlie the pathogenesis of EH in two subgroups of MD patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:2761-2769, 2023.

Auditory and imaging markers of atypical enlarged vestibular aqueduct.

PURPOSE: To characterize the auditory and imaging markers of atypical enlarged vestibular aqueduct (EVA). METHODS: 15 EVA cases (26 ears) confirmed via high-resolution MRI (HRMRI) that did not meet the Valvassori criterion on high-resolution CT (HRCT) were classified as atypical EVA. Another 21 EVA cases (40 ears) meeting the Valvassori criterion were randomly chosen as typical EVA. The hearing loss (HL), HRCT, and HRMRI findings were compared between the two groups. RESULTS: The difference of HL severity between atypical and typical EVA was not statistically significant (χ2 = 0.12, P > 0.05. The vestibular aqueducts (VA) of atypical EVA cases manifested as borderline dilation (n = 17), focal dilation (n = 3), and normal appearance (n = 6) on the HRCT. The midpoint width of atypical and typical EVA cases was 1.06 ± 0.18 mm and 2.10 ± 0.55 mm, respectively, exhibiting a significant difference (t = - 9.20, P < 0.05). In the HRMRI, the degree of dilation and shape of the intraosseous partition of endolymphatic duct and sac (ES) was similar to that of VA on HRCT, while their extraosseous ES was depicted variable slighter dilation compared to that of typical one, the difference between them was statistically significant (t = - 4.10, P < 0.05). CONCLUSION: The HL severity of atypical EVA ears was similar to that of typical ones. Nevertheless, borderline, focal dilation and normal-like appearance of VAs on HRCT and variablely slighter dilation of the extraosseous ES on HRMRI are its characteristic imaging findings.

A comparison of endolymphatic duct blockage, endolymphatic sac drainage and endolymphatic sac decompression surgery in reversing endolymphatic hydrops in Meniere's disease.

BACKGROUND: To explore the differences between endolymphatic duct blockage, endolymphatic sac drainage and endolymphatic sac decompression surgery in the reversal of endolymphatic hydrops (EH) in patients with intractable Meniere's disease (MD). METHODS: A total of 27 MD patients receiving endolymphatic duct blockage surgery (n = 10), endolymphatic sac drainage surgery (n = 9) and endolymphatic sac decompression surgery (n = 8) underwent gadolinium-enhanced inner ear magnetic resonance imaging (MRI) scans prior to, 2 weeks after and at > 12 months following surgery. RESULTS: In the group with endolymphatic duct blockage, the second MRI revealed no changes in EH, whereas the third MRI revealed a reversal of vestibular EH in 3 patients and a downgrading of cochlear hydrops in 2 of these 3 patients, who presented with an improvement in their hearing and complete control of vertigo. In the group with endolymphatic sac drainage, the second MRI showed a reversal of EH in 4 patients, and no changes in EH in the remaining 5 patients, whereas the third MRI showed that those 4 patients who presented with a reversal of EH at the second MRI stage remained unchanged except a recurrence of vestibular hydrops in 1 patient. All 4 patients exhibited a complete control of vertigo, but hearing improved in 1, worsened in 1 and remained unchanged in 2. In the group with endolymphatic sac decompression, both the second and third MRI examination revealed no reversal of EH. CONCLUSIONS: The present study has shown that both endolymphatic duct blockage surgery and endolymphatic sac drainage surgery have the potential to reduce EH in certain MD patients, but none of the patients receiving endolymphatic sac decompression surgery showed reversal of their EH.

3 Tesla MR imaging of the large endolymphatic duct and sac anomaly with audiological correlation.

PURPOSE: Large endolymphatic duct and sac (LEDS) is one of the most common imaging abnormalities in congenital sensorineural hearing loss and is frequently seen with coexistent cochlear anomalies, especially incomplete partition type II. However, MRI findings of accompanying cochlear and especially modiolar dysplasias may be subtle. The purpose of this study is to evaluate the imaging findings of LEDS with high-resolution imaging at 3 T and correlate with the audiological data. METHODS: 3 T temporal bone MRIs of 54 ears in 30 LEDS patients were retrospectively evaluated. The cochlear dysmorphism and modiolar deficiency were assessed qualitatively and quantitatively. The severity of LEDS anomaly, the signal changes within the LEDS and cochlea were also noted. The imaging findings were correlated to the audiological data. RESULTS: The cochlea was abnormal in 77.8% of the ears with an isolated modiolar deficiency in 11.1%. Cochlea and modiolus were completely normal in 11.1% of the ears. In 63% of the ears X-distance was increased. T2 hypointensity within LEDS and cochlea were detected in 42.6%, and 7.4% of the ears, respectively. The median diameters of LEDS were higher in ears with severe to profound HL than ears with normal to moderate HL (p < 0.05). The X-distance, presence of T2 hypointensity within LEDS, and diameters of modiolus did not show statistical correlation with the audiographic data. CONCLUSION: High-resolution 3 T imaging of patients with LEDS anomaly revealed a spectrum of cochlear anomalies, but up to 11.1% of the ears had no underlying anomaly despite severe (endolymphatic duct/sac) dilatation and/or profound HL.

