Advances in Evaluation of Electrode Insertion Trauma Induced Residual Hearing loss in Cochlear Implant Recipients and its significance- A Narrative Review.

Cochlear implant surgery has revolutionized the management of profound hearing loss, with a growing focus on preserving residual hearing, particularly low-frequency hearing. This review synthesizes existing literature on cochlear implantation techniques, surgical principles, and emerging therapies aimed at reducing post-implantation hearing loss. Methodologically, a comprehensive narrative literature review was conducted, encompassing various study designs and participant demographics. The search strategy involved major biomedical databases, focusing on articles in English. Surgical techniques such as "soft surgery" emphasize minimizing mechanical stress on the cochlea, while advancements in pharmacological agents explore the use of corticosteroids, neurotrophins, and growth factors to enhance hearing preservation. Electrode design and insertion strategies are evolving to minimize trauma and optimize hearing outcomes, including consideration of insertion forces and electrode array designs. Evaluating residual hearing loss involves sophisticated techniques like electrocochleography and radiological imaging. The impact of residual hearing on auditory verbal outcomes is variable, with studies indicating positive correlations with language development, particularly in speech production. Emerging strategies in electrode design, surgical techniques, and drug delivery hold promise for improving outcomes in cochlear implantation. However, challenges such as the lack of standardized guidelines and the need for further clinical trials remain. Future directions include the exploration of nanotechnologies, gene therapies, and stem cells for constructing bionic ears, although ethical and technical hurdles persist. This review underscores the ongoing efforts to enhance cochlear implant functionality and the need for continued research to optimize outcomes for patients with hearing loss.

Successful Pediatric Cochlear Implantation In Persistent Stapedial Artery: First Reported Case In India With Literature Review And Relevance of Preoperative Imaging Checklist.

We report the first successful pediatric cochlear implantation in bilateral persistent stapedial artery (pSA) in India. Another child with unilateral pSA, the contralateral side was initially implanted. Both children were preoperatively diagnosed. Preoperative imaging checklist for pSA, facilitates counselling for bilateral and decision-making for the contralateral side in unilateral abnormality.

Changes of Otolith and Balance Function Related to Cochlear Implant in Hearing Loss With Inner Ear Malformations Children.

OBJECTIVES: The increase of bilateral cochlear implantation (CI) in recent years has made it essential to comprehend the effects of CI on otolith function. This study aimed to investigate the development of gross motor and otolith function in patients with inner ear malformations (IEMs) using vestibular-evoked myogenic potentials (VEMPs). MATERIALS AND METHODS: Overall, 78 patients with sensorineural hearing loss (SNHL) (age 5.7 ± 4.1 years) were divided into two groups based on the presence (IEM group, n = 39) or absence (control group, n = 39) of IEMs. VEMP testing was performed both before and 1-3 months after CI, and the evaluation of gross motor development was carried out. RESULTS: The mean ages for achieving head control and independent walking were delayed in the IEM group compared with the control group (p = 0.02). The preoperative cervical VEMP (cVEMP) and ocular VEMP (oVEMP) response rates were higher in the control group (60% and 86.95%) than in the IEM group (57.69% and 74.35%) (p < 0.05). Additionally, abnormal cVEMP was associated with delayed acquisition of independent walking (p = 0.017). Saccular and utricular functions after CI were lost by 40% and 31.75%, respectively, in patients who elicited preoperative VEMPs waveform (n = 25). CONCLUSIONS: Among SNHL patients, balance development is more delayed in patients of IEMs than in patients without IEMs. The cVEMP and oVEMP waveforms differed greatly between the two groups. The otolith-vestibular nerve conduction pathway can be affected by CI, potentially leading to otolith function impairment. Therefore, it is essential to assess otolith and balance functions before CI, and this evaluation should be considered an integral part of clinical practice.

Speech-Processing Network Formation of Cochlear-Implanted Toddlers With Early Hearing Experiences.

