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Endolymphatic sac tumour (ELST) is a rare low-grade locally aggressive neoplasm arising from the endolymphatic duct or sac. It presents mostly with vestibulo-cochlear symptoms either sporadically or as part of von Hippel–Lindau (VHL) syndrome. Micro-neurosurgical excision remains the cornerstone of therapy with the role of radiotherapy (RT) being controversial. This is a clinico-pathological analysis of consecutive ELST patients presenting to a single-institution in India. Neuropathology database of a tertiary-care comprehensive cancer centre was searched electronically to identify consecutive patients with histopathological diagnosis of ELST registered at the institute over last one decade. Data regarding demographic profile, clinical presentation, histopathological features, treatment details and outcomes were retrieved from electronic medical records for this retrospective analysis. Electronic search identified seven unique patients with biopsy-proven ELST registered at the institute between 2009 and 2020. Median age of the study cohort was 39 years (range 24–65 years) with strong male predilection (5:2 ratio) and left-sided preponderance (71%). Most common presenting symptoms were hearing loss (86%) and earache (71%) on affected side followed by headache (43%). All patients underwent maximal safe resection at initial diagnosis and were followed-up closely with periodic surveillance imaging. Two patients underwent salvage RT using high-precision conformal techniques at recurrence/progression. ELST is a rare low-grade locally aggressive neoplasm that arises generally as part of VHL syndrome or sometimes sporadically. Gross total resection provides the best chance of cure with RT being reserved for unresectable disease, large residue, medical inoperability, or as salvage therapy for recurrent/progressive tumor.

OBJECTIVE To analyse application value of CT and MRI in the diagnosis of large vestibular aqueduct syndrome (LVAS) in children. STUDY DESIGN A descriptive study. PLACE AND DURATION OF STUDY Department of ENT, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, China, from January 2014 to January 2018. METHODOLOGY Children with LVAS confirmed by CT, with different degrees of hearing loss and vertigo, less than 18 years, with complete clinical and imaging data, were included. Children under 2 years, with other serious diseases in organs, poor compliance, with other genetic diseases, were excluded. CT and MRI diagnosis data of 25 cases (50 diseased ears) with LVAS were retrospectively analysed. CT and MRI imaging results were observed. Midpoint and external aperture diameter of vestibular aqueduct in CT, MRI diagnosis were compared. RESULTS CT images showed visible vestibular aqueducts in different degrees of enlargement and bone defect shadow in different shapes. Vestibular aqueducts were enlarged in the 3D image after VR reconstruction. MRI images showed higher signal of endolymphatic sac and endolymphatic ducts in varying degrees of enlargement, and endolymphatic sac was enlarged in the 3D image after VR reconstruction. Midpoint diameter of vestibular aqueduct was larger in CT than in MRI diagnosis (p

In an attempt to develop an animal model of immune mediated Meniere's disease, we have injected lipopolysaccharide (LPS) directly into scala media of guinea pigs and monitored functional and morphological changes over a period of 6 weeks. Depending on the concentration of LPS, changes ranged from moderate-to-severe hearing loss and endolymphatic hydrops with minimal cellular infiltrate or fibrosis, to dense cellular infiltration that filled the scalae. Interestingly, higher concentrations of LPS not only induced severe cellular infiltration, hydrops, and hearing loss, but also a substantial enlargement of the endolymphatic duct and sac. Moreover, LPS injections into perilymph failed to induce hydrops, yet still resulted in cellular infiltration and fibrosis in the cochlea. This suggests that chronic hydrops resulting from an immune challenge of the cochlea may not be due to blockage of the endolymphatic duct and sac, restricting fluid absorption. Furthermore, injecting antigen into endolymph may produce chronic immune-mediated hydrops, and provide a more promising animal model of Meniere's, although animals did not display signs of vestibular dysfunction, and the hearing loss was relatively severe.

Objective Pediatric sudden sensorineural hearing loss (pSSNHL) is a rare phenomenon. There is currently no consensus on the role of imaging in the work-up for this patient population. We aim to evaluate the efficacy of magnetic resonance imaging (MRI) and high-resolution computed tomography (CT) studies in determining the etiology of pSSNHL. Study design Retrospective case review. Setting Tertiary Hospital and Ambulatory Otolaryngology Clinic. Patients Patients ≤18 years of age with sudden sensorineural hearing loss (SSNHL) and who had either MRI or CT imaging between January 2010 and May 2019 were included. Intervention Diagnostic imaging. Main outcome measures Clinical characteristics and radiology impressions. Results A total of 11 patients were identified, and 10 had unilateral SSNHL. MRI was performed on all patients, five patients had additional CT imaging. Abnormal imaging findings relevant to SSNHL were observed in five patients (45.5%), which included enlarged endolymphatic duct and sac, labyrinthine ossification, apical petrositis, hypoplastic cochlear nerve, and arachnoid cyst in the internal auditory canal; one patient had unrelated findings (enlarged pituitary gland), all remaining imaging studies were normal. Conclusion In our cohort, we found a higher imaging yield on pSSNHL than what has been reported for adult populations, indicating that the use of imaging in the diagnostic work-up is especially important in children.

Background: The etiology of Meniere's disease (MD) and endolymphatic hydrops believed to underlie its symptoms remain unknown. One reason may be the exceptional complexity of the human inner ear, its vulnerability, and surrounding hard bone. The vestibular organ contains an endolymphatic duct system (EDS) bridging the different fluid reservoirs. It may be essential for monitoring hydraulic equilibrium, and a dysregulation may result in distension of the fluid spaces or endolymphatic hydrops.Material and Methods: We studied the EDS using high-resolution synchrotron phase contrast non-invasive imaging (SR-PCI), and micro-computed tomography (micro-CT). Ten fresh human temporal bones underwent SR-PCI. One bone underwent micro-CT after fixation and staining with Lugol's iodine solution (I2KI) to increase tissue resolution. Data were processed using volume-rendering software to create 3D reconstructions allowing orthogonal sectioning, cropping, and tissue segmentation.Results: Combined imaging techniques with segmentation and tissue modeling demonstrated the 3D anatomy of the human saccule, utricle, endolymphatic duct, and sac together with connecting pathways. The utricular duct (UD) and utriculo-endolymphatic valve (UEV or Bast's valve) were demonstrated three-dimensionally for the first time. The reunion duct was displayed with micro-CT. It may serve as a safety valve to maintain cochlear endolymph homeostasis under certain conditions.Discussion: The thin reunion duct seems to play a minor role in the exchange of endolymph between the cochlea and vestibule under normal conditions. The saccule wall appears highly flexible, which may explain occult hydrops occasionally preceding symptoms in MD on magnetic resonance imaging (MRI). The design of the UEV and connecting ducts suggests that there is a reciprocal exchange of fluid among the utricle, semicircular canals, and the EDS. Based on the anatomic framework and previous experimental data, we speculate that precipitous vestibular symptoms in MD arise from a sudden increase in endolymph pressure caused by an uncontrolled endolymphatic sac secretion. A rapid rise in UD pressure, mediated along the fairly wide UEV, may underlie the acute vertigo attack, refuting the rupture/K+-intoxication theory.

