A wide range of therapeutic strategies are available for the therapy of hearing disorders including pharmaceutical, acoustic, electrical, surgical, radiological, cognitive-behavioural and so-called "alternative" strategies. This review focuses on general conservative strategies and specific therapeutic approaches mainly for inner ear disorders, whereas surgical and device-based therapies including hearing aids and cochlear implants are described in other chapters in this volume.In addition to the systemic medication-based therapies for the treatment of hearing disorders, the rapidly growing field of local drug delivery to the inner ear as a promising therapeutic strategy is discussed on the background of unresolved issues. After description of non-drug-based therapeutic procedures, the conservative therapy of specific diseases and syndromes is reviewed.In general, there is a major discrepancy between promising animal studies up to regeneration and stem-cell transplantation, and uncontrolled experimental studies in humans on the one hand and the shortage of randomized controlled clinical trials with a high level of evidence on the other hand. Therefore, the review and comments on published clinical studies should assist the reader in making his/her own decision about the effectiveness of various, especially pharmaceutical treatments. From a critical analysis - particularly of the clinical studies presented - conclusions are drawn for the therapy of hearing disorders in the future.

The intensive clinical use of Electric Response Audiometry (ERA) has recently improved the diagnosis of sensorineural hearing loss. The Auditory Evoked Potentials (AEP) allow a precise topodiagnosis of the whole auditory system. However, specific limitations of the different potentials (cochlear, neural, brainstem, thalamic, cortical) have to be considered to avoid an overestimation of ERA. Based on the author's own material of more than 3500 recordings, most cases of a retrocochlear hearing loss are located at the auditory nerve and the brainstem. Therefore, brainstem electric response audiometry (BERA) and electrocochleography (ECoG) are the two most important methods of ERA. Typical Brainstem AEP (BAEP) features of retrocochlear disorders are shown. They are of different diagnostic value. A prolongation of the central conduction time or a break down of the later BAEP, both unequivocal signs of a retrocochlear lesion, were found in only 62 per cent of 100 cases of acoustic neuroma. However, diagnostic sensitivity can be improved to 96 per cent by additional use of ECoG and electrical promontory testing of the excitability of the auditory nerve. This value cannot be attained by any other audiometric test. These results show that BERA and ECoG are essential screening methods of high sensitivity in the differential diagnosis of sensorineural hearing loss. Additional values for diagnostic specificity and efficacy are also given in comparison with a group of patients initially suspected of having a cerebellopontine angle tumour. These values exceed those of conventional audiometric tests by far. Therefore, BERA and ECoG are reliable predictors of a retrocochlear lesion and can be judged as the best indicators for a CT scan or magnetic resonance imaging at present.

A relationship between microvascular disorders and sensorineural hearing loss (SNHL) has been widely proposed. The vascular hypothesis, theorized for the onset of sudden SNHL (SSNHL), is among the most acknowledged: a localized acute cochlear damage, of ischemic or haemorrhagic nature, could be considered a causative factor of SSNHL. The aim of this review is to assess (i) the effect on hearing in patients affected by blood coagulation disorders (prothrombotic or haemorrhagic) and (ii) the possible etiopathogenetic mechanisms of the related hearing loss. A PRISMA-compliant review was performed. Medline, Embase, and Cinahl databases were searched from inception to 31 January 2023, and a total of 14 studies have been included in the review. The available data suggest that it is possible to consider clotting disorders as a potential condition at risk for sensorineural hearing loss; in particular, coagulation tests and eventually the assessment of genetic and acquired prothrombotic factors should be recommended in patients with SSNHL. Also, an audiological evaluation should be recommended for patients with blood coagulation disorders presenting cochlear symptoms, especially in those suffering from clotting diseases.