To reveal the formation process of speech processing with early hearing experiences, we tracked the development of functional connectivity in the auditory and language-related cortical areas of 84 (36 female) congenitally deafened toddlers using repeated functional near-infrared spectroscopy for up to 36 months post cochlear implantation (CI). Upon hearing restoration, the CI children lacked the modular organization of the mature speech-processing network and demonstrated a higher degree of immaturity in temporo-parietal than temporo-frontal connections. The speech-processing network appeared to form rapidly with early CI experiences, with two-thirds of the developing connections following nonlinear trajectories reflecting possibly more than one synaptogenesis-pruning cycle. A few key features of the mature speech-processing network emerged within the first year of CI hearing, including left-hemispheric advantage, differentiation of the dorsal and ventral processing streams, and functional state (speech listening vs. resting) specific patterns of connectivity development. The developmental changes were predictable of future auditory and verbal communication skills of the CI children, with prominent contribution from temporo-parietal connections in the dorsal stream, suggesting a mediating role of speech-processing network formation with early hearing experiences in speech acquisition.

Impact of Cochlear Implant Electrode Array Design on Post-Op Speech Perception.

OBJECTIVE: Electrode array design may impact hearing outcomes in patients who receive cochlear implants. The goal of this work was to assess differences in post operative speech perception among patients who received cochlear implants of differing designs and lengths. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary Care Hospital. METHODS: Patients (n = 129) received 1 of 9 electrode arrays, which were categorized by design: Lateral wall electrodes (n = 36) included CI522, CI622 (Cochlear Americas), Flex24, and Flex28 (Med El). Midscala electrodes (n = 16) included HiRes Ultra 3D (Advanced Bionics). Perimodiolar electrodes (n = 77) included CI512, CI532, CI612, and CI632 (Cochlear Americas). Speech perception was evaluated using consonant-nucleus-consonant (CNC) tests and at 3, 6, 12, and 24 months postimplantation. RESULTS: Perimodiolar electrodes showed significantly higher CNC scores compared to lateral wall electrodes at 6 and 24 months. Perimodiolar electrodes also outperformed midscala electrodes at 12 months. An inverse relationship was observed between electrode length and CNC scores noted at 6, 12, and 24 months. CONCLUSION: Perimodiolar electrode arrays, which tend to be shorter, demonstrated better speech perception outcomes compared to the longer lateral wall and midscala arrays at some timepoints. These findings suggest a potential advantages of perimodiolar electrodes for optimizing hearing outcomes.

Comparison of Outcomes After Cochlear Implantation in a Veteran Versus Nonveteran Population.

Objective: To evaluate for equivalence in postoperative changes of speech recognition scores in a veteran patient population undergoing cochlear implantation (CI) compared to matched nonveteran patients. Study Design: Retrospective chart review. Setting: Tertiary referral center. Patients: A total of 83 veteran patients who underwent CI at a single Veterans Affairs Medical Center (VA cohort) were matched to 83 nonveteran patients from the Health Insurance Portability and Accountability Act-secure, Encrypted, Research, Management and Evaluation Solution database (HERMES cohort) based on age, sex, and baseline Consonant-Nucleus-Consonant (CNC) scores. Intervention: Patients underwent CI. Main Outcome Measures: Comparison of postoperative CNC and Arizona Biomedical Institute recognition scores. Results: The mean difference and lower confidence interval of CNC scores between matched Veterans Affairs and HERMES cohorts were within a -ΔNI boundary of -15% at the 3-month (mean = 6.15, lower confidence interval = -2.38), 6-month (mean = 7.36, lower confidence interval = -2.21), and 12-month (mean = 4.03, lower confidence interval = -4.88) postoperative time points. The mean difference and lower confidence interval of Arizona Biomedical Institute scores between cohorts were within the -ΔNI boundary of -30% at 3 months (mean = 1, lower confidence interval = -8.71), 6 months (mean = 0.31, lower confidence interval = -12.30), and 12 months (mean = 0.72, lower confidence interval = -10.48). Conclusion: Our veteran population demonstrated improvements in speech recognition scores after CI comparable to a matched nonveteran population. Although veterans face unique factors that affect their hearing, access to medical care, and baseline general health, these findings affirm appropriate veteran candidates should be offered CI.

