Response to OKN-007 and NAC in a Patient with Unilateral Hearing Loss and Chronic Tinnitus from Vestibular Schwannoma.

BACKGROUND: Tinnitus is the perception of sound in the absence of external acoustic stimulation. Being one of the most common diseases of the ear, it has a global prevalence ranging from 4.1 to 37.2%. To date, it has been difficult to treat tinnitus as its pathophysiology is poorly understood and there are limited treatment options. OBJECTIVE: To investigate the effect of OKN-007 (also known as HPN-07), a nitrone-based investigational drug, in combination with oral N-acetylcycsteine (NAC), for the treatment of hearing loss and chronic tinnitus under an individual expanded access protocol. PATIENT CASE: We report the case of a patient who presented with left-sided ear fullness, mild tinnitus, and mild high frequency sensorineural hearing loss with 100% word recognition. A large enhancing mass seen on MRI revealed a vestibular schwannoma. He underwent subtotal resection of the tumor resulting in a moderate-to-profound sensorineural hearing loss and catastrophic tinnitus. The patient was treated with intravenous OKN-007 at 60 mg/kg dosed three times per week and oral NAC 2500 mg twice daily. RESULTS: Post-treatment audiometric testing revealed an average of 16.66 dB in hearing threshold improvement in three frequencies (125, 250 and 500 Hz) with residual hearing in the affected left ear. His tinnitus loudness matching improved from 90 dB to 19 dB post-treatment. His Tinnitus Handicap Inventory improved from 86/100 (Catastrophic) to 40/100 (Moderate). He also experienced improvements in sleep, concentration, hearing, and emotional well-being, and reported significantly decreased levels of tinnitusrelated distress. CONCLUSIONS: This case report highlights the feasibility and therapeutic potential of the combination of OKN-007 and NAC in treating hearing loss and tinnitus that warrants further investigation.

Cochlear Implantation in Very Young Children With Single-Sided Deafness.

OBJECTIVE: Cochlear implants (CIs) for single-sided deafness (SSD) have only been approved for patients 5 years and older despite data supporting that younger children can also benefit from implantation. This study describes our institution's experience with CI for SSD in children 5 years and younger. STUDY DESIGN: Case series with chart review. SETTING: Tertiary referral center. METHODS: A case series with chart review identified 19 patients up to age 5 years who underwent CI for SSD between 2014 and 2022. Baseline characteristics, perioperative complications, device usage, and speech outcomes were collected. RESULTS: The median age at CI was 2.8 (range, 1.0-5.4) years, with 15 (79%) patients being below age 5 at implantation. Etiologies of hearing loss were idiopathic (n = 8), cytomegalovirus (n = 4), enlarged vestibular aqueduct (n = 3), hypoplastic cochlear nerve (n = 3), and meningitis (n = 1). The median preoperative pure-tone average was 90 (range, 75-120) and 20 (range, 5-35) dB eHL in the poor and better hearing ears, respectively. No patients had postoperative complications. Twelve patients achieved consistent device use (average, 9 h/d). Three of the seven who were not consistent users had hypoplastic cochlear nerves and/or developmental delays. The three patients with available preoperative and postoperative speech testing showed significant benefits, and five patients with available postoperative testing demonstrated speech recognition in the implanted ear when isolated from the better ear. CONCLUSION: CI can safely be performed in younger children with SSD. Patients and families accept early implantation, as evidenced by consistent device use, and derive notable benefits in speech recognition. Candidacy can be broadened to include SSD patients under age five years, particularly individuals without hypoplastic cochlear nerves or developmental delay.

Chiari Type I Malformation Presenting with Unilateral Hearing Loss.

