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Objective: The aim of this study was to conduct a bibliometric and visualization analysis of research on cochlear implantation (CI) for inner ear malformations (IEMs) from 1986 to 2024., Methods: A comprehensive literature search was performed using the Web of Science Core Collection Database, resulting in the identification of 431 relevant publications. Various data analysis and visualization tools, including VOSviewer, CiteSpace, and Bibliometrix, were utilized to analyze annual publication outputs, countries/regions and institutions, authors, journals and studies, keywords, and theme evolution., Results: The study revealed an overall increasing trend in research output on CI for IEMs, with significant contributions from countries such as the United States, China, Turkey, Germany, and Italy. The analysis also identified key authors, research teams, journals, and studies that have made substantial contributions to the field. Furthermore, the study highlighted important research hotspots and trends, such as the classification of IEMs, outcomes of CI for IEMs, and the management of pediatric patients with IEMs., Conclusion: The findings of this study provide a comprehensive overview of the research landscape surrounding CI for IEMs. The results serve as a basis for future research topic selection and emphasize the need for enhanced international collaboration and the publication of high-impact research to further advance this field., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: We assessed three cochlear implant (CI) suppliers: Advanced Bionics, Cochlear Limited, and MED-EL, for implant revision requiring reoperation after CI placement., Study Design: Retrospective cohort study of integrated-health-system database between 2010 and 2021. Separate models were created for pediatric (age <18) and adult (age ≥18) cohorts., Patients: Pediatric (age <18) and adult (age ≥18) patients undergoing cochlear implantation within our integrated healthcare system., Main Outcome Measure: Revision after CI placement. Cox proportional hazard regression was used to evaluate revision risk and adjust for confounding factors. Hazard ratios (HRs) and 95% confidence intervals (CIs) are presented., Results: A total of 2,347 patients underwent a primary CI placement, and Cochlear Limited was most implanted (51.5%), followed by Advanced Bionics (35.2%) and MED-EL (13.3%). In the pediatric cohort, the 7-year crude revision rate was 10.9% for Advanced Bionics and 4.8% for Cochlear Limited, whereas MED-EL had insufficient cases. In adults, the rates were 9.1%, 4.5%, and 3.3% for Advanced Bionics, MED-EL, and Cochlear Limited, respectively. After 2 years of postoperative follow-up, Advanced Bionics had a significantly higher revision risk (HR = 8.25, 95% CI = 2.91-23.46); MED-EL had no difference (HR = 2.07, 95% CI = 0.46-9.25)., Conclusion: We found an increased revision risk after 2 years of follow-up for adults with Advanced Bionics CI devices. Although we found no statistical difference between manufacturers in the pediatric cohort, after 2 years of follow-up, there were increasing trends in the revision probability for Advanced Bionics. Further research may determine whether patients are better suited for some CI devices., Competing Interests: The authors disclose no conflicts of interest., (Copyright © 2024, Otology & Neurotology, Inc.)

Objectives: To describe trends in cochlear implantation (CI) disparities in Texas using an all-payer database from 2010 to 2017., Methods: Texas Outpatient Surgical and Radiological Procedure Data, a public use data file, was accessed to analyze outpatient CI cases for Texas. Variables analyzed include patient age, sex, race/ethnicity, and insurance status. Population data from the American Community Survey generated CI utilization rates by patient demographic characteristics., Results: There were 6158 CI cases identified during the study period. The number of CI per year nearly doubled from 497 in 2010 to 961 in 2017. The majority of CI recipients were white (59.5%), male (51.9%), and privately insured (47.9%). All sub-populations statewide had more CI in 2017 compared to 2010, with the overall CI per 100 000 population increasing from 1.98 to 3.50 per 100 000 population. Patients over 75 demonstrated the greatest increase in the CI rate per 100 000 population, increasing from 4.60 in 2010 to 14.30 in 2017. Regarding race/ethnicity, all sub-populations noted an increase in the CI per 100 000 population, with white patients demonstrating the highest rate in 2017, at 4.36 CI per 100 000 population. Asian patients had a 502% increase in the CI rate (from 0.42 to 2.53), compared with 87.9%, 84.4%, and 69.2% increases for white, Black, and Hispanic populations, respectively., Conclusions: CI became more widespread between 2010 and 2017, benefiting certain populations more than others. Black and Hispanic populations had lower CI per 100 000 population than their white peers, while patients >65 years of age accounted for the greatest increase in CI.

Objective: To conduct a longitudinal national survey of cochlear implantation (CI) in Japan from 1985 through 2017., Methods: A retrospective analysis of adult and pediatric CI cases from 1985 to 2017 using the Oto-Rhino-Laryngological Society of Japan CI registration database was conducted. Surgical statistics were obtained, including number of surgeries, age, implanted side, facilities, and preoperative threshold levels for CI., Results: Since 1985, more than 11,100 CI surgeries have been conducted in Japan. The number exceeded 500 in 2005 and 1,000 in 2015. Since 2007, pediatric cases consistently surpassed adult cases until 2016. More facilities meet criteria for conducting CI as determined by Ministry of Health, Labor and Welfare and have now reached more than 100. Adult patients over 70 years old have become proportionally higher. Age at implantation steadily reduced in accordance with modifications of Japanese CI guidelines for children but is still not comparable to that in other developed countries. Although the number of CI surgeries for patients with moderate to severe hearing loss increased in the past ten years, the proportion was small., Conclusions: The CI database in Japan is quite unique in that it documents almost all the CI surgeries in Japan, allowing us to summarize the present situation as follows: fewer CI surgeries occur than are necessary, and children receiving implants are older than those in other developed countries. Continuous improvement of CI awareness is needed in Japan., (Copyright © 2020. Published by Elsevier B.V.)