The Long-Term Effect of Cochlear Implantation on Tinnitus: A Systematic Review and Meta-Analysis.

OBJECTIVE: This systematic review investigates the long-term effect of cochlear implantation (CI) on clinical outcomes in tinnitus patients with sensorineural hearing loss (SNHL). DATABASE SOURCES: PubMed, Embase, and the Cochrane Library were searched from inception to 30 April 2024. Manual searches of reference lists supplemented these searches when necessary. REVIEW METHODS: Original studies included in the meta-analysis had to contain comparative pre- and postoperative data for SNHL patients who underwent CI. Outcomes measured were the Tinnitus Handicap Inventory (THI), Visual Analog Scale (VAS), and Tinnitus Questionnaire (TQ). RESULTS: A total of 28 studies comprising 853 patients showed significant tinnitus improvement after CI: THI mean difference (MD) -14.02 [95%CI -15.29 to -12.76, p < 0.001], TQ MD -15.85 [95%CI -18.97 to -12.74, p < 0.05], and VAS MD -3.12 [95%CI -3.49 to -2.76, p < 0.05]. Subgroup analysis indicated a significant difference between follow-up periods in THI (p < 0.0001) and VAS loudness (p = 0.02). CONCLUSIONS: Cochlear implantation substantially improves tinnitus in patients with hearing loss, though the effect may diminish over time. Further research is needed to confirm these findings.

Does cochlear implantation affect personality of hearing-impaired patients? A five-year follow-up study.

BACKGROUND: Previous studies found that in patients with profound hearing loss the NEO- personality factor Openness-to-experience is lowered. OBJECTIVE: Assuming that lowered Openness-to-experience may be due to limited access to sounds, we hypothesized that levels of Openness-to-experience would increase in these patients after cochlear implantation. MATERIAL AND METHODS: Twenty adults (mean age: 61 years; active CI users) with bilateral profound hearing loss were assessed with the NEO-Five-Factor-Inventory before cochlear implantation (pre) and five years later (post). RESULTS: No significant pre-post changes in personality were seen. Both before and five years after cochlear implantation, the sample had normal age- and gender-specific mean values on the factors Extraversion, Neuroticism, Agreeableness, and Conscientiousness (T ≈ 50), but significantly lowered mean values on Openness-to-experience (T ≈ 42, p < 0.001). CONCLUSIONS AND SIGNIFICANCE: Cochlear implantation apparently has no (or at best very little) effect on Openness-to-experience in profoundly hearing impaired patients. While this study demonstrates once again, that high-grade hearing loss may be associated with less openness to new experiences, the reason for this association remains unclear.

Exploring cross-modal plasticity in the auditory-visual cortex post cochlear implantation: implications for auditory and speech function recovery and mechanisms.

Objective: The aim of this is to explore changes in cross-modal reorganization within the auditory-visual cortex after cochlear implantation, examining their influence on auditory and speech functions along with their underlying mechanisms. Methods: Twenty prelingually deaf children who received cochlear implantation and rehabilitation training at our hospital between February 2022 and February 2023 comprised the prelingual deaf group. Simultaneously, 20 healthy children served as the control group. The prelingual deaf group underwent brain cortical activity assessment and evaluation of auditory-speech recovery pre-surgery, at postoperative weeks 1 and 2, and at months 1, 3, 6, 9, and 12. The control group underwent parallel assessments and evaluations. We analyzed the correlation between cortical activity in the auditory-visual cortex of patients and their auditory-speech functional recovery. Results: The group with prelingual deafness displayed elevated levels of auditory and visual cortical electromagnetic intensity compared to the control group, both prior to and 9 months after surgery. However, by the 12-month mark post-surgery, there was no discernible distinction between the two groups. Following surgery, the prelingually deaf group exhibited a progressive improvement in both Categories of Auditory Performance (CAP) and Speech Intelligibility Rate (SIR), initially lagging behind the control group. Notably, a negative correlation emerged between auditory and visual cortical electromagnetic intensity values and CAP/SIR scores at the 12-month post-surgery assessment. Conclusion: Cochlear implantation in prelingually deaf children results in elevated activity within the auditory and visual cortices, demonstrated by heightened electromagnetic intensity readings. Cross-modal reorganization is observed temporarily at 3 months post-surgery, which resolves to baseline levels by 12 months post-surgery. This phenomenon of reversal correlates with the restoration of auditory and speech functions in these children.