Effectiveness of endolymphatic duct blockage versus endolymphatic sac decompression in patients with intractable Ménière's disease: study protocol for a double-blinded, randomised controlled trial.

INTRODUCTION: Outcomes of surgery for Ménière's disease (MD) remain discordant. Recently, a new surgical procedure in which the endolymphatic duct is clipped was proposed. To date, only one prospective trial assessing this technique was published, yielding promising results. This protocol describes a prospective, double-blinded, randomised controlled trial that will be carried out to assess the effectiveness of this surgical intervention. METHODS: Eighty-four patients with intractable MD will be recruited from 13 hospitals in the Netherlands. Intraoperatively, randomisation will determine whether endolymphatic duct blockage (EDB) or endolymphatic sac decompression (ESD) will be performed. Randomisation will be 1:1 stratified for gender and duration of MD (recent-onset versus mature MD). All participants receive vestibular rehabilitation after surgery. Patients are followed up during 1 year after surgery. Follow-up visits will take place at 1 week, 3 months, 6 months and 12 months after surgery. The main study endpoint is proportion of patients who are free of vertigo spells at 12 months postoperatively. Secondary parameters include cumulative number of vertigo bouts, co-intervention, tinnitus, hearing, quality of life, cost effectiveness and a budget impact analysis. Total duration of the study is 4 years. ANALYSIS: The primary analysis will follow the intention-to-treat principle. For the primary outcome, a χ2 test will be performed. Secondary outcomes will be analysed using a linear mixed model (EDB versus decompression group) at the different time measurement point. ETHICS AND DISSEMINATION: This study was reviewed and approved by a board of specialists before funding was obtained, as well as by the Medical Research Ethics Committee Leiden-The Hague-Delft and the boards of all participating centres. Results of this study will be published in international peer-reviewed scientific journals and will be presented on (inter)national scientific conferences and meetings. TRIAL REGISTRATION NUMBERS: NL9095 and ISRCTN12074571; Pre-Results.

MRI Evaluation of the Normal and Abnormal Endolymphatic Duct in the Pediatric Population: A Comparison with High-Resolution CT.

BACKGROUND AND PURPOSE: An enlarged vestibular aqueduct is the most commonly reported imaging abnormality in children with sensorineural hearing loss. MR imaging is often used to evaluate pediatric sensorineural hearing loss; however, there are no well-established size criteria on MR imaging to diagnose an enlarged endolymphatic duct. The first purpose of the study was to determine a range of normal endolymphatic duct sizes on MR imaging and compare it with that in high-resolution CT. The second purpose was to assess the sensitivity and specificity of MR imaging in diagnosing an enlarged endolymphatic duct in patients with an enlarged vestibular aqueduct on CT. MATERIALS AND METHODS: Endolymphatic duct midaperture measurements were analyzed in 52 patients with no history of sensorineural hearing loss. Comparison of CT and MR imaging was made in a second cohort of 41 patients with a normal midaperture width on CT. The sensitivity and specificity of MR imaging were then evaluated in a third cohort of 24 patients with a documented enlarged vestibular aqueduct on CT. RESULTS: In 94 ears, normal endolymphatic duct midaperture measurements ranged from 0 to 0.9 mm on MR imaging. A significant correlation (P <.001) and moderate agreement were found between CT and MR imaging in 81 ears with a normal vestibular aqueduct on CT. Twenty-four patients had bilateral (n = 14) or unilateral (n = 10) enlarged vestibular aqueducts on CT, and the sensitivity and specificity of MR imaging were 97% and 100%, respectively, for a diagnosis of an enlarged endolymphatic duct. CONCLUSIONS: MR imaging measurements of the normal endolymphatic duct are similar to those established for CT. MR imaging is a useful tool for the diagnosis of enlarged vestibular aqueduct.