Objective: The presence of a cochlear implant is being considered an absolute contraindication for experiments and/or treatments. We aimed to verify TMS (Transcranial Magnetic Stimulation) compatibility of a new generation of cochlear implants., Methods: In a series of experiments, we test if MED-EL cochlear implants -compatible with stable fields of magnetic resonance imaging scanning- are fully resistant even to rapidly varying magnetic fields as those generated by single pulses and low and high-frequency trains of repetitive TMS (rTMS) applied with a figure of eight coil and different magnetic stimulators., Results: With a TMS intensity equal or below 2.2 Tesla (T) the cochlear implant and all its electronic components remain fully functional, even when the combination of frequency, intensity and number of pulses exceeds the currently available safety guidelines. Induced forces on the implant are negligible. With higher magnetic fields (i.e., 3.2 T), one device was corrupted., Conclusions: Results exclude the risk of electronic damaging, demagnetizing or displacements of the studied cochlear implants when exposed to magnetic fields of up to 2.2 T delivered through a focal coil., Significance: They open the way to use focal rTMS protocols with the aim of promoting neural plasticity in auditory networks, possibly helping the post-implant recovery of speech perception performance., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Binaural hearing has certain benefits while listening in noisy environments. It provides the listeners with access to time, level and spectral differences between sound signals, perceived by the two ears. However, single sided deaf (SSD) or unilateral cochlear implant (CI) users cannot experience these binaural benefits due to the acoustic input coming from a single ear. The translational research on bilateral CIs started in the year 1998, initiated by J. Müller and J. Helms from Würzburg, Germany in association with MED-EL. Since then, several clinical studies were conducted by different research groups from across the world either independently or in collaboration with MED-EL. As a result, the bilateral CI has become the standard of care in many countries along with reimbursement by the health care systems. Recent data shows that children particularly, are given high priority for the bilateral CI implantation, most often performed simultaneously in a single surgery, as the binaural hearing has a positive effect on their language development. This article covers the milestones of translational research from the first concept to the widespread clinical use of bilateral CI.

Five categories of cochlear implants are introduced: The 'classic CI', the 'combined CI' - which can be combining a CI based on electric stimulation with acoustic stimulation (EAS) or with mechanical stimulation (EMS) or with electrical stimulation of the vestibular system (VICI) -, the 'individualised CI', the 'augmented CI' and the 'totally implantable CI'. The translational research activities leading to and within these categories have been, are and will be numerous and are the subject of the compendium for which this paper is the concluding chapter. Early translational research has resulted in the 'classic CI' in 1994. From then on translational research enabled the developments respectively the new indications and reimbursement of CI-systems for bilateral CIs, CI in single sided deafness, the auditory brainstem implant, speech coding and signal processing advances, electrophysiologic measurements for evaluation of cochlear health, all within the classic CI category. Starting points for the four newer categories of CI are either ideas of professionals treating hearing loss or of CI developers. The translational research performed also triggered research that led and leads to improved understanding of the fundamental mechanisms of hearing.

Electric-acoustic stimulation (EAS) is a special treatment modality for those patients who are profoundly deaf in the high-frequency (HF) region and retain usable hearing in the low-frequency (LF) region. Combining the electric stimulation with cochlear implant (CI) in the HF and acoustic amplification of residual hearing using a conventional hearing aid (HA) in the LF region defines EAS. The EAS concept was first proposed by C. von Ilberg from Frankfurt, Germany in the year 1997. In association with MED-EL, all the necessary safety studies were performed in non-human subjects before the first patient received it in 1997. In association with MED-EL, all the necessary safety studies were performed in non-human subjects before the first patient received it in 1999. For the patient to successfully use the EAS concept, the residual hearing needs to be preserved to a high extent and for several years. This requires a highly flexible electrode array in safeguarding the intra-cochlear structures during and after the CI electrode array insertion. Combining the HA unit with the audio processor unit of the CI was necessary for the convenient wearing of the unified audio processor. Fitting of the unified audio processor is another important factor that contributes to the overall success of the EAS treatment. The key translational research efforts at MED-EL were on the development of flexible electrodes, a unified audio processor, innovations in the fitting process, intra-operative monitoring of cochlear health during electrode insertion, pre-operative soft-ware tool to evaluate the cochlear size and electrode selection and some new innovations tried within EAS topic. This article covers the milestones of translational research from the first concept to the widespread clinical use of EAS.

Introduction: Using the United States Food and Drug Administration (FDA) as example, we argue that regulatory agencies worldwide should review their guidance on cochlear implants (CIs)., Methods: This is a position paper, thus the methods are strictly argumentation. Here we give the motivation for our recommendation. The FDA's original approval of implantation in prelingually deaf children was granted without full benefit of information on language acquisition, on childcaregiver communication, and on the lived experience of being deaf. The CI clinical trials, accordingly, did not address risks of linguistic deprivation, especially when the caregiver's communication is not fully accessible to the prelingually deaf child. Wide variability in the effectiveness of CIs since initial and updated approval has been indicated but has not led to new guidance. Children need to be exposed frequently and regularly to accessible natural language while their brains are still plastic enough to become fluent in any language. For the youngest infants, who are not yet producing anything that could be called language although they might be producing salient social signals (Goldstein et al. Child Dev 80:636-644, 2009), good comprehension of communication from caregiver to infant is critical to the development of language. Sign languages are accessible natural languages that, because they are visual, allow full immersion for deaf infants, and they supply the necessary support for this comprehension. The main language contributor to health outcomes is this combination of natural visual language and comprehension in communication. Accordingly, in order to prevent possible language deprivation, all prelingually deaf children should be exposed to both sign and spoken languages when their auditory status is detected, with sign language being critical during infancy and early childhood. Additionally, all caregivers should be given support to learn a sign language if it is new to them so that they can comprehend their deaf children's language expressions fully. However, both languages should be made accessible in their own right, not combined in a simultaneous or total communication approach since speaking one language and signing the other at the same time is problematic., Results: Again, because this is a position paper, our results are our recommendations. We call for the FDA (and similar agencies in other countries) to review its approval of cochlear implantation in prelingually deaf children who are within the sensitive period for language acquisition. In the meantime, the FDA should require manufacturers to add a highlighted warning to the effect that results with CI vary widely and CIs should not be relied upon to provide adequate auditory input for complete language development in all deaf children. Recent best information on users' experience with CIs (including abandonment) should be clearly provided so that informed decisions can be made. The FDA should require manufacturers' guidance and information materials to include encouragement to parents of deaf children to offer auditory input of a spoken language and visual input of a sign language and to have their child followed closely from birth by developmental specialists in language and cognition. In this way parents can align with providers to prioritize cognitive development and language access in both audio-vocal and visuo-gestural modalities., Discussion: The arguments and recommendations in this paper are discussed at length as they come up.

