Objectives:Intracochlear electrocochleography (ECochG) in cochlear implant (CI) recipients is a potential tool for monitoring cochlear function during and after electrode array (EA) insertion. However, mechanisms underlying ECochG amplitude variations along the cochlear duct, and their significance for hearing preservation (HP), remain unclear. Therefore, a longitudinal study was conducted to monitor maximum ECochG amplitude and its tonotopic location from EA insertion to 1 yr postimplantation. It was hypothesized that changes in maximum amplitude (>30%) and/or shifts in its location (>1 octave) across timepoints reflect intracochlear alterations associated with residual hearing changes. Design: ECochG recordings were obtained in 80 adult CI recipients with measurable residual hearing. For Contour Advance (CI612) and Slim Straight (CI622) arrays (Cochlear Ltd.), recordings were taken from every second intracochlear electrode. For HiFocus SlimJ and MidScala arrays (Advanced Bionics LLC), recordings were obtained from all electrodes. Measurements were conducted at four timepoints: (1) intraoperatively, during EA insertion (Intraop1), (2) intraoperatively, immediately after full insertion (Intraop2), (3) approximately 7 wk after surgery (Postop1), and (4) approximately 1 yr after surgery (Postop2). 500 Hz tone bursts were used for acoustic stimulation and the magnitude of the difference between responses to alternating-polarity stimuli was analyzed. Tonotopic electrode locations were determined from postoperative cone beam computed tomography scans. Pure-tone audiograms were obtained preoperatively and at approximately 7 wk and 1 yr postoperatively. HP was determined using the HEARRING group formula. Results: Maximum ECochG amplitudes remained largely stable intraoperatively, with no significant difference between Intraop1 and Intraop2 in complete-case analysis (n = 44). In contrast, a significant decrease in maximum amplitude was observed between Intraop2 and Postop1 (p < 0.001). Participants with >30% amplitude reduction between the 2 intraoperative recordings (Intraop1 versus Intraop2) did not differ significantly in HP from those with stable amplitudes. However, those showing a >30% reduction in the early postoperative period (Intraop2 versus Postop1) showed significantly lower HP (p = 0.028). Nonapical peak location during Intraop1 occurred in 41% of the cases, although tonotopic location of the maximum peak during insertion monitoring (Intraop1) did not show a relationship with HP. Tonotopic location shifts of the maximum amplitude (>1 octave) were observed in a small subset of cases between consecutive recordings up to Postop2. However, peak location changes (apical, basal, stable) were not associated with significant differences in HP. Conclusions: Our results suggest that nonapical peak patterns are not necessarily markers of insertion trauma and may instead reflect variability in cochlear integrity (e.g., dead regions). Peak location during insertion monitoring was not associated with postoperative HP, and both maximum amplitude and tonotopic peak location remained stable intraoperatively. In contrast, early postoperative reductions in ECochG amplitude were common and associated with HP, highlighting the need to investigate strategies to minimize early intracochlear reactions. Overall, the study demonstrates the value of ECochG for monitoring intracochlear processes over time.

Hearing and balance disorders are among the most prevalent sensory impairments globally, yet their cellular and molecular basis remains poorly understood. This gap stems from the inaccessibility of the inner ear, which is encased in the temporal bone (TB)—the hardest bone in the body—and cannot be biopsied in living patients. Conventional histopathology workflows, particularly the century-old celloidin method, are time-consuming, labor-intensive, and incompatible with modern molecular analyses. We aimed to develop a faster, more versatile histology workflow for human TBs that preserves both morphology and molecular integrity. We developed a reversible polymethyl methacrylate (rPMMA) embedding protocol for formalin-fixed, calcified TBs using low-temperature resin infiltration (−40 to +4 °C). Precision near-serial sections (10–50 µm) were generated via femtosecond laser microtomy or precision diamond wire sawing. Deacrylation was performed to restore tissue accessibility for histological staining, multiplex immunofluorescence, whole-genome sequencing, and in situ RNA detection (RNAscope™). Compared to the celloidin workflow, our method reduced processing time and costs by over 90