Modulation of hearing function following the downgrading or upgrading of endolymphatic hydrops in Meniere's disease patients with endolymphatic duct blockage.

The present study was to investigate the dynamics of endolymphatic hydrops (EH) and hearing function, and explore whether the hearing loss is caused by EH alone and whether the hearing function can be modulated by changes in the EH. The extent of EH visualized by gadolinium (Gd)-enhanced inner ear magnetic resonance imaging, hearing thresholds and the summating potential/action potential ratio (-SP/AP ratio) of electrocochleography (ECochG) were recorded prior to and following surgery in 22 patients with intractable Meniere's disease (MD) who underwent endolymphatic duct blockage (EDB). The difference value of the hearing threshold and -SP/AP ratio was significantly positively correlated with the difference value of the endolymph to vestibule-volume ratio (EVVR) and grading of cochlear hydrops between prior to and following surgery. Among patients with a decreased EVVR, the average hearing threshold and -SP/AP ratio was significantly decreased following surgery, as compared to that prior to surgery. Six out of seven patients with a hearing improvement (≥10-dB decline) and 4/5 patients with a negative conversion of EcochG showed downgrading of their hydrops in the cochlea and/or vestibule. By contrast, among patients with an increased EVVR, the average hearing threshold and -SP/AP ratio tended to increase following EDB, as compared with that prior to surgery. One out of two patients with a hearing deterioration (≥10-dB elevation) showed upgrading of her hydrops in both cochlea and vestibule. The present results showed the downgrading of cochlear and/or vestibular hydrops accompanied by the downregulation of the hearing threshold and -SP/AP ratio of EcochG, as well as the upgrading of cochlear and/or vestibular hydrops that tended to upregulate the hearing threshold and -SP/AP ratio of EcochG; this suggested that hearing loss is likely to be caused by hydrops and that the impaired hearing function be modulated by changes in the hydrops.

Significance of high signal intensity in the endolymphatic duct on magnetic resonance imaging in ears with otological disorders.

BACKGROUND: High signal intensity in the endolymphatic duct (ED) is occasionally observed on magnetic resonance imaging (MRI) in ears that have otological disorders. OBJECTIVE: The signal intensity (SI) in the ED on post-contrast MRI was investigated in subjects with various otological disorders, and the meaning of high SI in the ED was evaluated. MATERIAL AND METHODS: 392 patients with otological disorders and 21 controls without otological symptoms underwent 3 T MRI. The SIs of the ED and the cerebellum were measured, the SI ratio (SIR) was calculated, and ears with SIR ≥4 were identified. RESULTS: A high SIR was identified in the ED of 3.7% of ears affected by definite Meniere's disease (dMD), 100% of ears affected by large vestibular aqueduct syndrome (LVAS), and 7.1% of ears with no otological symptoms. On the whole, a significant relationship was found between the existence of vestibular or cochlear EH and the SIR in the ED. CONCLUSION: The MRI finding of high SI in the ED may indicate the mechanism of inner ear disturbances in ears with otological disorders, especially in those with LVAS, and it may suggest an underlying disorder in some ears in which otological symptoms are not apparent.

Detailed MR imaging assessment of endolymphatic hydrops in patients with SLC26A4 mutations.

OBJECTIVE: Mutations in SLC26A4 represent the second most common mutations in deafness patients. The majority of patients with SLC26A4 mutations have a large vestibular aqueduct (LVA). Recently, some reports showed the presence of endolymphatic hydrops (ELH) in patients with LVA on the basis of high-resolution enhanced 3T-MRI. However, detailed evaluation has not been performed. We provide the first report on ELH in LVA patients with biallelic SLC26A4 mutations. In this study, we focused on 1) the findings of ELH in LVA patients with biallelic SLC26A4 mutations, and 2) the findings of the endolymphatic duct (ED) and endolymphatic sac (ES) by using two different gadodimide (Gd) enhancement methods. SUBJECTS AND METHODS: Five patients with SLC26A4 mutations underwent enhanced 3T-MRI using the intratympanic (IT) or intravenous (IV) injection of Gd for the diagnosis ELH. RESULTS: All of the patients had ELH in at least one ear. ELH was identified in the vestibule (8/10 ears) as well as in the cochlea (7/10 ears). With regard to the ED and ES, all ears for which MRI was performed with an IT injection of Gd had black areas in the ES or VA or both; however, all of the ears receiving an IV injection had no black areas and were well enhanced. CONCLUSIONS: A majority of the patients had severe ELH in the cochleo-vestibular endolymph, with two different patterns observed in the MRI findings of the ED and ES.