INTRODUCTION: Chiari type I malformations can present in different ways, but the most frequent symptom is an occipitocervical headache. Hearing loss as the main presenting symptom is rare. CASE: A young woman with progressive left-sided unilateral hearing loss was diagnosed with a Chiari type I malformation. She underwent a suboccipital craniectomy with C1 laminectomy and duraplasty. The hearing loss had resolved postoperatively with normalization of the audiometry. CONCLUSION: Chiari type I malformation can present solely with hearing loss. Improvement after surgical decompression is possible. This phenomenon is not emphasized well enough within the neurologic community. In this report, we present a summary of the pathophysiology and management in Chiari type I malformations.

Musical Ear Syndrome in a Patient with Unilateral Hearing Loss: A Case Report.

BACKGROUND Hearing music that has no source is known as musical ear syndrome, also known as musical hallucinations (MH), and is often associated with hearing impairment. This report is of a 62-year-old man with a 20-year history of unilateral hearing loss and continuous MH. We investigated the neural basis of MH in a subject without any known neurological or psychiatric disorders. CASE REPORT A 62-year-old man had a history of 20 years of symptomatic mild hearing loss accompanied with continuous MH in the form of multiple tones. The MH were unilateral in the left side and much more likely to be experienced as externally located and uncontrollable. He underwent structural and functional magnetic resonance imaging (fMRI). Results indicated increased activity and reduced cortical thickness in multiple cortical areas, such as the prefrontal cortex (PFC) and temporal and limbic regions, indicating complex processing and involvement. CONCLUSIONS The neurological findings indicate differentiated or multiple-area involvement in MH. These morpho-functional changes may represent a neural reorganization causing MH to arise. The altered or activated regions are all related to the processing of emotions and the processing of episodic memory, which has been seen in the MH of schizophrenic patients. This report also highlights that patients with hearing loss may present with continuous MH, and that these patients should not be assumed to have delusions or psychosis, but should be investigated for underlying auditory abnormalities and treated appropriately.

Ipsilateral auditory cortex responses to the intact ear after unilateral noise trauma in juvenile rats.

BACKGROUND: While ear stimulation produces a robust response in the contralateral auditory cortex (AC), it produces only a weak response in the ipsilateral AC, known as interhemispheric asymmetry. Unilateral deafness can lead to AC plastic changes, resulting in reduced interhemispheric asymmetry and auditory perceptual consequences. However, the unilateral hearing loss-associated plastic changes are far from fully understood. The purpose of this study was to investigate AC responses to the ipsilateral unimpaired ear after noise injury to the contralateral ear in juvenile rats. METHODS: Rats (50 days) were monaurally exposed to an intense noise (10.0-12.5 kHz, 126 dB SPL) for 2 hours. The unexposed ear-induced ipsilateral AC responses were recorded 2 days and 4 months after exposure and compared between groups. RESULTS: The noise exposure resulted in complete hearing loss in the exposed ear, but normal function in the other. Two days after exposure, the ipsilateral AC response induced by the intact ear was significantly enhanced and the threshold decreased (the early-onset effect). Four months after noise exposure, in addition to the increased response amplitude, the "slow-increasing" firing pattern of the neurons in the ipsilateral AC turned into the contralateral-AC-response-like "sharp-increasing" pattern (the late-onset effect) with shortened response latency. DISCUSSION: The early-onset effect can result from release of inhibition due to decreased contralateral input, while the late-onset effect may imply the formation of direct connections in the ipsilateral auditory pathway. The enhanced AC response may help maintain loudness perception and monaural sound localization after unilateral deafness.