Objectives:Silent sinus syndrome (SSS) arises from negative pressure in the maxillary sinus through occlusion of the ethmoidal infundibulum. Convexity of the surrounding bone towards the lumen and a hypoglobus can occur. It may endanger surrounding structures during endoscopic sinus surgery. This research identifies and quantifies radiological changes in inferoposterior anatomical structures associated with SSS. Study design:Retrospective case series study. Setting:Computed tomography and magnetic resonance imaging scans of 23 patients with SSS who were treated at the University Hospital of Zurich between 2013 and 2023 were evaluated. Methods:The volume of the maxillary sinus, the orbital floor and sinus rear wall convexity, the height of the tuber maxillae, and the pterygopalatine fossa dimension were measured. The affected side was quantitatively compared with the healthy side. Results:The extension of the pterygopalatine fossa and the height of the tuber maxillae were significantly larger on the affected side (mean difference = 2.354 mm, 4.99 mm; P < .01 for both). A stronger indentation of the back wall (mean difference = 3.763 mm; P < .01) and the orbital floor (mean difference = 2.268 mm; P < .01) was measured in SSS. In addition, the syndrome reduces the volume of the affected maxillary sinus (mean difference = 8.885 mL; P < .01). Conclusion:SSS causes a marked enlargement of the neighbouring inferoposterior anatomical spaces. Shrinking of the sinus' volume could explain this effect. These findings have direct clinical implications, as the surgeon might inadvertently enter these structures more easily in SSS.

Der Morbus Menière ist eine chronische Innenohrerkrankung mit rezidivierenden Schwindelattacken, Tinnitus und Hörverlust, die bei einem Teil der Patienten zu hochgradiger Schallempfindungsschwerhörigkeit führt. Die Diagnostik erfolgt seit 2015 anhand international konsentierter Kriterien, welche zwischen definitivem und wahrscheinlichem Morbus Menière unterscheiden. Therapeutisch wird ein stufenweises Vorgehen empfohlen, das von nicht-ablativen bis hin zu ablativen Verfahren reicht. Cochleaimplantate (CI) haben sich als effektive Option zur Hörrehabilitation etabliert und zeigen zudem günstige Effekte auf Schwindel- und Tinnitussymptomatik. Kombinationsstrategien mit Saccuschirurgie werden diskutiert, während die Labyrinthektomie mit simultaner CI-Implantation eine hochwirksame, jedoch irreversible Maßnahme darstellt. Besondere Herausforderungen bestehen bei bilateralen Verläufen, bei denen radiologische Endotypisierungen (z. B. hypoplastischer Typus des vestibulären Aquädukts) künftig die Therapieplanung präzisieren könnten. Studien belegen, dass die CI-Versorgung sowohl nach ablativen Eingriffen als auch bei einseitigem Morbus Menière mit Erhalt von Restgehör möglich ist und zu einer signifikanten Verbesserung der Lebensqualität führt. Systematische Übersichten bestätigen die hohe Wirksamkeit und Sicherheit der CI-Therapie, wodurch sie eine zentrale Rolle in der Versorgung fortgeschrittener Erkrankungsverläufe einnimmt. Erste Ansätze zur Entwicklung vestibulocochleärer Implantate (VCI) eröffnen zudem die Perspektive einer kombinierten auditiven und vestibulären Rehabilitation, befinden sich jedoch noch im experimentellen Stadium.