Objective: The purpose of the present study was to evaluate the dynamics of endolymphatic hydrops (EH) and symptoms in a group of patients who underwent endolymphatic duct blockage (EDB) for treatment of intractable Meniere's Disease (MD), and to explore a metric for verifying the effectiveness of EDB procedure.Methods: A total of 22 patients with intractable MD patients who underwent EDB participated in the present study. EH was visualized using locally enhanced inner ear magnetic resonance imaging (MRI) prior to and following surgery. The vestibular hydrops ratio (VHR) in the second MRI examination was compared with the pre-surgery recordings.Results: Following EDB, 6 patients exhibited complete or partial reversal of EH, complete control of vertigo spells and reported improvement in hearing; 13 patients showed no changes in EH or hearing, but 5 of these patients exhibited complete control of vertigo attacks, and the other 8 patients exhibited improved control of vertigo attacks. The final 3 patients showed an increase in EH, but symptomatic worsening in 2 patients, and symptomatic improvement in 1 patient. There was a significant difference in the average VHR prior to and following EDB. Postoperative VHR was positively correlated with the frequency of vertigo spells in the latest 6 months of follow-up and improvement of postoperative average hearing threshold.Conclusion: The decreased EH accompanying the reduction in vertigo attacks and hearing preservation may provide a metric for verifying the effectiveness of EDB treatment in patients with MD.

Background: Reports vary on the incidence of vestibular dysfunction and dizziness in patients following cochlear implantation (CI). Disequilibrium may be caused by surgery at the cochlear base, leading to functional disturbances of the vestibular receptors and endolymphatic duct system (EDS) which are located nearby. Here, we analyzed the three-dimensional (3D) anatomy of this region, aiming to optimize surgical approaches to limit damage to the vestibular organ.Material and Methods: A total of 22 fresh-frozen human temporal bones underwent synchrotron radiation phase-contrast imaging (SR-PCI). One temporal bone underwent micro-computed tomography (micro-CT) after fixation and staining with Lugol's iodine solution (I2KI) to increase tissue contrast. We used volume-rendering software to create 3D reconstructions and tissue segmentation that allowed precise assessment of anatomical relationships and topography. Macerated human ears belonging to the Uppsala collection were also used. Drilling and insertion of CI electrodes was performed with metric analyses of different trajectories.Results and Conclusions: SR-PCI and micro-CT imaging demonstrated the complex 3D anatomy of the basal region of the human cochlea, vestibular apparatus, and EDS. Drilling of a cochleostomy may disturb vestibular organ function by injuring the endolymphatic space and disrupting fluid barriers. The saccule is at particular risk due to its proximity to the surgical area and may explain immediate and long-term post-operative vertigo. Round window insertion may be less traumatic to the inner ear, however it may affect the vestibular receptors.

IntroductionOutcomes 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.MethodsEighty-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.AnalysisThe 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 disseminationThis 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 numbersNL9095 and ISRCTN12074571; Pre-Results.

To characterize the auditory and imaging markers of atypical enlarged vestibular aqueduct (EVA). 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. 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

To explore the differences between endolymphatic duct blockage (EDB) and endolymphatic sac drainage (EDD) surgery in the reversal of endolymphatic hydrops (EH) in patients with intractable Meniere’s disease (MD). A total of 19 MD patients receiving EDB (n=10) and EDD (n=9) treatment underwent gadoliniumenhanced inner ear magnetic resonance imaging (MRI) scans prior to, 2 weeks after and at >12 months following surgery. In the EDB group, 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 EDD group, 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, with the exception of one patient who experienced a recurrence of vestibular hydrops. All 4 patients exhibited a complete control of vertigo, although hearing improved in only 1 of them, worsened in 1 and remained unchanged in 2. The present study showed the reversal in EH was likely due to the delayed effect of surgery accompanied by an improvement in hearing in EDB group, whereas the reduction in the endolymph volume presented as an acute reversal of hydrops in EDD group without a causeeffect relationship with hearing function.

Endolymphatic hydrops is an enlargement of scala media that is most often associated with Meniere's disease, though the pathophysiologic mechanism(s) remain unclear. In order to adequately study the attributes of endolymphatic hydrops, such as the origins of low-frequency hearing loss, a reliable model is needed. The guinea pig is a good model because it hears in the low-frequency regions that are putatively affected by endolymphatic hydrops. Previous research has demonstrated that endolymphatic hydrops can be induced surgically via intradural or extradural approaches that involve drilling on the endolymphatic duct and sac. However, whether it was possible to create an endolymphatic hydrops model using an extradural approach that avoided dangerous drilling on the endolymphatic duct and sac was unknown. The objective of this study was to demonstrate a revised extradural approach to induce experimental endolymphatic hydrops at 30 days post-operatively by obliterating the endolymphatic sac and injuring the endolymphatic duct with a fine pick. The sample size consisted of seven guinea pigs. Functional measurements of hearing were made and temporal bones were subsequently harvested for histologic analysis. The approach had a success rate of 86% in achieving endolymphatic hydrops. The risk of cerebrospinal fluid leak was minimal. No perioperative deaths or injuries to the posterior semicircular canal occurred in the sample. The presented method demonstrates a safe and reliable way to induce endolymphatic hydrops at a relatively quick time point of 30 days. The clinical implications are that the presented method provides a reliable model to further explore the origins of low-frequency hearing loss that can be associated endolymphatic hydrops.

