Search Results (500)

Background: Sudden-onset bilateral mixed hearing loss in adults is an extremely rare condition but challenging to diagnose and treat. Conductive hearing loss is associated with otitis media, while the simultaneous presence of a sensorineural component requires supplementary investigation for possible shared pathophysiological mechanisms. Case Presentation: We report the case of a 41-year-old male who was admitted to our hospital with a 48 h history of bilateral, fast progressive hearing loss following a viral illness. The audiologic testing revealed bilateral severe mixed hearing loss. Tympanometry indicated the presence of middle-ear effusion, and myringotomy confirmed the existence of pressurized serous fluid. Treatment consisted of systemic and intratympanic corticosteroids, antibiotics, and supportive therapy. The patient had an unexpected full recovery of auditory function within one month. Discussion: Multiple hypotheses were considered. We hypothesized the coexistence of unrelated conductive and sensorineural hearing loss or a unifying pathological process. Theories discussed include a direct viral insult to the cochlear structures or even pressure-mediated damage to the basal cochlea due to the simultaneous inward displacement of the oval and round windows. The complete resolution of hearing loss is the indicator of a reversible etiology, possibly due to transient inner ear dysfunction secondary to middle-ear pathology or viral infection. Conclusions: This case illustrates the complexity of diagnosing acute mixed hearing loss. This report emphasizes a rare case of sudden-onset bilateral mixed hearing loss with a complete recovery, contributing valuable insight into under-reported and diagnostically complex presentations. Full article

Background: Cochlear implantation is widely used to provide auditory rehabilitation to individuals with severe-to-profound sensorineural hearing loss. However, electrode insertion during cochlear implantation leads to inner ear trauma, damage to sensory structures, and consequently, loss of residual hearing. There is very limited information regarding the target proteins involved in electrode insertion trauma (EIT) following cochlear implantation. Methods: The aim of our study was to identify target proteins and host molecular pathways involved in cochlear damage following EIT utilizing the iTRAQ™ (isobaric tags for relative and absolute quantification) technique using our ex vivo model. The organ of Corti (OC) explants were dissected from postnatal day 3 rats and subjected to EIT or left untreated (control). The proteins were extracted, labelled, and subjected to ultra-high performance liquid chromatography–tandem mass spectrometry. Results: We identified distinct molecular pathways involved in EIT-induced cochlear damage. Confocal microscopy confirmed the expression of these identified proteins in OC explants subjected to EIT. By separating the apical, middle, and basal cochlear turns, we deciphered a topographic array of host molecular pathways that extend from the base to the apex of the cochlea, which are activated post-trauma following cochlear implantation. Conclusions: The identification of target proteins involved in cochlear damage will provide novel therapeutic targets for the development of effective treatment modalities for the preservation of residual hearing in implanted individuals. Full article

Objectives: Observational studies have shown that chronic obstructive pulmonary disease (COPD) is associated with an increased risk of hearing impairment. However, causality remains unclear, including with respect to lung function. This study aimed to investigate the associations of lung function and COPD with hearing impairment in the UK Biobank and confirm potential causalities using Mendelian randomization (MR). Methods: Cross-sectional analyses were performed using logistic regression models in a subsample of the UK Biobank. Two-sample MR analyses were performed on summary statistics for forced expiratory volume in one second (FEV1), forced vital capacity (FVC), COPD, and sensorineural hearing loss. Results: FEV1 and FVC were negatively associated with hearing impairment, with odds ratios (95% confidence intervals) of 0.80 (0.77, 0.84) and 0.80 (0.76, 0.83), respectively. COPD was positively associated with hearing impairment, with an odds ratio (95% confidence interval) of 1.10 (1.02, 1.18). In the MR analyses, a negative association was found between FVC and sensorineural hearing loss, with an odds ratio (95% confidence interval) of 0.91 (0.83, 0.99). For FVE1 and COPD, no significant associations were found. Conclusions: The results of this study showed that FVC was causally associated with hearing impairment, suggesting a potential protective effect of FVC on hearing impairment. Full article