Importance:Many cochlear implant candidates retain residual hearing, which can improve speech perception and overall outcomes. However, residual hearing is frequently lost during implantation. Intraoperative electrocochleography may enable monitoring of residual hearing, but its clinical relevance is currently limited due to reliance on expert interpretation, the absence of real-time analysis algorithms, and signal variability. Objective:To assess whether automated analysis of intraoperative cochlear microphonic amplitude decreases (events) is associated with hearing preservation and to evaluate additional electrocochleography features enhancing potential predictive performance. Design, Setting, and Participants:This multicenter, cross-sectional cohort study included adults receiving a cochlear implant with a preoperative hearing threshold not greater than 85 dB hearing level at 0.5 kHz and cochlear microphonic amplitude of 5 μV or higher across 3 tertiary referral centers in Melbourne, Australia; Bern, Switzerland; and Zurich, Switzerland. Intraoperative real-time electrocochleography and impedance data were collected between 2017 and 2025, with audiometric follow-up 3 months postoperatively. Exposures:Cochlear implantation with the Slim Straight Electrode array (Cochlear Limited). Main Outcomes and Measures:Primary outcome was binary hearing preservation at 3 months postoperatively, defined as less than 25% loss relative to the preoperative low-frequency pure-tone average at 0.25 to 1 kHz. Primary variables assessed as possible predictors included magnitude, location, and persistence of cochlear microphonic events. Post hoc analysis explored associated changes in the auditory nerve neurophonic:cochlear microphonic amplitude ratio and cochlear microphonic phase. Results:A total of 112 patients met inclusion criteria and were analyzed (median [IQR] age at surgery, 68 [58-75] years; 57 [51%] female and 55 [49%] female). Cochlear microphonic events persisting or occurring near the end of insertion were associated with loss of residual hearing (adjusted odds ratio, 31.58 [95% CI, 6.36-205.36] and 52.96 [95% CI, 8.02-472.63], respectively), independent of age, preoperative hearing, and participating hospital. Events with rising amplitude ratio between auditory nerve neurophonic and cochlear microphonic were associated with better hearing preservation (mean difference in hearing preservation, 24.4% [95% CI, 7.3%-41.5%]). Stable cochlear microphonic phase showed a similar trend (mean difference in hearing preservation, 20.9% [95% CI, 2.9%-38.9%]). Conclusions and Relevance:This cross-sectional study demonstrates the feasibility of automated intraoperative electrocochleography for possible prediction of hearing preservation during cochlear implantation. Persistent cochlear microphonic events near the end of insertion were associated with hearing loss. Additional electrocochleography features may improve signal interpretation. These findings support the development of real-time feedback systems to guide cochlear implantation.

INTRODUCTION:Current cochlear implant systems do not yet provide recipients invisible, carefree, and 24/7 hearing. The main technical challenge for a totally implantable cochlear implant (TICI) system is the development of a suitable implantable microphone (IM). One promising approach involves an IM that detects sound pressure within the middle ear cavity (MEC), eliminating the need for complex mechanical coupling with the ossicular chain. The present study investigates whether and under what conditions an MEC microphone (MECM) can meet the performance criteria required for TICI systems. METHOD:The analysis considers an MECM design concept that uses a micro-electromechanical systems (MEMS) microphone enclosed in a hermetic and biocompatible housing. A lumped element model (LEM) of the MECM, combined with sound pressure measurements in an intact and surgically modified MEC of human cadaver temporal bones, was employed to address the research question. RESULTS:The experimental study showed that sealing the MEC at the aditus ad antrum increases sound pressure by up to 15 dB at frequencies below 3 kHz compared to an MEC configuration with an intact mastoid. However, a decrease of approximately 10 dB in the middle ear transfer function (METF) was observed due to stiffening of the middle ear caused by a smaller MEC size. The LEM indicated that an MECM with a 5 mm diameter and optimized enclosure geometry meets the performance criteria for a TICI, but only when the MEC is acoustically isolated from the mastoid cavity. Our analysis shows that the MECM can be seen as a promising IM concept for TICIs.

Menière's disease is a chronic inner ear disorder characterized by recurrent vertigo attacks, tinnitus, and fluctuating hearing loss, which may progress to severe sensorineural hearing impairment in a subset of patients. Since 2015, international consensus criteria distinguish between definite and probable disease. Current therapeutic strategies follow a stepwise approach, ranging from non-ablative to ablative interventions. Cochlear implantation (CI) has emerged as an effective option for auditory rehabilitation and has also shown beneficial effects on vertigo and tinnitus. Combined strategies with endolymphatic sac surgery are discussed, while labyrinthectomy with simultaneous CI represents a highly effective yet irreversible intervention. Particular challenges arise in bilateral cases, where radiological endotyping (e.g., hypoplastic vestibular aqueduct type) may improve future treatment planning. Evidence demonstrates that CI is feasible after ablative procedures as well as in unilateral Menière's disease with hearing preservation, resulting in significant improvements in quality of life. Systematic reviews confirm the safety and efficacy of CI, establishing its central role in the management of advanced disease stages. Early developments of vestibulocochlear implants (VCI) additionally open perspectives for combined auditory and vestibular rehabilitation, although clinical application remains experimental.