Three vascular routes to the inner ear are known: (a) through the internal acoustic meatus with the vestibulocochlear nerve; (b) from the endolymphatic duct aperture; and (c) along the canal of Cotugno (CC) inserted into the vestibular part of the ear from the superior or brain side. The third is believed to contain only veins. Examinations of 33 human embryos and fetuses at 6-40 weeks demonstrated that (a) the CC appeared as a recess of epidural mesenchymal tissues at the superior aspect of the otic capsule cartilage in embryos and it was inserted deeply to issue multiple peripheral divisions inferolaterally and posteriorly at midterm; (b) the CC consistently passed through a ring of the superior or anterior semicircular canal and contained both, the arteries from the vestibulocochlear nerve origin at the midbrain and the vein draining into the sigmoid sinus or petrosal sinuses; and (c) the CC appeared not to contribute to ossification of the otic capsule cartilage but, after endochondral ossification of the internal ear, woven bone development occurred along a smooth interface of the CC with the ossified ear. In contrast, another interface between the developing bone and the residual cartilage of the otic capsule was rough and wavy with many short bony columns, called osseous globules. In addition, the endolymphatic duct accompanied veins but no arteries. Our results show that the CC is a major vascular route to the vestibular part of the otic capsule cartilage, but its role appears to be limited after ossification.

Application of surgical endoscope, used alone or in combination with the surgical microscope, for the operative management of ear and temporal bone conditions may allow improved access and clearance of disease. Preservation of normal structures may also be improved.As the use of this tool is increasing, the need for better understanding of the anatomy of the ear is becoming evident. This is particularly so for endoscopic surgery aiming at removal of lesions involving the infra-cochlear corridor and/or petrous apex.Human temporal bone-derived labyrinth casts (molds), originally made for endolymphatic duct and sac analysis which genuinely represent the membranous labyrinth and its adjacent soft tissues, were morphometrically analyzed in terms of the anatomic relations between structures in and around the infra-cochlear corridor. The distance between the petrous carotid artery (PCA) and the basal turn of the cochlea, the distance between PCA and infra-cochlear vein (ICV)/cochlear aqueduct (CA), and the distance between the lower surface of basal cochlear turn and the point where the carotid artery and jugular vein (JV) meet close to the jugular foramen, were measured to be around 1.3 mm, 6 mm and 8 mm respectively, thus constituting an approximate 6 × 8 mm2 infra-cochlear corridor. This analysis and further study with larger samples might be helpful for operation via this corridor led to the petrous apex where cholesterol granuloma, cholesteatoma and other lesions are not uncommon. Keywords: Infra-cochlear corridor, Petrous apex, Anatomical study, Ear endoscopy, Surgery

Objectives Endolymphatic sac (ELS) pathophysiology in Ménière's disease (MD) remains poorly understood. We identified from the literature a group of proteins expressed on the ELS and involved in endolymph volume regulation: aquaporin-2 (AQP2), vasopressin receptor V2R, sodium potassium chloride cotransporter 2 (NKCC2), and transient receptor potential cation channel V4 (TRPV4). Our objective was to determine whether their ELS expression was altered in MD, to better understand the pathophysiology of endolymphatic hydrops. Study Design Prospective case-control study. Setting Tertiary care center. Subjects Twenty-four patients with definite MD undergoing endolymphatic duct blockage surgery were recruited, as well as 23 controls with no history of MD undergoing surgery for vestibular schwannoma (VS). Methods ELS biopsies and blood samples for plasma arginine vasopressin (AVP) were obtained. Immunohistochemistry for AQP2, V2R, NKCC2, and TRPV4 was performed. Slides were scanned digitally for highly sensitive pixel density analysis by specialized software (VIS; Visiopharm). Results Global scores generated by the software represent total and relative protein expression density of 3 staining intensity levels, exclusively on ELS epithelium. AQP2 expression density was significantly elevated in MD compared to VS ( P = .003). There was no significant difference in plasma AVP, V2R, NKCC2, and TRPV4 expression. Conclusion This original study evaluates simultaneous in situ expression of AQP2, V2R, NKCC2, and TRPV4 on the human ELS in MD, with a control group. Our results show only AQP2 upregulation on the ELS of patients with MD. We suggest a constitutively increased expression of AQP2 in MD, independent of its regulatory axis (AVP-V2R). Acquired regulator sequence mutations could support this model.

Objectives Vestibular schwannomas (VS) extending into the internal auditory canal (IAC) are currently considered as an unfavorable condition for hearing preservation surgery (HPS) via retrosigmoid (RS) approach due to the poor direct visualization of the facial and cochlear nerves course through the IAC and the fundus during microsurgery. Design The operative steps are described in a surgical instructional video. Setting The surgery took place at a tertiary-care center. Participants Patient is a 45-year-old man who was incidentally diagnosed with an extrameatal VS extending for 9 mm into the left cerebellopontine angle (CPA). Hearing function at diagnoses was excellent, with pure tone average (PTA) = 15 dB and speech discrimination score (SDS) = 100% (class A according to the Tokyo classification) and minimal impairments on auditory brainstem response (ABR). Given these preoperative features in small VS, hearing was the main function to look into in the treatment planning. Initial observation or HPS were proposed. Results The patient underwent surgical excision for HPS via RS approach combined with retrolabyrinthine meatotomy (RLM). RLM enables the complete exposure of the IAC to the fundus, after drilling the bony surface of the posterior IAC wall, under guidance of the anatomical landmarks, namely, the endolymphatic duct, the blue lines of the posterior, and superior semicircular canals, and common crus. Nor intra-, neither postoperative complications occurred. Histologic examination confirmed the diagnosis of VS. A 3-month short-term follow-up revealed a class B hearing function with PTA = 30 dB, SDS = 100%, and normal facial nerve status. Conclusions RLM via RS approach proved to be effective for HPS, enabling the full course of the facial and cochlear nerves through the IAC to be directly exposed.The link to the video can be found at: https://youtu.be/KC1S4pxpLCk.