Objective : To collect figures on the numbers of children and adults receiving cochlear implants across Europe, compare the figures for 2016 with those for 2010, and identify any trends. Materials and methods : In 2018 EURO-CIU invited their 23 member countries to conduct a survey collecting data on the number of CI recipients in 2016 and 2017. Data were received from 15 countries, representing more than 100 000 CI recipients in Europe. Results : For paediatric CI, there was an increase in nearly all European countries (except Denmark, the UK and Luxembourg) between 2010 and 2016. We found an annual figure of one CI per 1000 newborns common in most countries where reimbursement of paediatric CI's is available. Conversely the adult data reveals no increase between 2010 and 2016 and the data is less homogeneous than the paediatric data with huge differences across countries. Conclusion : There is little agreement on data on numbers of CI across Europe, which makes it difficult to plan public health policy, funding or services. In all European countries included in this study (except Germany) there needs to be work on raising more awareness of adult hearing loss and adult cochlear implantation to improve access.

Objective: To review the growth of a pediatric cochlear implant (CI) program at one large tertiary care medical center over a 25-year period in order to (1) describe the population of pediatric cochlear implant recipients, (2) document word recognition outcomes, and (3) describe changes in candidacy criteria over time. Design: A retrospective review of population demographics and trends included etiology of hearing loss, device use and type, expansion of inclusion criteria, and word recognition outcomes. Results: Ninety-one percent of the children studied were from North Carolina and reflect the ethnic distribution of the state. The population is heterogeneous for etiology and the presence of syndromes and/or co-morbidities. A trend of lower age of implant and greater residual hearing was documented overtime. As a single metric, monosyllable word recognition for the children assessed is good with the mean CNC test word score of 76.13% (range 0-100, S.D = 19.94). Conclusions: Pediatric cochlear implant candidacy criteria have evolved despite no change in FDA-approved regulations since 2000. There is great diversity among recipients but word recognition outcomes are generally good in this population and have improved over time. Professionals who may refer children for cochlear implantation should be aware of current clinical practices and general outcomes.

The electrode array of a cochlear implant forms a permanent, often lifelong interface between the implanted electronics and neural structures of the cochlea. A cochlear implant is primarily prescribed to restore hearing via electrical stimulation of the auditory nerve. As with any neural stimulator intended to either deliver electrical stimulus or record a neural response, the aim is to place the electrodes in close proximity to the target neural structures. The broadening of indications and the concept of preservation of low-frequency residual hearing over the last two decades has resulted in an increased understanding of the mechanisms and implications of intracochlear trauma for both the hearing preservation surgery and electrical stimulation outcomes with cochlear implantation, as well as the influence of many biographic and audiological patient factors correlated with achieving better hearing outcomes. These two goals, the proximity to the cochlear nerve for electrical stimulation and the preservation of cochlear structures, have typically been viewed as mutually exclusive, with perimodiolar electrode arrays being preferred for the former, and lateral wall electrode arrays for the latter. The design evolution of both the lateral wall and perimodiolar electrodes is presented, considering the cochlea anatomy and continued understanding of the mechanics and dynamics of electrode insertion, along with the influence of the ongoing changes to the intracochlear environment to provide a rationale for the electrode design with the intent to provide the greatest patient benefit over their implanted lifetime.

Objective: Sociodemographic disparities of cochlear implantation in children have been reported. This study sought to determine if disparities in children receiving cochlear implants have narrowed, widened or remained constant., Methods: Children 18 years or younger who underwent cochlear implantation from 1997 to 2012 were selected using the Kids' Inpatient Database. Demographic data included primary insurance payer, income quartile and race. The Cochran-Armitage test was used to determine if trends were significant. Prevalence rates of cochlear implantation by race were generated. A Poisson regression model was used to evaluate the rates of cochlear implantation within each racial group., Results: The proportion of children receiving cochlear implants with private insurance decreased from 79.3% to 42.6% (p < .0001), whereas children with Medicaid increased from 17.4% to 35.2% (p < .0001). Proportion of implanted children from the lowest two income quartiles increased from 15.5% to 24.4% (p < .0001) and 10.3%-21.8% (p < .0035), respectively. Rates of implantation among children from income quartile four decreased from 50.9% to 35.3% (p < .0001). White children were implanted twice as often as Black or Hispanic children (p = .007 and p = .0012 respectively). Asian children were implanted more than twice as often as Black or Hispanic Children (p = .0154 and p = .0098 respectively)., Conclusions: Income and insurance disparities have narrowed within the inpatient pediatric cochlear implantation cohort. Racial disparities still exist. White and Asian children are implanted at higher rates than Black or Hispanic children., (Copyright © 2018. Published by Elsevier B.V.)