Aim: There are a range of approaches to intraoperative electrocochleography (ECochG) monitoring across different implant systems, and these show inconsistent results. Here, we synthesize by meta-analysis the evidence for real-time intracochlear ECochG recorded during cochlear implantation predicting residual hearing. Methods: Inclusion criteria included original studies in which real-time ECochG was undertaken on a commercial cochlear implant (CI) and residual hearing outcomes at least 4 weeks after implantation were reported. Thirteen studies comprising 313 individual patient data sets met inclusion criteria. Full data sets were sought from the authors. Studies were rated for quality and bias. Details about study design (observational or interventional) and electrode characteristics (lateral wall or perimodiolar) were extracted. Relative hearing loss across the low frequencies (250–1,000 Hz) was the main outcome, with decibel loss and functional hearing as secondary outcomes. Effects were explored by forest plot, and then linear mixed modelling on the full data sets. Sensitivity analyses included recalculation of hearing preservation using thresholds across different frequencies. Results: Thirteen studies, including 313 full patient data sets, were included, and meta-analysis was performed on lateral wall electrodes. A drop of ECochG amplitude of >30%, even if transient, predicted residual hearing across all metrics (decibel, relative, and functional), and data-synthesis methods (forest plots and linear modelling) for all systems where real-time measurements were available. A drop of amplitude of at least 60% across insertion predicted relative but not decibel hearing loss in linear mixed modelling. The “pattern” of ECochG drop, as described by Harris in 2017, did not predict residual hearing by any method. Discussion: The only truly “real-time” measurement that predicted residual hearing was an instantaneous drop in ECochG amplitude, with or without recovery. Large drops over the insertion did too, but these can only be calculated after insertion, and after the cochlear trauma has been done. All CI systems now offer real-time monitoring – these results provide guidance on how best to use it to optimize clinical outcomes.

OBJECTIVE:To investigate whether one of the two recently described MD endotypes-defined by either endolymphatic sac degeneration (MD-dg patients) or hypoplasia (MD-hp patients)-is associated with an increased likelihood of undergoing CI. STUDY DESIGN:Retrospective multicenter cross-sectional study. SETTING:Five tertiary referral centers. PATIENTS:CI cohort: 115 adult MD patients with a history of uni- or bilateral CI. Non-CI cohort: 72 MD patients with no CI history. All included patients matched current diagnostic criteria for definite MD. INTERVENTION:Cochlear implantation. MAIN OUTCOME MEASURES:Endotype distribution (MD-dg versus MD-hp) between the CI cohort and the non-CI cohort. The endotype was determined using high-resolution CT data based on the angular trajectory of the vestibular aqueduct, following established protocols. Secondary outcomes included disease laterality, age at MD diagnosis, duration of MD, and pre-CI hearing thresholds. RESULTS:The CI cohort included significantly more MD-hp patients than the non-CI cohort (72% versus 24%, p < 0.0001). The odds ratio of CI for an MD-hp patient relative to an MD-dg patient was 8.4 (95% confidence interval, 4.3-16.1). Pre-CI audiometric data showed no significant differences in hearing thresholds between endotypes, neither in the implanted nor in the non-implanted ear. CONCLUSIONS:The MD-hp endotype, frequently associated with bilateral disease and early-age disease onset, is strongly linked to a higher likelihood of CI. Endotyping of MD patients based on endolymphatic sac pathology can effectively stratify their risk of severe hearing loss, guiding personalized audiological follow-up and clinical decisions regarding potential CI.

