Bioethics and medical/legal considerations on cochlear implants in children

Cochlear implants are the best treatment for congenital profound deafness. Pediatric candidates to implantation are seen as vulnerable citizens, and the decision of implanting cochlear devices is ultimately in the hands of their parents/guardians. The Brazilian Penal Code dictates that deaf people may enjoy diminished criminal capacity. Many are the bioethical controversies around cochlear implants, as representatives from the deaf community have seen in them a means of decimating their culture and intrinsic values.ObjectiveThis paper aims to discuss, in bioethical terms, the validity of implanting cochlear hearing aids in children by analyzing their vulnerability and the social/cultural implications of the procedure itself, aside from looking into the medical/legal aspects connected to their criminal capacity.Materials and MethodsThe topic was searched on databases Medline and Lilacs; ethical analysis was done based on principialist bioethics.ResultsCochlear implants are the best therapeutic option for people with profound deafness and are morally justified. The level of criminal capacity attributed to deaf people requires careful analysis of the subject's degree of understanding and determination when carrying out the acts for which he/she has been charged.ConclusionCochlear implants are morally valid. Implantations must be analyzed on an each case basis. ENT physicians bear the ethical responsibility for indicating cochlear implants and must properly inform the child's parents/guardians and get their written consent before performing the procedure.     

Hearing performance in noise of cochlear implant patients versus severely-profoundly hearing-impaired patients with hearing aids

It is possible for most post-lingually deaf patients to attain significant open speech recognition following cochlear implantation. In contrast, many severely-profoundly sensorineural hearing-impaired patients receive no benefit from their hearing aids, especially in situations with background noise. The aim of the study was to evaluate the speech recognition ability in quiet and in noise of post-lingually deaf adults implanted with Combi 40/40+ cochlear implants versus severely-profoundly sensorineural hearing-impaired patients fitted with hearing aids. For this purpose, we tested two groups of patients: one that had received cochlear implants (n=22) and a group of subjects with severe-profound sensorineural hearing impairment, fitted with hearing aids (n = 15). All of the patients were tested using the Hochmaier, Schultz, and Moser Discrimination Test in quiet and noise. The results of the study demonstrate that most of our cochlear implant patients received a substantial benefit from their implant, achieving scores of 70 to 100 per cent (mean, 90 per cent) for the numbers test and 10 to 72 per cent (mean, 43 per cent) for the monosyllable test 1 year after implantation. Even in situations with background noise, scores of 1 to 99 per cent (mean, 45.65 per cent) for a signal to noise ratio (SNR) of +15 dB 1 year following the implantation improved to 7 to 95 per cent (mean, 50.7 per cent) at 2 years and 8 to 99 per cent (mean, 60 per cent) at 3 years after implantation. These results are significantly (p<0.04) superior to the hearing aid patients' scores of 1 to 64.2 per cent (mean, 26.7 per cent) for a SNR of 15 dB. The results of the present study may have clinical implications in regard to selection of candidates for cochlear implantation.     

Comparison of outcomes in children with hearing aids and cochlear implants

Abstract

Objectives

The purpose of this study was to document the performance of a group of children with moderately severe to severe hearing loss who use hearing aids on a range of speech recognition, speech–language, and literacy measures and to compare these results to children with severe to profound hearing loss, who have learned language through cochlear implants.

Methods

This study involved 41 children with bilateral sensorineural hearing impairment, aged 6–18 years. Twenty children had moderately severe/severe hearing loss and used hearing aids, and 21 had severe to profound hearing loss and used cochlear implants. Communication and academic skills were assessed using speech recognition tests and standardized measures of speech production, language, phonology, and literacy.

Results

The two groups did not differ in their open-set speech recognition abilities or speech production skills. However, children with hearing aids obtained higher scores than their peers with cochlear implants in the domains of receptive vocabulary, language, phonological memory, and reading comprehension. The findings also indicate that children with moderately severe or severe hearing loss can develop spoken language skills that are within the range expected for normal hearing children.