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

Objective The purpose of the study was to investigate the difference in the responses of endolymphatic hydrostatic pressure to isoproterenol, β-adrenergic receptor agonist, between pars superior and pars inferior. Methods The hydrostatic pressure of endolymph and perilymph and endolymphatic potential in the ampulla and the cochlea during the intravenous administration of isoproterenol were recorded using a servo-null system in guinea pigs. Results The hydrostatic pressure of endolymph and perilymph in the ampulla and cochlea was similar in magnitude. Isoproterenol significantly increased hydrostatic pressure of ampullar and cochlear endolymph and perilymph with no change in the ampullar endolymphatic potential and endocochlear potential, respectively. The isoproterenol-induced maximum change of endolymphatic hydrostatic pressure in ampulla was significantly (p

Introduction The endolymphatic sac is thought to maintain the hydrostatic pressure and endolymph homeostasis for the inner ear, and its dysfunction may contribute to the pathophysiology of Ménière's disease. Throughout the years, different surgical procedures for intractable vertigo secondary to Ménière's disease have been described, and though many authors consider these procedures as effective, there are some who question its long-term efficacy and even those who think that vertigo control is achieved more due to a placebo effect than because of the procedure itself. Objective To review the different surgical procedures performed in the endolymphatic sac for the treatment of Ménière's disease. Data Sources PubMed, MD consult and Ovid-SP databases. Data Synthesis We focus on describing the different surgical procedures performed in the endolymphatic sac, such as endolymphatic sac decompression, endolymphatic sac enhancement, endolymphatic sac shunting and endolymphatic duct blockage, their pitfalls and advantages, their results in vertigo control and the complication rates. The senior author also describes his experience after 30 years of performing endolymphatic sac surgery. Conclusions The endolymphatic sac surgery, with all its variants, is a good option for patients with incapacitating endolymphatic hydrops, providing a high percentage of vertigo control and hearing preservation.

Objective Endolymphatic sac decompression (ESD) for the treatment of Meniere's disease (MD) has had limited success and variable results in the literature. We have devised a novel technique that involves blocking the endolymphatic duct with surgical clips. In a separate effort to study the endolymphatic sac (ELS), we have sectioned the lateral part of the main body of the ELS as biopsies from a subset of patients. We aimed to evaluate the effect of the lateral part sectioning of the ELS on short-term surgical outcomes. Materials and methods This was a single-physician, retrospective study in a tertiary medical center. MD patients underwent endolymphatic duct blockage (EDB) surgery with or without ELS biopsy. The assessed surgical outcomes were the occurrence of benign paroxysmal positional vertigo (BPPV), intraoperative CSF leaks, aural fullness, tinnitus, vertigo spells, and pure tone audiometry. Data were collected at the following visits: preoperatively 1st week, 1st month, and 6th months. Results A total of 63 patients were included. The outcomes of the biopsy group (EDB+B) (n=27) were compared to those of the EDB group (n=36) at each visit. There was no significant difference in the occurrence of postoperative BPPV, CSF leaks, aural fullness, tinnitus, or vertigo spells. The SDS, the PTA, and bone conduction were not significantly different at any visit, and PTA variations were similar in both groups. Conclusion Our results suggest that aggressive decompression of the ELS by sectioning the sac does not benefit patients in the early postoperative period. The short-term success of EDB surgery is attributable to the effective obstruction of the endolymphatic duct regardless of pressure in the ELS.

Hizli, Omer/0000-0001-6822-2679; (Bingol) Hizli, Pelin/0000-0001-8919-3125 WOS: 000383312600004 PubMed: 26860231 Objective: To observe any changes in stria vascularis and cochlear hair cells in patients with syphilis. Materials and methods: We examined 13 human temporal bone samples from 8 patients with syphilis (our syphilis group), as well as 12 histopathologically normal samples from 9 age-matched patients without syphilis (our control group). We compared, between the two groups, the mean area of the stria vascularis (measured with conventional light microscopy connected to a personal computer) and the mean percentage of cochlear hair cell loss (obtained from cytocochleograms). Results: In our syphilis group, only 1 (7.7%) of the 13 samples had precipitate in the endolymphatic or perilymphatic spaces; 8 (61.5%) of the samples revealed the presence of endolymphatic hydrops (4 cochlear, 4 saccular). The mean area of the stria vascularis did not significantly differ, in any turn of the cochlea, between the 2 groups (P > 0.1). However, we did find significant differences between the 2 groups in the mean percentage of outer hair cells in the apical turn (P < 0.026) and in the mean percentage of inner hair cells in the basal (P = 0.001), middle (P = 0.004), and apical (P = 0.018) turns. In 7 samples in our syphilis group, we observed either complete loss of the organ of Corti or a flattened organ of Cord without any cells in addition to the absence of both outer and inner hair cells. Conclusion: In this study, syphilis led either to complete loss of the organ of Corti or to significant loss of cochlear hair cells, in addition to cochleosaccular hydrops. But the area of the stria vascularis did not change. (C) 2016 Elsevier Ireland Ltd. All rights reserved. NIH (NIDCD)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Deafness & Other Communication Disorders (NIDCD) [U24 DC011968-01]; International Hearing Foundation; Starkey Foundation; 5M Lions International; Scientific and Technological Research Council of Turkey (TUBITAK) ScholarshipTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) This project was funded by NIH (NIDCD), grant number U24 DC011968-01; the International Hearing Foundation; the Starkey Foundation; and the 5M Lions International. Omer Hizh and Serdar Kaya received the Scientific and Technological Research Council of Turkey (TUBITAK) Scholarship.

An ideal treatment for Meniere’s Disease would be nonablation of the vestibular system, with a conservative effect on hearing. We have reported in January 2015 a novel surgical technique for the treatment of Meniere’s Disease—endolymphatic duct blockage (EDB)—performed as an outpatient surgical operation. It is an effective surgical nonablative technique in the event of failure of medical therapy; there is no cochlear damage clinically, and no additional vestibular damage. There is a significantly better control of the vertigo attacks when compared with the traditional endolymphatic sac decompression. We block the dissected endolymphatic duct with two small titanium clips. Postoperative wound management and postoperative care are similar to those in other mastoid surgical operation. Our hypothesis is that in Meniere’s Disease there is imbalance of the homeostasis of the endolymph at the level of the endolymphatic sac, with an increased secretion outweighing a decreased absorption resulting in an increased pressure in the inner ear. Thus, by blocking the endolymphatic duct, we decrease the volume of endolymph in the inner ear coming from the sac, which helps alleviate the symptoms of Meniere’s Disease; in absence of this result, all our patients operated by the EDB should develop a worsening of their symptoms, which is not the case. EDB operation remains a safe and effective novel procedure for the treatment of intractable Meniere’s Disease with minimal adverse effects.