INTRODUCTION:Recent advancements toward minimizing surgical trauma and preserving residual hearing during cochlear implantation have promoted the use of intracochlear electrocochleography (ECochG) for intraoperative surveillance. However, variations in the distribution of response generators throughout the cochlea complicate the interpretation of signal changes during electrode array insertion. This exploratory study aimed to investigate whether simultaneous recordings from 2 locations within the cochlea could address this issue. This was done by (1) comparing recordings acquired simultaneously from an apical and a more basal electrode contact during atraumatic electrode array insertions; and (2) comparing these response patterns with preoperative pure-tone audiograms. MATERIALS AND METHODS:In 10 standard CI recipients, ECochG recordings were obtained during stepwise insertion of a short-temporary electrode array. Simultaneous intracochlear recordings were acquired from 2 contacts separated by 4.2 mm in response to 500 Hz tone bursts. For both electrode contacts, the differences between responses to alternating-polarity stimuli, hereafter named "ECochG responses," were derived. After completion of the recordings, the temporary electrode array was removed and a standard CI electrode array inserted. RESULTS:In 6 of 10 participants, ECochG response amplitude decreases of ≥3 dB were recorded at the more basal electrode contact. In 4 cases, these amplitude drops were preceded by amplitude drops recorded at the apical electrode contact, with both occurring no more than 1.7 mm apart along the cochlear duct. Trauma would be expected to produce a simultaneous amplitude drop-at different recording locations-for both electrodes. In contrast, a drop at the basal electrode that is preceded by a drop in the ECochG recording at the apical electrode, with both drops occurring at approximately the same location, is likely atraumatic. These atraumatic drops may also be associated with large phase shifts. Overall, the ECochG response tracks recorded at the apical and more basal contact were similar, while the ECochG response patterns and audiogram did not show a strong resemblance. CONCLUSION:The proposed approach could facilitate the detection of ECochG response changes relevant for predicting hearing preservation during cochlear implantation. By distinguishing between simultaneous and sequential amplitude drops, this method could provide additional insights into the atraumatic nature of certain ECochG response changes.

OBJECTIVES:The inter-phase gap (IPG) offset effect is defined as the dB offset between the linear parts of electrically evoked compound action potential (ECAP) amplitude growth functions for two stimuli differing only in IPG. The method was recently suggested to represent neural health in cochlear implant (CI) users while being unaffected by CI electrode impedances. Hereby, a larger IPG offset effect should reflect better neural health. The aims of the present study were to (1) examine whether the IPG offset effect negatively correlates with the ECAP threshold and the preoperative pure-tone average (PTA) in CI recipients with residual acoustic hearing and (2) investigate the dependency of the IPG offset effect on hair cell survival and intracochlear electrode impedances. DESIGN:Seventeen adult study participants with residual acoustic hearing at 500 Hz undergoing CI surgery at the University Hospital of Zurich were prospectively enrolled. ECAP thresholds, IPG offset effects, electrocochleography (ECochG) responses to 500 Hz tone bursts, and monopolar electrical impedances were obtained at an apical, middle, and basal electrode set during and between 4 and 12 weeks after CI surgery. Pure-tone audiometry was conducted within 3 weeks before surgery and approximately 6 weeks after surgery. Linear mixed regression analyses and t tests were performed to assess relationships between (changes in) ECAP threshold, IPG offset, impedance, PTA, and ECochG amplitude. RESULTS:The IPG offset effect positively correlated with the ECAP threshold in intraoperative recordings ( p < 0.001) and did not significantly correlate with the preoperative PTA ( p = 0.999). The IPG offset showed a postoperative decrease for electrode sets that showed an ECochG amplitude drop. This IPG offset decrease was significantly larger than for electrode sets that showed no ECochG amplitude decrease, t (17) = 2.76, p = 0.014. Linear mixed regression analysis showed no systematic effect of electrode impedance changes on the IPG offset effect ( p = 0.263) but suggested a participant-dependent effect of electrode impedance on IPG offset. CONCLUSIONS:The present study results did not reveal the expected relationships between the IPG offset effect and ECAP threshold values or between the IPG offset effect and preoperative acoustic hearing. Changes in electrode impedance did not exhibit a direct impact on the IPG offset effect, although this impact might be individualized among CI recipients. Overall, our findings suggest that the interpretation and application of the IPG offset effect in clinical settings should be approached with caution considering its complex relationships with other cochlear and neural health metrics.