Introduction  Several studies show correlations between congenital toxoplasmosis and hearing loss, with a broad diversity of levels of hearing loss and specifications of hearing disorders. Objective  To describe the studies found in the literature regarding hearing disorders in congenital toxoplasmosis. Data Synthesis  A literature review was conducted on the Lilacs, SciELO, PubMed and Scopus databases by combining the following keywords: congenital toxoplasmosis and hearing . Based on this search strategy, 152 papers were found, the majority published on the Scopus and PubMed databases from 1958 to 2015. After the application of the inclusion criteria, 8 articles published between 1980 and 2015 were included in the present study. Conclusion  This review showed a moderate evidence of the association between hearing disorders and congenital toxoplasmosis, which is characterized by sensorineural hearing loss. However, there are gaps in the description of the specific characteristics of the type and level of hearing loss, or of other possible disorders involved in the auditory processing.

Several causative factors are associated with hearing loss (HL) and brain disorders. However, there are many unidentified disease modifiers in these conditions. Our study summarised the most common brain disorders associated with HL and highlighted mechanisms of pathologies. We searched the literature for published articles on HL and brain disorders. Alzheimer's disease/dementia, Parkinson's disease, cognitive impairment, autism spectrum disorder, ataxia, epilepsy, stroke, and hypoxic-ischaemic encephalopathy majorly co-interact with HL. The estimated incidence rate was 113 per 10,000 person-years. Genetic, epigenetic, early life/neonatal stress, hypoxia, inflammation, nitric oxide infiltration, endoplasmic reticulum stress, and excess glutamate were the distinguished modifiers identified. Various mechanisms like adhesion molecules, transport proteins, hair cell apoptosis, and neurodegeneration have been implicated in these conditions and are serving as potential targets for therapies. To improve the quality of life of patients, these understandings will improve clinical diagnoses and management of HL and brain disorders.

Background. Defects of mitochondrial DNA (mtDNA) involved in the function of the mitochondrial electron transport chain can result in primary mitochondrial diseases (PMDs). Various features can influence the phenotypes of different PMDs, with relevant consequences on clinical presentation, including the presence of hearing impairment. This paper aims to describe the hearing loss related to different PMDs, and when possible, their phenotype. Methods. A systematic review was performed according to PRISMA guidelines, searching Medline until December 2022. A total of 485 papers were identified, and based on specified criteria, 7 were included in this study. Results. A total of 759 patients affected by PMDs and hearing loss were included. The age of patients ranged from 2 days to 78 years old, and the male-to-female ratio was 1.3:1. The percentage of subjects affected by hearing loss was 40.8%, (310/759), and in most cases, hearing impairment was described as sensorineural, bilateral, symmetrical, and progressive, with different presentations depending on age and syndrome severity. Conclusions. PMDs are challenging conditions with different clinical phenotypes. Hearing loss, especially when bilateral and progressive, may represent a red flag; its association with other systemic disorders (particularly neuromuscular, ocular, and endocrine) should alert clinicians, and confirmation via genetic testing is mandatory nowadays.

Introduction Childhood is a critical period for language development and maturation of the central auditory system. Unilateral hearing loss (UHL) is considered a minimal impairment, and little is discussed regarding its impact on the development of language, communication, and school performance. Objectives A bibliographical survey of scientific articles published from 2001 to 2011 was performed to verify which language disorders can occur in children with UHL and which tests were performed to identify them. Data Synthesis Three databases were used: PubMed, Lilacs, and The Cochrane Library. As inclusion criteria, the articles should have samples of children with UHL, without other impairments, aged between 3 months and 12 years, and reference to language tests applied in this population. Out of 236 papers initially selected, only 5 met the inclusion criteria. In the articles studied, 12 tests were used for language assessment in children with UHL, out of which 9 were directed toward expressive language, and 3 toward receptive language. Children with UHL demonstrated lower scores on receptive and expressive language tests when compared with children with normal hearing. However, they obtained better scores on expressive language tests than children with bilateral hearing loss. Conclusion The findings of this survey showed that only a small number of studies used language tests in children with UHL or addressed language alterations resulting from this type of impairment. Therefore we emphasize the importance of investments in new studies on this subject to provide better explanations related to language difficulties presented by children with UHL.