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. De tre sista författarna delar sistaförfattarskapet

Background: The endolymphatic sac (ES) is a cystic structure situated on the posterior fossa dura and is connected to the luminal space of the vestibular organ through the endolymphatic duct, which branches into the utricular and saccular ducts. Unlike the cochlea and vestibule, the ES does not contain sensory epithelium in its luminal space, and a single layer of epithelial cells line the luminal surface area. The ES in the inner ear is thought to play a role in the regulation of inner ear homeostasis, fluid volume, and immune reaction. If these functions of the ES are disrupted, dysfunction of the inner ear may develop. The most well-known pathology arising from dysfunction of the ES is endolymphatic hydrops, characterized by an enlarged endolymphatic space due to the accumulation of excessive endolymphatic fluid. Although, molecular identities and functional evidence for the roles were identified in animal studies, basic studies of the human ES are relatively uncommon compared with those using animal tissues, because of limited opportunity to harvest the human ES. Methods: In this study, molecular and functional evidence for the role of the human ES in the development of endolymphatic hydrops are reviewed. Results and Conclusions: Although evidence is insufficient, studies using the human ES have mostly produced findings similar to those of animal studies. This review may provide a basis for planning further studies to investigate the pathophysiology of disorders with the finding of endolymphatic hydrops.

Melanin pigmentation is present in the human inner ear. In this study, we quantify the melanin pigmentation in the vestibular system and examine racial differences of vestibular melanin pigmentation using human cadaveric temporal bone specimens.Basic research.Laboratory.Light microscopy was used to examine specimens from 40 left temporal bones from the Johns Hopkins Human Temporal Bone Collection. Color images of (1) ampulla of the horizontal canal, (2) utricular wall, (3) endolymphatic duct, and (4) posterior ampullary nerve as it enters the posterior canal were acquired with a digital camera attached to the microscope and image acquisition software. Acquired images of each anatomic area of interest were processed offline through ImageJ. Melanin content was then compared according to ethnicity, age, sex, and location.Fifteen African American and 25 Caucasian specimens were analyzed. Mean age was 68.8 years. African American specimens had a significantly greater amount of pigment at all 4 sampled locations as compared with Caucasian specimens (P.01). Between sexes, there was a statistically significant difference (P.05) at the posterior ampullary nerve, with males having more than females. Melanin content was not associated with age.There is greater melanin pigmentation within the vestibular system of African Americans than in Caucasians, similar to what has been described in the cochlea. Racial differences in vestibular physiologic function have been observed in the literature and may be explained by differences in melanin pigmentation.

Purpose During vestibular schwannoma surgery there is a risk of endolymphatic duct and sac injury, which may cause a loss or a deterioration of hearing. The goal of the study was to evaluate the empirical utility of presurgical planning using CT with the bone window for the hearing preservation surgery. Methods The study was performed on 14 human temporal bones. CT scans with the bone window were obtained in the standard position. Safe drilling line was evaluated and after that drilling distances were analysed: the lateral drilling distance, total length of internal acoustic meatus, drilled length of internal acoustic meatus. After this, a surgical exposure was performed, using size of a drill tip as measuring scale. The dura was excised and endolymphatic duct was injected with a latex. Revision of the internal acoustic meatus was performed with the use of a microscope. Results Mean results of safe drilling coefficients were: lateral drilling distance: 10 ± 2 mm, total length of internal acoustic meatus: 9 ± 2 mm, drilled length of internal acoustic meatus: 7 ± 2 mm. In all cases, no endolymphatic duct injury was observed. Conclusions Preoperative radiological planning using the safe drilling coefficients is of value for the hearing preservation surgery in vestibular schwannoma. The size of the drilling tip may be used as an intraoperative measuring scale during this procedure. However, CT with a bone window is a necessary tool for the purposes of this procedure.

The aim of this study is to evaluate the quality of life (QOL) of patients treated by endolymphatic duct blockage (EDB) for Meniere's disease with a dedicated questionnaire. This is a retrospective cross-sectional study which included 54 patients diagnosed with severe, refractory Meniere's disease according to the AAO-HNS criteria and treated with EDB between 2010 and 2013. Answers to the first 38 questions have assigned scores from 0 to 4 (0 corresponding to the poorest QOL). A preoperative score called S1 was calculated as follows: S1 = sum of preoperative question scores/maximum possible preoperative score ×100. The same formula was used to calculate the postoperative score S2. The change in QOL score, S3, was then calculated (S3 = S2-S1). All answers were analyzed anonymously. Statistical analysis was done using Student t test and Chi square test. A response rate of 89 % was obtained with the Meniere's disease outcome questionnaire. The preoperative (S1) score was 21.4 (±12.6) and the postoperative score (S2) was 64.6 (±21.6) with a change in QOL (S3) of 43.3 (p

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.

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.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.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=ALHLSDcMD=uMD: p0.05 for CS vs. SD and p0.01 for CS vs. cMD). The vestibular ELS/TFS volume ratio in patients with uMD was significantly higher than that in the CS and all other patient groups (CS=ALHL=SD=cMDuMD: p0.01 for uMD vs. all other groups).The cochlear ELS volume of patients with MD and other endolymphatic hydrops-related diseases differed from that of CS. Our results suggest that ALHL may not be caused by endolymphatic hydrops. We confirmed the presence of extended ELS in patients with SD.

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.To assess the effect of intraoperative CSF Leak on short-term surgical outcomes.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.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.Intraoperative CSF Leak may cause a temporary non-significant worsening of hearing in the first-month postoperatively without any difference at 6 months.

Noninvasive standard evaluation of normal endolymphatic space and endolymphatic hydrops using magnetic resonance imaging (MRI) in various age groups is reported for the first time.To compare the standard evaluation of endolymphatic space in healthy volunteers in the cochlea and the vestibule among different age groups by applying noninvasive intratympanic gadolinium (Gd) perfusion through the eustachian tube and three-dimensional fluid-attenuated inversion recovery MRI (3D-FLAIR MRI).This was a prospective study. 3D-FLAIR MRI was performed with a 3 T unit 24 h after intratympanic administration of Gd through the eustachian tube in 60 healthy volunteers aged 20-55 years. Pure-tone test and tympanometry were performed 24 h before and 1 week after Gd administration.There was no significant difference in the ratios of the area of the endolymphatic space to that of the fluid space in the cochlea and the vestibule between males and females, or among 20-30-, 31-44-, and 45-55-year-old healthy volunteers. In 20-55-year-old healthy volunteers, the normal value of the endolymphatic space in the cochlea ranged between 7% and 27%, and that in the vestibule was between 17% and 39%. No significant changes in pure-tone test or tympanometry were noted.