Background The aim of this study was to relate response patterns of electrocochleography (ECochG) recordings during cochlear implantation to pre- and postoperative hearing. Methods Thirty subjects with either flat (FA, n = 9) or sloping (SA, n = 21) audiograms before cochlear implantation were prospectively included. Real-time ECochG recordings were conducted via the cochlear implant. The difference curve (DIF) signal of the ECochG recordings was analyzed regarding alteration of the waveform, amplitude changes, and relative phase shifts during insertion. Results Five subjects (56%) with FA and 13 (62%) with SA exhibited DIF signal drops in the early phase of the insertion. In subjects with FA, alterations of the DIF signal waveform in the early phase of the insertion occurred in 8 subjects (90%), whereas such changes were detectable in only 2 out of 21 subjects (10%) with SA (p < 0.001). DIF signal drops with relative phase shifts of >0.7 radians but without alterations of the waveform occurred in 5 subjects (56%) with FA and 11 (52%) with SA. Such drops were associated with larger postoperative hearing losses than DIF signal drops without phase changes in both groups (FA: 43 versus 20 dB, p = 0.045; SA: 30 versus 14 dB, p = 0.001). Conclusion Residual cochlear function in basal regions leads to alteration of the DIF signal waveform during insertion, probably not associated with cochlear injury. A decrease of the DIF signal amplitude with a simultaneous relative phase shift but no alteration of the waveform is associated with greater loss of residual hearing independent from the preoperative hearing.

BACKGROUND/OBJECTIVES:Electrocochleography (ECochG) is a promising tool to monitor preservation of cochlear structures and function during cochlear implant (CI) surgery. However, the interpretation of ECochG signal changes during insertion of the CI electrode array remains controversial. This study investigates the influence of the degree and localization of cochlear trauma on ECochG signal changes using a mouse model. METHODS:C57BL/6J-Crl1 mice underwent intracochlear ECochG recordings during the insertion of a platinum-iridium electrode. RESULTS:In case of grade 1 and 2 cochlear trauma, as determined by post-mortem histological analysis, we found that a reduction in intracochlear cochlear microphonic (CM) amplitude correlates more significantly with the location of the trauma than with its severity. The more basally a trauma is located, the larger the CM amplitude drop. Furthermore, the results revealed that grade 1 or 2 trauma was detectable through ECochG before more severe trauma developed. CONCLUSIONS:These findings suggest that intracochlear ECochG can serve as a reliable intraoperative tool for detecting early and possibly reversible cochlear trauma, preventing more severe damage and aiding hearing preservation. The results emphasize the need for a nuanced interpretation of CM signal drops, considering trauma location and cochlear structure integrity at the site of trauma and apical to it.

Background: The brainstem auditory-evoked response (BAER) is an established electrophysiological measure of neural activity from the auditory nerve up to the brain stem. The BAER is used to diagnose abnormalities in auditory pathways and in neurophysiological human and animal research. However, normative data for BAERs in sheep, which represent an adequate large animal model for translational and basic otological research, are lacking. Objective: The aim of this study was to assess the function of the ovine auditory nervous system by determining normative values for the BAER and to compare sheep with human BAER data. Methods: In this retrospective study, BAER data for click stimuli at a range of sound pressure levels (SPLs) were analyzed. A series of 15 samples from six sheep with a mean age of 41.8 months was included. Results: The mean BAER threshold was 45.3 dB SPL. At 100 dB SPL, the mean (±standard deviation, SD) latency of wave V was 4.35 (±0.18) ms, that of wave III was 2.44 (±0.15) ms, and that of wave I was 0.88 (±0.13) ms. At 100 dB SPL, the mean interpeak latency of waves I–III was 1.56 (±0.18) ms, that of waves III–V was 1.91 (±0.16) ms, and that of waves I–V was 3.47 (±0.20) ms. The mean amplitudes at 100 dB SPL were 0.04 (±0.03) µV for wave I, 0.50 (±0.24) µV for wave III, and 0.40 (±0.25) µV for wave V. Conclusions: The normative values for sheep BAERs were reproducible and similar to those of humans. The normative BAER values further support sheep as an adequate animal model for otological research.