Hipoacusia sensorioneural unilateral: Revisión de los manejos posibles en nuestra realidad nacional / Unilateral sensorineural hearing loss: Review of possible management in our national reality

La hipoacusia unilateral (HUL) definida como la pérdida auditiva de cualquier grado en un solo oído tiene prevalencias en edad escolar de 3% a 6%. La etiología es desconocida en la mayoría de los casos, pero destacan las anormalidades anatómicas severas a diferencia de las hipoacusias bilaterales, lo que le otorga importancia al estudio de imágenes. También se recomienda realizar evaluación oftalmológica. El impacto de la HUL se observa en la localización sonora, reconocimiento del habla, desarrollo del lenguaje, desempeño social y conducta, pero por sobre todo en el rendimiento académico. En este sentido es relevante mencionar que además de existir mayor probabilidad de repitencia de curso, es necesario mayor apoyo educacional individualizado para evitar dicha repitencia o lograr mismo éxito académico que un normoyente. En relación al diagnóstico aún faltan normas o protocolos, siendo éste un desafío en las zonas donde no hay screening universal. Se discute la importancia de las encuestas para realizar evaluaciones y seguimiento en estos casos. Finalmente se abordan las estrategias de intervención disponibles, además de un plan individualizado considerando al niño, su familia y sus expectativas, particularmente se discuten las características o factores a tomar en cuenta en el momento de la adaptación, para así lograr un tratamiento tendiente al éxito.

Unilateral hearing loss (UHL) defined as hearing loss of any degree in only one ear has a school-age prevalence of 3% to 6%. The etiology is unknown in most cases, but severe anatomical abnormalities stand out as opposed to bilateral hearing loss, which gives importance to the study of images. Ophthalmological evaluation is also recommended. The impact of UHL is observed in sound localization, speech recognition, language development, social performance and behavior, but above all in academic performance. In this sense, it is relevant to mention that in addition to having a higher probability of repeating the course, it is necessary to have more individualized educational support to avoid this repetition or achieve the same academic success as a normal listener. Regarding the diagnosis, there are still missing norms or protocols, this being a challenge in areas where there is no universal screening. The importance of surveys to carry out evaluations and follow-up in these cases is discussed. Finally, the available intervention strategies are discussed, in addition to an individualized plan considering the child, his family and his expectations, particularly, the factors to be taken into account at the time of adaptation, in order to achieve a success treatment.

Vestibular nerve deficiency and vestibular function in children with unilateral hearing loss caused by cochlear nerve deficiency.

BACKGROUND: High-resolution MR imaging enables the visualization of individual nerves in the internal auditory canal (IAC). Cochlear nerve deficiency (CND) is recognized as one of the major causes of sensory neural hearing loss (SNHL), especially in cases of unilateral hearing loss in childhood. Some patients with CND are thought to have accompanying vestibular nerve deficiency (VND). However, there have been few reports focusing on VND and vestibular function in these children. AIMS: The aim of this study was to evaluate the frequency of VND and vestibular dysfunction in children with unilateral SNHL caused by CND. MATERIAL AND METHODS: Thirty-eight children with unilateral SNHL, who were diagnosed with CND by 3 T-MRI, were evaluated for VND and underwent caloric testing and cervical vestibular evoked potential (cVEMP). RESULTS: Fourteen of 38 patients (37%) had VND, and eleven (29%) of the patients [ten of the patients (71%) with VND] had at least one vestibular dysfunction. The patients with VND had significantly worse hearing and an IAC of smaller diameter than did patients without VND. CONCLUSIONS AND SIGNIFICANCE: We should pay attention to VND as well as vestibular dysfunction in hearing loss patients with CND.

Cochlear implantation after radiosurgery for vestibular schwannoma.