Objective: To reveal the age distribution and capture the longitudinal trend in otolaryngological surgeries performed in Japan, where society is rapidly aging., Methods: Using the Diagnosis Procedure Combination database, we extracted data on patients who were hospitalized and underwent any type of otolaryngological surgery in departments of otolaryngology or head and neck surgery from fiscal year 2007 to fiscal year 2013. Type of surgery, patient's age, and fiscal year were compared. We categorized >200 types of surgeries into eight specialties: ear surgery, functional endoscopic sinus surgery (FESS), other types of paranasal surgery (except for malignancy), head and neck cancer surgery, benign tumor surgery, upper airway surgery (including pharynx and larynx), removal of foreign body, and other., Results: In total, 558,732 patients were included. The proportions of patients in each age category formed two peaks in middle age and in children aged ≤9years. The proportion of all surgeries made up by FESS, other paranasal surgery, benign tumor surgery, and head and neck cancer surgery gradually increased with age, forming a peak in patients in their 60s. The proportion of ear surgery was highest in patients aged ≤9years (34.0% of all surgeries, mostly myringotomy and transtympanic ventilation tube insertion) and formed a gradual peak in patients in their 60s (mostly tympanoplasty). The proportion of upper airway surgery (tonsillectomy and adenoidectomy) was highest in patients aged ≤9years (25.3% of all surgeries). The proportion of foreign body removal was highest in patients aged ≤9years (52.2% of all surgeries) and increased slightly with age. In 2013, compared with 2007, those aged 65-74 years and ≥75years made up a larger percentage of patients undergoing each specific surgery, including tympanoplasty, stapedectomy/stapedotomy, FESS, head and neck cancer surgery, pharyngolaryngectomy, total/subtotal glossectomy, thyroid lobectomy, parotidectomy (for a benign tumor), submandibular gland resection, tonsillectomy, and vocal fold polypectomy., Conclusion: The age distribution of otolaryngological surgeries varied by specialty. We found an increased proportion of patients aged 65-74 and ≥75years in most specific surgeries., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Many factors affect an individual's outcomes with a cochlear implant (CI); however, quality of device programming and consistency of follow-up appointments have been shown to be crucial contributors. As audiologists' CI caseloads increase, time constraints on appointments also increase, thus fueling the need for efficient and effective programming strategies. Currently, there are no standardized guidelines describing what methods should be used during programming, nor are there standardized schedules that delineate what procedures should be performed at specific appointment intervals. Without standardized programming guidelines, clinical practices may be variable and may not align with best practice research; thus, outcomes with a CI, particularly for pediatrics, may not be reflective of the actual potential available., Purpose: The purpose of this study was to identify the clinical practice patterns used by U.S. audiologists when programming and providing follow-up care to children who use CIs. This study aimed to determine the following: common programming approaches, provision intervals for these procedures, common validation assessments, typical follow-up care schedules, and source(s) of CI training. In addition, this study sought to evaluate if training and/or follow-up care differed between small and large CI centers., Research Design: A cross-sectional survey design was used., Study Sample: Target population included practicing audiologists working with pediatric CI users throughout the United States. Participation was voluntary, thus random selection could not be used. A total of 167 participants opened and began the online survey and 113 successfully completed the survey instrument (23.99% return rate)., Data Collection and Analysis: Potential participants were identified using the "find a clinic" function on three CI manufacturers' websites. Potential participants were asked to complete an online survey seeking information about practices they employ in their clinical setting. Survey responses were analyzed for trends., Results: Overall, a common follow-up schedule was determined, which included an average of 6.8 appointments within the first year. Minor differences in training and programming practices between small and large CI centers emerged; however, no statistically significant results were noted. Results did reveal trends in the use of certain clinical practices. This was particularly evident in the limited use of objective measures., Conclusions: Overall, the findings support other recent studies that suggest the development of CI guidelines that may standardize programming and follow-up practices of CI audiologists. This could prove valuable for the continual improvement of CI outcomes, particularly in the pediatric population., (American Academy of Audiology.)

Objectives/hypothesis: Cochlear implantation (CI) is a well-accepted surgical option for the treatment of moderate to profound deafness. The purpose of this study was to evaluate the temporal and geographic trends of this procedure nationwide in the Medicare population in an attempt to explore the impact of evolving technologies and changes in healthcare policy., Methods: Medicare Part B national summary procedural datasets from 2007 to 2016 were obtained. Current Procedural Terminology codes for CI as well as auditory osseointegrated implantation were obtained. Centers for Medicare and Medicaid Services (CMS) datasets were evaluated to determine temporal trends. For geographic trends, specific carrier datasets from 2007 and 2016 were used., Results: From 2007 through 2016, the number of CI procedures increased annually from 1603 to 3600 (124.6%). Other procedures to treat hearing loss including bone-anchored implantation exhibited comparatively modest increases (23%, 90%). CI procedures increased every year in contrast to bone-anchored implants. Controlling for Medicare population, the greatest number of CI procedures performed per capita in the United States was in the West North Central, with an average 1.05 CIs per 10,000 beneficiaries., Conclusion: The number of CI procedures performed in the elderly population has increased markedly over the past 10 years, far outpacing growth in other hearing surgeries. Potential reasons may relate to changes in criteria for CI candidacy over the past decade, although significant regional variability demonstrated suggests a lack of consensus. Further studies would be necessary to ascertain the true reason for geographic disparities.

Patients suffering from neuronal degenerative diseases are increasingly being equipped with neural implants to treat symptoms or restore functions and increase their quality of life. Magnetic resonance imaging (MRI) would be the modality of choice for the diagnosis and compulsory postoperative monitoring of such patients. However, interactions between the magnetic resonance (MR) environment and implants pose severe health risks to the patient. Nevertheless, neural implant recipients regularly undergo MRI examinations, and adverse events are rarely reported. However, this should not imply that the procedures are safe. More than 300 000 cochlear implant recipients are excluded from MRI, unless the indication outweighs the excruciating pain. For 75 000 deep brain stimulation (DBS) recipients quite the opposite holds true: MRI is considered an essential part of the implantation procedure and some medical centres deliberately exceed safety regulations, which they refer to as crucially impractical. Permanent MRI-related neurological dysfunctions in DBS recipients have occurred in the past when manufacturer recommendations were exceeded. Within the last few decades, extensive effort has been invested to identify, characterise and quantify the occurring interactions. Yet today we are still far from a satisfying solution concerning a safe and beneficial MR procedure for all implant recipients. To contribute, we intend to raise awareness of the growing concern, summon the community to stop absurdities and instead improve the situation for the increasing number of patients. Therefore, we review implant safety in the MRI literature from an engineering point of view, with a focus on cochlear and DBS implants as success stories of neural implants in clinical practice. We briefly explain fundamental phenomena which can lead to patient harm, and point out breakthroughs and errors made. Then, we end with conclusions and strategies to avoid future implants from being contraindicated in MR examinations. We believe that implant recipients should enter MRI, but before doing so, it should be made sure that the procedure is reasonable.

