Profound Deafness Research Articles

Electrophysiological study of visual processing in children with cochlear implants

Electrophysiological studies of congenitally deaf children and adults have reported atypical visual evoked potentials (VEPs) which have been associated with both behavioral enhancements of visual attention as well as poorer performance and outcomes in tests of spoken language speech processing. This pattern has often been interpreted as a maladaptive consequence of early auditory deprivation, whereby a remapping of auditory cortex by the visual system ultimately reduces resources necessary for optimal rehabilitative outcomes of spoken language acquisition and use. Making use of a novel electrophysiological paradigm, we compare VEPs in children with severe to profound congenital deafness who received a cochlear implant(s) prior to 31 months (n = 28) and typically developing age matched controls (n = 28). We observe amplitude enhancements and in some cases latency differences in occipitally expressed P1 and N1 VEP components in CI-using children as well as an early frontal negativity, N1a. We relate these findings to developmental factors such as chronological age and spoken language understanding. We further evaluate whether VEPs are additionally modulated by auditory stimulation. Collectively, these data provide a means to examine the extent to which atypical VEPs are consistent with prior accounts of maladaptive cross-modal plasticity. Our results support a view that VEP changes reflect alterations to visual-sensory attention and saliency mechanisms rather than a re-mapping of auditory cortex. The present data suggests that early auditory deprivation may have temporally prolonged effects on visual system processing even after activation and use of cochlear implant.

Therapeutic impact of music in young deaf patients with aggressive behavior disorder

In France metropolitan, 5 182 000 people have hearing loss (8.7% of the population), of which 4.1% are under 20 years of age. In children, hearing impairment is sought in the presence of depression, hyperactivity, impulsivity, instability accompanied by intense anger, and aggressive behavior. So far, the impact of dance and music on deaf people has been little studied. In this context, we recently initiated a project in mediated therapeutic workshops; Devoted to hearing-impaired adolescents or young adults with behavioral problems. The main objective of this project is to foster the adaptability of these young people with severe behavior problems. Protocol: 4 volunteers with moderate to profound deafness were included in this prospective study (2 F and 2 M, aged 19.5 ± 5.0 years). These patients exhibited daily behavioral disorders with stereotypies and aggressiveness with moderate to severe intensity according to the Behavior Problems Inventory (BPI-01). These young people attended weekly sessions lasting more than 12 months at the Music / Percussion Workshop in the presence of an instructor and nurse therapist. Outcome and Discussion: No voluntary withdrawal of the project was recorded. A very strong behavioral improvement was noted in 3/4 of the cases and a slight improvement in 1/4 of the cases. This study has shown that hearing loss is compensated by various adaptive processes, in particular by multi sensorial interactivity (such as the interactivity between touch and vision) and through mirror neuronal system. Conclusion: This study showed hearing impaired people are sensitive and receptive to the sound world and to rhythmic movement. This finding has been put to the benefit of rehabilitation through Music and Dance Therapies which has improved the behavioral disorder and blossoming of the group rehabilitation through Music and Dance Therapies of young people suffering from medium to profound deafness with severe behavior problems.

Preclinical Efficacy And Safety Evaluation of AAV-OTOF in DFNB9 Mouse Model And Nonhuman Primate.

OTOF mutations are the principal causes of auditory neuropathy. There are reports on Otof-related gene therapy in mice, but there is no preclinical research on the drug evaluations. Here, Anc80L65 and the mouse hair cell-specific Myo15 promoter (mMyo15) are used to selectively and effectively deliver human OTOF to hair cells in mice and nonhuman primates to evaluate the efficacy and safety of OTOF gene therapy drugs. A new dual-AAV-OTOF-hybrid strategy to transfer full-length OTOF is generated, which can stably restore hearing in adult OTOFp.Q939*/Q939* mice with profound deafness, with the longest duration being at least 150 days, and the best therapeutic effect without difference in hearing from wild-type mice. An AAV microinjection method into the cochlea of cynomolgus monkeys without hearing impairment is further established and found the OTOF can be safely and effectively driven by the mMyo15 promoter in hair cells. In addition, the therapeutic dose of AAV drugs has no impact on normal hearing and does not cause significant systemic toxicity both in mouse and nonhuman primates. In summary, this study develops a potential gene therapy strategy for DFNB9 patients in the clinic and provides complete, standardized, and systematic research data for clinical research and application.