Introduction Endolymphatic sac tumours are benign, slowly growing tumours that invade the temporal bone, and present clinically in the form of unilateral hearing loss. They can be sporadic or occur in the context of Von Hippel-Lindau disease (VHL). Case summary The authors report a case of endolymphatic sac tumour arising in the utricle presenting histological and immunohistochemical features corresponding to endolymphatic sac tumour in a patient without VHL. Discussion Endolymphatic sac tumours invade the posterior part of the petrous temporal bone. According to two studies concerning patients with Von Hippel-Lindau disease, endolymphatic sac tumours arise from the endolymphatic duct. This case of intralabyrinthine sporadic endolymphatic sac tumour supports this hypothesis for sporadic forms, indicating the need for labyrinthectomy associated with tumour resection to avoid recurrence.

Meniere's disease is an inner ear disorder characterized by vertigo attacks, fluctuating and progressive hearing loss, tinnitus, and aural fullness in the affected ear. The pathophysiology of Meniere's disease remains elusive. Theories so far are anatomical variation in the size or position of the endolymphatic sac and duct, viral inflammation or autoimmune involvement of the sac, or a genetically determined abnormality of endolymph control. Animal studies on blocking the ductus reuniens and endolymphatic duct have produced hydrops in the cochlea, saccule, and utricle. Cone beam computed tomography images show a similar pattern with apparent obstruction of the ductus reuniens, saccular duct, and endolymphatic sinus. New studies documenting the age of onset of Meniere's disease show a pattern similar to benign paroxysmal positional vertigo, raising the possibility that the fundamental cause of Meniere's disease might be detached saccular otoconia.

Primary adenomatous and adenocarcinomatous lesions of the temporal bone are rare tumors. Primary low-grade papillary adenocarcinomas of the endolymphatic sac origin were first reported by Heffner. These lesions, which are referred to as "Heffner tumors," are slow-growing, bone-destructive infiltrating tumors. Owing to the local bone destruction (usually centered at posterior petromastoid plate), the general consensus favors the endolymphatic sac as being the origin of these tumors. However, controversies regarding the cellular origins of adenomatous tumors of the temporal bone have been reported. Mafee and Shah reported a unique case in which histology was identical to papillary adenocarcinoma of endolymphatic sac in which the sac and duct showed normal findings on magnetic resonance images, which were confirmed on surgery. Computed tomography and magnetic resonance imaging are excellent imaging methods for evaluation of normal and anomaly of the vestibular aqueduct and endolymphatic duct and sac and for the diagnosis of these endolymphatic tumors. This article reviews computed tomography and magnetic resonance imaging characteristics of adenocarcinomatous tumors of temporal bone. This report also concerns a unique case of a papillary adenocarcinoma of presumed endolymphatic sac in a 12-year-old child, in which tumor replaced almost the entire petromastoid resulting in a markedly egg-shell appearance of the bone. To the best of our knowledge, this is the youngest child with papillary endolymphatic sac tumor reported.

The commonest sequelae of bacterial meningitis are related to the inner ear. Little is known about the inner ear immune defense. Evidence suggests that the endolymphatic sac provides some protection against infection. A potential involvement of the endolymphatic sac in bacterial meningitis is largely unaccounted for, and thus the object of the present study. A well-established adult rat model of Streptococcus pneumoniae meningitis was employed. Thirty adult rats were inoculated intrathecally with Streptococcus pneumoniae and received no additional treatment. Six rats were sham-inoculated. The rats were killed when reaching terminal illness or on day 7, followed by light microscopy preparation and PAS-Alcian blue staining. The endolymphatic sac was examined for bacterial invasion and leukocyte infiltration. Neither bacteria nor leukocytes infiltrated the endolymphatic sac during the first days. Bacteria invaded the inner ear through the cochlear aquaduct. On days 5-6, the bacteria invaded the endolymphatic sac through the endolymphatic duct subsequent to invasion of the vestibular endolymphatic compartment. No evidence of direct bacterial invasion of the sac through the meninges was found. Leukocyte infiltration of the sac occurred prior to bacterial invasion. During meningitis, bacteria do not invade the endolymphatic sac through the dura, but solely through the endolymphatic duct, following the invasion of the vestibular system. Leukocyte infiltration of the sac occurs prior to, as well as concurrent with bacterial invasion. The findings support the endolymphatic sac as part of an innate immune defense system protecting the inner ear from infection.

Endolymphatic sac tumors (ELST) are rare invasive lesions of the temporal bone that are commonly associated with von Hippel-Lindau disease. This report describes serial magnetic resonance imaging (MRI) and computed tomography (CT) findings over a period of 6 years in a 12-year-old patient who developed an ELST after 3.5 years surveillance for a cerebellar hemangioblastoma. A 1.5 × 8 mm tumor was identified on MRI within the endolymphatic duct when the patient presented with audiovestibular symptoms due to intralabyrinthine hemorrhage. The tumor demonstrated subsequent growth over 25 months until the patient agreed to undergo surgical resection by subtotal petrosectomy. De novo development and the natural history have been described only in six previous cases. MRI is regarded to be unreliable with respect to the ability to demonstrate an ELST in the presence of intralabyrinthine hemorrhage, with only two out of four previously reported patients demonstrating positive MRI findings. Little is known about the precise origin (endolymphatic duct versus sac), growth, and symptom correlation. This case highlights that new audiovestibular symptoms are a potential clinical clue and intralabyrinthine hemorrhage is a neuroimaging indicator for the presence of an ELST, which based on high-resolution MRI appears to originate in the endolymphatic duct rather than sac.