The diagnostics of inner ear diseases are primarily functional, but there is a growing interest in inner ear biomarkers. The present scoping review aimed to elucidate gaps in the literature regarding the definition, classification system, and an overview of the potential uses of inner ear biomarkers. Relevant biomarkers were categorized, and their possible benefits were evaluated. The databases OVID Medline, EMBASE, EBSCO COINAHL, CA PLUS, WOS BIOSIS, WOS Core Collection, Proquest Dissertations, Theses Global, PROSPERO, Cochrane Library, and BASE were searched using the keywords "biomarker" and "inner ear". Of the initially identified 1502 studies, 34 met the inclusion criteria. The identified biomarkers were classified into diagnostic, prognostic, therapeutic, and pathognomonic; many were detected only in the inner ear or temporal bone. The inner-ear-specific biomarkers detected in peripheral blood included otolin-1, prestin, and matrilin-1. Various serum antibodies correlated with inner ear diseases (e.g., anti-type II collagen, antinuclear antibodies, antibodies against cytomegalovirus). Further studies are advised to elucidate the clinical significance and diagnostic or prognostic usage of peripheral biomarkers for inner ear disorders, filling in the literature gaps with biomarkers pertinent to the otology clinical practice and integrating functional and molecular biomarkers. These may be the building blocks toward a well-structured guideline for diagnosing and managing some audio-vestibular disorders.

Claudin-11 plays a critical role in multiple physiological processes, including myelination, auditory function, and spermatogenesis. Recently, stop-loss mutations in CLDN11 have been identified as a novel cause of hypomyelinating leukodystrophy (HLD22). Understanding the multifaceted roles of claudin-11 and the potential pathogenic mechanisms in HLD22 is crucial for devising targeted therapeutic strategies. This review outlines the biological roles of claudin-11 and the implications of claudin-11 loss in the context of the Cldn11 null mouse model. Additionally, HLD22 and proposed pathogenic mechanisms, such as endoplasmic reticulum stress, will be discussed.

Trendy technologies, such as artificial intelligence, virtual reality (VR), and augmented reality (AR) are being increasingly used for hearing loss, tinnitus, and vestibular disease. Thus, we conducted this systematic review and meta-analysis to identify the possible benefits of the use of VR and AR technologies in patients with hearing loss, tinnitus, and/or vestibular dysfunction, with the aim of suggesting potential applications of these technologies for both researchers and clinicians.

Sensorineural hearing loss (SNHL) is a heterogeneous family of hearing disabilities with congenital (including genetic) as well as acquired etiology. Congenital SNHL of genetic etiology is further sub-divided into autosomal dominant, autosomal recessive and X-linked SNHL. More than 60 genes are involved in the etiology of autosomal recessive non-syndromic hearing loss (ARNSHL) commonly manifesting as heterogeneous pre-lingual profound to severe non-progressive clinical phenotype. ILDR1-dependent ARNSHL (DFNB42, OMIM: # 609646) is a very rare sub-type of hearing disability, with unknown prevalence, caused by function-damaging genetic variants in ILDR1 gene reported in families of Middle-Eastern origin. ILDR1 (Immunoglobulin-Like Domain-containing Receptor 1) is involved in the development of semicircular canal, tricellular tight junction and auditory hair cells. An apparently non-consanguineous family of European ancestry with two affected siblings with profound progressive hearing loss characterized in their infancy and successfully treated with cochlear implants (CI) is presented. Genetic analysis of common ARNSHL genetic causes in the population of origin was negative, thus the next-generation sequencing (NGS) and family segregation analysis to identify underlying causative genetic variant was performed. Unexpectedly and atypical for the population of origin a homozygous non-sense variant ILDR1 c.942C > A (p.Cys314Ter) inherited from both heterozygous parents was identified in both patients. Contrary to the commonly reported phenotype, indices of a progressive hearing loss and potential compensatory mechanism of vestibular function were revealed with the analysis of clinical data. The utilization of NGS was demonstrated as an invaluable tool for the detection of atypical rare variants in diagnostics of unidentified hearing loss disorders.

