Posterior Semicircular Canal Dehiscence with Vestibulo-Ocular Reflex Reduction for the Affected Canal at the Video-Head Impulse Test: Considerations to Pathomechanisms.

Posterior semicircular canal dehiscence (PSCD) has been demonstrated to result in a third mobile window mechanism (TMWM) in the inner ear similar to superior semicircular canal dehiscence (SSCD). Typical clinical and instrumental features of TMWM, including low-frequency conductive hearing loss (CHL), autophony, pulsatile tinnitus, sound/pressure-induced vertigo and enhanced vestibular-evoked myogenic potentials, have been widely described in cases with PSCD. Nevertheless, video-head impulse test (vHIT) results have been poorly investigated. Here, we present six patients with PSCD presenting with a clinical scenario consistent with a TMWM and an impaired vestibulo-ocular reflex (VOR) for the affected canal on vHIT. In two cases, an additional dehiscence between the facial nerve and the horizontal semicircular canal (HSC) was detected, leading to a concurrent VOR impairment for the HSC. While in SSCD, a VOR gain reduction could be ascribed to a spontaneous "auto-plugging" process due to a dural prolapse into the canal, the same pathomechanism is difficult to conceive in PSCD due to a different anatomical position, making a dural herniation less likely. Alternative putative pathomechanisms are discussed, including an endolymphatic flow dissipation during head impulses as already hypothesized in SSCD. The association of symptoms/signs consistent with TMWM and a reduced VOR gain for the posterior canal might address the diagnosis toward PSCD.

Decompression sickness of the inner ear and relationship with a patent oval foramen: a study of 61 cases.

OBJECTIVE: To discuss the link between inner ear decompression sickness and patent foramen ovale. MATERIALS AND METHODS: Monocentric and retrospective study on decompression sickness of the inner ear requiring hyperbaric chamber treatment, from 2014 to 2021. RESULTS: Sixty-one patients of inner ear decompression sickness were included in this study. Twenty-four patients had vestibular injuries, 28 cochlear injuries and 9 cochleo-vestibular injuries. Compression chamber treatment was given, using an oxygen-helium mixture with oxygen partial pressure (PIO2) limited to 2.8 atmosphere absolute (ATA). All vestibular accidents completely recovered without clinical sequelae. For cochlear accident only 10 out of 37 patients (27%) recovered completely. A right-left shunt (patent foramen oval or intra-pulmonary shunt) was found in 31.1% of patients with inner ear decompression sickness (p > 0.05). CONCLUSION: The presence of patent foramen oval in patients with inner ear decompression was not statistically significant in our study. Understanding of the pathophysiology of decompression illness and the physiology and anatomy of the labyrinth would suggest a mechanism of supersaturation with degassing in intra-labyrinthine liquids.

Skull Vibration-Induced Nystagmus in Superior Semicircular Canal Dehiscence: A New Insight into Vestibular Exploration-A Review.

The third window syndrome, often associated with the Tullio phenomenon, is currently most often observed in patients with a superior semicircular-canal dehiscence (SCD) but is not specific to this pathology. Clinical and vestibular tests suggestive of this pathology are not always concomitantly observed and have been recently complemented by the skull-vibration-induced nystagmus test, which constitutes a bone-conducted Tullio phenomenon (BCTP). The aim of this work was to collect from the literature the insights given by this bedside test performed with bone-conducted stimulations in SCD. The PRISMA guidelines were used, and 10 publications were included and analyzed. Skull vibration-induced nystagmus (SVIN), as observed in 55 to 100% of SCD patients, usually signals SCD with greater sensitivity than the air-conducted Tullio phenomenon (ACTP) or the Hennebert sign. The SVIN direction when the test is performed on the vertex location at 100 Hz is most often ipsilaterally beating in 82% of cases for the horizontal and torsional components and down-beating for the vertical component. Vertex stimulations are more efficient than mastoid stimulations at 100 Hz but are equivalent at higher frequencies. SVIN efficiency may depend on stimulus location, order, and duration. In SCD, SVIN frequency sensitivity is extended toward high frequencies, with around 400 Hz being optimal. SVIN direction may depend in 25% on stimulus frequency and in 50% on stimulus location. Mastoid stimulations show frequently diverging results following the side of stimulation. An after-nystagmus observed in 25% of cases can be interpreted in light of recent physiological data showing two modes of activation: (1) cycle-by-cycle phase-locked activation of action potentials in SCC afferents with irregular resting discharge; (2) cupula deflection by fluid streaming caused by the travelling waves of fluid displacement initiated by sound or vibration at the point of the dehiscence. The SVIN direction and intensity may result from these two mechanisms' competition. This instability explains the SVIN variability following stimulus location and frequency observed in some patients but also discrepancies between investigators. SVIN is a recent useful insight among other bedside examination tests for the diagnosis of SCD in clinical practice.