Cochlear implantation (CI) surgery is a very successful technique, performed on more than 300,000 people worldwide. However, since the challenge resides in obtaining an accurate surgical planning, computational models are considered to provide such accurate tools. They allow us to plan and simulate beforehand surgical procedures in order to maximally optimize surgery outcomes, and consequently provide valuable information to guide pre-operative decisions. The aim of this work is to develop and validate computational tools to completely assess the patient-specific functional outcome of the CI surgery. A complete automatic framework was developed to create and assess computationally CI models, focusing on the neural response of the auditory nerve fibers (ANF) induced by the electrical stimulation of the implant. The framework was applied to evaluate the effects of ANF degeneration and electrode intra-cochlear position on nerve activation. Results indicate that the intra-cochlear positioning of the electrode has a strong effect on the global performance of the CI. Lateral insertion provides better neural responses in case of peripheral process degeneration, and it is recommended, together with optimized intensity levels, in order to preserve the internal structures. Overall, the developed automatic framework provides an insight into the global performance of the implant in a patient-specific way. This enables to further optimize the functional performance and helps to select the best CI configuration and treatment strategy for a given patient.

Objective: The objective is to determine if eligibility (as defined as the duration of severe to profound hearing loss before cochlear implantation [CI]) has changed over the 30 years since Food and Drug Administration approval., Data Sources: English-language, peer-reviewed articles, theses, and trial data available through PubMed and Cochrane Library databases up until and including May 31, 2016., Study Selection: One thousand six unique articles were identified. Prospective studies that reported duration of severe/profound hearing loss before CI in adult patients were included. Retrospective studies, reviews, meta-analyses, articles reporting pediatric or mixed data, hybrid/electroacoustic CI, and articles from centers outside the United States were excluded. Seventy-one studies met inclusion criteria and were included for analysis., Data Extraction: Contributing authors independently reviewed included studies for data validity and applicability., Data Synthesis: Metaregression was used to assess the relationship between the year of publication and duration of hearing loss. To account for a possible age effect, a second model was estimated including mean age at the time of study as a covariate., Conclusion: A positive association between study year and the duration of hearing loss before implantation was found showing a 0.28-year increase in the duration of hearing loss for every increasing study year. Contrary to conventional assumption, duration of eligibility for CI appears to be increasing. Though the reasons for this are not clear, current strategies to increase both awareness and access to CI seem to be falling short.

Twenty years ago, cochlear implants (CI) were indicated only in cases of profound hearing loss or complete deafness. While from today's perspective the technology was clumsy and provided patients with only limited speech comprehension in quiet scenarios, successive advances in CI technology and the consequent substantial hearing improvements over time have since then resulted in continuous relaxation of indication criteria toward residual hearing. While achievements in implant and processor electronics have been one key factor for the ever-improving hearing performance, development of electro-acoustic CI systems-together with atraumatic implantation concepts-has led to enormous improvements in patients with low-frequency residual hearing. Manufactures have designed special processors with integrated hearing aid components for this patient group, which are capable of conveying acoustic and electric stimulation. A further milestone in improvement of hearing in challenging listening environments was the adoption of signal enhancement algorithms and assistive listening devices from the hearing aid industry. This article gives an overview of the current state of the art in the abovementioned areas of CI technology.

Introduction: Electrical stimulation has long been the most effective strategy for evoking neural activity from bionic devices and has been used with great success in the cochlear implant to allow deaf people to hear speech and sound. Despite its success, the spread of electrical current stimulates a broad region of neural tissue meaning that contemporary devices have limited precision. Optical stimulation as an alternative has attracted much recent interest for its capacity to provide highly focused stimuli, and therefore, potentially improved sensory perception. Given its specificity of activation, optical stimulation may also provide a useful tool in the study of fundamental neuroanatomy and neurophysiological processes. Areas covered: This review examines the advances in optical stimulation - infrared, nanoparticle-enhanced, and optogenetic-based - and its application in the inner ear for the restoration of auditory function following hearing loss. Expert opinion: Initial outcomes suggest that optogenetic-based approaches hold the greatest potential and viability amongst optical techniques for application in the cochlea. The future success of this approach will be governed by advances in the targeted delivery of opsins to auditory neurons, improvements in channel kinetics, development of optical arrays, and innovation of opsins that activate within the optimal near-infrared therapeutic window.

Importance: Barriers to early pediatric cochlear implantation in underinsured populations have been previously reported. However, to our knowledge, the effect of this delay on the development of auditory and speech-language objectives has not been evaluated., Objective: To determine if health care insurance status affects the achievement of proficiency in basic sound access and imitation tasks in children with cochlear implants., Design, Setting, and Participants: A retrospective review of 123 children aged 1 to 12 years receiving cochlear implants at the single tertiary referral academic free-standing Children's National Health System in Washington, DC, between January 1, 2008, and December 31, 2015., Main Outcomes and Measures: Auditory function after cochlear implantation, time to proficiency in Ling-6 scores, and number of speech therapy and audiological appointments, as well as current educational setting, were compared with patient age at diagnosis of hearing loss, age at cochlear implantation, cochlear implantation insertion technique, and health care insurance status for recipients of cochlear implants., Results: A total of 123 children aged 1 to 12 years (mean [SD] age, 64.0 [57.4] years) with cochlear implants were included in the study. Of 37 patients with complete and accurate Ling-6 test scores, 23 (62.1%) were able to have proficiency a mean of 5.1 months at follow-up. Despite equal auditory performance on pure-tone audiometry after cochlear implantation, publicly insured recipients had Ling-6 proficiency a mean of 6.0 months (95% CI, 5.5-6.5 months) later than privately insured recipients (11.0 vs 5.0 months). When controlling for patient age, time to cochlear implantation, number of therapy sessions, and cochlear implantation insertion technique, multivariable logistic regression analysis revealed health care insurance status to be the independent variable associated with inadequate Ling-6 discrimination scores (odds ratio, 46.2; 95% CI, 2.9-729.4)., Conclusions and Relevance: Despite equal speech detection scores, publicly insured recipients of cochlear implantation had a significant and critical delay in attaining proficiency in a fundamental measure of sound recognition and imitation.