A Micro-CT and Synchrotron Imaging Study of the Human Endolymphatic Duct with Special Reference to Endolymph Outflow and Meniere's Disease.

Meniere's disease remains enigmatic, and has no treatment with sufficient evidence. The characteristic histopathological finding is endolymphatic hydrops, suggesting either an overproduction or decreased reabsorption of endolymph in the human inner ear. This study presents the first analysis of the vascular plexus around the human endolymphatic duct using micro computed tomography and coherent synchrotron radiation with phase contrast imaging. Using a software program, data were processed by volume-rendering with scalar opacity mapping to create transparent three-dimensional reconstructions. A rich vascular plexus was discovered around the endolymphatic duct that drained into collecting channels, linked to the vestibular venous outflow system. This network is believed to make up the principal route for endolymph outflow, and its associated malfunction may result in endolymphatic hydrops and Meniere's disease.

Magnetic resonance imaging of endolymphatic space in patients with sensorineural hearing loss: comparison between fluctuating and idiopathic sudden sensorineural hearing loss.

Background: Recently, 3-Tesla magnetic resonance imaging (MRI) after an intravenous gadolinium injection has been used to describe the endolymphatic space (ELS).Objectives: This study described the histopathological differences between idiopathic sudden sensorineural hearing loss (ISSNHL) and fluctuating sensorineural hearing loss (FSNHL) by examining the ELS. Additionally, the relationship between the affected cochlear and vestibular ELS/total fluid space (TFS) volume ratio and the duration from the onset to MRI in patients with FSNHL were evaluated.Material and methods: This study included 205 individuals without vertigo: 47 controls, 94 with ISSNHL, and 64 with FSNHL. The TFS and ELS volumes were measured and the ELS/TFS volume ratios (%) were evaluated.Results: The cochlear and vestibular ELS/TFS volume ratios of the affected ear in patients with FSNHL were significantly higher than that in those with ISSNHL. There was no correlation between the duration from FSNHL onset to the MRI scan in the affected cochlea and vestibule.Conclusion and significance: There were differences in the form of hearing fluctuation and the extended ELS volume between ISSNHL and FSNHL. ISSNHL cases with severe ELS extension were likely to change to FSNHL.

Magnetic resonance-based volumetric measurement of the endolymphatic space in patients with Meniere's disease and other endolymphatic hydrops-related diseases.

OBJECTIVE: To employ magnetic resonance imaging (MRI) to measure the volume of the inner ear endolymphatic space (ELS) in patients with acute low-tone sensorineural hearing loss (ALHL), sudden deafness (SD), cochlear Meniere's disease (cMD), and unilateral MD (uMD) compared with control subjects (CS) with chronic rhinosinusitis. METHODS: Forty-one patients with ALHL, 82 with SD, 48 with cMD, 72 with uMD, and 47 CS participated in the study. With the exception of all uMD patients, none of the subjects had vertigo. Images of the inner ear fluid space, positive perilymph signal, and positive endolymph signal were acquired using a 3-T MRI scanner. Three-dimensional images were reconstructed semi-automatically by using anatomical and tissue information to fuse the inner ear fluid space images and the ELS images. RESULTS: The cochlear ELS/total fluid space (TFS) volume ratio was 10.2±6.7% (mean±standard deviation) in the CS group, 12.1±5.7% in ALHL patients, 15.2±8.7% in SD patients, 18.1±8.2% in cMD patients, and 21.9±16.4% in uMD patients. The vestibular ELS/TFS volume ratio was 17.7±10.2% in the CS group, 18.9±8.3% in ALHL patients, 19.9±11.3% in SD patients, 22.5±13.7% in cMD patients, and 35.7±24.1% in uMD patients. The cochlear ELS/TFS volume ratio in patients with uMD was similar to that in the cMD group and significantly higher than that in the CS, ALHL, and SD groups (CS=ALHL

MR Imaging in Menière Disease: Is the Contact between the Vestibular Endolymphatic Space and the Oval Window a Reliable Biomarker?