Improving rehabilitation of deaf patients by advanced imaging before cochlear implantation.

INTRODUCTION: Cochlear implants have advanced the management of severe to profound deafness. However, there is a strong disparity in hearing performance after implantation from one patient to another. Moreover, there are several advanced kinds of imaging assessment before cochlear implantation. Microstructural white fiber degeneration can be studied with Diffusion weighted MRI (DWI) or tractography of the central auditory pathways. Functional MRI (fMRI) allows us to evaluate brain function, and CT or MRI segmentation to better detect inner ear anomalies. OBJECTIVE: This literature review aims to evaluate how helpful pre-implantation anatomic imaging can be to predict hearing rehabilitation outcomes in deaf patients. These techniques include DWI and fMRI of the central auditory pathways, and automated labyrinth segmentation by CT scan, cone beam CT and MRI. DESIGN: This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were selected by searching in PubMed and by checking the reference lists of relevant articles. Inclusion criteria were adults over 18, with unilateral or bilateral hearing loss, who had DWI acquisition or fMRI or CT/ Cone Beam CT/ MRI image segmentation. RESULTS: After reviewing 172 articles, we finally included 51. Studies on DWI showed changes in the central auditory pathways affecting the white matter, extending to the primary and non-primary auditory cortices, even in sudden and mild hearing impairment. Hearing loss patients show a reorganization of brain activity in various areas, such as the auditory and visual cortices, as well as regions involved in language and emotions, according to fMRI studies. Deep Learning's automatic segmentation produces the best CT segmentation in just a few seconds. MRI segmentation is mainly used to evaluate fluid space of the inner ear and determine the presence of an endolymphatic hydrops. CONCLUSION: Before cochlear implantation, a DWI with tractography can evaluate the central auditory pathways up to the primary and non-primary auditory cortices. This data is then used to generate predictions on the auditory rehabilitation of patients. A CT segmentation with systematic 3D reconstruction allow a better evaluation of cochlear malformations and predictable difficulties during surgery.

A bone-conducted Tullio phenomenon-A bridge to understand skull vibration induced nystagmus in superior canal dehiscence.

Nystagmus produced in response to air-conducted sound (ACS) stimulation-the Tullio phenomenon-is well known in patients with a semicircular canal (SCC) dehiscence (SCD). Here we consider the evidence that bone-conducted vibration (BCV) is also an effective stimulus for generating the Tullio phenomenon. We relate the clinical evidence based on clinical data extracted from literature to the recent evidence about the physical mechanism by which BCV may cause this nystagmus and the neural evidence confirming the likely mechanism. The hypothetical physical mechanism by which BCV activates SCC afferent neurons in SCD patients is that traveling waves are generated in the endolymph, initiated at the site of the dehiscence. We contend that the nystagmus and symptoms observed after cranial BCV in SCD patients is a variant of Skull Vibration Induced Nystagmus (SVIN) used to identify unilateral vestibular loss (uVL) with the major difference being that in uVL the nystagmus beats away from the affected ear whereas in Tullio to BCV the nystagmus beats usually toward the affected ear with the SCD. We suggest that the cause of this difference is a cycle-by-cycle activation of SCC afferents from the remaining ear, which are not canceled centrally by simultaneous afferent input from the opposite ear, because of its reduced or absent function in uVL. In the Tullio phenomenon, this cycle-by-cycle neural activation is complemented by fluid streaming and thus cupula deflection caused by the repeated compression of each cycle of the stimuli. In this way, the Tullio phenomenon to BCV is a version of skull vibration-induced nystagmus.

Difference in cochlear length between male and female patients.