Genetic testing and prenatal diagnosis for a Chinese pedigree affected with Waardenburg syndrome type 4C due to heterozygous deletion of SOX10 gene

To explore the genetic basis for a Chinese pedigree featuring congenital profound syndromic deafness and chronic constipation, and provide prenatal diagnosis for a high-risk fetus. Whole-exome sequencing was carried out to analyze the sequences of genes associated with hereditary deafness, and multiplex ligation-dependent probe amplification (MLPA) was used to verify the candidate variant in the proband's parents and the fetus. The proband was found to have harbored a heterozygous deletion of SOX10, a pathogenic gene associated with Waardenburg syndrome type 4C (WS4C). The same deletion was found in her mother (with profound syndromic deafness and chronic constipation) and the fetus, but not in her father with normal hearing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) and Association for Molecular Pathology (AMP), the SOX10 gene deletion was predicted to be a pathogenic variant (PVS1+PM2_Supporting+PP1+PP4). The pedigree was diagnosed with WS4C, which has conformed to an autosomal dominant inheritance. Deletion of the entire SOX10 gene, as a loss-of-function variant, probably underlay its pathogenesis. Above finding has facilitated genetic counseling and prenatal diagnosis for this family.

Understanding identity construction among deaf adolescents and young adults: implications for the delivery of person and family-centered care in audiological rehabilitation.

The provision of holistic person and family-centered care in the audiological rehabilitation of adolescents and young adults (AYA) requires in-depth consideration of identity construction. The purpose of this research study was to describe the lived experience of identity construction among deaf AYA. The thoughts, perceptions, and feelings of AYA on their identity and the processes underlying the construction of identity, with a focus on navigating disability, social relations and roles, community assimilation and self-perception were explored. A qualitative interpretive phenomenological approach was adopted. Participants were a purposive sample of 5 AYA, aged 15 to 19 years. Participants had moderate to profound deafness and were enrolled in schools for the deaf where they partook in semi-structured phenomenological conversations, detailing their lived experiences with identity construction. The superordinate themes of creating a self-concept, belonging, stress and being deaf emerged from participants' narratives. Identity construction occurs concurrently at several levels. At the personal level, AYA create self-conceived ideals of who they are. At relational level, identity is fostered through person-to-person and person-to-group interactions. At societal level, AYA navigate inherent challenges with hearing impairment and their positionality as deaf individuals. Understanding the nuances of identity construction gives insights for further research and highlights the self-ascribed identity domains and related psychosocial variables that appeal to person and family-centered care, uncovering opportunities and barriers to successful delivery. Findings have implications for the transitional care of deaf AYA that is responsive to their needs.

A Comparative Study of Voice Characteristics in Children With Cochlear Implants and Typically Hearing Children: Insights From an Indian Context.