BACKGROUND AND PURPOSE: No reliable MR imaging marker for the diagnosis of Menière disease has been reported. Our aim was to investigate whether the obliteration of the inferior portion of the vestibule and the contact with the stapes footplate by the vestibular endolymphatic space are reliable MR imaging markers in the diagnosis of Menière disease. MATERIALS AND METHODS: We retrospectively enrolled 49 patients, 24 affected by unilateral sudden hearing loss and 25 affected by definite Menière disease, who had undergone a 4-hour delayed 3D-FLAIR sequence. Two readers analyzed the MR images investigating whether the vestibular endolymphatic space bulged in the third inferior portion of the vestibule contacting the stapes footplate. This sign was defined as the vestibular endolymphatic space contacting the oval window. RESULTS: We analyzed 98 ears: 27 affected by Menière disease, 24 affected by sudden sensorineural hearing loss, and 47 that were healthy. The vestibular endolymphatic space contacting the oval window showed an almost perfect interobserver agreement (Cohen κ = 0.87; 95% CI, 0.69-1). The vestibular endolymphatic space contacting oval window showed the following: sensitivity = 81%, specificity = 96%, positive predictive value = 88%, and negative predictive value = 93% in differentiating Menière disease ears from other ears. The vestibular endolymphatic space contacting the oval window showed the following: sensitivity = 81%, specificity = 96%, positive predictive value = 96%, negative predictive value = 82% in differentiating Menière disease ears from sudden sensorineural hearing loss ears. CONCLUSIONS: The vestibular endolymphatic space contacting the oval window has high specificity and positive predictive value in differentiating Menière disease ears from other ears, thus resulting in a valid tool for ruling in Menière disease in patients with mimicking symptoms.

Endolymphatic duct blockage for refractory Ménière's disease: assessment of intraoperative CSF leak on short-term surgical outcomes.

BACKGROUND: Endolymphatic sac decompression has shown limited success for the treatment of Ménière's disease (MD). We have published a novel technique with very promising results for the treatment of refractory MD: the Endolymphatic Duct Blockage (EDB) with two titanium clips. One of the challenges of this technique was an increased incidence of intraoperative Cerebrospinal Fluid (CSF) Leak. OBJECTIVE: To assess the effect of intraoperative CSF Leak on short-term surgical outcomes. METHODS: Retrospective comparative study in a tertiary care center (61 patients). MD patients who underwent EDB were included. Intraoperative CSF Leaks were documented. Surgical outcomes assessed were the presence of postoperative Benign Paroxysmal Positional Vertigo (BPPV), aural fullness, tinnitus, vertigo spells and pure tone average (PTA), speech discrimination scores (SDS) and bone conduction thresholds (BCT). Data were collected for these visits: preoperative, 1 week, 1 and 6 months postoperatively. RESULTS: Outcomes for the CSF Leak group (CSF +) (n = 22) were compared to remaining patient (CSF-) (n = 39). There was no significant difference in the occurrence of postoperative BPPV, aural fullness, tinnitus and vertigo spells. There was no significant difference in PTA, BCT or SDS between our groups at any visit. CONCLUSIONS: Intraoperative CSF Leak may cause a temporary non-significant worsening of hearing in the first-month postoperatively without any difference at 6 months.

Claudin expression in the rat endolymphatic duct and sac - first insights into regulation of the paracellular barrier by vasopressin.

Hearing and balance functions of the inner ear rely on the homeostasis of the endolymphatic fluid. When disturbed, pathologic endolymphatic hydrops evolves as observed in Menière's disease. The molecular basis of inner ear fluid regulation across the endolymphatic epithelium is largely unknown. In this study we identified the specific expression of the tight junction (TJ) molecules Claudin 3, 4, 6, 7, 8, 10, and 16 in epithelial preparations of the rat inner ear endolymphatic duct (ED) and endolymphatic sac (ES) by high-throughput qPCR and immunofluorescence confocal microscopy. Further we showed that Claudin 4 in the ES is a target of arginine-vasopressin (AVP), a hormone elevated in Menière's disease. Moreover, our transmission-electron microscopy (TEM) analysis revealed that the TJs of the ED were shallow and shorter compared to the TJ of the ES indicating facilitation of a paracellular fluid transport across the ED epithelium. The significant differences in the subcellular localization of the barrier-forming protein Claudin 3 between the ED and ES epithelium further support the TEM observations. Our results indicate a high relevance of Claudin 3 and Claudin 4 as important paracellular barrier molecules in the ED and ES epithelium with potential involvement in the pathophysiology of Menière's disease.