Objective: To compare cochlear duct length (CDL) between male and female patients by evaluating the diameter of the basal turn (distance A) on CT scans.Method: All temporal bone CT scans performed between 2014 and 2020 were reviewed in our medical center. Using multiplanar reconstructions, the length A, which is the greatest distance of the basal turn was measured on both sides. We performed an analysis of variance considering two factors: sex and side. Two different physicians carried out the measurements, an otolaryngologist and a neuroradiologist. The patients who had several CT scans allowed us to evaluate the reliability of our procedure.Results: Among the 888 CT scans reviewed, 8 were excluded because of cochlear malformations. The inter-sex difference of length A was found to be 0.29 millimeters(mm) 95% IC [0.26-0.34] and was longer in the male group (p < 0.0001). Using Alexiades' equation, we found that CDL was 34.5mm [34.37-34.61] in the male group and 33.3mm [33.13-33.38] in the female group. When one side was compared to the other, there was no significant difference (p = 0.226). An intra-class correlation found a good absolute agreement between the two screeners of 0.79.Conclusion: Males have a statistically significant longer CDL than females.

Perilymph metabolomic and proteomic MALDI-ToF profiling with porous silicon chips: A proof-of-concept study.

INTRODUCTION: Sensorineural hearing losses (SNHLs) are a significant public health issue, and the hearing loss field is desperately in need of effective therapy. Pathophysiological mechanisms are not yet clearly understood in the absence of validated methods to assess the inner ear content. Proteomic and metabolomic analysis of perilymph is opening new research perspectives for SNHLs. We aimed to demonstrate the feasibility of an innovative mass spectrometry (MS) strategy using porous silicon chips (PSCs) to investigate the low molecular weight (LMW) protein and metabolite content of human perilymph. Our second objective was to stratify perilymph samples according to their MS profiles and compare these results with clinical data. MATERIAL AND METHODS: Perilymph samples obtained during cochlear implant surgery from patients with SNHLs were retrieved from a validated biobank. To focus on LMW entities, we used a PSC enrichment protocol before MALDI-ToF MS analysis. PSCs were used as a LMW molecular preanalytical stabilizer and amplifier. Patients' clinical data and SNHL characteristics were retrieved retrospectively from medical charts. RESULTS: We successfully acquired and compared 59 exploitable MS profiles out of 71 perilymph samples. There was a good correlation between duplicates. Comparing both ears from the same patient, we found good reproducibility even when there was a one-year interval between samplings. We identified three distinct groups when comparing the samples' metabolomic profiles and four homogeneous groups comparing their LMW proteome profiles. Clinical data analysis suggested that some groups shared clinical or preanalytical characteristics. CONCLUSION: This proof-of-concept study confirms that LMW proteome and metabolome content of perilymph can be analyzed with PSCs. Based on protein profiles, we managed to stratify perilymp samples according to their molecular composition. These results must be confirmed with a larger population, and sampling methods require improvement, but this approach seems promising. In the future, this approach may pave the way for companion test strategies to precisely diagnose and define potential molecular targets for audioprotective therapies.

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

PURPOSE: Benign recurrent vestibulopathy is a recent entity, close to probable Meniere's disease and vestibular-migraine. So far, no study has systematically investigated the presence of endolymphatic hydrops of the lateral semicircular canal in benign recurrent vestibulopathy using magnetic resonance imaging. The aim of this study was to determine magnetic resonance imaging data and vestibular test results in patients with benign recurrent vestibulopathy. METHODS: 128 patients with benign recurrent vestibulopathy included since 2010 were retrospectively analyzed. Patients had magnetic resonance imaging with a delayed acquisition, audiogram, head shaking test, caloric-test, skull-vibration-induced-nystagmus-test, video-head- impulse-test, and vestibular evoked myogenic potential. Endolymphatic hydrops presence was classified into four categories: cochlear, saccular, lateral semicircular canal and association with saccule. RESULTS: In benign reccurent vestibulopathy, 23% of cases showed an endolymphatic hydrops on magnetic resonance imaging, more frequently located in the lateral semicircular canal (59%) and related to the disease duration. The most often impaired tests were caloric-test (49%) with fluctuations of hypofunction in 67% and skull-vibration-induced-nystagmus-test (61%). No correlation between the caloric-test and the presence and location of the endolymphatic hydrops was observed. CONCLUSION: In our series of benign reccurent vestibulopathy, a rare endolymphatic hydrops was most often observed for the lateral semicircular canal and correlated with the seniority of the pathology. Hydrops identified at the magnetic resonance imaging was not correlated with the caloric-test results. Skull-vibration-induced-nystagmus-test and caloric-test were the most often modified vestibular tests.

Binaural squelch effect in unilateral otosclerosis surgery: comparison of speech intelligibility in noise before-after surgery.