OBJECTIVE: The object of this study was to ascertain outcomes of cochlear implantation (CI) following stereotactic radiosurgery (SRS) for vestibular schwannoma (VS). METHODS: The authors conducted a retrospective chart review of adult patients with VS treated with SRS who underwent CI between 1990 and 2019 at a single tertiary care referral center. Patient demographics, tumor features, treatment parameters, and pre- and postimplantation audiometric and clinical outcomes are presented. RESULTS: Seventeen patients (18 ears) underwent SRS and ipsilateral CI during the study period. Thirteen patients (76%) had neurofibromatosis type 2 (NF2). Median age at SRS and CI were 44 and 48 years, respectively. Median time from SRS to CI was 60 days, but notably, 4 patients underwent SRS and CI within 1 day and 5 patients underwent CI more than 7 years after SRS. Median marginal dose was 13 Gy. Median treatment volume at the time of SRS was 1400 mm3 (range 84-6080 mm3, n = 15 patients). Median post-CI PTA was 28 dB HL, improved from 101 dB HL preoperatively (p < 0.001). Overall, 11 patients (12 ears) exhibited open-set speech understanding. Sentence testing was performed at a median of 10 months (range 1-143 months) post-CI. The median AzBio sentence score for patients with open-set speech understanding was 76% (range 19%-95%, n = 10 ears). Two ears exhibited Hearing in Noise Test (HINT) sentence scores of 49% and 95%, respectively. Four patients achieved environmental sound awareness without open-set speech recognition. Two had no detectable auditory percepts. CONCLUSIONS: Most patients who underwent CI following SRS for VS enjoyed access to sound at near-normal levels, with the majority achieving good open-set speech understanding. Implantation can be performed immediately following SRS or in a delayed fashion, depending on hearing status as well as other factors. This strategy may be applied to cases of sporadic or NF2-associated VS. ABBREVIATIONS: AAO-HNS = American Academy of Otolaryngology-Head and Neck Surgery; ABI = auditory brainstem implant; CI = cochlear implantation; CN = cranial nerve; CNC = consonant-nucleus-consonant; CPA = cerebellopontine angle; EPS = electrical promontory stimulation; ESA = environmental sound awareness; HINT = Hearing in Noise Test; IAC = internal auditory canal; NF2 = neurofibromatosis type 2; OSP = open-set speech perception; PTA = pure tone average; SRS = stereotactic radiosurgery; VS = vestibular schwannoma; WRS = word recognition score.

Cochlear implantation for single-sided deafness after COVID-19 hospitalization.

INTRODUCTION: Understanding the clinical manifestations of the coronavirus disease (COVID-19) has become an urgent objective in the research community. Amongst the emerging neurologic complications is sensorineural hearing loss. While several cases of hearing loss amongst COVID-19 patients have been reported, the management of these patients has yet to be discussed and determined. Herein we present cochlear implant outcomes for a patient who suffered from unilateral sensorineural hearing loss after a prolonged hospital course for COVID-19. METHODS: A patient who was hospitalized for COVID-19 for one month and subsequently developed unilateral profound sensorineural hearing loss underwent cochlear implantation for single-sided deafness. His COVID-19 hospital course was reviewed in detail. Speech perception and audiometric assessments were used to evaluate cochlear implant outcomes. RESULTS: After cochlear implantation, the patient demonstrated improved speech perception on the implanted side and decreased tinnitus within 1 month of activation. CONCLUSIONS: Cochlear implantation may be an appropriate intervention for patients who suffer from severe sensorineural hearing loss following infection with COVID-19.

Congenital Unilateral Hearing Loss: Characteristics and Etiological Analysis in 121 Patients.

OBJECTIVE: To describe the characteristics and etiological analysis in patients with congenital unilateral hearing loss. STUDY DESIGN: Retrospective cohort analysis. SETTING: Tertiary referral center. PATIENTS: Children with permanent congenital unilateral hearing loss born between 2007 and 2018. Patients were referred after universal newborn hearing screening or by a colleague to confirm the diagnosis and perform etiological examinations. MAIN OUTCOME MEASURES: Hearing loss type, severity, and evolution linked with the results of etiological testing. RESULTS: In the 121 included children, aural atresia is the leading cause of congenital unilateral hearing loss (32%), followed by structural anomalies (19%) and cCMV (13%), whereas 24% remained idiopathic after etiological work-up. Severity is mainly moderately severe (33% with 56-70 dB hearing loss, majority aural atresia) or profound (31% with > 90 dB hearing loss, predominantly cochlear nerve deficiency). Syndromic features were present in 26%. Although discussed with all parents, only 26% of the children regularly used hearing amplification. CONCLUSIONS: Congenital conductive unilateral hearing loss is mainly caused by aural atresia, which proportion in congenital unilateral hearing loss proved higher than previously reported. Cochlear nerve deficiency and cCMV are the predominant etiologies of congenital unilateral sensorineural hearing loss. Etiological work-up in affected patients is mandatory as it might impact the approach, and syndromic features should be actively searched for.