Pituitary carcinoma is characterized by the presence of a metastatic lesion(s) in a location non-contiguous with the original pituitary tumor. The mechanism(s) of malignant transformation are not known. A 15 year-old male was diagnosed in 1982 with a pituitary macroadenoma and acromegaly (random GH 67 ng/ml and no suppression by oral glucose). His prolactin was normal between 18 and 23 ng/ml. Transcranial resection in July 1983 was followed by radiation therapy. The tumor was immunopositive for GH and prolactin. The proliferation MIB-1 index was 0-1%. With aqueous Octreotide 100 mcg 4× daily both GH and IGF-1 became normal. The patient was lost to follow-up and was treated by his local physician. In 2001, his IGF-1 level was 1271 ng/ml, and his random GH was 1.8-2.4 ng/ml by ILMA despite progressive increase in the dose of Sandostatin LAR to 140 mg/month in divided doses. Prolactin remained normal or minimally increased between 15 and 25 ng/ml. In 2009 he was diagnosed with the tumor in the location of left endolymphatic sac. Histological examination showed low grade pituitary carcinoma strongly immunopositive for prolactin but negative for GH. MIB-1 antibody labeled 0-5% cells. In 2012 endoscopic resection of the pituitary tumor remnant was attempted. Immunohistochemical stains were strongly immunopositive for both prolactin and GH, similar to his original pituitary tumor. The MIB-1 proliferation index was low from 0 to 1%. To our knowledge this is the first case of pituitary carcinoma in the endolymphatic sac region. The dichotomy between the cell population of the pituitary lesion (GH/prolactin producing) and the metastasis (purely prolactin-producing) may suggest that the metastatic pituitary lesion derived from a clone distinct from the original one.

Objectives/Hypothesis To measure the volume of the endolymph drainage system in temporal bone specimens with Meniere disease, as compared with specimens with endolymphatic hydrops without vestibular symptoms and with nondiseased specimens Study Design Comparative human temporal bone analysis. Methods We generated three-dimensional models of the vestibular aqueduct, endolymphatic sinus and duct, and intratemporal portion of the endolymphatic sac and calculated the volume of those structures. We also measured the internal and external aperture of the vestibular aqueduct, as well as the opening (if present) of the utriculoendolymphatic (Bast's) valve and compared the measurements in our three study groups. Results The volume of the vestibular aqueduct and of the endolymphatic sinus, duct, and intratemporal endolymphatic sac was significantly lower in the Meniere disease group than in the endolymphatic hydrops group (P

Background The pathogenesis of Meniere disease (MD) has not been fully understood. According to the widely accepted theory, imbalances due to overproduction and/or impaired absorption of endolymph may cause endolymphatic hydrops, which is the hallmark pathological finding in MD. Some developmental temporal bone abnormalities may impair endolymph circulation and absorption, and these abnormalities could be a part of MD pathophysiology. However, structural features of the temporal bone cannot explain MD pathophysiology definitively. The authors aimed to determine the length and width of the endolymphatic duct (ED) along with jugular bulb (JB) abnormalities in MD patients and normal controls using high-resolution computed tomography, and to discuss the results supporting and opposing endolymphatic hydrops based on the data obtained. Methods Thirty-six ears of 18 patients with unilateral MD and 34 ears of 17 normal subjects were enrolled. Jugular bulb abnormalities and ED dimensions were evaluated in 3 groups: affected and unaffected ears of MD patients, and healthy controls. The ED dimensions and JB abnormalities were evaluated with high-resolution computed tomography. Results The ED was found to be significantly shorter and narrower in the affected ears of the MD patients than in the healthy control group. In addition, more JB abnormalities were detected in the affected ears of the MD patients than in the healthy control group. However, there was no difference between the affected and unaffected ears of the MD patients. Conclusion Structural ED abnormalities and JB abnormalities may be predisposing factors for the development of Meniere disease, but cannot fully explain MD pathophysiology.

Introduction:Inner ear homeostasis is dependent on the vestibular aqueduct and its content, the endolymphatic duct. Narrow and enlarged vestibular aqueducts have both been associated with hearing loss in Ménière's and large vestibular aqueduct syndromes. This review investigated the correlation between vestibular aqueduct diameter and pure tone average, and the effect of measurement site (i.e. the midpoint or the external aperture).Materials and methods:A systematic review of the literature and meta-analysis of large case series published on the Allied and Complementary Medicine, British Nursing Index, Cumulative Index to Nursing and Allied Health, Embase, Health Business Elite, Health Management Information Consortium, Medline, PsycInfo and PubMed databases. References and personal books were also scrutinised.Results:A linear relationship between vestibular aqueduct diameter and hearing loss was observed, with a projected increase of 6 dBHL per unit of vestibular aqueduct diameter (95 per cent confidence interval, 2–10;p = 0.003). This relationship was independent of measurement site.Discussion:This dose-dependent or linear relationship supports the role of flow and/or pressure change as aetiological factors in the pathogenesis of hearing loss, as per Poiseuille's law. This aetiological association is strengthened by the fact that the observed relationship is independent of measurement site.

Conclusion: Blockage of the endolymphatic duct is a significant finding in Meniere's disease. The position of the utriculo-endolymphatic valve (UEV) and blockage of the ductus reuniens in the temporal bones were not found to be directly indicative of Meniere's disease. Objective: Comparison of blockage of the longitudinal flow of endolymph between ears affected by Meniere's disease and normal ears. Methods: We examined 21 temporal bones from 13 subjects who had Meniere's disease and 21 normal temporal bones from 12 controls. Results: The endolymphatic duct was blocked in five (23%) ears affected by Meniere's disease (p = 0.016). The utricular duct was blocked in 16 (76%) ears affected by Meniere's disease and 11 (52%) normal ears (p = 0.112). The saccular duct was blocked in 6 (28%) of ears affected by Meniere's disease and 16 (76%) normal ears (p = 0.001). The ductus reuniens was blocked in 10 (47%) ears affected by Meniere's disease and 10 (47%) normal ears (p = 1.000).

