Animal models of cochlear implant: Classification and update

Cochlear implantation(CI)is currently recognized as the most effective treatment for severe to profound sensorineural deafness and is considered one of the most successful neural prostheses.Since its inception in 1961,cochlear implantation has expanded its range of applications to encompass younger newborns,older people,and individuals with unilateral hearing loss.In addition,it has improved its surgical methods to minimize the occurrence of complications.Furthermore,notable advancements have been made in the design of electrodes,techniques for speech processing,and software for programming.Nevertheless,inflammation,fibrosis,and even ossification are observed in the cochlea of nearly all cochlear implant(CI)patients.These tissue responses might have a negative impact on the performance of the implants,residual hearing,and the results of post-operative CI rehabilitation.Animal models are significant translational tools that offer essential preclinical data for possible therapeutics.Thus,this study concentrates on the existing animal models used for cochlear implantation,highlights the advancements made in research,and offers insights into potential future research areas.

Establishment of quantitative evaluation system for cochlear implant effectiveness for hearing-impaired children

Introduction:Cochlear implant is currently the most widely proven interventions for auditory rehabilitation for children with severe sensorineural hearing impairment.However,there are obvious limitations in these current evaluation methods.This study aims to develop an evaluation system for quantitatively evaluating the effectiveness of cochlear implants for hearing-impaired children.Methods:A correspondence questionnaire was developed based on an initial indicator system that was developed based on the literature focused on the evaluation of cochlear implant outcomes in children.Twenty-five experts in otology,clinical audiology,rehabilitation audiology,and mental health from nine provinces in China were consulted.The degree of authority and coordination of experts and the indicators and weights of the quantitative evaluation system were analyzed.Seventy-eight children aged 3–11 years after cochlear implantation were recruited from two centers in Hubei province to evaluate the reliability and validity of the quantitative evaluation system.Results:The opinions of experts converged after the second round of correspondence,and the coordination and authority of the expert consensus were met.The recall rate of the questionnaire was 100%for both rounds.Five secondary indicators,including auditory ability,verbal ability,behavioral assessment,learning capabilities,and quality of life,and 13 tertiary indicators were reserved for the evaluation of cochlear implant effectiveness.The weight of each indicator was calculated.The Cronbach’sαcoefficient of the quantitative evaluation system based on the standardized items was 0.930,and the three extracted common factors could explain 78.86%of the total variance.Conclusions:An expert consensus-based evaluation system that can quantitatively evaluate the effectiveness of cochlear implants in children has been developed with good reliability and validity.

Thiamine responsive megaloblastic Anemia and deafness: A rare case of Roger’s syndrome with successful hearing rehabilitation by cochlear implantation

Thiamine responsive megaloblastic anemia(TRMA),also known as Roger’s syndrome,is an exceptionally rare autosomal recessive disorder stemming from mutations in the SLC19A2 gene responsible for encoding a thiamine carrier protein.This syndrome manifests as the classic triad of megaloblastic anemia,sensorineural hearing loss,and diabetes mellitus.Here,we present the case of a one-and-a-half-year-old male infant born to non-consanguineous parents in India,a region where TRMA cases are seldom reported.At five months of age,the child exhibited the characteristic symptoms,prompting immediate treatment involving thiamine therapy,insulin administration,and blood transfusions.Notably,the child exhibited significant improvement in all aspects except for hearing loss,which conventional hearing aids failed to alleviate.However,following a cochlear implant procedure conducted within a few months,the child regained hearing abilities.This case underscores the importance of early recognition and intervention in the form of cochlear implant,demonstrating the potential to reverse TRMA symptoms and provide affected individuals with a substantially improved quality of life.

Analysis of the Influence of Sound Source Position and Electrode Placement on the Stimulation Pattern of the Cochlear Implant under Noise Conditions: Optimization of Auditory Perceptual Effects

Background: Cochlear implants (CI) are widely used to restore hearing in people with severe to profound hearing loss. However, optimizing CI performance, especially in difficult listening environments with background noise, remains a major challenge. Understanding the influence of factors such as sound source position and electrode placement on CI stimulation patterns is critical to improving auditory perception. Methods: In this study, an analysis was conducted to investigate the influence of sound source position and electrode placement on CI stimulation patterns under noisy conditions. For this purpose, a special measurement setup with a CI speech processor-microphone test box was used to simulate realistic listening scenarios and measure CI performance. Results: The results show that the effectiveness of CI noise reduction systems is influenced by factors such as the position of the sound source and electrode placement. In particular, the beamforming ultra zoom mode showed significantly better noise reduction than the omnidirectional mode, especially under real listening conditions. Furthermore, differences in electrode responses indicate individual variability in the CI user experience, highlighting the importance of personalized fitting algorithms. Conclusions: The results demonstrate the importance of considering environmental factors and individual differences when optimizing CI performance. Future research efforts should focus on the development of personalized fitting algorithms and the exploration of innovative strategies, such as the integration of artificial intelligence, to improve CI functionality in different listening environments. This study contributes to our understanding of CI stimulation patterns and lays the foundation for improving auditory perception in CI users.