Adults with unilateral congenital ear canal atresia - sound localization ability and recognition of speech in competing speech in unaided condition.

BACKGROUND: Individuals with unilateral hearing loss show poor spatial hearing, but individual variability is high. AIMS/OBJECTIVES: To investigate if the degree of hearing loss in unilateral ear canal atresia affects horizontal sound localization and speech recognition. MATERIALS AND METHODS: Twelve subjects with unilateral ear canal atresia without childhood hearing intervention. Previously published data from eight normal-hearing subjects in normal binaural as well as experimentally induced unilateral hearing loss served as a reference. Horizontal sound localization and recognition of speech in spatially separate competing speech were assessed. RESULTS: Linear regression analysis demonstrated a relationship between sound localization accuracy (SLA) and the air conduction pure tone average of the atretic ear (r = 0.85, p=.007). The large proportion of variability in SLA (72%) explained by the degree of hearing loss of the atretic ear indicates that binaural processing is possible. SLA was worse than for normal hearing individuals (p<.0001), and comparable to moderate simulated unilateral hearing loss (p=.13). Speech discrimination was significantly worse than normal (p<.0001) and not dependent on degree of hearing loss of the atretic ear. CONCLUSIONS AND SIGNIFICANCE: Individuals with congenital unilateral ear canal atresia show impaired horizontal SLA and recognition of speech in competing speech.

Another 'BEE'? - Brain-Eye-Ear (BEE) Disease Secondary to HbSC Disease Masquerading as Multiple Sclerosis.

Recurrent episodes of neurological dysfunction and white matter lesions in a young adult raise suspicion for multiple sclerosis (MS). However, occlusive retinopathy, hearing loss and absence of CSF oligoclonal bands are atypical for MS and should make the clinician consider an alternative diagnosis. We describe a man with hearing loss, visual signs and symptoms, and an accumulating burden of brain lesions, who was treated for a clinical diagnosis of MS for nearly two decades. Genetic testing revealed a unifying diagnosis.

Predicting Potential of Rapid Tumor Growth in Small to Medium Vestibular Schwannomas on the Basis of Sway Assessed Using Posturography.

OBJECTIVE: The relationship between quantitative posturography results and growth of vestibular schwannomas (VSs) during conservative management has not been studied. We aimed to clarify the relationship between the presence of disequilibrium based on posturographic measurement and VS growth. METHODS: This retrospective, single-center study included 53 patients with VSs (Koos stage I or II) managed conservatively after initial diagnosis. Radiographic progression was considered present if 20% volumetric growth was observed over the imaging interval. Posturography was performed at initial diagnosis, and sway velocity (SV) and sway area were calculated. Tumor growth-free survival was estimated using the Kaplan-Meier method. RESULTS: Mean follow-up period was 2.87 ± 2.58 years, up to tumor growth detection or last follow-up magnetic resonance imaging. Tumor growth incidence was 40.8% and 61.2% at 2 and 5 years, respectively. Cerebellopontine angle extension and SV with eyes open were related to tumor growth. Tumor growth-free survival of patients with cerebellopontine angle extension and patients with intracanalicular tumor at 2 years was 37.3% and 76.4%, respectively. Tumor growth-free survival of patients with SV >2.06 cm/second and patients with SV ≤2.06 cm/second at 2 years was 30.8% and 68.9%, respectively. The Cox hazard model demonstrated a significant risk for future tumor growth with SV >2.06 cm/second (relative risk, 2.475; 95% confidence interval, 1.11-5.37, P = 0.027). CONCLUSIONS: We demonstrated a positive correlation between SV with eyes open and future tumor growth. Posturographic data are objective and quantitative; thus, SV may be a potential predictor of future growth of VSs.