Fifty percent of inner ear disorders are caused by genetic mutations. To develop treatments for genetic inner ear disorders, we designed gene replacement therapies using synthetic adeno-associated viral vectors to deliver the coding sequence for Transmembrane Channel-Like (Tmc) 1 or 2 into sensory hair cells of mice with hearing and balance deficits due to mutations in Tmc1 and closely related Tmc2. Here we report restoration of function in inner and outer hair cells, enhanced hair cell survival, restoration of cochlear and vestibular function, restoration of neural responses in auditory cortex and recovery of behavioral responses to auditory and vestibular stimulation. Secondarily, we find that inner ear Tmc gene therapy restores breeding efficiency, litter survival and normal growth rates in mouse models of genetic inner ear dysfunction. Although challenges remain, the data suggest that Tmc gene therapy may be well suited for further development and perhaps translation to clinical application.

Congenital sensorineural hearing loss may occur in association with inborn pigmentary defects of the iris, hair, and skin. These conditions, named auditory-pigmentary disorders (APDs), represent extremely heterogeneous hereditary diseases, including Waardenburg syndromes, oculocutaneous albinism, Tietz syndrome, and piebaldism. APDs are part of the neurocristopathies, a group of congenital multisystem disorders caused by an altered development of the neural crest cells, multipotent progenitors of a wide variety of different lineages, including those differentiating into peripheral nervous system glial cells and melanocytes. We report on clinical and genetic findings of two monozygotic twins from a large Albanian family who showed a complex phenotype featured by sensorineural congenital deafness, severe neuropsychiatric impairment, and inborn pigmentary defects of hair and skin. The genetic analyzes identified, in both probands, an unreported co-occurrence of a new heterozygous germline pathogenic variant (c.2484 + 5G > T splicing mutation) in the KIT gene, consistent with the diagnosis of piebaldism, and a heterozygous deletion at chromosome 15q13.3, responsible for the neuropsychiatric impairment. This case represents the first worldwide report of dual locus inherited syndrome in piebald patients affected by a complex auditory-pigmentary multisystem phenotype. Here we also synthesize the clinical and genetic findings of all known neurocristopathies characterized by a hypopigmentary congenital disorder.

Objective This literature review and meta-analysis was performed to evaluate the correlations among hearing and vestibular clinical symptoms, temporal bone findings, and pathological mechanisms in patients with systemic lupus erythematosus (SLE). Study design Relevant papers in the literature were retrospectively reviewed. Clinical hearing aspects in patients with SLE and relevant temporal bone studies in the same field were analyzed. Methods PubMed and Google Scholar searches were performed using the following keywords: "auto-immune disease," "systemic lupus erythematosus (SLE)," "hearing loss," "temporal bone study," "vertigo," "dizziness," "tinnitus," "ear symptoms," "treatment," "diagnosis," "symptoms," "etiopathogenesis," "Wegener granulomatosis," "Sjogren," "polyarteritis nodosa," "Cogan syndrome," and "granulomatosis." Also included were reviews in which the following terms were present: "SLE," "temporal bone," and "hearing symptoms." Review and conclusion This literature review and meta-analysis focused on the pathological mechanisms through which SLE can damage inner ear structures and determinate hearing and vestibular symptoms. The main mechanisms involved in inner ear damage include the autoimmune response, deposition of immune complexes in the vessels and, to a lesser extent, cytotoxic damage.

We report a large family with four successive generations, presenting with a complex phenotype of severe congenital neutropenia (SCN), partially penetrant monocytosis, and hearing loss of varying severity.