Safety and outcomes of cochlear implantation in the elderly:A review of recent literature

Global demographic changes related to longevity are leading to increasing numbers of the elderly, for whom hearing loss is a significant cause of morbidity and disability. Once met with reticence, severely hearing impaired older adults are increasingly being considered for cochlear implantation (CI). Significant data indicate that CI in the elderly population is safe, well-tolerated, and effective. Risks from CI surgery and anesthesia are low and generally comparable to rates in other age groups. Outcomes studies regarding CI in older adults have shown excellent improvements to speech perception, quality of life, and even cognition. Overall, currently available data suggests that advanced age should not, in itself, be considered a barrier to implantation. This review paper will highlight selected articles from recent medical literature regarding the safety and efficacy of CI in the elderly population. Copyright ? 2016, PLA General Hospital Department of Otolaryngology Head and Neck Surgery. Production and hosting by Elsevier (Singapore) Pte Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

After cochlear implantation: Complications related to flap around implants

Objective: To report complications related to flap around implants after cochlear implantation, possible causes of such complications and treatments. Methods and material:We performed a retrospective analysis of children in whom complications related to flap around implants occurred after undergoing cochlear implantation in our department from 2005 to 2016. Results:Complications among 1500 cochlear implantation (CI) recipients by the same surgeon included hematoma (n ? 20) and seroma around implants (n ? 15), of which most (n ? 10) recovered in 2 weeks after effective drainage, utility of antibiotics and pressure dressing, but 5 developed flap necrosis and had to undergo contralateral re-implantation. Four patients developed abscess around implants, of whom 2 recovered after 2 weeks of drainage, gentamicin irrigation and use of antibiotics, but 2 patients ended up with flap necrosis and had to receive contralateral reimplantation. Conclusions: Immediate drainage, pressure dressing and antibiotics can be used to effectively control seroma around implants. For seroma lasting for more than two weeks without improvement, surgical drainage may be need.

MUSIC AND COCHLEAR IMPLANTS

Currently, most people with modern multichannel cochlear implant systems can understand speech in qui-et environment very well. However, studies in recent decades reported a lack of satisfaction in music percep-tion with cochlear implants. This article reviews the literature on music ability of cochlear implant users by presenting a systematic outline of the capabilities and limitations of cochlear implant recipients with regard to their music perception as well as production. The review also evaluates the similarities and differences be-tween electric hearing and acoustic hearing regarding music perception. We summarize the research results in terms of the individual components of music (e.g., rhythm, pitch, and timbre). Finally, we briefly intro-duce the vocal singing of prelingually-deafened children with cochlear implants as evaluated by acoustic measures.

Assessment of outcomes of hearing and speech rehabilitation in children with cochlear implantation

Objectives:This study aimed to assess the effect of hearing and speech rehabilitation in patients with Nurotron■cochlear implants.Design:Ninety-eight paediatric patients with bilateral severe-to-profound sensorineural deafness who received cochlear implantation were divided into three groups according to age:group A(≤3 years),group B(4-7 years),and group C(8-16 years).All patients were followed up for one year for hearing and speech performance after the surgery.The comprehensive Auditory Perception Assessment,MAIS,CAP and SIR hearing and speech assessments and rating materials were used for assessment before the surgery and at 3,6,and 12 months after implant activation.Results:The scores of patients in the open-set speech assessment,Chinese Auditory Perception Assessment,MAIS,CAP and SIR significantly improved after cochlear implantation in all age groups.The younger the age at implantation,the better the results.Moreover,the hearing and speech performance of cochlear implant recipients gradually improved with the extension of rehabilitation time.Conclusions:Nurotron■Venus^TM cochlear implantation can improve the hearing and speech performance of patients with bilateral severe-to-profound sensorineural deafness.