Generic and Hearing-Specific Quality of Life in Older Adult Cochlear Implant Users.

Background This study aimed to evaluate the quality of life (QOL) of older adults using cochlear implants (CIs) by focusing on how individual characteristics and speech perception are related to generic QOL ratings and utilizing the Health Utilities Index Mark III (HUI3) for assessment. Methodology A cross-sectional study was conducted with 19 participants aged ≥60 years, who were within one to five years post-implant activation. Data were obtained through self-administered questionnaires, including the HUI3 for generic QOL assessment and disease-specific indexes. Speech perception tests and chart reviews provided personal characteristic data. Statistical analysis was performed using the Mann-Whitney U-test, one-way analysis of variance, and Pearson's correlation coefficient. Results In total, 18 patients responded to the study. This study revealed that the generic QOL in older adult CI users was lower than that in the general older adult population. There was no significant association between QOL and variables such as sex, duration of implant usage, or age. However, a longer duration of hearing loss before receiving an implant was associated with higher generic QOL scores. Additionally, a strong correlation was observed between the hearing-related QOL score and utility scores. Conclusions Longer pre-implantation hearing loss correlated with better post-implantation QOL. Additionally, a reduced QOL, specifically within the hearing attribute, a subdomain of the HUI3, was associated with a lower overall generic QOL. The results suggest that generic QOL cannot be evaluated based on hearing ability alone and that cochlear implantation does not completely improve generic QOL. This study represents an important first step in understanding the QOL of older adult CI users from a variety of backgrounds.

Cochlear Implantation for Isoleucyl-tRNA Synthetase Mutation-Associated Mitochondrial Disease: A Case Report.

Biallelic missense mutations in the nuclear-encoded, cytosolic isoleucyl-tRNA synthetase (IARS) gene are associated with a rare and complex multisystemic phenotype, including growth retardation, intellectual disability, muscular hypotonia, diabetes mellitus, and deafness. These mutations impact the cytosolic isoform of IARS, which plays a crucial role in protein synthesis. The pathogenesis involves mitochondrial dysfunction, despite IARS being primarily a cytosolic enzyme, potentially linking it to the observed clinical manifestations. The efficacy of cochlear implantation for deafness due to IARS mutations and the safety of general anesthesia in such patients remain unclear. This report describes a rare case of progressive sensorineural hearing loss caused by IARS mutation-associated mitochondrial disease, which was successfully treated with cochlear implantation. Additionally, we discuss the safety of general anesthesia in this patient. A Japanese woman with IARS mutation-associated mitochondrial disease was diagnosed with severe bilateral sensorineural hearing loss at five years of age and immediately received hearing aids. Her hearing progressively deteriorated to profound impairment, necessitating cochlear implantation at 26 years of age, which resulted in satisfactory hearing. Furthermore, no perioperative general anesthesia-related adverse events were reported. Our case demonstrates that cochlear implantation can effectively restore hearing. This suggests that sensorineural hearing loss caused by IARS deficiency is primarily due to cochlear dysfunction. This case demonstrated that hearing loss is a crucial feature of IARS mutation-associated mitochondrial disease, which can be mitigated by cochlear implantation. While general anesthesia can be safely administered, careful consideration of anesthetic choices, such as avoiding depolarizing muscle relaxants and prolonged use of propofol, is essential to prevent complications. In this case, general anesthesia was well tolerated without perioperative events, providing valuable insight into the potential safety of such procedures in similar patients. Nevertheless, further studies are needed to confirm these findings across a broader population.