Objective:Semicircular canal dehiscence (SCD) and vestibular aqueduct (VA) hypoplasia are developmental anomalies associated with distinct inner ear syndromes-SCD syndrome and Meniere's disease (MD). Our previous work found frequent SCD in MD patients with VA hypoplasia, suggesting a shared developmental origin. To further explore this association, we adopted a reciprocal approach by assessing VA hypoplasia prevalence in patients diagnosed with SCD.Study Design:Retrospective cohort study.Setting:Tertiary referral center.Patients:A total of 219 ears from 173 patients (mean age 53.5 years, standard deviation 16.6 years; 54.3% females) were evaluated for suspected SCD, confirmed by temporal bone computed tomography (CT).Interventions:Radiological analysis of temporal bone CT scans using the angular trajectory of the vestibular aqueduct (ATVA) marker; review of clinical records for diagnosis of MD.Main Outcome Measures:Prevalence of VA hypoplasia among SCD patients; association of radiological findings with clinical diagnosis of MD.Results:VA hypoplasia was identified in 4 of 173 patients (2.3%), representing a 46-fold increase compared with the estimated 0.05% prevalence of MD patients with VA hypoplasia in the general population. These cases showed an atypical SCD localization in the posterior limb of the superior semicircular canal. All 4 patients were diagnosed with MD ipsilateral to the SCD/VA hypoplasia.Conclusions:SCD and VA hypoplasia are associated in a distinct patient group, suggesting a shared developmental etiology. These patients may be predisposed to an early overlap of SCD syndrome and MD, with their clinical course eventually dominated by the progressive nature of MD.

Introduction: Otosclerosis is a known cause of particularly conductive hearing loss of a variable extent. Radiological examination reveals footplate thickening in addition to heterogeneously distributed hypodense foci. The objective of this study was to investigate the correlation between a thickened stapes footplate and its association with perioperative audiometric findings and postoperative complications. METHODS:This was a retrospective data analysis conducted at a single tertiary referral center on 63 surgically confirmed otosclerotic ears from 56 patients. Stapes footplate thickness was measured in the stapes axial plane of a preoperative computed tomography scan. Measured stapes footplate thickness was assessed regarding its relationship between pre- and postoperative audiometric data and vestibulocochlear complications associated with stapedotomy. RESULTS:Radiological assessment of stapes footplate thickness demonstrated considerable variation between otosclerotic ears, with a mean value of 0.85 mm (range 0.5-1.37 mm). No statistically significant correlation was identified between pre- and postoperative audiometric data for air-bone gap, air conduction, and bone conduction in the overall population or within subgroups. One case showed postoperative inner ear hearing loss (PTA-BC 26.3-37.5 dB HL), resulting in severe combined hearing loss, occurring 40 days after uneventful surgery (footplate thickness 0.79). Regardless of footplate thickness, no further cases of postoperative sensorineural hearing loss were reported. Postoperative vertigo was observed in 20 patients, none of whom showed pathological findings in clinical head impulse testing or exhibited spontaneous nystagmus, without association with footplate thickness (t(61) = 0.83, p = 0.41). Significant improvements regarding the air-bone gap (26.45 dB HL, SD 9.24 to 7.70 dB HL, SD 5.69, p < 0.0001), as well as air-conduction (48.65 dB HL, SD 14.24-26.29 dB HL, SD 10.24, p < 0.0001) and bone-conduction (22.20 dB HL, SD 9.20-18.13 dB HL, SD 10.11, p < 0.0001) pure-tone average thresholds, were observed from last pre- to last postoperative audiometric data after stapedotomy. Comparison of first to last postoperative audiometric data revealed significant improvement in air-bone gap (10,74 dB HL, SD 7.20-7.70 dB HL, SD 5.691, p = 0.0002), as well as air conduction (31.63 dB HL, SD 12.30-26.29 dB HL, SD 10.24, p < 0.0001) and bone conduction (20.08 dB HL, SD 10.26-18.13 dB HL, SD 20.11, p = 0.011), at a mean postoperative follow-up time of 12.6 months, SD 9 months (2.4-37.3 months). CONCLUSION:Stapes footplate thickness in otosclerosis cases is not correlated with presurgical or postoperative hearing, nor with the incidence of postoperative complications. Stapedotomy can be performed safely regardless of the thickness of the stapes footplate. .