Double challenge:cochlear implantation in the only hearing ear with progressive hearing loss following meningitis and vestibular dysfunction after implantation

Objective:Vestibular dysfunction associated with cochlear implantation is rare.It is usually seen in patients with otosclerosis due to spread of electrical activity throughout the demineralized bone.A 17-year old female with progressive hearing loss 2 years after meningitis and vestibular dysfunction in the implanted ear is presented in this study.Findings:The patient had mild hearing loss in the right ear and total hearing loss on the left side because of complete ossification of the cochlea following meningitis.She had to have cochlear implantation in the right ear because of progression of hearing loss.She had successful implantation but she experienced vestibular dysfunction following activation of cochlear electrodes.Closure of two electrodes caused disruption of auditory programming.Then the patient was subjected to long term vestibular rehabilitation program.Conclusion:Timing for implantation before the completion of cochlear ossification is crucial not to miss the chance for hearing restoration.However,difficulties in hearing rehabilitation due to extensive ossification can be doubled by vestibular problems triggered by stimulation of the vestibular nerve by cochlear electrodes.Attempts to reduce the balance problem will complicate auditory programming.Vestibular rehabilitation for long term helps to carry on hearing progress.

Cochlear implantation in a child with auditory neuropathy spectrum disorder

Objective To report outcomes of cochlear implantation (CI) in a child with auditory neuropathy spectrum disorder (ANSD) and to provide preliminary clinical evidence of the efficacy of CI in ANSD patients.Methods A 4-year-old boy with diagnosed auditory neuropathy spectrum disorder (ANSD) received implantation of a Nucleus CI24R after an unsatisfactory trial of amplification.Post-implantation performance in both hearing sensitivity and speech recognition was assessed in different sessions.Aided hearing thresholds were tested by behavioral audiometry.Mandarin Early Speech Perception Test (MESP),Meaningful Auditory Integration Scale (MAIS),category of auditory performance (CAP) and Speech Intelligibility Rating (SIR) were used to assess the benefits in auditory skills or speech recognition the boy obtained from CI.The tests were administered before surgery and at 3 months and 7 months after opening.Results The boy demonstrated improved auditory sensitivity by using CI.Concerning speech recognition and communication,both speech audiometry and questionnaires showed an obvious benefit from CI.Conclusions CI has worked efficiently in this ANSD boy.But because of limited understanding of ANSD and rehabilitation effect by cochlear implantation in this condition,the clinical decision to implant should be cautious and only after a thorough evaluation.Meanwhile,well controlled and long term studies are needed to confirm the efficacy of cochlear implantation in patients with ANSD.

Cochlear implantation outcomes in children with common cavity deformity;a retrospective study

Objective: A common cavity deformity(CCD) is a deformed inner ear in which the cochlea and vestibule are confluent forming a common rudimentary cystic cavity that results in profound hearing loss. There are few studies paying attention to common cavity. Our group is engrossed in observing the improvement of auditory and verbal abilities in children who have received cochlear implantation(CI), and comparing these targets between children with common cavity and normal inner ear structure.Material and methods: A retrospective study was conducted in 12 patients with profound hearing loss that were divided into a common cavity group and a control group, six in each group matched in sex, age and time of implantation, based on inner ear structure. Categories of Auditory Performance(CAP) and speech intelligibility rating(SIR) scores and aided hearing thresholds were collected and compared between the two groups. All patients wore CI for more than 1 year at the Cochlear Center of Anhui Medical University from 2011 to 2015.Results: Postoperative CAP and SIR scores were higher than before operation in both groups(p < 0.05), although the scores were lower in the CCD group than in the control group(p < 0.05). The aided threshold was also lower in the control group than in the CCD group(p < 0.05).Conclusion: Even though audiological improvement in children with CCD was not as good as in those without CCD, CI provides benefits in auditory perception and communication skills in these children.

Cochlear implant challenges encountered in tuberculous otitis media

Tuberculous otitis media(TOM) is rare in ENT department,and is frequently misdiagnosed as otitis media.Thus early systemic treatment is very important for TOM.We reported a case report with TOM to highlight development of the disease and difficulties in clinical treatment in late stage of TOM.Implantation of ossified and eroded cochlea poses many unique challenges to both the surgeon and programming learn.With thorough preparation and complete knowledge about characters of specific issues,implantation would be performed successfully,and patients with ossified cochlear could benefit from cochlear implantation.