Cochlear implantation in otosclerosis: surgical and audiological outcomes between ossified and non-ossified cochlea.

AIM: To evaluate (1) Audiological and surgical outcomes in patients with otosclerosis following cochlear implantation. (2) surgical difficulties and outcomes between both groups. (3) Audiological outcomes between both groups. STUDY DESIGN AND SETTING: Retrospective study conducted at Otology and Skull Base Surgery Center. SUBJECTS AND METHODS: Data were analyzed from 111 patients with otosclerosis (114 ears) who underwent cochlear implant surgery using the cochlear implant database. Demographic characteristics (age, sex, and operated ear), auditory outcomes, and operative details (extent of cochlear ossification, surgical approach [posterior tympanotomy or subtotal petrosectomy], electrode insertion [partial/complete, scala tympani or vestibuli], and complications) were analyzed Auditory outcomes were assessed over at least one year follow-up period using pure tone audiometry and speech discrimination scores. Patients were divided into two groups (with and without cochlear ossification) to compare auditory outcomes and surgical outcomes. RESULTS: The mean age of patients with ossified and non-ossified cochlea was 60.04 and 62.22 years respectively. Sixty-five of 114 ears had cochlear ossification, with complete round window involvement in 75.4% of these patients, while the rest had partial or complete basal turn ossification. Subtotal petrosectomy was performed in 63.1% and 28.6% of ossified and non-ossified cochlea respectively while the rest underwent cochlear implantation through posterior tympanotomy. Only one case had scala vestibuli insertion and four had incomplete electrode insertion. Six patients underwent re-implantation due to infection, device failure, and erosion of the posterior canal wall. Auditory outcomes among patients with ossified otosclerosis were slightly better than those without ossification but this difference was not statistically significant. CONCLUSION: Cochlear implantation for otosclerosis yields excellent auditory outcomes with a low rate of surgical complications, despite the high incidence of cochlear ossification.

Changes in participatory and societal outcomes during the waiting period for cochlear implantation - an observational study.

INTRODUCTION: Various factors, including an aging population and expanding eligibility criteria, may increase the demand for cochlear implants (CIs), potentially resulting in longer waiting times. In most Dutch CI centers, the time between referral and surgery exceeds 6 months. Clinical experience suggests that during the waiting period for cochlear implantation, hearing and communication difficulties increase. Simultaneously, there is an interest in outcomes more closely aligned with patient values and needs, which resulted in the SMILE (Societal Merit of Interventions on hearing Loss Evaluation) study. This paper presents results on observed changes in societal and participatory outcomes during waiting time in participants with a time to CI surgery exceeding 6 months. METHODS: SMILE is a prospective multi-center study including 232 individuals who were referred for unilateral CI. Continuous and nominal data from multiple questionnaires, sent immediately after referral and shortly before surgery, were analyzed by computing differences, Cohen's D, and odds ratios. RESULTS: Of the total 232 participants, 102 had a time between inclusion and surgery exceeding 6 months. Of these, 89 had (partially) filled out surveys at both time points. Of all the domain scores 55% did not show differences between timepoints. All Cohen's D estimates were relatively small, ranging from - 0.298 to 0.388 for those outcomes that showed noteworthy changes. CONCLUSION: Waiting time from referral to surgery, even though exceeding 6 months, was observed to not seriously affect non-clinically-prioritized patients in an adverse way. Future investigations should identify subgroups on tolerable waiting times regarding short- and long-term outcomes. TRIAL REGISTRATION: Trial registration number at ClinicalTrials.gov: NCT05525221, 25-8-2022.

Minimum intraoperative testing battery for cochlear implantation: the international practice trend.