PURPOSE: We aimed to evaluate the speech intelligibility benefit in noise provided by stapedotomy in the treatment of unilateral otosclerosis. METHODS: We enrolled adults suffering from unilateral conductive hearing loss and followed them up until 9 months after surgery. The patients underwent a free field speech hearing evaluation using the French Matrix test before and after stapedotomy. Speech material was sent to the front of the patients (S0) and noise was presented either at the front (N0), or at the operated ear (N-90) or at the non-operated ear (N + 90). The speech intelligibility benefit in noise was assessed by comparing Squelch effect (SE), Head shadow effect (HS) and Binaural redundancy (BR) before and after surgery. SE was measured as the difference in speech reception thresholds (SRT) between S0N + 90 situations before and after surgery, HS as the difference in SRT between S0N + 90 and S0N-90 situations, and BR as the difference in SRT between S0N0 situations before and after surgery. In addition, two quality of life's questionnaires were completed by patients to evaluate their discomfort. RESULTS: Among 25 patients, 19 were followed up during 9 months, 4 were excluded and 2 were lost for the following-up. Stapedotomy provided a restoration of SE of 3.7 dB SNR (p < 0.001) and a BR gain of 1.8 dB SNR (p < 0.001). HS did not show any statistical variation after surgery (p = 0.077). Finally, the questionnaires showed a residual hearing discomfort. CONCLUSION: Stapedotomy provided a binaural benefit with the restoration of the SE and BR but which remained lower than in the normal-hearing population. TRIAL REGISTRATION: The 07/02/2018 on Clinical.Trial.Gouv: NCT03587792.

Correlation Between Cochlear Length, Insertion Angle, and Tonotopic Mismatch for MED-EL FLEX28 Electrode Arrays.

OBJECTIVE: To investigate the relationship between cochlear length, insertion angle, and tonotopic mismatch and to compare the tonotopic mismatches with respect to the spiral ganglion and the organ of Corti. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center with cochlear implant program. PATIENTS: Analyses of patients' computed tomography images after cochlear implant surgery. INTERVENTION: Cochlear implantation with 28-mm-long straight lateral wall electrode arrays. MAIN OUTCOME MEASURE: Cochlear length, insertion angle, and insertion depth were assessed using the OTOPLAN software. Tonotopic mismatch for each electrode contact was estimated using the Greenwood (organ of Corti) and the Stakhovskaya (spiral ganglion) maps and compared. RESULTS: 106 cochleae were analyzed. 99% of the electrode arrays were located in the tympanic ramp. The insertion was complete in 96% of cases. The mean cochlear length was 34.5 mm and the mean insertion angle of the apical electrode was 545°. Cochlear length was negatively correlated with the insertion angle of the contacts E1 to E9 (all p < 0.004). The tonotopic mismatch was greater at the organ of Corti than at the spiral ganglion. It was also greater at the organ of Corti in larger cochleae (correlation with mismatch for E1 r = 0.421, p < 0.0001) and in the apical than in the middle and basal regions of the cochlea. CONCLUSION: Small cochlea size corresponded to higher insertion angle and reduction of tonotopic mismatch on a 28-mm-long straight lateral wall electrode array. Tonotopic mismatch could be minimized preoperatively by choosing electrode arrays according to the individual cochlear morphology and postoperatively by appropriate frequency fitting.

Skull Vibration Induced Nystagmus Test: Correlations with Semicircular Canal and Otolith Asymmetries.

BACKGROUND: To establish in patients with peripheral vestibular disorders relations between skull vibration-induced nystagmus (SVIN) different components (horizontal, vertical, torsional) and the results of different structurally related vestibular tests. METHODS: SVIN test, canal vestibular test (CVT: caloric test + video head impulse test: VHIT), otolithic vestibular test (OVT: ocular vestibular evoked myogenic potential oVEMP + cervical vestibular evoked myogenic potential cVEMP) performed on the same day in 52 patients with peripheral vestibular diseases (age < 65 years), and 11 control patients were analyzed. Mixed effects logistic regression analysis was performed to assert whether the presence of nystagmus in SVIN (3D analysis) have an association with the presence of peripheral vestibular dysfunction measured by vestibular explorations (CVT or OVT). RESULTS: We obtained different groups: Group-Co (control group), Group-VNT (dizzy patients with no vestibular tests alterations), Group-O (OVT alterations only), Group-C (CVT alterations only), Group-M (mixed alterations). SVIN-SPV horizontal component was significantly higher in Group-M than in the other groups (p = 0.005) and correlated with alterations of lateral-VHIT (p < 0.001), caloric test (p = 0.002) and oVEMP (p = 0.006). SVIN-SPV vertical component was correlated with the anterior-VHIT and oVEMP alterations (p = 0.007; p = 0.017, respectively). SVIN-SPV torsional component was correlated with the anterior-VHIT positivity (p = 0.017). SVIN was the only positive test for 10% of patients (83% of Group-VNT). CONCLUSION: SVIN-SPV analysis in dizzy patients shows significant correlation to both CVT and OVT. SVIN horizontal component is mainly relevant to both vestibular tests exploring lateral canal and utricle responses. SVIN-SPV is significantly higher in patients with combined canal and otolith lesions. In some patients with dizziness, SVIN may be the only positive test.