Speech intelligibility and auditory perception of pre-school children with Hearing Aid,cochlear implant and Typical Hearing

Purpose:There is a growing interest in speech intelligibility and audito ry perception of deaf children.The aim of the present study was to compare speech intelligibility and auditory perception of pre-school children with Hearing Aid(HA),Cochlear Implant(Cl),and Typical Hearing(TH).Methods:The research design was descriptive-analytic and comparative.The participants comprised 75 male pre-school children aged 4-6 years in the 2017-2018 from Tehran,Iran.The participants were divided into three groups,and each group consisted of 25 children.The first and second groups were respectively selected from pre-school children with HA and CI using the convenience sampling method,while the third group was selected from pre-school children with TH by random sampling method.All children completed Speech Intelligibility Rating and Catego ries of Auditory Performance Questionnaires.Results:The findings indicated that the mean scores of speech intelligibility and auditory perception of the group with TH were significantly higher than those of the other groups(P<0.0001).The mean scores of speech intelligibility in the group with CI did not significantly differ from those of the group with HA(P<0.38).Also,the mean scores of auditory perception in the group with CI were significantly higher than those of the group with HA(P<0.002).Conclusion:The results showed that auditory perception in children with CI was significantly higher than children with HA.This finding highlights the importance of cochlear implantation at a younger age and its significant impact on auditory perception in deaf children.

Binaural integration abilities in bilateral cochlear implant user

Bilateral Cochlear implants (CIs) improved speech intelligibility, speech perception in background noise, and sound localization in quiet and noisy situations. However, it is unclear whether these advantages essentially result in binaural integration of acoustic stimuli from each ear. In this study, we investigated the effectiveness of binaural integration by bilateral CIs placement using binaural hearing tests and subjective auditory perceptual assessment. A 61-year-old bilateral CIs subject underwent the following four tests:the Japanese Hearing in Noise Test (HINT-J), the dichotic listening test (DLT), the Rapidly Alternating Speech Perception (RASP) test, and subjective auditory perceptual assessment. The HINT-J score was significantly higher for bilateral CIs than for a unilateral CI. However, DLT and the RASP test revealed contradictory results. Subjective auditory perceptual assessment revealed active and bright impressions for bilateral hearing, which were also noisy and strong compared with those for unilateral hearing. The results of this study revealed that bilateral CIs improved speech perception in background noise and an improved auditory impression, although the bilateral integration abilities were not improved. This was probably because the patient was required to combine information from the two ears into a single perception in DLT and the RASP test. More longitudinal data should be collected and analyzed in future studies to evaluate the long-term effects of bilateral CIs. Copyright ? 2016, PLA General Hospital Department of Otolaryngology Head and Neck Surgery. Production and hosting by Elsevier (Singapore) Pte Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Molecular mechanisms and roles of inflammatory responses on low-frequency residual hearing after cochlear implantation

Preservation of low-frequency residual hearing is very important for combined electro-acoustic stimulation after cochlear implantation.However,in clinical practice,loss of low-frequency residual hearing often occurs after cochlear implantation and its mechanisms remain unclear.Factors affecting lowfrequency residual hearing after cochlear implantation are one of the hot spots in current research.Inflammation induced by injury associated with cochlear implantation is deemed to be significant,as it may give rise to low-frequency residual hearing loss by interfering with the blood labyrinth barrier and neural synapses.Pathological changes along the pathway for low-frequency auditory signals transmission may include latent factors such as damage to neuroepithelial structures,synapses,stria vascularis and other ultrastructures.In this review,current research on mechanisms of low-frequency residual hearing loss after cochlear implantation and possible roles of inflammatory responses are summarized.

One-year experience with the Cochlear^(TM) Paediatric Implanted Recipient Observational Study(Cochlear P-IROS) in New Delhi, India

Background： Currently, there is a significant lack of data concerning long-term outcomes following paediatric cochlear implantation in terms of quality of life. There is a need for a long-term, prospective study in this regard. This study aims at highlighting the preliminary results, one year post surgery of a five year prospective study. Methods： The CochlearTM Paediatric Implanted Recipient Observational Study （P-IROS） is a prospective, patient outcomes registry for routinely implanted children. The study collects data using questionnaires post-surgery and at regular intervals up to five years. Results： At our Centre, 159 cochlear implant surgery procedures were carried out between January 2014 and December 2014. Category of Auditory Performance II score increased from ‘0＇ to ‘3＇ at six months and to ‘5＇ at 12 months for children aged 0-3 years, although this was not statistically significant. However, the same trend was statistically significant for the age 3-6 year and age 6-10 year brackets. The quality of life of the child improved significantly. Analysis of communication mode revealed a statistically significant overall shift to the auditory-oral mode from total communication. Conclusion： Cochlear implantation is a life-changing intervention. The evidence in support of what it can achieve safely is clear. However, the costs associated with it raise the question if it will remain an effective option for life in all children. The Cochlear P-IROS is an attempt to answer the same over a five year period. Our study in New Delhi, so far concludes that cochlear implantation in a population with limited access to funds is very effective, one year after surgery.