Conclusions

School-aged children with moderately severe and severe hearing loss performed better in several domains than their peers with profound hearing loss who received cochlear implants between age 2 and 5 years. Further research is required to evaluate the benefits of hearing aids and cochlear implants in children with hearing loss who are diagnosed and receive intervention within the first year of life.     

Effectiveness of multi‐channel unilateral cochlear implants for profoundly deaf children: a systematic review

Background: Annually an estimated 223 children in the UK are born with or acquire permanent profound bilateral deafness (PBHL ≥ 95 dB). These children may gain little or no benefit from acoustic hearing aids. However, cochlear implants might enable them to hear. Objectives of the review: To bring together the diverse research in this area under the rigor of a systematic review to discover the strength of evidence when comparing the effectiveness of unilateral cochlear implants with non‐technological support or acoustic hearing aids in children with PBHL. Type of review: Systematic review. Search strategy: This examined 16 electronic data bases, plus bibliographies and references for published and unpublished studies. Evaluation method: Abstracts were independently assessed against inclusion criteria by two researchers, results were compared and disagreements resolved. Included papers were then retrieved and further independently assessed in a similar way. Remaining studies had their data independently extracted by one of five reviewers and checked by another reviewer. Results: From 1,580 abstracts and titles 15 studies were included. These were of moderate to poor quality. The large amount of heterogeneity in design and outcomes precluded meta‐analysis. However, all studies reported that unilateral cochlear implants improved scores on all outcome measures. Additionally five economic evaluations found unilateral cochlear implants to be cost‐effective for profoundly deaf children at UK implant centres. Conclusions: The robustness of systematic review methods gives weight to the positive findings of 15 papers reporting on this subject that they individually lack; while an RCT to show this would be unethical.     

Cochlear implant in patients with residual hearing

Objective: The postoperative speech perception abilities of severely hearing-impaired patients with multi-channel cochlear implant were compared with preoperative speech perception performance with conventional hearing aids. Methods: Cochlear implantation was performed in six severely to profoundly hearing-impaired patients. They had unaided pure-tone thresholds of 70–100-dB HL and aided thresholds of 35–90-dB HL in the better ear, but were not able to perceive speech sounds well with hearing aids. Results: Postoperatively, all the patients had significantly improved speech perception performance, exceeded the average skills of profoundly deaf cochlear implant users, and were able to communicate without writing. Conclusion: These results imply that cochlear implant may be indicated for severely to profoundly deaf subjects, if they receive little or no benefit from conventional hearing aids.     

语前聋患儿一侧人工耳蜗对侧助听器效果分析

目的:通过对人工耳蜗植入对侧耳不同听力损失的患儿联合使用助听器与人工耳蜗语前聋患儿的听觉、语言及学习能力进行评估和比较,探索对患儿更为有效的助听方法,帮助患儿获得最大限度的言语交流。方法:将30例3～6岁语前聋患儿按照植入人工耳蜗对侧耳听力损失程度及是否佩戴助听器,分为一侧人工耳蜗+对侧重度听力损失助听器组(CI+SHA组)、一侧人工耳蜗+对侧极重度听力损失助听器组(CI+PHA组)、单耳人工耳蜗组(CI组)。评估各组在康复3、6、9、12、15、18个月时听觉、语言及学习能力,并记录结果。结果:随着术后康复时间的延长,聋儿听觉、语言及学习能力逐渐提高(P<0.05),CI+SHA组听觉能力优于CI+PHA组及CI组(均P<0.05),语言能力及学习能力无明显差异(P>0.05)。结论:语前聋患儿单耳人工耳蜗植入后,若对侧耳尚有残余听力,佩戴助听器后听觉能力效果显著,长期佩戴有助于患儿的康复。     

Communication development in young deaf children: review of the video analysis method