Aminoglycoside antibiotics are critical in clinical use for treating severe infections, but they can occasionally cause irreversible sensorineural hearing loss. To establish a rational pathway for otoprotectant discovery, we provide an integrated, three-tier methodology—comprising cell-model selection, transcriptomic analysis, and a gentamicin–Texas Red (GTTR) uptake assay—to guide the development of otoprotective strategies. We first utilized two murine auditory cell lines—UB/OC-2 and HEI-OC1. We focused on TMC1 and OCT2 and further explored the underlying mechanisms of ototoxicity. UB/OC-2 exhibited a higher sensitivity to gentamicin, which correlated with elevated OCT2 expression confirmed via RT-PCR and Western blot. Transcriptomic analysis revealed upregulation of PI3K-Akt, calcium, and GPCR-related stress pathways in gentamicin-treated HEI-OC1 cells. Protein-level analysis further confirmed that gentamicin suppressed phosphorylated Akt while upregulating ER stress markers (GRP78, CHOP) and apoptotic proteins (cleaved caspase 3, PARP). Co-treatment with PI3K inhibitors (LY294002, wortmannin) further suppressed Akt phosphorylation, supporting the role of PI3K-Akt signaling in auditory cells. To visualize drug entry, we used GTTR to evaluate its applicability as a fluorescence-based uptake assay in these cell lines, which were previously employed mainly in cochlear explants. Sodium thiosulfate (STS) and N-acetylcysteine (NAC) significantly decreased GTTR uptake, suggesting a protective effect against gentamicin-induced hair cell damage. In conclusion, our findings showed a complex ototoxic cascade involving OCT2- and TMC1-mediated drug uptake, calcium imbalance, ER stress, and disruption of PI3K-Akt survival signaling. We believe that UB/OC-2 cells serve as a practical in vitro model for mechanistic investigations and screening of otoprotective compounds. Additionally, GTTR may be a simple, effective method for evaluating protective interventions in auditory cell lines. Overall, this study provides molecular-level insights into aminoglycoside-induced ototoxicity and introduces a platform for protective strategies. Full article

Background/Objectives: Congenital cytomegalovirus (cCMV) infection is the most common non-genetic cause of sensorineural hearing loss (SNHL) in children. In cases of severe-to-profound SNHL, cochlear implantation (CI) is a widely used intervention, but outcomes remain variable due to possible neurodevelopmental comorbidities. This study aimed to evaluate the long-term auditory and language outcomes in children with cCMV after CI and to explore clinical and radiological predictors of post-CI performance. Methods: Fifty-three children with cCMV and bilateral severe-to-profound SNHL who underwent CI at five tertiary referral centers in Italy were included in the study. Auditory and language outcomes were assessed pre- and post-implantation using the Categories of Auditory Performance II (CAP-II) scale, the Nottingham 3-Level Classification, and the Bates Language Development Scale. Brain MRI abnormalities were classified according to the Alarcón classification. Correlations were explored between outcome scores and symptomatic status at birth, MRI findings, and neurodevelopmental comorbidities. Results: At birth, 40 children (75.5%) were symptomatic and 13 (24.5%) asymptomatic. Neurodevelopmental comorbidities were present in 19 children (35.8%). MRI was normal in 15 (28.3%), mildly abnormal in 26 (49%), and moderately to severely abnormal in 12 (22.6%). Auditory and language outcomes improved significantly post-CI (p < 0.001), though the outcomes varied widely. Twenty-five children (47%) reached CAP level ≥ 6, and thirteen (23%) reached Bates Level 6. Symptomatic status at birth correlated weakly with worse CAP (ρ = −0.291, p = 0.038) and Bates (ρ = −0.310, p = 0.028) scores. Higher Alarcón scores were significantly associated with neurodevelopmental comorbidities, though not directly with post-CI auditory and language outcomes. Finally, the presence of neurodevelopmental disabilities was generally associated with lower results, even if without statistical significance. Conclusions: CI provides substantial auditory and language benefit in children with cCMV, even in cases of severe neurodevelopmental comorbidities. MRI and developmental assessments, as well as perinatal history for clinical signs and symptoms, are helpful in guiding expectations and personalizing post-implantation support. Full article

Acute vertigo or dizziness that is accompanied by a sudden sensorineural hearing loss (SSNHL) often poses a diagnostic challenge. While a combined audiovestibular deficit makes an inner ear pathology most likely, this does not necessarily exclude a vascular pathology that may be a harbinger of future sinister events. This is especially true for strokes within the territory of the anterior inferior cerebellar artery (AICA), because the labyrinth receives its vascular supply most often by branches of the AICA. Thus, acute labyrinthine ischemia may present in combination with focal neurologic deficits, but also in isolation or as a warning sign before focal stroke signs arise. How can labyrinthine ischemia be differentiated from an idiopathic SSNHL? In this critical review, we discuss both the pathophysiology and the differential diagnosis of acute audiovestibular deficits. We will also address the value of state-of-the-art MR imaging in visualizing labyrinthine ischemia. Finally, we will discuss treatment options and review the prognosis of acute audiovestibular deficits. Full article