PURPOSE: In cochlear implantation (CI) surgery, there are a wide variety of intraoperative tests available. However, no clear guide exists on which tests must be performed as the minimum intraoperative testing battery. Toward this end, we studied the usage patterns, recommendations, and attitudes of practitioners toward intraoperative testing. METHODS: This study is a multicentric international survey of tertiary referral CI centers. A survey was developed and administered to a group of CI practitioners (n = 34) including otologists, audiologists and biomedical engineers. Thirty six participants were invited to participate in this study based on a their scientific outputs to the literature on the intraoperative testing in CI field and based on their high load of CI surgeries. Thirty four, from 15 countries have accepted the invitation to participate. The participants were asked to indicate the usage trends, perceived value, influence on decision making and duration of each intraoperative test. They were also asked to indicate which tests they believe should be included in a minimum test battery for routine cases. RESULTS: Thirty-two (94%) experts provided responses. The most frequently recommended tests for a minimum battery were facial nerve monitoring, electrode impedance measurements, and measurements of electrically evoked compound action potentials (ECAPs). The perceived value and influence on surgical decision-making also varied, with high-resolution CT being rated the highest on both measures. CONCLUSION: Facial nerve monitoring, electrode impedance measurements, and ECAP measurements are currently the core tests of the intraoperative test battery for CI surgery.

A Pediatric Case of Cogan's Syndrome With Internal Otitis.

Cogan's syndrome is characterized by ocular symptoms and auditory vestibular dysfunction. Auditory vestibular dysfunction in Cogan's syndrome is believed to be similar to Ménière's disease, but the cause is not known in detail. We present the case of a 10-year-old boy with Cogan's syndrome. The patient had panuveitis, bilateral hearing loss, and bilateral vestibular dysfunction. MRI revealed no evidence of endolymphatic hydrops, which is a cause of Ménière's disease, and enhanced contrast effects on the bilateral cochlear and vestibular apparatus. The caloric test, the video-head impulse test, and the vestibular evoked muscle potential test also showed severe vestibular dysfunction. Based on the above, the auditory vestibular dysfunction in this patient was considered to be caused by internal otitis. The patient's vision recovered after treatment with steroids and immunosuppressive drugs, but his hearing did not recover. He underwent bilateral cochlear implantation and had a good postoperative course but we encountered difficulty in deciding when to perform cochlear implantation. This case demonstrates the importance of determining the timing of surgery in consideration of the ossification and fibrosis of the inner ear and the drug administration status.

Influence of Cochlear Anatomy on Intraoperative Electrically Evoked Compound Action Potentials.

Objective: The electrically evoked compound action potential (ECAP) is an objective measure to indirectly assess spiral ganglion neurons. The ECAP provides inputs about the prognoses of cochlear implant (CI) recipients. Several factors such as cochlear morphology can affect ECAP measurements. This study aims to investigate the variation effect of cochlear parameters on intraoperative ECAP thresholds. Methods: This is a retrospective study on patients who underwent CI surgery with normal inner ear morphology at our center between 2017 and 2023. Cochlear anatomical parameters, including diameter (A value), width (B value), and height (H value), as well as cochlear duct length (CDL), were measured pre-operatively using OTOPLAN software (Version 3.0). Cochlear implant intraoperative objective measures were also collected. The correlation between the cochlear parameters and intraoperative objective measures was studied. Results: A total of 45 patients underwent cochlear implantation. The mean age was 2.4 ± 0.9 years. The mean CDL and cochlear coverage values were 33.2 ± 2.0 mm and 76.0 ± 5.7%, respectively. The ECAP threshold increased toward basal electrodes, with ECAP values as follows: apical 13.1 ± 3.8; middle 14.3 ± 3.7; and basal 15.6 ± 4.8. Additionally, the A, B, and H values showed a positive correlation with ECAP thresholds in different cochlear regions. The B value showed a significant moderate correlation with ECAP thresholds in the middle and basal electrodes but not in the apical electrodes. Conclusions: Cochlear anatomical parameters correlate with intraoperative ECAP thresholds. The B value showed a significant association with ECAP thresholds in the middle and basal electrodes. These findings could delineate the impact of the B value in CI and optimize electrode selection. Further research is required to study this correlation and its impact on postoperative outcomes.