Skull Vibration-Induced Nystagmus Test in a Human Model of Horizontal Canal Plugging.

BACKGROUND/AIM: the aim of this study was to assess the skull vibration-induced nystagmus test (SVINT) results and vestibular residual function after horizontal semicircular canal (HSCC) plugging. METHODS: In this retrospective chart review performed in a tertiary referral center, 11 patients who underwent unilateral horizontal semicircular canal plugging (uHSCCP) for disabling Menière's disease (MD) were included. The skull vibration-induced nystagmus (SVIN) slow-phase velocity (SPV) was compared with the results of the caloric test (CaT), video head impulse test (VHIT), and cervical vestibular-evoked myogenic potentials (cVEMP) performed on the same day. RESULTS: Overall, 10 patients had a strong SVIN beating toward the intact side (Horizontal SVIN-SPV: 8.8°/s ± 5.6°/s), 10 had a significant or severe ipsilateral CaT hypofunction, 10 had an ipsilateral horizontal VHIT gain impairment, and 3 had altered cVEMP on the operated side. Five had sensorineural hearing worsening. SVIN-positive results were correlated with CaT and horizontal VHIT (HVHIT) results (p < 0.05) but not with cVEMP. SVIN-SPV was correlated with CaT hypofunction in % (p < 0.05). Comparison of pre- and postoperative CaT % hypofunction showed a significant worsening (p = 0.028). CONCLUSION: SVINT results in a human model of horizontal canal plugging are well correlated with vestibular tests exploring horizontal canal function, but not with cVEMP. SVINT always showed a strong lesional nystagmus beating away from the lesion side. SVIN acts as a good marker of HSCC function. This surgical technique showed invasiveness regarding horizontal canal vestibular function.

Cochlear Implantation and Other Treatments in Single-Sided Deafness and Asymmetric Hearing Loss: Results of a National Multicenter Study Including a Randomized Controlled Trial.

INTRODUCTION: Cochlear implantation is a recent approach proposed to treat single-sided deafness (SSD) and asymmetric hearing loss (AHL). Several cohort studies showed its effectiveness on tinnitus and variable results on binaural hearing. The main objective of this study is to assess the outcomes of cochlear implantation and other treatment options in SSD/AHL on quality of life. METHODS: This prospective multicenter study was conducted in 7 tertiary university hospitals and included an observational cohort study of SSD/AHL adult patients treated using contralateral routing of the signal (CROS) hearing aids or bone-anchored hearing systems (BAHSs) or who declined all treatments, and a randomized controlled trial in subjects treated by cochlear implantation, after failure of CROS and BAHS trials. In total, 155 subjects with SSD or AHL, with or without associated tinnitus, were enrolled. After 2 consecutive trials with CROS hearing aids and BAHSs on headband, all subjects chose any of the 4 treatment options (abstention, CROS, BAHS, or cochlear implant [CI]). The subjects who opted for a CI were randomized between 2 arms (CI vs. initial observation). Six months after the treatment choice, quality of life was assessed using both generic (EuroQoL-5D, EQ-5D) and auditory-specific quality-of-life indices (Nijmegen Cochlear implant Questionnaire [NCIQ] and Visual Analogue Scale [VAS] for tinnitus severity). Performances for speech-in-noise recognition and localization were measured as secondary outcomes. RESULTS: CROS was chosen by 75 subjects, while 51 opted for cochlear implantation, 18 for BAHSs, and 11 for abstention. Six months after treatment, both EQ-5D VAS and auditory-specific quality-of-life indices were significantly better in the "CI" arm versus "observation" arm. The mean effect of the CI was particularly significant in subjects with associated severe tinnitus (mean improvement of 20.7 points ± 19.7 on EQ-5D VAS, 20.4 ± 12.4 on NCIQ, and 51.4 ± 35.4 on tinnitus). No significant effect of the CI was found on binaural hearing results. Before/after comparisons showed that the CROS and BAHS also improved significantly NCIQ scores (for CROS: +7.7, 95% confidence interval [95% CI] = [4.5; 10.8]; for the BAHS: +14.3, 95% CI = [7.9; 20.7]). CONCLUSION: Cochlear implantation leads to significant improvements in quality of life in SSD and AHL patients, particularly in subjects with associated severe tinnitus, who are thereby the best candidates to an extension of CI indications.