Sensorineural hearing loss occurs when cochlear hair cells fail to convert mechanical sound waves into electrical signals transmitted via the auditory nerve. Cochlear implants (CIs) restore hearing by directly stimulating the auditory nerve with electrical impulses, often while preserving residual hearing. Over the past two decades, robotic-assisted techniques in otologic surgery have gained prominence for improving precision and safety. Robotic systems support critical procedures such as mastoidectomy, cochleostomy drilling, and electrode array (EA) insertion. These technologies aim to minimize trauma and enhance hearing preservation. Despite the outpatient nature of most CI surgeries, surgeons still face challenges, including anatomical complexity, imaging demands, and rising costs. Robotic systems help address these issues by streamlining workflows, reducing variability, and improving electrode placement accuracy. This review evaluates robotic systems developed for cochlear implantation, focusing on their design, surgical integration, and clinical outcomes. This review concludes that robotic systems offer low insertion speed, which leads to reduced insertion forces and lower intracochlear pressure. However, their impact on trauma, long-term hearing preservation, and speech outcome remains uncertain. Further research is needed to assess clinical durability, cost-effectiveness, and patient-reported outcomes. Full article

Waardenburg syndrome (WS) is a rare genetic disorder that affects both hearing and pigmentation. The wide divergence of WS poses significant diagnostic and management challenges. This study investigated type 4 WS within an underrepresented Mongolian population. Whole-exome sequencing revealed that two unique heterozygous variants were identified in the SOX10 gene: c.393C>G (p.Asn131Lys) in a five-year-old female patient presenting with profound sensorineural hearing loss (SNHL), dystopia canthorum, and a white forelock; and c.535A>T (p.Lys179Ter) in a nine-year-old male patient presenting with profound SNHL, dystopia canthorum, and Hirschsprung’s disease. Temporal bone imaging revealed abnormalities in the inner ear structure in both patients. The genotypic and phenotypic characteristics were meticulously delineated, incorporating the deleterious effects of these variants, as evaluated by multiple predictive tools and the American College of Medical Genetics and Genomics (ACMG) criteria. In addition, structural characterizations were also presented using AlphaFold. The findings of this study contribute valuable genetic data to the limited literature on type 4 WS within this ethnic group and highlight the importance of genetic testing and multidisciplinary care for this rare disorder in settings with limited resources. Full article

Background/Objectives: The vestibulo-respiratory reflex regulates the tension of the respiratory muscles, which prevents apneas and awakenings during sleep. This study aimed to determine whether functional deficits in the inner ear disturb sleep quality. Methods: We compared sleep parameters in patients with their first episode of acute inner ear deficit (Group A: sudden idiopathic vertigo attack, sudden sensorineural hearing loss), chronic functional inner ear impairment (Group B: chronic peripheral vertigo, permanent hearing loss), and in healthy individuals (Group C). Polygraphy recordings were performed twice, in Group A at the onset of acute otoneurological symptoms and the second time after their withdrawal with an interval of 1 to 13 days, in Group B after 1 to 6 days, and in Group C after 1 to 8 days. Results: In Group A during the symptomatic night, overall and central apnea-hypopnea indices were significantly higher and snoring time was longer. Group A also had higher central apnea-hypopnea index on the first night compared to healthy individuals. In chronic disorders, sleep recordings showed lower autonomic arousal index than in controls or symptomatic nights in Group A. Conclusions: These findings highlight the severity of sleep apnea indicators in Group A. Our results suggest that acute dysfunction of the inner ear substantially impacts central neuronal signaling responsible for regulating normal sleep-related breathing and leads to a deterioration in sleep quality in contrast to individuals with chronic inner ear impairments. It can also be assumed that people with chronic vertigo or hearing loss experience less interrupted sleep than healthy individuals. Full article