Novel Variant of FDXR as a Molecular Etiology of Postlingual Post-synaptic Auditory Neuropathy Spectrum Disorder via Mitochondrial Dysfunction: Reiteration of the Correlation between Genotype and Cochlear Implantation Outcomes.

OBJECTIVES: FDXR encodes mitochondrial ferredoxin reductase, which is associated with auditory neuropathy spectrum disorder (ANSD) and optic atrophy. To date, only two studies have described FDXR-related hearing loss. The auditory rehabilitation outcomes of this disease entity have not been investigated, and the pathophysiological mechanisms remain incompletely understood. Here we report a hearing-impaired individual with co-segregation of the FDXR variant and post-synaptic type ANSD, who underwent cochlear implantation (CI) with favorable outcomes. We suggest a possible pathophysiological mechanism of adult-onset ANSD involving mitochondrial dysfunction. METHODS: A 35-year-old woman was ascertained to have ANSD. Exome sequencing identified the genetic cause of hearing loss, and a functional study measuring mitochondrial activity was performed to provide molecular evidence of pathophysiology. Expression of FDXR in the mouse cochlea was evaluated by immunohistochemistry. Intraoperatively, electrically evoked compound action potential (ECAP) responses were measured, and the mapping parameters were adjusted accordingly. Audiological outcomes were monitored for over 1 year. RESULTS: In lymphoblastoid cell lines (LCLs) carrying a novel FDXR variant, decreased ATP levels, reduced mitochondrial membrane potential, and increased reactive oxygen species levels were observed compared to control LCLs. These dysfunctions were restored by administering mitochondria isolated from umbilical cord mesenchymal stem cells, confirming the pathogenic potential of this variant via mitochondrial dysfunction. Partial ECAP responses during CI and FDXR expression in the mouse cochlea indicate that FDXR-related ANSD is post-synaptic. As a result of increasing the pulse width during mapping, the patient's CI outcomes showed significant improvement over 1-year post-CI. CONCLUSION: A novel FDXR variant associated with mitochondrial dysfunction and post-synaptic ANSD was first identified in a Korean individual. Additionally, 1-year post-CI outcomes were reported for the first time in the literature. Excellent audiologic. RESULTS: were obtained, and our. RESULTS: reiterate the correlation between genotype and CI outcomes in ANSD.

Alzheimer's Disease-Related Analytes Amyloid-ß and Tau in Perilymph: Correlation With Patient Age and Cognitive Score.

OBJECTIVE: To describe the collection methods for perilymph fluid biopsy during cochlear implantation, detect levels of amyloid ß 42 and 40 (Aß42 and Aß40), and total tau (tTau) analytes with a high-precision assay, to compare these levels with patient age and Montreal Cognitive Assessment (MoCA) scores, and explore potential mechanisms and relationships with otic pathology. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. METHODS: Perilymph was collected from 25 patients using polyimide tubing to avoid amyloid adherence to glass, and analyzed with a single-molecule array advanced digital enzyme-linked immunosorbent assay platform for Aß40, Aß42, and tTau. Cognition was assessed by MoCA. RESULTS: Perilymph volumes ranged from ∼1 to 13 µL, with analyte concentrations spanning 2.67 to 1088.26 pg/mL. All samples had detectable levels of tTau, Aß40, and Aß42, with a significant positive correlation between Aß42 and Aß40 levels. Levels of Aß42, Aß40, and tTau were positively correlated with age, while MoCA scores were inversely correlated with age. tTau and Aß42/Aß40-ratios were significantly correlated with MoCA scores. CONCLUSION: Alzheimer's disease-associated peptides Aß42, Aß40, and tau analytes are detectable in human perilymph at levels approximately 10-fold lower than those found in cerebrospinal fluid (CSF). These species increase with age and correlate with cognitive impairment indicators, suggesting their potential utility as biomarkers for cognitive impairment in patients undergoing cochlear implantation. Future research should investigate the origin of these analytes in the perilymph and their potential links to inner ear pathologies and hearing loss, as well as their relationships to CSF and plasma levels in individuals.

Validating an Evoked Potential Platform for Electrocochleography During Cochlear Implantation.