It is widely recognised that preverbal communication skills underpin development of spoken language. This historical review outlines the establishment of a quantitative methodology for assessing preverbal communication skills in children with hearing aids and cochlear implants. The method is shown to be reliable and free from observer bias. The review also summarises findings from a series of cross-sectional and longitudinal observational studies utilising the methodology. Profoundly deaf young children, either with cochlear implants or successful users of hearing aids, show similar patterns of preverbal communication development that contrast with those of unsuccessful hearing-aid users. Preverbal measures obtained 12 months after implantation are predictive of late performance on speech perception tasks. Moreover, there is a significant association between the preverbal measure of 'autonomy' obtained before implantation and later speech perception performance. This latter finding has important theoretical implications for understanding of language development and suggests that intervention that promotes autonomy in adult-child interaction may lead to improved outcomes. Such intervention could be commenced as soon as deafness is discovered.     

Behavioral and electrophysiological investigation of hearing and speech outcomes in pre-linguistic deaf children with white matter changes after cochlear implantation

Abstract

Background: There are some debates regarding the benefit from cochlear implantation (CI) for prelingually deaf children with white matter changes.

Objective: To assess the hearing and speech outcomes of prelingually deaf children with white matter changes (group A), and those with complete deafness (group B), at 2?years after CI.

Material and Methods: Study 1 included 32 and 34 children in group A and B, respectively. The Categories of Auditory Performance (CAP) and Speech Intelligibility Rate (SIR) were used to assess the performance on hearing and speech. Study 2 included eight children with white matter changes and eight with complete deafness at 2?years post-CI, and nine normal-hearing peers. The mismatch response (MMR) to the stimulus pair ‘ba’/‘pa’ was investigated.

Results: There was no significant difference on CAP or SIR scores between the children in group A and B. All children with white matter changes showed MMRs to Mandarin consonants at 2?years post-CI. And there was no significant difference on the incidence, the latency or amplitude of MMR among three groups.

Conclusions and significance: Most prelingually deaf children with white matter changes got good outcomes from CI. CI is not a contraindication for most individuals with white matter changes.     

Cochlear Implantation in a Profoundly Deaf Patient Who also Suffers from Multiple Sclerosis — A Case Study

Outcomes of cochlear implantation in individuals with known central nervous system conditions are varied. Long-standing deafness is also thought to correlate negatively with auditory performance in post-linguistically deaf adult implant users.

We present a case study of cochlear implantation in a post-lingual adult having bilateral profound hearing loss for over 30 years in addition to multiple sclerosis unrelated to his deafness. Assessment of benefit in terms of speech-perception ability and quality of life reveal that long-term auditory deprivation and co-incidental multiple sclerosis are not a contraindication for cochlear implantation.     

The effect of psychosocial factors on outcomes of cochlear implantation

Conclusion: Psychosocial factors should be considered during cochlear implantation (CI). There were differences in psychosocial characteristics according to the etiology of deafness. The outcomes may be affected by psychosocial variables such as the severity of mental distress and social problems as well as duration of deafness. Objective: To evaluate the psychosocial characteristics of deaf people undergoing CI and to determine which psychosocial factors affect performance after CI. Methods: A total of 289 subjects who underwent CI were enrolled. The participants were classified into prelingually deaf (pre-LD) and postlingually deaf groups (post-LD), including progressive and sudden deafness subgroups. The Minnesota Multiphasic Personality Inventory (MMPI) was administered before CI to measure psychosocial and emotional problems. To measure CI outcomes, speech perception ability was assessed by the open-set Korean version of the Central Institute of Deafness (K-CID) test and categories of auditory performance (CAP) scores before and after CI. Results: Approximately 45% of subjects experienced psychological problems before undergoing CI. Subjects in the Pre-LD group had more psychosocial distress and were more likely to be oversensitive in interpersonal situations, while those in the post-LD group were more depressed. Deafness duration and psychosocial factors significantly predicted hearing ability after CI. Deafness duration directly and indirectly affected the outcome of CI. That is, duration of deafness caused psychosocial problems, which may have resulted in negative effects on outcomes of CI.     