Fifty Years of Development of the Skull Vibration-Induced Nystagmus Test.

This review enumerates most of the studies on the Skull Vibration-Induced Nystagmus Test (SVINT) in the past 50 years from different research groups around the world. It is an attempt to demonstrate the evolution of this test and its increased interest around the globe. It explores clinical studies and animal studies, both permitting a better understanding of the importance of SVINT and its pathophysiology.

Treatment choice in single-sided deafness and asymmetric hearing loss. A prospective, multicentre cohort study on 155 patients.

OBJECTIVES: To describe the treatment choice in a cohort of subjects with single-sided deafness (SSD) and asymmetric hearing loss (AHL). To assess the reliability of the treatment trials. DESIGN: In this national, multicentre, prospective study, the choice of subjects was made after two consecutive trials of Contralateral Routing Of the Signal (CROS) hearing aids and a Bone Conduction Device (BCD) on a headband. Subjects could proceed with one of these two options, opt for cochlear implantation or decline all treatments. SETTING: Seven tertiary university hospitals. PARTICIPANTS: One hundred fifty-five subjects with SSD or AHL fulfilling the candidacy criteria for cochlear implantation, with or without associated tinnitus. MAIN OUTCOME MEASURES: After the two trials, the number of subjects choosing each option was described. Repeated assessments of both generic and auditory-specific quality of life were conducted, as well as hearing assessments (speech recognition in noise and horizontal localization). RESULTS: CROS was chosen by 75 subjects, followed by cochlear implantation (n = 51), BCD (n = 18) and abstention (n = 11). Patients who opted for cochlear implantation had a poorer quality of life (P = .03). The improvement of quality of life indices after each trial was significantly associated with the final treatment choice (P = .008 for generic indices, P = .002 for auditory-specific indices). The follow-up showed that this improvement had been overestimated in the CROS group, with a long-term retention rate of 52.5%. CONCLUSIONS: More than one third of SSD/AHL subjects are unsatisfied after CROS and BCD trials. Repeated quality of life assessments help counselling the patient for his/her treatment choice.

Covid-19 and Otologic/Neurotologic Practices: Suggestions to Improve the Safety of Surgery and Consultations.

: Since the beginning of 2020, the world has been confronted by the Covid-19 pandemic. The lock-down aims to limit the circulation of the virus and thus avoid overwhelming healthcare systems. Healthcare workers have had to adapt by postponing consultation and surgical activities. Otolaryngologists are particularly exposed to infection from the upper airway where the virus is highly concentrated. Literature has previously reported other human coronaviruses in the middle ear and mastoid, suggesting a risk of infection to staff during ear surgery where aerosolizing procedures are usually used. The aim of this article is to propose a strategy for planning consultations and surgeries for ear and lateral skull base diseases, in the context of the current active evolution of the pandemic and of the future gradual recovery to normal practice.

Intratemporal facial nerve schwannomas: multicenter experience of 80 cases.

PURPOSE: To provide more data on the clinical presentation and natural evolution of facial nerve schwannomas and to provide guidance for therapeutic decision making. METHODS: A retrospective case review of eighty patients diagnosed with a facial nerve schwannoma between 1990 and 2018 in ten tertiary referral centers in Europe was performed. Patients' demographics, symptomatology, audiometry, anatomical site (segments involved), size and whenever possible volume measurement were registered. RESULTS: At presentation, transient or persistent facial palsy was the most common symptom, followed by hearing loss. The schwannoma involved more than one segment in the majority of the patients with the geniculate ganglion being most commonly involved. Initial treatment consisted of a wait and scan approach in 67.5%, surgery in 30% and radiation therapy in 2.5% of the patients. Tympanic segment schwannomas caused mainly conductive hearing loss and were more prone to develop facial palsy at follow-up. Internal auditory canal or cerebellopontine angle schwannomas presented with significantly more sensorineural hearing loss. CONCLUSIONS: Although modern imaging has improved diagnosis of this tumor, choosing the best treatment modality remains a real challenge. Based on the literature review and current findings, more insights into the clinical course and the management of facial nerve schwannomas are provided.