Hearing-related quality of life, developmental outcomes and performance in children and young adults with unilateral conductive hearing loss due to aural atresia.

BACKGROUND: While research has shown that children with single sided deafness have a lower quality of life and developmental outcomes compared to normal hearing peers, little is known about these domains in children with unilateral congenital conductive hearing loss due to aural atresia. OBJECTIVES: This study aims to investigate the hearing-related quality of life, developmental outcomes and educational performance in children and young adults with unilateral conductive hearing loss due to aural atresia. METHODS: Nineteen children and young adults with unilateral aural atresia received a set of five questionnaires. Hearing-related quality of life (SSQ), general quality of life (Kidscreen-27), speech and language development (CCC-2-Nl), educational performance and problems in social-emotional and behavioral domains (CBCL/YSR/ASR) were measured with validated questionnaires. Scores on the questionnaires were compared to their norm scores. Mann-Whitney U tests and independent t-tests were used to identify significant differences between age groups. RESULTS: Mean scores on the SSQ subscales were speech 6.78, spatial 5.00 and quality 6.98. Mean scores on the Kidscreen-27, CCC-2-NL, CBCL/YSR/ASR fell within normal or non-clinical range. A high number of cases needed speech therapy (60.7%) or special measures in class (79.3%) or showed grade repetition (>30%) in primary or secondary school. CONCLUSION: Children and young adults with unilateral conductive hearing loss due to congenital aural atresia showed lower scores regarding hearing-related quality of life compared to normal-hearing peers. The result show similarities with children with single sided deafness. Regarding general quality of life, speech and language development and in social-emotional and behavioral domains the studied children and young adults seem to develop according to norm scores. It is important to observe these children closely as they may need guidance during education to allow them to thrive.

Progressive cerebral and coronary aneurysms in the original two patients with Kosaki overgrowth syndrome.

Skeletal overgrowth accompanied by de novo heterozygous activating mutations in PDGFRB (platelet-derived growth factor receptor beta), that is, p.Pro584Arg and p.Trp566Arg, defines Kosaki overgrowth syndrome (OMIM #616592). Emerging evidence suggests a role of PDGFRB in the genesis of cerebral aneurysms. The delineation of the range and progression of the vascular phenotype of Kosaki overgrowth syndrome is urgently needed. Herein, we conducted subsequent analyses of serial neurovascular imaging studies of two original patients with a de novo heterozygous mutation in PDGFRB, that is, p.Pro584Arg. The analysis showed the progressive dilation of basilar and vertebral arteries and coronary arteries commencing during the teenage years and early 20s. The radiographic appearance of the basilar vertebral aneurysms showed signs of arterial wall dilation, compatible with the known vascular pathology of vascular-type Ehlers-Danlos syndrome and Loeys-Dietz syndrome. The dolichoectasia in cerebrovascular arteries can lead to fatal complications, even with neurosurgical interventions. To prevent the progression of artery dilation, preventative and therapeutic medical measures using tyrosine kinase inhibitors may be necessary in addition to optimal control of the systemic blood pressure. Kosaki overgrowth syndrome is a clinically recognizable syndrome that can exhibit progressive dilatory and tortuous vascular changes in basilar/vertebral and coronary arteries as early as in the teenage years. We recommend careful counseling regarding the risk of future vascular complications, optimal blood pressure control, and regular systemic vascular screening during follow-up examinations.

Fibrous dysplasia limited to an ossicle.