Predicting speech perception outcomes following cochlear implantation in adults with unilateral deafness or highly asymmetric hearing loss

Objective: Unilateral deafness and highly asymmetric hearing loss can impair listening abilities in everyday situations, create substantial audiological handicap, and reduce overall quality of life. Preliminary evidence suggests that cochlear implantation may be effective in reversing some of these detrimental effects. Patient-level data from existing studies were re-analysed to explore potential factors that may be predictive of improved speech perception scores following implantation.

Methods: Logistic regression modelling examined whether improved speech perception following implantation under various listening conditions was related to the duration of deafness of the severe-to-profoundly deaf ear and/or the level of hearing in the better ear.

Results: Patients with a shorter duration of deafness were more likely to improve in listening conditions that created a less favourable SNR at the implanted ear than the non-implanted ear. Those with more residual hearing in the better ear were more likely to improve in the listening condition that created a less favourable SNR at that ear.

Discussion: The analysis suggests that characteristics of both ears may be relevant when seeking to identify those candidates who are likely to obtain benefit to speech perception following cochlear implantation.     

Bimodal benefits in Mandarin-speaking cochlear implant users with contralateral residual acoustic hearing

Abstract

Objective: The present study aimed to measure bimodal benefits and probe their underlying mechanisms in Mandarin-speaking cochlear implant (CI) subjects who had contralateral residual acoustic hearing. Design: The subjects recognised words or phonemes from the Mandarin Lexical Neighborhood Test in noise at a 10-dB signal-to-noise ratio (SNR) with acoustic stimulation, electric stimulation or the combined bimodal stimulation. Study sample: Thirteen Mandarin-speaking subjects wore a CI in one ear and had residual acoustic hearing in the contralateral ear. Six of the subjects (5.2–13.0 years) had pre-lingual onset of severe hearing loss, and seven of them (8.6–45.8 years) had post-lingual onset of severe hearing loss. Results: Both groups of subjects produced a significant bimodal benefit in word recognition in noise. Consonants and tones accounted for the bimodal benefit. The bimodal integration efficiency was negatively correlated with the duration of deafness in the implanted ear for vowel recognition but positively correlated with CI or bimodal experience for consonant recognition. Conclusions: The present results support preservation of residual acoustic hearing, early cochlear implantation and continuous use of bimodal hearing for subjects who have significant residual hearing in the non-implanted ear.     

Systematic reviews of the effectiveness and cost-effectiveness of multi-channel unilateral cochlear implants for adults

Clin. Otolaryngol. 2010, 35 , 87–96 Objective: In the UK approximately 3% of over 50 years olds and 8% of over 70 year olds have severe (794–94 dBHL) to deafness. As deafness increased, hearing aids become increasingly ineffective. Cochelear implants can provide an alternative treatment. Objective of review: To bring together the research evidence through the robustness of a systematic review of the effectiveness of unilateral cochlear implants for adults. We also sought to systematically review the published literature on cost-effectiveness. Types of review: Systematic review. Search strategy: This examined 16 electronic databases, plus bibliographies and references for published and unpublished studies from inception to june 2009. Evaluation method: Abstracts were independently assessed against inclusion criteria by two researchers were compared and disagreements resolved. Included papers were then retrieved and further independently assessed in a similar way. Remaining studies had their data independently extracted by one of five reviewers and checked by another reviewer. Results: From 1,580 titles and abstracts nine studies were included. These were of variable quality; some study's results should be viewed with caution. The studies were too hetrogeneous to pool the data. However, overall the results firmly supported the use of unilateral cochler implants for severe to profoundly deaf adults. Additionally, four UK based economic evaluations found unilateral cochlear implants to be cost-effectivene in adults at UK implants centres. Conclusion: The methodologically weak but universally positive body of effectiveness evidence supports the use of unilateral cochlear implants in adults. Previous economic evaluations indicate that such implants are likely to be cost-effective.     