Local drug application to the inner ear offers a number of advantages over systemic delivery. Local drug therapy currently encompasses extracochlear administration (i. e., through intratympanic injection), intracochlear administration (particularly for gene and stem cell therapy), as well as various combinations with auditory neurosensory prostheses, either evaluated in preclinical or clinical studies, or off-label. To improve rehabilitation with cochlear implants (CI), one focus is the development of drug-releasing electrode carriers, e. g., for delivery of glucocorticosteroids, antiapoptotic substances, or neurotrophins to the inner ear. The performance of cochlear implants may thus be improved by protecting neuronal structures from insertion trauma, reducing fibrosis in the inner ear, and by stimulating growth of neuronal structures in the direction of the electrodes. Controlled drug release after extracochlear or intracochlear application in conjunction with a CI can also be achieved by use of a biocompatible, resorbable controlled-release drug-delivery system. Two case reports for intracochlear controlled release drug delivery in combination with cochlear implants are presented. In order to treat progressive reduction in speech discrimination and increased impedance, two cochlear implant patients successfully underwent intracochlear placement of a biocompatible, resorbable drug-delivery system for controlled release of dexamethasone. The drug levels reached in inner ear fluids after different types of local drug application strategies can be calculated using a computer model. The intracochlear drug concentrations calculated in this way were compared for different dexamethasone application strategies., Competing Interests: Compliance with ethical guidelinesConflict of interestS.K. Plontke, G. Götze, T. Rahne, and A. Liebau declare that they have no competing interests.All patients were informed about the off-label use of the controlled-release drug-delivery system and signed an informed consent form.

Objective: Identify variables associated with paediatric access to cochlear implants (CIs)., Design: Part 1. Trends over time for age at CI surgery (N = 802) and age at hearing aid (HA) fitting (n = 487) were examined with regard to periods before, during, and after newborn hearing screening (NHS). Part 2. Demographic factors were explored for 417 children implanted under 3 years of age. Part 3. Pre-implant steps for the first 20 children to receive CIs under 12 months were examined., Results: Part 1. Age at HA fitting and CI surgery reduced over time, and were associated with NHS implementation. Part 2. For children implanted under 3 years, earlier age at HA fitting and higher family socio-economic status were associated with earlier CI. Progressive hearing loss was associated with later CIs. Children with a Connexin 26 diagnosis received CIs earlier than children with a premature / low birth weight history. Part 3. The longest pre-CI steps were Step 1: Birth to diagnosis/identification of hearing loss (mean 16.43 weeks), and Step 11: MRI scans to implant surgery (mean 15.05 weeks) for the first 20 infants with CIs under 12 months., Conclusion: NHS implementation was associated with reductions in age at device intervention in this cohort.

Objectives: Identification and evaluation of prognostic factors that are associated with paediatric cochlear implantation (PCI) outcomes was the aim of this study., Methods: A retrospective review of 174 charts was performed at the Royal Children's Hospital and the Hear and Say Centre, Brisbane. This examined the possible influence of a number of variables (including age at implant, family, additional disabilities, surgical complications, gender, GJB2 mutations, meningitis, inner ear malformations, and prematurity) on outcome measures: receptive, expressive, and total language, receptive and expressive vocabulary, speech articulation and categories of auditory performance at 18-24 months post-implant. Multiple regression analysis was used to identify variables related to language and vocabulary outcomes., Results: The findings suggest that inner ear malformations and family concern are negatively associated with receptive and expressive language and receptive vocabulary scores. There was marginal evidence to suggest that increasing age at implantation was associated with lower receptive and expressive language scores., Discussion: Prognostic factors that have been adequately validated statistically include inner ear malformations, the influence of family and late age at implantation. However, this study identified a need to define better the impact of the various degrees of inner ear malformations, to particularly emphasize the role of family as a strong predictor of PCI outcomes, and to confine the study of 'age at implantation' to pre-lingually deafened children., Conclusion: Evaluation of prognostic factors is a key element in PCI. This study confirmed several factors that are strongly associated with outcomes. For better research, there is a need for universal standardized outcome measures and development of a standardized framework for recording patient data.

FUNDING FOR COCHLEAR IMPLANTS: The Japanese health-care system provides universal health coverage for the entire 127 million population of Japan. This includes all aspects of cochlear implantation, from diagnosis to implantation to mapping and habilitation aftercare. Japan has the third largest developed economy; however, the uptake rate for cochlear implants is lower than that of countries with similar economic status. Japan has an uptake rate of approximately 1% of potentially suitable subjects of all ages, compared with 5.6% in the USA., Cochlear Implant Provision for Children: In Japan, about 55% of cochlear implant recipients are children of less than 18 years of age. This represents an increase of 20% in the last 10 years, with a relative increase in the numbers of children receiving implants compared with the numbers of adults. However, only 3-4% of children under the age of 3 years are being implanted at less than 18 months of age. This is in accordance with the Japanese ENT Academy's guidelines, which currently puts the minimum age limit for implants in children at 18 months., Neonatal Screening: For hearing loss was first piloted nationally in Japan in 2000. Funding for screening subsequently stopped in 2005, though the national treasury provided a further 2 years' funding. Since 2007 local government organizations have been given responsibility to support these screening programs, but there remains considerable variation in funding between different prefectures. In one prefecture, Okayama, 95% of babies were screened and followed up for 2 years. However, the support system for children who need further diagnostic testing after screening remains insufficient., Referral: When diagnosed, children with hearing loss are referred for counselling, hearing aids and habilitation. The responsibility for these is divided between the Ministry of Health and Welfare (including surgery, device programming, and therapy) and the Ministry of Education. Schools for the deaf and preschool hearing impaired education centers have had most of the responsibility for early intervention, educational choices and referral for cochlear implantation. In the past 98% of schools for children with hearing loss have used communication methods relying mostly on visual cues. In recent years, however, there has been a shift toward 'inclusive' mainstream education. Between 2008 and 2011 the number of children with cochlear implants in special needs schools increased to 16%. It is now estimated that 67% of children with cochlear implants may now be in mainstream schools. There is still the need for support services for these implanted children attending mainstream schools, with adequate provision of resources., Conclusion: Cochlear Implantation has had a significant role in changing the medical management and education of children in Japan with hearing loss. Much remains to be done, though the situation has greatly improved in recent years and continues to do so.