Objective To investigate the ability to detect the in vivo cochlear changes associated with vasopressin-induced and surgically induced endolymphatic hydrops using MRI at 3 tesla (T). Study Design Prospective, animal model. Setting Animal laboratory. Subjects and Methods In group 1, five guinea pigs underwent post–gadolinium temporal bone MRI before and after seven and 14 days of chronic systemic administration of vasopressin by osmotic pump. In group 2, five guinea pigs underwent temporal bone MRI eight weeks after unilateral surgical ablation of the endolymphatic sac. Three-tesla high-resolution T1-weighted sequences were acquired pre- and postcontrast administration. Region of interest signal intensities of the perilymph and endolymph were analyzed manually. Quantitative evaluation of hydrops was measured histologically. Results Gadolinium preferentially concentrated in the perilymph, allowing for distinction of cochlear compartments on 3.0-T MRI. The T1-weighted contrast MRI of vasopressin-induced hydropic cochlea showed significant increases in signal intensity of the endolymph and perilymph. Surgically induced unilateral hydropic cochlea also showed increased signal intensity, compared with the control cochlea of the same animal, but less of an increase than the vasopressin group. The histological degree of hydrops induced in the vasopressin group was comparable to previous studies. Conclusions In vivo postcontrast MRI of the inner ear demonstrated cochlear changes associated with chronic systemic administration of vasopressin and surgical ablation of the endolymphatic sac. Understanding the MRI appearance of endolymphatic hydrops induced by various methods contributes to the future use of MRI as a possible tool in the diagnosis and treatment of Meniere's disease.

The first description of the presence of a utriculo-endolymphatic valve in human fetuses was given by Bast in 1928. Since then this valve-like structure is called Bast's valve. Its exact function has not yet been established. The general opinion is that it has a protective function by having the possibility to separate the superior endolymphatic compartments of the labyrinth from the inferior compartment. Phylogenetically seen birds are the first vertebrates with a cochlear duct and a distinct inferior and superior part of the labyrinth. A structure in the pigeon inner ear, resembling Bast's valve in mammals, is described.

The objective of the present study was to investigate endolymphatic space images in patients with fluctuating hearing loss without vertigo, and to elucidate its underlying pathophysiology. Eight patients with fluctuating hearing loss without vertigo were included in this study. 3T MRI was taken, 24 h after intratympanic injection of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Electrocochleography and VEMP tests were performed to evaluate cochlear and vestibular functions. Endolymphatic hydrops were observed both in the cochlea and in the vestibule of all eight patients. Three patients out of six whose summating potential/action potential (SP/AP) ratio was recordable showed an elevation of SP/AP ratio. In the two patients with remarkable endolymphatic hydrops in the vestibule, VEMP was absent from the affected ear. In conclusion, 3T MRI after intratympanic injection of Gd-DTPA revealed endolymphatic hydrops both in the cochlea and in the vestibule in the patients with fluctuating hearing loss without vertigo.

Spontaneous recovery or central compensation makes surgical procedures rare in patients with vertigo. Surgery for vertigo proposed after pharmacological or physical therapy fails to eliminate Meniere's disease and some very rare cases of paroxystic positional vertigo. The main target in treating Meniere's disease is to promote vestibular compensation, which is possible only with a nonprogressive and stable deficit leading to readjustment of vestibular reflexes. Surgical procedures can be classified as nondestructive (endolymphatic sac decompression, vestibular nerve decompression, patching of perilymphatic fistulas), selectively destructive (middle fossa or retrosigmoid vestibular neurotomy, lateral semi-circular plugging) and destructive (labyrinthectomy). Surgical indications essentially concern incapacitating vertigo and depend mainly on hearing status. In Meniere's disease, vestibular neurotomy can be regarded as the gold standard considering its good results on vertiginous episodes; however, scoring with functional and quality-of-life scales bring out residual deficiency in some cases.

OBJECTIVE The aim of this study was to clarify the clinical course of large endolymphatic duct and sac syndrome (LEDS). Although LEDS is the most common form of radiologically detectable inner ear malformation associated with sensorineural hearing loss (SNHL), it is relatively unknown in the German-speaking countries. We hoped to derive useful pointers for clinical care. METHODS We evaluated the clinical audiometric records and imaging findings of 169 patients with clinically suspected inner ear malformation seen between 1994 and 2003. Following identification of all LEDS cases, we serially investigated the anamnestic and functional data with regard to severity and course. RESULTS Among 169 patients, 17 (median age 12 years; 12 females) showed LEDS. A total of 28 ears were affected. Clinically, most cases were of prelingual or perilingual onset and displayed steady or fluctuatingly progressive severe SNHL with emphasis on the high frequencies or deafness. Episodes of sudden hearing loss were relatively frequent. No correlation could be demonstrated between the severity of morphological changes and the degree of SNHL. CONCLUSION Progression of SNHL and episodes of sudden hearing loss were seen mainly in late childhood or adolescence. This should be taken into account when informing and advising patients and planning therapy.

Conclusion. A new murine model for the study of Meniere's disease has been developed by treatment with both lipopolysaccharide (LPS) and aldosterone. Induction of vestibular dysfunction in the hydropic animal model may entail additional stress such as reduced inner ear blood flow, and sudden acute changes in endolymph volume and/or pressure. Objective. The purpose of this study was to develop a more suitable animal model, showing closer resemblance to the pathophysiological process in Meniere's disease. Materials and methods. Adult CBA/J mice were treated by intratympanic injection of LPS, intraperitoneal injection of aldosterone, or injection of both LPS and aldosterone. Morphological analyses were performed in the cochlea and endolymphatic sac. Results. All experimental animals showed mild to moderate endolymphatic hydrops. Those treated with both LPS and aldosterone showed reversible vestibular dysfunction after the intratympanic injection of epinephrine.

Objective:To evaluate the vestibular aqueduct in patients with sudden sensorineural hearing loss.Methods:We evaluated 19 patients (12 men and seven women; age range, 22−79 years) with unilateral sudden sensorineural hearing loss, using computed tomography and magnetic resonance imaging. All these patients had unilateral sudden sensorineural hearing loss. We also evaluated 47 control subjects (22 men and 25 women; age range, 22–79 years).Results:In sensorineural hearing loss affected ears, the width of the vestibular aqueduct at the midpoint and at the operculum was significantly greater than that in contralateral ears or in control ears. The width of the vestibular aqueduct at the midpoint and the operculum did not correlate with the audiometric threshold or the audiogram configuration. Contrast enhancement of the ipsilateral endolymphatic sac was observed in 17 of 19 patients with sudden sensorineural hearing loss (89 per cent). Eleven of these 17 patients also showed enhancement on the contralateral side, but no patient showed enhancement only on the contralateral side. In sensorineural hearing loss affected ears, the width of the vestibular aqueduct did not differ significantly between those patients with and without enhancement.Conclusions:The vestibular aqueducts of sudden sensorineural hearing loss affected ears are wider than those of controls. Precise imaging and evaluation of the inner ear is essential when investigating the pathological conditions responsible for sudden sensorineural hearing loss.