Internet-based interventions are emerging as an alternative way of delivering accessible healthcare for various conditions including hearing and balance disorders. A comprehensive review regarding the evidence-base of Internet-based interventions for auditory-related conditions is required to determine the existing evidence of their efficacy and effectiveness. The objective of the current protocol is to provide the methodology for a systematic review regarding the effects of Internet-based interventions for adults with hearing loss, tinnitus and vestibular disorders.

Internet-based interventions have been developed to improve access to audiovestibular health care. This review aimed to identify outcomes of Internet interventions for adults with hearing loss, tinnitus, and vestibular disorders. Electronic databases and manual searches were performed to identify studies meeting eligibility for inclusion. Fifteen studies (1,811 participants) met the inclusion criteria, with nine studies targeting tinnitus distress, five considering hearing loss, and one for vestibular difficulties. Only the tinnitus and hearing loss Internet intervention studies were eligible for data synthesis. Internet-based interventions for hearing loss were diverse. Overall, they showed no significant effects, although a statistically significant moderate effect (d = 0.59) was found after removing the study with the highest risk of bias (as a result of high attrition). Most Internet-based interventions for tinnitus provided cognitive behavioural therapy. They yielded statistically significant mean effect sizes for reducing tinnitus distress compared with both inactive (d = 0.59) and active controls (d = 0.32). Significant effects were also present for the secondary outcomes of anxiety, depression, insomnia, and quality of life (combined effect d = 0.28). Only Internet-based interventions for tinnitus evaluated the 1-year postintervention effects indicated that results were maintained long term (d = 0.45). Scientific study quality was appraised using the Grading of Recommendations Assessment, Development and Evaluation approach and found to vary from very low to moderate. This review indicates the potential of Internet interventions for tinnitus to provide evidence-based accessible care. There is a need for additional high-quality evidence before conclusive results can be established regarding the effects of audiovestibular Internet interventions.

Nonmuscle myosin heavy chain IIA (NMMHCIIA) encoded by MYH9 is associated with autosomal dominantly inherited diseases called MYH9 disorders. MYH9 disorders are characterized by macrothrombocytopenia and very characteristic inclusion bodies in granulocytes. MYH9 disorders frequently cause nephritis, sensorineural hearing disability and cataracts. One of the most common and deleterious mutations causing these disorders is the R702C missense mutation. We generated knock-in mice expressing the Myh9 R702C mutation. R702C knock-in hetero mice (R702C+/- mice) showed macrothrombocytopenia. We studied megakaryopoiesis of cultured fetal liver cells of R702C+/- mice and found that proplatelet formation was impaired: the number of proplatelet tips was decreased, proplatelet size was increased, and proplatelet shafts were short and enlarged. Although granulocyte inclusion bodies were not visible by May-Grünwald Giemsa staining, immunofluorescence analysis indicated that NMMHCIIA proteins aggregated and accumulated in the granulocyte cytoplasm. In other organs, R702C+/- mice displayed albuminuria which increased with age. Renal pathology examination revealed glomerulosclerosis. Sensory hearing loss was indicated by lowered auditory brainstem response. These findings indicate that Myh9 R702C knock-in mice mirror features of human MYH9 disorders arising from the R702C mutation.

Auditory and vestibular disorders are prevalent sensory disabilities caused by genetic and environmental (noise, trauma, chemicals) factors that often damage mechanosensory hair cells of the inner ear. Development of treatments for inner ear disorders of hearing and balance relies on the use of animal models such as fish, amphibians, reptiles, birds, and non-human mammals. Here, we aimed to augment the utility of the genus Xenopus for uncovering genetic mechanisms essential for the maintenance of inner ear structure and function.

Occupational activities performed by sound engineers are associated with hearing loss. However, there is a dearth of research on the hearing functions and the related hearing loss for sound engineers.