Objectives: To review worldwide data on cochlear implant adverse events, test for significant trends over a 10-year period and discuss possible reasons behind such trends. To evaluate the suitability of the Manufacturer and User Facility Device Experience (MAUDE) database for analysis of trends in cochlear implant adverse events., Study Design: Retrospective analysis of cochlear implant adverse events reported to the U.S. Food and Drug Administration (FDA) as recorded on the MAUDE database. Data for each adverse event reported in the years 2000 (n = 237), 2005 (n = 1089), and 2010 (n = 2543) were evaluated and assigned to one of 14 categories according to report content. Incidence data were compared across the 3 sampling points to determine trends., Hypothesis: Improvements in cochlear implant manufacturing processes and surgical techniques would result in a decrease in the proportion of CI adverse events because of primary device failure or surgical factors, relative to those with complex, multi-factorial or idiopathic origins, over the 10 year sampling period., Results and Conclusion: Statistical analyses showed a significant increase over time in the proportion of CI adverse events that had multiple or unknown causes, particularly cases of gradual idiopathic loss of performance, as compared with those with a clearly defined underlying device-related or medical cause., Conclusions: Findings suggest that there is an urgent need to undertake further research to investigate causes for idiopathic and gradual CI adverse events to continue the overall improvement in CI outcomes.

In recent years the indication criteria for cochlear implantation (CI) have changed. To gain optimal benefits, early implantation in prelingually deaf children is necessary. Even additional disabilities are no longer contraindications for CI. Nowadays the criteria for implantation not only include deafness but also residual hearing. Combined electric-acoustic stimulation has been established as a treatment option in patients with hearing still functioning in the low frequencies. Due to the benefits of binaural hearing, bilateral CI has become standard over the last decade. Recent experience has shown the benefits of CI in unilateral deafness and in cases of severe tinnitus. The actual benefit of CI shows great inter-individual differences. We usually expect (re-)habilitation of language communication skills with implantation.

It has been over 50 years since Djourno and Eyries first attempted electric stimulation in a patient with deafness. Over this time, the Cochlear Implant (CI) has become not only remarkably successful, but increasingly complex. Although the basic components of the system still comprise an implanted receiver stimulator and electrode, externally worn speech processor, microphone, control system, and power source, there are now several alternative designs of these components with different attributes that can be variably combined to meet the needs of specific patient groups. Development by the manufacturers has been driven both by these various patient needs, and also by the desire to achieve technological superiority, or at least differentiation, ultimately in pursuit of market share. Assessment of benefit is the responsibility of clinicians. It is incumbent on both industry and clinicians to ensure appropriate, safe, and affordable introduction of new technology. For example, experience with the totally implanted cochlear implant (TIKI) has demonstrated that quality of hearing is the over-riding consideration for CI users. To date, improved hearing outcomes have been achieved by improvements in: speech processing strategies; microphone technology; pre-processing strategies; electrode placement; bilateral implantation; use of a hearing aid in the opposite ear (bimodal stimulation); and the combination of electric and acoustic stimulation in the same ear. The resulting expansion of CI candidacy, with more residual hearing, further improves the outcomes achieved. Largely facilitated by advances in electronic capability and computerization, it can be expected that these improvements will continue. However, marked variability of results still occurs and we cannot assure any individual patient of their outcome. Realistic goals for implementation of new technology include: improved hearing in noise and music perception; effective invisible hearing (no external apparatus); automated fitting; and reduction in outcome variability. This paper provides examples of relevant potential future technologies that can be applied to reach these goals. In the quest for better outcomes, future technology must deliver improved reliability and usability for both clinicians and recipients that does not compromise safety and is affordable. One of the challenges related to the introduction of new technologies is the 'classification' of CI systems and the framework under which sufficient change and increased benefit can be demonstrated to establish a claim of 'new generation CI' and hence increased reimbursement from third-party payers. Significant improvements in hearing outcomes and quality of life associated with CI design changes are difficult to measure, particularly when there is such dramatic benefit from the intervention of cochlear implantation from the individual's perspective. Manufacturers and clinicians need to be objective and undertake appropriate safety studies and long-term and multi-centre clinical trials to ensure that the introduction of new technology is both safe and effective and supported by health systems worldwide.

The selection of cochlear implant (CI) candidates requires consideration of a variety of clinical and radiographic factors. The present article reviews the current knowledge regarding the preoperative imaging of CI candidates and explores emerging developments in different imaging modalities. Preoperative radiologic assessment should evaluate the status of the middle/inner ear, auditory nerve and central acoustic pathways. Preoperative computed tomography displays anatomic middle ear variations of surgical importance. MRI can demonstrate fluid/obliteration in the inner ear and depict the retrocochlear auditory pathways. Dual modality imaging with high-resolution computed tomography and MRI of the petrous bone and brain can provide the maximum information regarding surgical landmarks and detect deafness-related abnormalities. Cost-effectiveness issues also justify its use. New systems are now becoming available, offering improved soft-tissue delineation, sophisticated segmentation techniques, volumetric measurements, semitransparent views and superior surface resolution, thus significantly advancing our diagnostic acumen and making the preoperative evaluation of CI candidates more accurate and reliable.