Background: Wolfram syndrome (WFS), also known as DIDMOAD, is a rare monogenic neurodegenerative disorder characterized by four key components: non-autoimmune insulin-dependent diabetes mellitus (DM), optic atrophy, sensorineural hearing loss, and diabetes insipidus. Although it significantly affects quality of life, gonadal dysfunction, particularly hypogonadism, remains underrecognized. Methods: In total, 45 patients (25 men, 20 women) with genetically confirmed WFS from a single tertiary-care center were prospectively followed to assess gonadal function. Men underwent hormonal evaluations, semen analysis, imaging tests, and testicular biopsies. In women, data on age at menarche, menstrual irregularities, and age at menopause were recorded. Hormonal analyses, including anti-Müllerian hormone (AMH) levels, and imaging tests were also conducted. Results: Hypogonadism was identified in 19 men (76.0%), of whom 17 (68.0%) had hypergonadotropic hypogonadism and 2 (8.0%) had hypogonadotropic hypogonadism. Testicular biopsies showed seminiferous tubule damage, Sertoli cell predominance, and reduced Leydig cells. Azoospermia was observed in 12 patients, whereas others presented with oligozoospermia, teratozoospermia, or asthenozoospermia. Most patients exhibited low testosterone levels along with elevated LH and FSH, suggesting primary testicular failure, except for two cases of hypogonadotropic hypogonadism. Correlations between biomarkers, onset age and severity have been analyzed and provide important insights regarding medical treatment. In women, menstrual irregularities were universal, with 20% experiencing premature menopause. Four patients had low AMH levels, with ovarian atrophy in three and a postmenopausal uterus in two, indicating early hypogonadism risk. Conclusions: Gonadal dysfunction is a significant yet overlooked feature of WFS, requiring systematic evaluation during puberty and beyond. Proper management is essential to mitigate metabolic disturbances and psychological impacts, including infertility distress, relationship challenges, and quality of life concerns. Addressing sexual health is crucial as WFS patients live longer and aspire to establish relationships or start families. Full article

Background/Objectives: Autoimmune inner ear disease (AIED) causes sensorineural hearing loss that classically presents as fluctuating, asymmetric loss of hearing. Associated vestibular and other ear symptoms can be present in many patients. First-line treatment of AIED is high-dose corticosteroids. AIED can present either as a primary condition limited to ear involvement or secondary, as part of an underlying systemic autoimmune rheumatic disease, the most common of which include vasculitis and relapsing polychondritis. We described our cohort of primary AIED, including demographics, treatment, and outcomes. We excluded from this review sensorineural hearing loss in the context of vasculitis and relapsing polychondritis. Methods: We performed a chart review of patients with the diagnosis of AIED at Mayo Clinic and compared the cohort by sex. Results: Thirty-one patients met the inclusion criteria. The mean age was 48.5 years, and 17 were men. Patients were initially evaluated at the Department of Otorhinolaryngology or Internal Medicine, and 29 patients were subsequently referred to the Department of Rheumatology, with a mean of 12.2 weeks after the first evaluation. Treatment with corticosteroids showed improvement in hearing and vestibular symptoms during the first month but no further improvement by the end of the third month. Other immunosuppressive medications were used with various degrees of response. Methotrexate was the second most used therapy, with 11 of 17 patients reporting an improvement in symptoms. Conclusions: Corticosteroid therapy is an effective initial treatment for AIED and should be followed with corticosteroid-sparing agents to prevent further damage to the cochlea. Full article

Background and Objectives: Systemic small-vessel vasculitis (SV) represents a group of rare autoimmune disorders with varied etiologies and clinical manifestations. Audiovestibular involvement in SV may present with a broad spectrum of symptoms, often complicating diagnosis and management. This study aimed to evaluate auditory function and speech perception in individuals diagnosed with SV and to investigate associations with disease-specific clinical parameters. Materials and Methods: A total of 40 patients diagnosed with SV (mean age: 48.9 years; range: 28–65 years) were recruited for comprehensive audiological assessment. The evaluation protocol included otoscopic examination, tympanometry, pure-tone audiometry, and speech audiometry. Statistical analysis was conducted using R software (version 4.3.1), and significance was set at p < 0.05. Results: Diagnoses included granulomatosis with polyangiitis (52.5%), eosinophilic granulomatosis with polyangiitis (27.5%), necrotizing vasculopathy (12.5%), and microscopic polyangiitis (7.5%). Mean disease duration was 4.14 years. Hearing complaints were reported by 77.5%; in 20%, they were the initial symptoms. Audiometry identified hearing loss in 50% of patients—predominantly sensorineural (33.8%), followed by mixed (13.7%) and conductive (2.5%) types. Hearing loss was most frequent in necrotizing vasculopathy (60%) and among ANCA-positive individuals (53.7%). Conclusions: Sensorineural hearing loss is common in SV, particularly in ANCA-positive patients, highlighting the need for routine hearing assessment in SV management. Full article