Purpose The aim of the study was to evaluate speech outcomes in children with cochlear implants compared to normally hearing children in terms of fundamental frequency, shimmer, and jitter. The study also aims to assess the intelligibility of speech in children with cochlear implants using a speech intelligibility rating scale. Methods This was a hospital-based comparative study conducted at JIPMER, a major tertiary referral center. A total of 25 prelingually deaf children with profound deafness, who underwent cochlear implantation at the institute, were recruited from the outpatient department of the Department of Otorhinolaryngology. Twenty-five children under seven years of age who underwent cochlear implantation and received a minimum of 36 speech therapy sessions were included in the study. Subjects with incomplete electrode array insertion and any neurological maldevelopment were excluded. Age- and gender-matched controls comprising 25 individuals were selected from the Ophthalmology Outpatient Department at JIPMER. Study procedure The study commenced in January 2019. Test subjects were asked to visit the Audiology and Speech and Language Pathology Department at JIPMER. Voice recordings were conducted in a soundproof room using a microphone, with the mouthpiece held at a distance of 10-15 cm from the patient. The patient was instructed to say "a" three times. Their voice was recorded and analyzed using Praat software (Version 6.1.15, developed by Paul Boersma and David Weenink, Phonetic Sciences, University of Amsterdam). Data were analyzed using IBM SPSS Statistics for Windows, Version 19 (Released 2010; IBM Corp., Armonk, New York) (Department of Biostatistics, Vanderbilt University, Nashville, Tennessee, USA), and the results were derived. Results The mean fundamental frequency for Group 1 (CI) was 266.03 ± 57.46 Hz, compared to 312.97 ± 22.15 Hz for Group 2 (NH). There was a statistically significant difference between the values of both groups, indicating that cochlear implantation positively impacted the fundamental frequency of speech. The study revealed a significant change in the fundamental frequency when children were implanted at an early age and received effective speech therapy post-implantation. This change was assessed after one year post-implant. Perturbation measures such as shimmer and jitter were lower in the cochlear implant group but were not statistically significant. Conclusion Children with congenital bilateral severe to profound sensorineural hearing loss tend to have higher values of the fundamental frequency of speech. However, when implanted at an early age, they showed a significant difference in the fundamental frequency of speech (p < 0.001). Speech perturbation was lower in the post-cochlear implant group, with a statistically significant difference in the values of shimmer alone. The study concludes that children with cochlear implants can achieve normal voice parameters with early intervention and training. However, the variability range is much higher than in typically hearing individuals.

Cochlear implant and tinnitus

Cochlear implant (CI) treatment is now established as asuccessful standard of care for auditory rehabilitation of profoundly deaf or severe hearing loss patients. CI candidates with tinnitus also benefit from improved health-related quality of life (HRQoL) and tinnitus burden. Current CI indications include bilateral (double-sided) profound hearing loss and deafness (DSD), unilateral (single-sided) deafness (SSD), and asymmetric hearing loss (AHL). The new and expanded indications for cochlear implants result in different healthcare situations, which may also be associated with differences in tinnitus burden before and after CI treatment. In this article, we discuss the prevalence of tinnitus in different patient groups and the influence of CI on tinnitus prevalence and severity in these groups. In addition, further therapeutic options for tinnitus suppression based on the CI principle are presented, including the development of an anti-tinnitus implant (proof of concept).

Balance of peripheral input and integrity of the electrode-nerve interface in a large cohort of children with bilateral cochlear implants

The study aim was to determine whether asymmetries in the electrode-nerve interface were present in children using bilateral cochlear implants (CIs). Bilateral CIs improve hearing over unilateral CIs in children with profound deafness in both ears but benefits decrease with increasing asymmetric activity and function between ears. Effects of asymmetry between bilateral CI arrays, CI stimulation parameters, impedance and transimpedance measurements, and electrophysiological thresholds could exacerbate asymmetries at the electrode-nerve interface but these factors have not been assessed in children using bilateral CIs. Clinically generated data from a large cohort of Canadian children (n = 669 children, n = 1332 devices) was gathered retrospectively for analyses. To account for repeated measures, a mixed effects modeling analysis was conducted. Despite CI electrical stimulation levels and electrophysiological thresholds being largely stable over time, asymmetries based on implantation sequence were observed. The observed bilateral differences suggest spread of current and sensitivity to electrical stimulation vary between devices in the same individual. These peripheral asymmetries may coincide with previously reported plasticity-induced cortical changes to increase asymmetries in auditory function between ears and restrict access to binaural hearing cues.