Objectives: (1) To analyze if socioeconomic status influences access to cochlear implantation in an environment with adequate Medicaid reimbursement. (2) To determine the impact of socioeconomic status on outcomes after unilateral cochlear implantation., Design: Retrospective cohort study., Setting: University Hospitals Case Medical Center and Rainbow Babies and Children's Hospital (tertiary referral center), Cleveland, Ohio., Participants: Pediatric patients (age range, newborn to 18 years) who received unilateral cochlear implantation during the period 1996 to 2008., Main Outcome Measures: Access to cochlear implantation after referral to a cochlear implant center, postoperative complications, compliance with follow-up appointments, and access to sequential bilateral cochlear implantation., Results: A total of 133 pediatric patients were included in this study; 64 were Medicaid-insured patients and 69 were privately insured patients. There was no statistical difference in the odds of initial cochlear implantation, age at referral, or age at implantation between the 2 groups. The odds of prelingual Medicaid-insured patients receiving sequential bilateral cochlear implantation was less than half that of the privately insured group (odds ratio [OR], 0.43; P = .03). The odds of complications in Medicaid-insured children were almost 5-fold greater than the odds for privately insured children (OR, 4.6; P = .03). There were 10 complications in 51 Medicaid-insured patients (19.6%) as opposed to 3 in 61 privately insured patients (4.9%). Medicaid-insured patients missed substantially more follow-up appointments overall (35% vs 23%) and more consecutive visits (1.9 vs 1.1) compared with privately insured patients., Conclusions: In an environment with adequate Medicaid reimbursement, eligible children have equal access to cochlear implantation, regardless of socioeconomic background. However, lower socioeconomic background is associated with higher rates of postoperative complications, worse follow-up compliance, and lower rates of sequential bilateral implantation, observed herein in Medicaid-insured patients. These findings present opportunities for cochlear implant centers to create programs to address such downstream disparities.

Objectives/hypothesis: The goal of this study is to ascertain worldwide experience with bilateral cochlear implantation (BCI) with regard to patient demographics, trends in provision of BCI to adult and child patient populations, differences and similarities in BCI candidacy criteria, diagnostic requirements, and treatment approaches among clinicians in high-volume cochlear implant centers., Study Design: Retrospective/prospective., Methods: : An electronic survey consisting of 59 mainly multiple-choice questions was developed for online completion. It examined the implant experience and clinical opinion of expert cochlear implant (CI) centers worldwide on the indications, motivations, and contraindications for adult and pediatric, simultaneous and sequential BCI candidacy. Centers were chosen to complete the survey based on their known reputation as a center of excellence. Patient demographics were queried for two time periods to elucidate trends: 2006 and prior, and for the year 2007., Results: Seventy-one percent (25/35) of the CI clinics approached completed the survey. Collectively, these 25 clinics represent experience with approximately 23,200 CI users globally, representing 15% of the total estimated CI population worldwide. The total number of BCI surgeries reflected in their experience (2,880) represents 36% of the estimated number worldwide as of December 2007. Cumulatively to the end of 2007, 70% of all BCI surgeries have occurred in children, with the 3- to 10-year-old age group having the highest representation (33% of all BCIs), followed in order by adults (30%), children under 3 years of age (26%), and children between 11 and 18 years of age (11%). Seventy-two percent of all BCI surgeries were performed sequentially (70% of children, 76% of adults). Children <3 years of age represent the only age group of all patients in which simultaneous surgeries predominate (58% simultaneous). For all other age groups, sequential surgeries far outnumber simultaneous (3-10 years, 84% sequential; 11-18 years, 94% sequential; adults, 76% sequential). Prior to January 2007, 68% of BCIs were performed in children. This increased to 79% for the year 2007 (P < .001). With regard to children only, a change is apparent over time in terms of the age group making up the majority of pediatric BCI surgeries performed. Prior to 2007, children 3 to 10 years of age made up 50% of the children undergoing BCI, whereas those <3 years made up only 33%. In 2007 this shifted more toward the younger age group (47% for those <3 years and 40% for 3-10-year-olds; P < .001). United States clinics had a higher proportion of adult BCI patients (59% children, 41% adults) than the non-United States clinics (78% children, 22% adults; P < .001). The majority of responders do not hold to a minimum or maximum age by which they limit BCI., Conclusions: Worldwide experience with BCI is now quite extensive and provides a useful base for evaluating clinical outcomes across patient categories and for providing further support during the patient/parent counseling process.

Over the last years, indications for cochlear implants (CIs) have changed dramatically. The benefits depend on the preconditions of the individual patient as well as on the subsequent (re)habilitation. Therefore, many variables influencing the hearing and speech perception of a CI user must be kept in mind. As an example, the special situation of children having Turkish as their mother tongue is described. The most convincing argument concerning (re)habilitation is its benefit. Indeed, this benefit represents the final standard of quality and serves as the yardstick for standard assessments of (re)habilitation quality. CI (re)habilitation includes medical, pedagogical, audiological, hearing and speech, and psychological therapeutic aspects.

The technique of cochlear implantation was the first method which allowed replacement of a sense organ by a (partially) implantable electronic prosthesis. By this method the cells of the spiral ganglion of the cochlea are directly stimulated by the electrodes introduced into the cochlea, bypassing the functions of the outer and middle ear as well as the cochlea. Treatment with a cochlear implant (CI) has been established over the last 20-30 years as a reliable method for restoring hearing in adults and children with severe hearing disorders and is now a routine method in many centers. For optimal results in understanding speech and for children in the speech development phase, rehabilitation must be an integral part of the total treatment and follow soon after implantation. To achieve this early diagnosis of hearing difficulties or deafness is necessary, which is simplified by a consistent hearing screening of newborns, now a statutory procedure in Germany.