Auditory results from cochlear implants in elderly people

According to data from the Brazilian Institute of Geography and Statistics, the elderly population grew 47.8% in the last decade in Brazil. A portion of this population has severe and/or profound hearing loss and do not benefit from conventional hearing aids. Thus, the use of cochlear implant is required.AimTo analyze the benefits of cochlear implants in the elderly based on the comparison of primary auditory thresholds before and after the operation, discrimination of sentences in speech and in talking on the telephone.MethodologyRetrospective cohort study, analyzing medical records from patients aged over 60 years, users of cochlear implant for at least 1 year.ResultsFourteen medical records were analyzed. Mean age of patients was 63.07 years. The mean pure tone thresholds between 500Hz, 1kHz, 2kHz and 4kHz before the implantation was 113dBHL. None of the patients, before operation, could discriminate sentences in open sets and only 3 scored 17% in closed sets sentence recognition. After one year of implantation, the mean sound field thresholds reached 34dBHL, and open set sentences recognition of 93.57%, while 71% of the patients had become able to have a conversation on the telephone.ConclusionThe elderly users of cochlear implant showed important outcomes, with significant improvement in understanding in the open set and in using the telephone.     

Music appreciation and music listening in prelingual and postlingually deaf adult cochlear implant recipients

Abstract

Objective: To explore the music appreciation of prelingually deaf adults using cochlear implants (CIs). Design: Cohort study. Adult CI recipients were recruited based on hearing history and asked to complete the University of Canterbury Music Listening Questionnaire (UCMLQ) to assess each individual’s music listening and appreciation. Results were compared to previous responses to the UCMLQ from a large cohort of postlingually deaf CI recipients. Study sample: Fifteen prelingually deaf and 15 postlingually deaf adult cochlear implant recipients. Results: No significant differences were found between the prelingual and postlingual participants for amount of music listening or music listening enjoyment with their CI. Sound quality of common instruments was favourable for both groups, with no significant difference in the pleasantness/naturalness of instrument sounds between the groups. Prelingually deaf CI recipients rated themselves as significantly less able to follow a melody line and identify instrument styles compared to their postlingual peers. Conclusions: The results suggest that the pre- and postlingually deaf CI recipients demonstrate equivalent levels of music appreciation. This finding is of clinical importance, as CI clinicians should be actively encouraging all of their recipients to explore music listening as a part of their rehabilitation.     

Pre-operative Brain Imaging Using Functional Near-Infrared Spectroscopy Helps Predict Cochlear Implant Outcome in Deaf Adults

Currently, it is not possible to accurately predict how well a deaf individual will be able to understand speech when hearing is (re)introduced via a cochlear implant. Differences in brain organisation following deafness are thought to contribute to variability in speech understanding with a cochlear implant and may offer unique insights that could help to more reliably predict outcomes. An emerging optical neuroimaging technique, functional near-infrared spectroscopy (fNIRS), was used to determine whether a pre-operative measure of brain activation could explain variability in cochlear implant (CI) outcomes and offer additional prognostic value above that provided by known clinical characteristics. Cross-modal activation to visual speech was measured in bilateral superior temporal cortex of pre- and post-lingually deaf adults before cochlear implantation. Behavioural measures of auditory speech understanding were obtained in the same individuals following 6 months of cochlear implant use. The results showed that stronger pre-operative cross-modal activation of auditory brain regions by visual speech was predictive of poorer auditory speech understanding after implantation. Further investigation suggested that this relationship may have been driven primarily by the inclusion of, and group differences between, pre- and post-lingually deaf individuals. Nonetheless, pre-operative cortical imaging provided additional prognostic value above that of influential clinical characteristics, including the age-at-onset and duration of auditory deprivation, suggesting that objectively assessing the physiological status of the brain using fNIRS imaging pre-operatively may support more accurate prediction of individual CI outcomes. Whilst activation of auditory brain regions by visual speech prior to implantation was related to the CI user’s clinical history of deafness, activation to visual speech did not relate to the future ability of these brain regions to respond to auditory speech stimulation with a CI. Greater pre-operative activation of left superior temporal cortex by visual speech was associated with enhanced speechreading abilities, suggesting that visual speech processing may help to maintain left temporal lobe specialisation for language processing during periods of profound deafness.