Zusammenfassung Die Elektrocochleographie (ECochG) bietet eine aussichtsreiche Möglichkeit zur Überwachung der cochleären Funktion während der Cochleaimplantation und zur Erforschung der Ursachen des Verlusts cochleärer Restfunktion nach der Implantation. Die vorliegende Arbeit gibt einen Überblick über den aktuellen Forschungs- und Anwendungsstand der ECochG, sowohl während als auch nach der Cochleaimplantation. Die intraoperative ECochG kann entweder durch das Implantat selbst oder mittels einer extracochleären Messelektrode durchgeführt werden. Postoperative ECochG-Aufnahmen sind über das Implantat möglich. Verschiedene Studien haben gezeigt, dass ein signifikanter Abfall der ECochG-Amplitude während der Elektrodeninsertion mit einem erhöhten Risiko für den Verlust der cochleären Restfunktion korreliert, wobei bedeutsame cochleäre Ereignisse vornehmlich gegen Ende der Insertion auftreten. Postoperative Daten deuten darauf hin, dass der Verlust der cochleären Funktion hauptsächlich in der frühen postoperativen Phase erfolgt. Zukünftige Forschungsansätze umfassen die Automatisierung und Objektivierung der Signalauswertung sowie eine vertiefte Untersuchung der den Signaländerungen zugrunde liegenden Mechanismen.

Electrocochleography (ECochG) represents a promising approach for monitoring cochlear function during cochlear implantation and for investigating the causes of residual cochlear function loss after implantation. This paper provides an overview of the current research and application status of ECochG, both during and after cochlear implantation. Intraoperative ECochG can be conducted either via the implant itself or an extracochlear measuring electrode. Postoperative ECochG recordings are also feasible via the implant. Various studies have demonstrated that a significant decrease in ECochG amplitude during electrode insertion correlates with an increased risk of losing residual cochlear function, with critical cochlear events occurring primarily towards the end of the insertion. Postoperative data suggest that the loss of cochlear function mainly occurs in the early postoperative phase. Future research directions include the automation and objectification of signal analysis, as well as a more in-depth investigation into the underlying mechanisms of these signal changes.

Background: Various representations exist in the literature to visualize electrocochleography (ECochG) recordings along the basilar membrane (BM). This lack of generalization complicates comparisons within and between cochlear implant (CI) users, as well as between publications. This study synthesized the visual representations available in the literature via a systematic review and provides a novel approach to visualize ECochG data in CI users. Methods: A systematic review was conducted within PubMed and EMBASE to evaluate studies investigating ECochG and CI. Figures that visualized ECochG responses were selected and analyzed. A novel visualization of individual ECochG data, the ZH-ECochG Bode plot (ZH = Zurich), was devised, and the recordings from three CI recipients were used to demonstrate and assess the new framework. Results: Within the database search, 74 articles with a total of 115 figures met the inclusion criteria. Analysis revealed various types of representations using different axes; their advantages were incorporated into the novel visualization framework. The ZH-ECochG Bode plot visualizes the amplitude and phase of the ECochG recordings along the different tonotopic regions and angular insertion depths of the recording sites. The graph includes the pre- and postoperative audiograms to enable a comparison of ECochG responses with the audiometric profile, and allows different measurements to be shown in the same graph. Conclusions: The ZH-ECochG Bode plot provides a generalized visual representation of ECochG data, using well-defined axes. This will facilitate the investigation of the complex ECochG potentials generated along the BM and allows for better comparisons of ECochG recordings within and among CI users and publications. The scripts used to construct the ZH-ECochG Bode plot are provided by the authors.

Objective: To study the additional use of topical antibiotic-loaded calcium sulfate pellets in difficult-to-treat cases of temporal bone infections. Patients: Four patients with advanced and pretreated temporal bone disease. Intervention: Application of topical antibiotic-loaded calcium sulfate pellets following surgical debridement in infections of the temporal bone. Main Outcome Measures: Reinfection- and revision-free follow-up analysis and assessment of audiometric data. Results: A total of 4 patients were included (3 females and 1 male, mean age of 29.5 years [SD 19.8]). All patients (4/4) had a revision-free follow-up during a mean of 24.5 (SD, 6.19) months. Reinfections (n = 3) were observed in 2 patients (2/4) occurring 1 and 15, as well as 8 months after surgery. Reinfections could be successfully treated using topically and/or orally applied antibiotic therapy. No change in air-conducted pure-tone average was observed after treatment (mean change 1.3 dB; P = 0.99). Conclusion: Local application of antibiotic-loaded calcium sulfate pellets in combination with surgical debridement represents an effective treatment for local infection control in difficult-to-treat cases of temporal bone infections.