Positive Effects of SIBI Alphabet Cards on Increasing Vocabulary Acquisition in Children with Special Needs Deaf

Children with Special Needs with hearing impairment have hearing loss, classified as deaf and hard of hearing. Hearing loss in children with special needs is associated with long-term academic and communication difficulties, so it will hinder the learning process and potentially experience obstacles in developing students' thinking or cognitive quality. This study aims to analyze the effect of Indonesian language learning media using the SIBI Alphabet Card on increasing vocabulary acquisition in children with hearing impairment. This research is true experimental research with the randomized three-group pretest-posttest only design. A total of 27 children with hearing impairment, categories slight, moderate, profound, male and female, aged 8-22 years. Subjects were randomly divided into three study groups, namely G1 (n = 10; Slight Deaf), G2 (n = 8; Moderate Deaf), G3 (n = 9; Profound Deaf). The Indonesian-language learning media intervention using the SIBI Alphabet Card was carried out 2x/week for four weeks. Data were collected before and after the intervention using a written test instrument. The data analysis technique used the Paired Samples T-Test test with the Packet for Social Science (SPSS) Statistics Software version 21. Based on the results of the study showed that there was an increase in vocabulary acquisition in the three groups before and after the intervention (p0.001). In general, concluded that the provision of Indonesian-language learning media using the SIBI Alphabet Card which is carried out two times/week for four weeks is effective in increasing vocabulary acquisition in deaf children with special needs.

An analysis of the spread of electric field within the cochlea for different devices including custom-made electrodes for subtotal cochleoectomy.

Cochlear implants (CIs) can restore hearing not only in patients with profound hearing loss and deafness, but also in patients following tumour removal of intra-cochlear schwannomas. In such cases, design and placement differ from conventional electrode insertion, in which the cochlea remains filled with fluid. Despite these technical and surgical differences, previous studies have tended to show positive results in speech perception in tumour patients. The purpose of this study is to retrospectively evaluate the ability to predict speech recognition outcomes using individual electric field spreads and to investigate worldwide unique tumour cases. In a retrospective analysis in a university tertiary center electric field spreads were compared between two groups of electrode designs implanted between 2009 and 2020 i.e., between lateral wall electrodes and custom-made perimodiolar electrode carriers from the same company. The voltage gradients were analysed and grouped with speech recognition results. Differences in electrical field spreads were found between lateral wall electrodes and the custom-made perimodiolar electrodes, whereas a significant influence of electric fields on scores in speech recognition cannot be demonstrated. Prediction of speech recognition outcome based on electric field propagation results seems not feasible. Significant differences in field spread between electrode arrays can be clearly demonstrated. This observation and its relevance to hearing treatment and speech recognition should therefore be further investigated in upcoming studies.

Severe KIDAR syndrome caused by deletion in the AP1B1 gene: Report of a teenage patient and systematic review of the literature

Autosomal recessive keratitis-ichthyosis-deafness syndrome (KIDAR MIM #242150) is a very rare disorder caused by pathogenic loss-of-function variants in the AP1B1 gene. So far, nine patients have been reported in the literature and more clinical descriptions are essential to further delineate the phenotype of KIDAR. Here we report a new patient with KIDAR and compare the clinical findings with those from the other published cases with molecular confirmation.We describe a 14-year-old male born to non-consanguineous parents with unremarkable family history. The patient had fetal ascites, neonatal pancreatic insufficiency with consequent failure to thrive, feeding difficulties, recurrent infections and sepsis. The skin examination was remarkable for an ichthyosis with conspicuous palmoplantar keratoderma, sparse and brittle hair with alopecia on the vertex and slight bilateral ectropion. He had short stature, thin build, frontal bossing, small teeth and prominent abdomen. Additional features were congenital profound bilateral sensorineural deafness, photosensitivity and photophobia. Mild global developmental delay was noted. Persistent mild anemia, neutropenia, thrombocytopenia, and low serum copper, ceruloplasmin and growth hormone were also present. Brain magnetic resonance imaging (MRI) showed cerebral atrophy and thin corpus callosum. Genetic testing revealed a homozygous deletion in the AP1B1 gene, possibly including the same exons as a previously reported deletion.Comparing the phenotypes of all reported individuals, they are highly concordant and major features are enteropathy with feeding difficulties, failure to thrive, ichthyosis, palmoplantar keratoderma, sensorineural deafness and sparse and brittle hair. Here we report other features present in more than one patient that could be part of the phenotypic spectrum and suggest copy number variation analysis to be performed alongside sequencing of the AP1B1 gene in case of suspicion.