     

Speech therapy with cochlear implant wearers

The speech production of three post-lingually deafened adults, who derived no benefit from wearing hearing aids, was assessed. Individual therapy programmes were devised based on these assessments and the subjects participated in a course of speech therapy. They then received cochlear implants and had a further course of speech therapy using their implants. Changes in speech production were judged by trained listeners, who heard tape-recorded samples of the subjects' speech. These samples were taken at various intervals before and after therapy alone, and with the cochlear implant. Significant improvement was heard in the speech production of two of the subjects following speech therapy alone. All three subjects were judged to have improved production of speech after using their cochlear implants for 6 months.     

Understanding the deafened brain: implications for cochlear implant rehabilitation

The cochlear implant (CI), by enabling oral communication in severely to profoundly deaf subjects, is one of the major medical advances over the last fifty years. Despite the globally very satisfactory results, individual outcomes vary considerably. The objective of this review is to describe the various factors influencing the results of CI rehabilitation with particular emphasis on the better understanding of neurocognitive mechanisms provided by functional brain imaging. The following aspects will be discussed: 1. Peripheral predictors such as the degree of preservation of nerve structures and the positioning of the electrode array. 2. The duration of auditory deprivation whose influence on brain reorganization is now becoming more clearly understood. 3. The age of initiation of hearing rehabilitation in subjects with pre-lingual deafness influencing the possibility of physiological maturation of nerve structures. 4. The concepts of sensitive period, decoupling and cross-modality. 5. In post-lingually deaf adults, brain plasticity can allow adaptation to the disability induced by deafness, subsequently potentiating CI rehabilitation, particularly as a result of audiovisual interactions. 6. Several studies provide concordant evidence that implanted patients present different phonological analysis and primary linguistic capacities. The results of CI rehabilitation are dependent on factors situated between the cochlea and cortical associative areas. The importance of higher cognitive influences on the functional results of cochlear implantation justify adaptation of coding strategies, as well as global cognitive management of deaf patients by utilising brain plasticity capacities.     

The clinical features and prognosis of mumps-associated hearing loss: a retrospective,multi-institutional investigation in Japan

Abstract

Conclusions: The majority of hearing loss due to mumps presents as unilateral profound sensorineural hearing loss, which is refractory to treatment. In rare cases of bilateral total deafness, cochlear implants were beneficial for speech perception. Vaccination against mumps is recommended to prevent mumps-associated hearing loss.

Objective: The objective of this study is to investigate the clinical characteristics of hearing loss due to mumps and to evaluate hearing outcomes.

Subjects and methods: The clinical parameters were analyzed under a retrospective multi-institutional study design in patients diagnosed with hearing loss due to mumps at the Otolaryngology departments of 19 hospitals between 1987 and 2016.

Results: Sixty-seven patients with hearing loss due to mumps were enrolled. The study population consisted of 35 males and 32 females, ranging in age from 1 to 54, with a median age of 9.5 years. Sixty-three patients presented with unilateral, and 4 with bilateral hearing loss. Profound hearing loss was observed in 65 ears. Only one ear with severe hearing loss showed complete recovery. Four patients with bilateral hearing loss received cochlear implant surgery. Most of the patients with hearing loss due to mumps had no history of vaccination.