Background/Objectives: Sudden sensorineural hearing loss (SSNHL) is an acute condition with unclear etiology, commonly hypothesized to be associated with viral infections. Acute respiratory tract infections (RTIs), particularly those of viral origin, have been implicated in SSNHL through proposed mechanisms such as cochlear invasion and immune-mediated damage. However, robust large-scale epidemiological evidence examining this association remains limited. This study aimed to investigate the potential association between acute RTIs and subsequent risk of developing SSNHL across diverse populations. Methods: We conducted a multinational retrospective cohort study using data from the TriNetX Global Collaborative Network. Adults diagnosed with acute RTIs between 1 January 2012 and 30 June 2023 were compared to matched controls without RTI exposure. Patients with predisposing conditions for SSNHL were excluded. Propensity score matching (1:1) was performed by age and sex. SSNHL diagnoses within 60 days post index were analyzed using Cox proportional hazards models. Subgroup and sensitivity analyses were conducted by race, sex, and age strata. Results: Among 37 million patients analyzed, individuals with acute RTIs had a lower incidence of SSNHL compared to matched controls. Hazard ratios (HRs) for SSNHL were significantly reduced across all racial groups: Whites (HR: 0.572), Blacks (HR: 0.563), and Asians (HR: 0.409). Subgroup analyses revealed stronger inverse associations in males and younger age groups, particularly those aged 18–25 years. Conclusions: Contrary to prior assumptions, acute RTIs were associated with a lower incidence of SSNHL in a large, diverse cohort. While the findings raise the possibility of immunological or physiological factors influencing this association, the results should be interpreted with caution due to unmeasured confounding and the observational nature of the study. Full article

Unilateral sudden sensorineural hearing loss (SSHL) presents substantial clinical challenges owing to its abrupt onset and multifactorial, poorly understood etiology. This study investigates the static and dynamic changes in local brain connectivity using regional homogeneity (ReHo) analyses in 102 SSHL patients and 73 healthy controls. A static ReHo analysis reveals pronounced disruptions in local synchronization within motor and cognitive-related brain regions in SSHL patients compared to controls. A dynamic ReHo analysis uncovers increased temporal variability, particularly in frontal regions, indicating potential adaptive neural plasticity to auditory deficits through enhanced neural plasticity. The correlation analyses further associate these neural changes with clinical parameters, highlighting the significant positive correlations between static ReHo in the left precentral gyrus and tinnitus severity (R = 0.39, p < 0.001), as well as the negative correlations between dynamic ReHo in the middle frontal gyrus and the duration of hearing loss (R = −0.35, p < 0.001). These findings underscore the complex interplay between static neural dysregulation and dynamic adaptive mechanisms in the pathophysiology of SSHL. Emphasizing dynamic metrics, our study provides a novel temporal perspective on how the brain reorganizes in response to acute sensory loss. Full article

Background and Objectives: Extracellular vesicles (EVs) derived from mesenchymal stem cells have gained much attention as potential therapeutic agents in many diseases, including hearing disorders such as sensorineural hearing loss (SNHL). EVs inherit similar therapeutic effects, including the stimulation of tissue regeneration from the parental cells. The aim of our study was to isolate EVs produced by MSCs and use them to treat inner ear cells in culture to evaluate their protective potential against the damaging effect of an ototoxic drug. Materials and Methods: We isolated MSC-derived EVs by precipitation and characterized them by number, size, and morphology using nanoparticle tracking analysis and TEM, evaluated the protein concentration by BCA assay and the presence of EV markers CD9, CD63, and CD81 by the Dot Blot immunoblotting method. HEI-OC1 inner ear cell line was treated with EVs either alone or followed by Cisplatin. We assessed the uptake of EVs in HEI-OC1 cells by fluorescence microscopy after PKH26 labeling, ROS production by the DCFDA (dichlorfluorescein diacetate) assay, cellular viability by Alamar Blue assay, and apoptosis with the Annexin V/Propidium Iodide method. Results: The isolated EVs had mean dimensions of 184.4 nms and the concentration of the EV suspension was 180 × 10⁶ particles/mL. TEM analysis showed intact vesicular structures with lipid-bilayer membranes having similar sizes with those measured by NTA. The PKH26-labeled EVs were observed in the HEI-OC1 cells after 24 h incubation, the amount increasing with the concentration. EVs reduced ROS production and increased the number of viable cells both alone and as pretreatment before Cisplatin, dose-dependently. Cells in early apoptosis were inhibited by EVs, while those in late apoptosis were enhanced, both with and without Cisplatin. Conclusions: EVs secreted by MSC protected HEI-OC1 cells against Cisplatin toxicity, reduced ROS production, and stimulated cell viability and the elimination of damaged cells by apoptosis, protecting the HEI-OC1 cells against Cisplatin-induced damage. Full article