Effects of Delayed Second Cochlear Implant

Objective Since Helms’ successful bilateral cochlear implantation with good results in 1996, there have been increasing number of reports on bilateral cochlear implantation. Most second device have been implantated within one year after the first. Considering effects of long time auditory deprivation, it is not clear whether a delayed second cochlear implant serves to add additional benefits and how it may interact with central nervous system plasticity. Methods Three cases who received delayed second cochlear implants at People’s Hospital of Peking University from 2002 to 2005 were reviewed. The interval between the first and second implants was longer than 2 years in all three patients. Sound perception, and unilateral/bilateral speech discrimination in quiet and noise were evaluated. In addition, GAP detection test was conducted in one patient. Results In one case, having both implants on provided improved performance compared to using only one implant both in quiet and noise. Presumably due to visual interference from lip-reading or short interval between second implant and testing, one patient showed no improvement from using the second implant either in quiet or noise, while the last case demonstrated additional benefits from the second implant only in quiet. In all three patients, performance in recognizing the four tones in Mandarin was superior over word recognition. Conclusions Considerable plasticity in the cerebral auditory center is preserved, despite long acoustic deprivation in some children who have received unilateral cochlear implant. Delayed second implants can result in significant improvements in some of these children. Visual interference from lip-reading may be an obstacle during retraining. The better recognition of tones in the Mandarin language may represent a different sound discrimination mechanism in the auditory system, although it may also be related to the signal processing mechanisms of the implant used (MED-EL COMBI 40+).

Communication outcomes following cochlear implantation in a child with cystic cochleovestibular anomaly

Cochlear implantation is one of the best amongst the various management options available for children and adults with severe to profound sensorineural hearing loss.Inner ear and internal auditory canal(IAC) malformations accounts to approximately 25% of congenital sensorineural hearing loss in children.The primary goal of this report was to evaluate the communication outcomes after cochlear implantation in a child with cystic cochleovestibular anomaly(CCVA).The child was evaluated through various standardized outcome measures at regular intervals to track the progress in terms of auditory and spoken language skills.The scores on Categories of Auditory Perception(CAP),Meaningful Auditory Integration Scale(MAIS),Speech Intelligibility Rating(SIR),Meaningful Use of Speech Scale(MUSS),and listening and spoken language skills showed a significant leap in 12 months duration post implantation.The report thus highlights and correlates the significant progress in auditory and spoken language skills of the child with congenital malformations to appropriate auditory rehabilitation and intensive parental training.

Improvements to the retractor and muscle flap design for minimally invasive cochlear implantation

Objective: The aim of this study was to improve muscle flaps and to evaluate surgical outcomes with the use of a novel specialized retractor, which is a surgical instrument used to locate and shape a bony seat for minimally invasive cochlear implantation.Methods: 50 patients aged 1 e75 years with sensorineural hearing loss who required cochlear implantation were recruited. A small incision(<3 cm) was made, and the novel specialized retractor was used in the study group during cochlear implantation. The incision length, surgical outcomes and operative time were recorded and analyzed.Results: The incision length, total operative time and drilling bony time were shorter in the study group than in the control group(P < 0.05, respectively). All patients recovered well after the surgery without any severe complications.Conclusion: The use of a novel specialized retractor standardized the surgical processes of cochlear implantation. The retractor helped locate and control the size of the bony well during bone drilling. The tool reduced the technical difficulty and improved the efficacy of this minimally invasive operation.

The role of cochlear implantation in alleviating Tumarkin drop attacks of Meniere's disease;a case report

Ménière’s disease(MD)patients may suffer episodes of sudden falls,named Tu markin drop attacks(DAs).This fall occurs abruptly and without warning or loss of consciousness.DAs usually aggravate the clinical picture of MD and are challenging to manage.The present report describes a case treated by cochlear implantation(CI)due to concomitant deafness and offers some clinical considerations for this condition.A male patient aged 48 years with a 10-year history of definite bilateral MD had profound SNHL on the right and severe SNHL on the left side.He suffered from intermittent attacks of vertigo,ear fullness,and tinnitus and,in the last year,had developed DAs and experienced 14 episodes in the previous six months.The preoperative category of acoustic performance was 3.The Dizziness Handicap Inventory(DHI)questionnaire showed a total score of 46,which indicated a moderate degree of disability.A CI was planned for the right side.The patient did not report any further DAs episode for two years since then.The postoperative category of acoustic performance became 11,and the postoperative DHI questionnaire showed a decrease in the total score(from 46 to 19),which indicated a mild disability.Unilateral CI effectively alleviated the DAs associated with bilateral MD.Our report proposes a new modality for managing vertiginous symptoms in cases of MD with hearing loss without the need for more aggressive surgical interventions with the need for clinical trials to confirm our results.