The vestibular aqueduct sign: Magnetic resonance imaging can detect abnormalities in both ears of patients with unilateral Meniere's disease.

BACKGROUND AND PURPOSE: In patients with Meniere's disease (MD), saccular hydrops can only be studied by magnetic resonance imaging (MRI) at a late stage when the disease is already responsible for moderate to severe hearing loss. However, these patients may also present vestibular aqueduct (VA) abnormalities. MATERIALS AND METHODS: In this prospective study (38RC14.428 for healthy subjects/38RC15.173 for patients), imaging was carried out on a 3T MRI scanner. Twenty healthy subjects (13 women, median age 53.5 [52.2-66.7]) and twenty MD patients (9 women, median age 54.5 [52-66.7]) had MRI scans with 3D-FLAIR sequences without injection, then 4 hours after a single intra-venous dose of contrast agent. Two radiologists independently ranked the morphology of the VA in the healthy subjects and in MD patients, using a three-level score (completely visible, discontinuous and not visible). Each subject was then graded, based on both the VA's appearance and on saccular hydrops presence. Inter-reader agreement tests were performed. RESULTS: In controls and patients, VA modifications were symmetrical without significant difference between the symptomatic and asymptomatic ears. The presence of at least one ear with discontinuous VA showed a correlation with clinical MD (P < 0.001) with a sensitivity of 90%. Ten patients had saccular hydrops, but only in the symptomatic ears. The evaluation of VA did not differ between MRI, both within MRI series or between the two radiologists (kappa without and with contrast agent = 0.9 and 0.92 respectively). CONCLUSION: Analysis of the vestibular aqueduct by MRI detects abnormalities in both ears of patients with unilateral MD.

Relationship Between Audio-Vestibular Functional Tests and Inner Ear MRI in Meniere's Disease.

OBJECTIVES: Meniere's disease is an inner ear disorder generally attributed to an endolymphatic hydrops. Different electrophysiological tests and imaging techniques have been developed to improve endolymphatic hydrops diagnosis. The goal of our study was to compare the sensitivity and the specificity of delayed inner ear magnetic resonance imaging (MRI) after intravenous injection of gadolinium with extratympanic clicks electrocochleography (EcochG), phase shift of distortion product otoacoustic emissions (shift-DPOAEs), and cervical vestibular-evoked myogenic potentials (cVEMP) for the diagnosis of Meniere's disease. DESIGN: Forty-one patients, with a total of 50 affected ears, were included prospectively from April 2015 to April 2016 in our institution. Patients included had definite or possible Meniere's disease based on the latest American Academy of Otolaryngology-Head and Neck Surgery guidelines revised in 2015. All patients went through delayed inner ear MRI after intravenous injection of gadolinium (three dimension-fluid attenuated inversion recovery sequences), pure-tone audiometry, extratympanic clicks EcochG, shift-DPOAEs, and cVEMP on the same day. Endolymphatic hydrops was graded on MRI using the saccule to utricle ratio inversion defined as when the saccule appeared equal or larger than the utricle. RESULTS: Abnormal EcochG and shift-DPOAEs in patients with definite Meniere's disease (DMD) were found in 68 and 64.5%, respectively. The two methods were significantly associated in DMD group. In DMD group, 25.7% had a positive MRI. The correlation between MRI versus EcochG and MRI versus shift-DPOAEs was not significant. MRI hydrops detection was correlated with hearing loss. Finally, 22.9% of DMD group had positive cVEMP. CONCLUSIONS: EcochG and shift-DPOAEs were both well correlated with clinical criteria of Meniere's disease. Inner ear MRI showed hydrops when hearing loss was higher than 35 dB. The shift-DPOAEs presented the advantage of a rapid and easy measurement if DPOAEs could be recorded (i.e., hearing threshold <60dB). In contrast, EcochG can be performed regardless of hearing loss. In combination with shift-DPOAEs, it enhances the chances to confirm the diagnosis with a better confidence.