Extended preoperative speech audiometric diagnostics for cochlear implant treatment

For severe hearing loss and even profound deafness, cochlear implants (CIs) have become the treatment of choice. For establishment of the CI indication, the preoperative Freiburger monosyllabic word recognition (EV) at 65 dB SPL in free field with ahearing aid (EVHG65) and the maximal understanding (mEV) without ahearing aid with headphones results are important. The goal of this retrospective study was to analyse the correlation of word recognition with ahearing aid at 80 dB SPL (EVHG80) and mEV. This represents an extension to measuring EVHG65 compared to mEV and to pure-tone audiometry (4FPTA). In this study, word recognition with and without ahearing aid was retrospectively analysed for 661ears. Inclusion criterium was CI implantation at alater date. During preoperative CI diagnostics, an mEV of 0% was found in334 ears. The EVHG65 for 485ears and the EVHG80 for 335ears were also 0%. The EV with hearing aid was found to worsen with increasing 4FPTA at both sound pressure levels, although this effect was smaller at 80 dB SPL than at 65 dB SPL. Including only ears with mEV > 0 % (N = 260 ears), astronger correlation between EVHG80 and mEV with adifference of (-4.0 ± 16.4%) in comparison to EVHG65 and mEV with adifference of (-18.3 ± 16.7%) is seen. This shows asignificant difference between mEV and EVHG80 compared to mEV and EVHG65. At asound pressure level of 65 dB SPL, EV with hearing aid often does not show the accordance with mEV specified by hearing aid and CI guidelines. The EVHG80 correlates better with mEV than EVHG65. For clinical diagnosis it is rational to measure speech discrimination with hearing aid at levels higher than 65 dB SPL.

Evolution of speech perception in patients with ossified cochlea and short array cochlear implant

Background: Short array cochlear implant is indicated as rehabilitation in patients with severe to profound deafness, especially when there is cochlear ossification. In these cases, with reduced intracochlear patency, total insertion becomes more difficult, requiring the use of this type of electrode (15 mm). Few studies have been published to evaluate auditory performance, presenting controversial audiological results.Aims/Objectives: To report the speech perception of users of cochlear implants (CI) with short array. Material and Methods: A retrospective analysis of medical records of patients who underwent surgery for cochlear implantation with a short array, between 2009 and 2020, at the Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo (HRAC-USP) was carried out. Results: There was performance evolution in the speech perception tests in the data analysis. Meningitis and congenital hearing loss were the main indications for CI in the sample. Conclusion. CI with a short array is an alternative in the management of patients with a history of cochlear ossification and severe or profound sensorineural hearing loss. Significance: To demonstrate the evolution of speech perception tests with short array cochlear implant in patients with or without ossified cochlea and its characteristics for application in clinical practice.

Auditory outcomes after scala vestibuli array insertion are similar to those after scala tympani insertion 1year after cochlear implantation.

In cochlear implantation, a scala vestibuli (SV) insertion of an electrode array is a rare occurrence and is reported to be linked to poor hearing outcomes. Using the same electrode array, the auditory performance of patients with a complete SV location was compared with that of patients having a complete scala tympani (ST) location 1year after implantation. Thirty-three patients were included in this retrospective case-control study (SV, n = 12; ST, n = 21). The matching criteria were electrode array type, age at implantation, and duration of severe or profound deafness. The array location was analyzed using 3D reconstruction of postoperative CT scans. Postoperative audiological evaluation of the implanted ear was performed using pure-tone audiometry, speech recognition of monosyllabic words in quiet, and words and sentences in noise. On the preoperative CT scan, six patients in the SV group presented with both round window (RW) and ST ossification, three with RW ossification alone, and three with no RW ossification. Auditory performance did not differ between SV and ST groups 1year after cochlear implantation. Speech recognition of words was 49 ± 7.6% and 56 ± 5.0% in quiet and 75 ± 9.5% and 66 ± 6.0% in noise in SV and ST groups, respectively. ST insertion is the gold standard that allows the three cochlear scalae to preserve scalar cochlear integrity. However, 1year after implantation, a planned or unexpected SV insertion is not detrimental to hearing outcomes, providing similar auditory performance in quiet and noise to ST insertion.