OBJECTIVE: To validate electrocochleography (ECochG) between an auditory evoked potential (AEP) machine and an established cochlear implant (CI) manufacturer ECochG system. METHODS: Intraoperative validation study at a tertiary referral center. Patients included adults and children undergoing cochlear implantation. Intraoperative ECochG was measured with both the Intelligent Hearing Systems (IHS) Duet AEP machine and Cochlear Corporation (CC) ECochG platform. Recording electrodes captured extracochlear measurements through a standard facial recess. Tone-bursts were presented from 250 Hz to 2 kHz (~110 dB SPL). A fast Fourier transform (FFT) of ECochG waveforms at key frequencies was summed into a total response (ECochG-TR). Pearson's correlation was utilized to evaluate the relationship between IHS-ECochG-TR and CC-ECochG-TR after confirming normality. RESULTS: Thirty patients were enrolled with an average age of 67 years (SD 18.8). In the ear that was implanted, mean preoperative pure-tone average (PTA; 0.5, 1, 2, and 4 kHz) was 87.4 dB HL (SD 19.3) and mean preoperative word-recognition scores (WRS) was 17.0% correct (SD 19.1). There was strong correlation (r = 0.905, 95% confidence interval: 0.809 to 0.954) between IHS-ECochG-TR (median 2.30 µV, range 0.1-148.26) and CC-ECochG-TR (median 3.00 µV, range 0.1-239.63). Four patients underwent transtympanic ECochG with the IHS system for feasibility evaluation and achieved similar responses. CONCLUSION: Extracochlear ECochG has been predictive of CI speech perception performance. The IHS duet system is a valid measure of extracochlear ECochG for the CI population. Future work will utilize this system for measuring transtympanic ECochG to improve preoperative estimation of CI performance. LEVEL OF EVIDENCE: 3 Laryngoscope, 2024.

A Case of Cochlear Implantation in a Deaf Patient With Eosinophilic Otitis Media in Whom Post-implantation Hearing Threshold Improved After Introduction of Dupilumab.

Eosinophilic otitis media (EOM) is a rare, intractable, and chronic form of otitis media. The associated hearing loss often progresses to deafness, necessitating cochlear implantation (CI). EOM is associated with type 2 inflammatory conditions such as asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). Dupilumab, a monoclonal antibody targeting the IL4Rα subunit, has shown efficacy in mitigating type 2 inflammatory diseases, including asthma and CRSwNP. Recent studies also suggest its effectiveness in treating EOM. We report a unique case of CI for EOM, in which the post-implant hearing threshold improved after the introduction of dupilumab. The patient was a 63-year-old man with a history of asthma and multiple nasal polypectomies. Eosinophils were detected in otorrhea samples from both ears, leading to an EOM diagnosis four years prior. Despite local corticosteroid therapy, his hearing gradually deteriorated. One month ago, he experienced sudden bilateral deafness and was referred to our hospital. The right tympanic membrane had a pinhole perforation but no otorrhea. CT showed a small amount of soft tissue density in the right middle ear, while the left side displayed cochlear osteolysis with soft tissue density. A right CI and myringoplasty were performed one and a half months after his visit. The cochleostomy revealed no perilymph leakage, confirming that the scala tympani was filled with granulation tissue. The electrode was inserted successfully despite the granulation, and all electrodes were placed correctly. Six months after CI, his hearing threshold with the cochlear implant remained poor at 67.5 dB. However, upon starting dupilumab therapy seven months postoperatively, his hearing threshold with the cochlear implant rapidly improved to 31.3 dB. Intraoperative findings suggested that the scala tympani was filled with granulation tissue, indicating significant cochlear inflammation due to EOM. The subsequent hearing improvement after introducing dupilumab may be attributed to the reduction or disappearance of granulation in the cochlea, allowing for effective electrical stimulation from the electrodes to the spiral ganglion. This case suggests the potential for improved postoperative hearing outcomes in CI for EOM when inflammation is effectively controlled with dupilumab.