Fibrous dysplasia is an unusual pathologic condition caused by abnormal bone metabolism. Temporal bone involvement is often seen, but it is uncommon to find fibrous dysplasia limited to the middle ear, especially originating in and confined to a single ossicle. Here we report a case of osteofibrous dysplasia limited exclusively to an ossicle (malleus) causing gradual conductive hearing loss, which recovered after eventual complete removal of the dysplastic area. The lesion showed firm attachment to adjacent structures and initial removal was not possible. This report provides information to help other otologic surgeons facing similar conditions.

Left Ear Hearing Predicts Functional Activity in the Brains of Patients with Alzheimer's Disease Dementia.

OBJECTIVES: To determine whether central speech processing ability, as measured by hearing in noise, differs between right and left ears in adults with Alzheimer's disease related dementia (AD) as well as whether differences in central speech processing ability correlate with an fMRI-based measurement of global functional brain connectivity. METHODS: This prospective study was carried out at a tertiary referral center. Patients with an AD diagnosis and pure tone averages 40 dB HL or better were included. They were examined using resting-state fMRI and underwent central audiometric testing using the Dichotic Sentence Identification Test (DSI), the Dichotic Digits Test (DD), and the Synthetic Sentence Identification Test (SS), which test hearing in noise. DSI scores were correlated with resting-state fMRI connectivity between 361 distinct gray matter brain regions of interest (ROIs). Average global connectivity was calculated as mean functional connectivity between an ROI and the other 360 regions, a quantitative marker representing overall functional connectivity in the brain. RESULTS: Sixteen subjects had adequate fMRI and hearing data. The average age was 71.5 years old (±6.0). The average DSI score for the left ear was 40% (±34%) compared to 90% (±10%) in the right ear (P < .001). No difference between ears was noted on the DD. SS does not differentiate between ears, but worsening scores were noted with increasing background noise. Of the fMRI ROIs, 269 of the 361 had multiple comparison corrected significant correlations between global connectivity and DSI of the left ear (P = .004, r = .673), and all 269 showed higher functional connectivity for individuals with higher left DSI score. No correlations between DSI of the right ear and functional connectivity were found. CONCLUSIONS: Correlation was noted between left sided DSI and functional connectivity in patients with AD. Auditory input from the left ear was more susceptible to impairment, suggesting that side-specific auditory input may influence central auditory processing.

Progression of hearing loss and cochlear implantation in large vestibular aqueduct syndrome.

OBJECTIVES: Large vestibular aqueduct syndrome (LVAS) is a congenital inner ear malformation that commonly results in progressive sensorineural hearing loss (SNHL) and cochlear implantation (CI). Though LVAS accounts for approximately 15% of pediatric SNHL, little is known regarding the rate and severity of SNHL in these patients. We sought to characterize the timing of SNHL progression to CI in patients with LVAS. METHODS: We performed a retrospective chart review at our institution from 2000 to 2018 using ICD-10 "large vestibular aqueduct syndrome," and through identifying patients with CI who had LVAS. Demographic, surgical, and audiometric data were collected. Theoretical CI candidacy was approximated using a pure tone average (PTA) HL threshold of 70 dB. RESULTS: Of 103 patients, 96 had bilateral LVAS, and 7 had unilateral LVAS. Forty-one patients had bilateral implants, 52 had unilateral implants, and 10 were not implanted. The mean age at first implant was 8.62 years old [95%CI = 6.75,10.49], the mean age at second implant was 12.24 years old [95%CI = 8.33,16.15], and the mean time between implants was 4.37 years [95%CI = 3.02,5.73]. LVAS patients reached HL threshold of 70 dB at a mean age of 5.16 years old (SD = 3.04) for the "worse ear" and 9.08 years old (SD = 4.96) for the "better ear." CONCLUSIONS: LVAS patients are a heterogenous population of patients, in which some may undergo progression of HL and some may not. Further, there may be a discrepancy in the timing between patients' theoretical CI candidacy and when they undergo CI. In order to optimize timing of CI, individual monitoring and close observation of LVAS patients is recommended.