Hearing aid through skin sensory for profound deaf people

An individual with profound deafness or total hearing loss has a hearing threshold of 80dB or more. The ineffectiveness of hearing aids, surging costs and complex surgeries for cochlear implants have discouraged many to opt for these types of treatments. Hence, this research aims to provide an alternative hearing aid that stimulates “hearing” through the skin sensory, which is more affordable and accessible for the profoundly deaf or total hearing loss community. We have developed four initial vibrating transducers with single spectrum, which are strapped to a belt. The transducers pick up audible sounds through a microphone, amplifies the sound to a high-level signal, stimulating a vibration pattern on the human skin sensory. The belt was tested on 30 random people who identified as normal, partial, and profoundly deaf. When the belt was strapped to the individual’s waist, audible sound was played (stimulus) and the individual was asked whether he/she can feel a stimulation or vibration on their skin, and if so, state the sound source direction. Based on the test, all individuals were able to feel the vibrating stimulation on their skin, and they were also able to state the directions accurately. The various vibrating pattern that stimulates the human sensory system for the profoundly deaf can be learned over time, which could serve as useful information. However, interpreting and identifying the different types of vibrating pattern perceived through the skin remains a huge challenge for profoundly deaf people. As hearing through skin sensory is a very new area of research, there are very limited research articles published in this field. Thus far, this is the first study to evaluate the method of audio spectrum to develop hearing aid through skin sensory.

Outcomes of Cochlear implantation in early-deafened patients with Waardenburg syndrome: A systematic review and narrative synthesis.

This systematic review aims to establish the expected hearing and speech outcomes following cochlear implantation (CI) in patients with profound congenital deafness secondary to Waardenburg syndrome (WS). A systematic review of the literature and narrative synthesis was performed in accordance with the PRISMA statement. Databases searched: Medline, Pubmed, Embase, Web of Science, Cochrane Collection, and ClinicalTrials.gov. No limits were placed on language or year of publication. Searches identified 186 abstracts and full texts. Of these, 16 studies met inclusion criteria reporting outcomes in 179 patients and at least 194 implants. Hearing outcomes of those receiving cochlear implantation were generally good. Five studies included genetic analysis of one or more of the participants. A total of 11 peri/post-operative complications were reported. The methodological quality of included studies was modest, mainly comprising noncontrolled case series with small cohort size. All studies were OCEBM grade III-IV. Cochlear implantation in congenitally deafened children with Waardenburg Syndrome is a well-established intervention as a method of auditory rehabilitation. Due to the uncommon nature of the condition, there is a lack of large-scale high-quality studies examining the use of cochlear implantation in this patient group. However, overall outcomes following implantation are positive with the majority of patients demonstrating improved audiometry, speech perception and speech intelligibility supporting its use in appropriately selected cases.

Novel biallelic variants in the PLEC gene are associated with severe hearing loss

Pediatric auditory neuropathy spectrum disorder is a particular type of hearing loss caused by abnormal sound transmission from the cochlea to the brain. It is due to defective peripheral synaptic function or improper neuronal conduction. Using trio whole-exome sequencing, we have identified novel biallelic variants in the PLEC gene in three individuals with profound deafness from two unrelated families. Among them, one pediatric patient diagnosed with auditory neuropathy spectrum disorder had a good cochlear implantation outcome. The other two adult patients were diagnosed with non-syndromic hearing loss. Studies in mice and zebrafish confirmed that plectin is developmentally expressed in the inner ear. Moreover, plectin's knockdown resulted in a reduction of synaptic mitochondrial potential and loss of ribbon synapses, reinforcing the idea of a role for plectin in neuronal transmission. Altogether, the results presented here, point to a new unconventional role for plectin in the inner ear. Contrary to the well-characterized association of plectin to skin and muscle diseases, we found that specific plectin mutations can result in hearing loss with no other clinical manifestations. This is important because 1) it provides evidence of plectin's involvement in inner ear function and 2) it will help clinicians at the time of diagnosis and treatment.

ZBTB20 is essential for cochlear maturation and hearing in mice

The mammalian cochlear epithelium undergoes substantial remodeling and maturation before the onset of hearing. However, very little is known about the transcriptional network governing cochlear late-stage maturation and particularly the differentiation of its lateral nonsensory region. Here, we establish ZBTB20 as an essential transcription factor required for cochlear terminal differentiation and maturation and hearing. ZBTB20 is abundantly expressed in the developing and mature cochlear nonsensory epithelial cells, with transient expression in immature hair cells and spiral ganglion neurons. Otocyst-specific deletion of Zbtb20 causes profound deafness with reduced endolymph potential in mice. The subtypes of cochlear epithelial cells are normally generated, but their postnatal development is arrested in the absence of ZBTB20, as manifested by an immature appearance of the organ of Corti, malformation of tectorial membrane (TM), a flattened spiral prominence (SP), and a lack of identifiable Boettcher cells. Furthermore, these defects are related with a failure in the terminal differentiation of the nonsensory epithelium covering the outer border Claudius cells, outer sulcus root cells, and SP epithelial cells. Transcriptome analysis shows that ZBTB20 regulates genes encoding for TM proteins in the greater epithelial ridge, and those preferentially expressed in root cells and SP epithelium. Our results point to ZBTB20 as an essential regulator for postnatal cochlear maturation and particularly for the terminal differentiation of cochlear lateral nonsensory domain.

Cochlear implantation - Adverse effects on the cochlea and the vestibular organ

Cochlear implantation is the treatment of choice for patients with profound hearing loss and deafness. At the same time, inserting a cochlear implant (CI) leaves damage to the inner ear. The preservation of inner ear structure and function has become a central issue in CI surgery. The reasons for this are i) electroacoustic stimulation (EAS), i.e., the option of joint stimulation by a hearing aid and a CI; ii) an improved audiologic outcome in electric-only stimulation; iii) the preservation of structures and residual hearing for potential future therapy options; and iv) the avoidance of side effects, such as vertigo. The exact mechanisms that determine the extent of damage to the inner ear and which factors contribute to preservation of residual hearing are not yet fully understood. In addition to the surgical technique, electrode selection may play a role. This article provides an overview of what is known about the direct and indirect adverse effects of cochlear implantation on the inner ear, of the methods available to monitor inner ear function during cochlear implantation, and of the focus of future research on preservation of inner ear structure and function.

USE OF THE NUCLEUS SMARTNAV® SYSTEM IN INTRAOPERATIVE TELEMETRY OF COCHLEAR IMPLANT

Tests performed intraoperatively are routine tools in cochlear implant (CI) programs worldwide. Recently, Cochlear™ launched the Nucleus Smartnav® system that describes new parameters measured during insertion of the electrode array into the cochlea, verifies its position, tests impedance and AutoNRT. Objective: To describe the use of the Cochlear™ Nucleus SmartNav® system as an intraoperative measurement tool in cochlear implant surgery. Material and Methods: Patient with bilateral and congenital profound prelingual deafness. He has been using an individual sound amplification device (PSAD) bilaterally since childhood, has reasonable speaking skills and good understanding of others’ speech. Although IC was previously indicated, he chose to keep the hearing aid. However, given the inefficient gain, mainly in the left ear, a bimodal adaptation was suggested: CI in the left ear and hearing aids in the right. At the age of 48, he underwent CI surgery on the left, using the Cochlear™ CI622 model with CP1001 speech processor and intraoperative measurements performed by the Nucleus® SmartNav system. The impedance test and NRT were also performed intraoperatively using the Nucleus® SmartNav system, after reviewing the insertion of the electrodes. Result: The measurements obtained during the insertion of the electrode array in the cochlea allowed greater intraoperative control by enabling fine adjustments in the surgical technique. Conclusion: The Nucleus Smartnav® system endorses technologies that aim to increase surgical precision and reduce complications.