A 15-year Review of 260 Children With Auditory Neuropathy Spectrum Disorder: II. Management and Outcomes.

OBJECTIVES: Following a review of the demographic and clinical characteristics of all pediatric patients diagnosed with auditory neuropathy spectrum disorder (ANSD) by a pediatric health care system from 2005 to 2020, the present report highlights the type and timing of intervention and outcomes in the same 260 patients with ANSD. DESIGN: This was a retrospective study reviewing the demographic data, medical history, imaging studies, audiological and speech language data, type of audiological intervention (hearing aids or cochlear implants), and mode of communication in 260 pediatric patients diagnosed with ANSD over a 15-year period. RESULTS: A significant decrease over time in the age at hearing aid fitting was observed. While a similar reduction in the age at implantation occurred over time, cochlear implantation is still rarely performed by 12 months of age in most ANSD patients. Among bilateral ANSD patients fitted with hearing aids, the majority (89.2%) did not benefit from conventional amplification and most received cochlear implants. Some hearing aid benefit for speech and language development was observed in 5.8%, though communication difficulties were persistent and most used a combination of oral and sign language for communication. Only six patients (5%) received significant benefit from their hearing aids for speech and language development. CONCLUSIONS: This review of ANSD management over a 15-year period reveals that hearing aids are not a viable option to develop speech and language for most infants and children with ANSD. This finding confirms previous reports and suggest that while hearing aid trials are warranted, children must be tracked closely so as to avoid delays in decision making. Cochlear implantation constitutes the major (if not only) rehabilitative intervention that allows for speech perception in patients who do not benefit from conventional amplification.

Prevalence, risk factors, and audiological characteristics of auditory neuropathy.

OBJECTIVE: The objective of this study was to determine the prevalence, risk factors, and audiological characteristics of auditory neuropathy spectrum disorder (ANSD) in the pediatric population. DESIGN: A retrospective review of medical charts was conducted for children visiting two hospitals in Saudi Arabia. STUDY SAMPLE: Medical records of 1025 patients with sensorineural hearing loss (SNHL) were reviewed. We analyzed the databases for results of audiological examinations, risk factors, and outcomes of intervention including hearing aid (HA) and cochlear implantation (CI). RESULTS: Out of 1025 children with SNHL, 101 patients (9.85%) were identified to have ANSD. Audiological characteristics of the ANSD group revealed a severe-to-profound degree of hearing loss, all showed type A tympanogram and absent reflexes, absent auditory brainstem response (ABR) findings with present cochlear microphonic while otoacoustic emissions were absent in 54.5% of patients. The most prevalent risk factors for ANSD in this group were family history of hearing loss, consanguinity, hyperbilirubinemia, and low birth weight. Pure tone and speech detection thresholds improved significantly with CI compared to HA use in this sample of patients with ANSD. CONCLUSION: This study shows that ANSD is not extremely rare among Saudi children with severe to profound hearing loss, with a prevalence of 9.85%.

Cochlear implantation in auditory neuropathy spectrum disorders: role of transtympanic electrically evoked auditory brainstem responses and serial neural response telemetry.

OBJECTIVE: To evaluate the utility of pre-operative transtympanic electrically evoked auditory brainstem responses and post-operative neural response telemetry in auditory neuropathy spectrum disorder patients. METHODS: Four auditory neuropathy spectrum disorder patients who had undergone cochlear implantation and used it for more than one year were studied. All four patients underwent pre-operative transtympanic electrically evoked auditory brainstem response testing, intra-operative and post-operative (at 3, 6 and 12 months after switch-on) neural response telemetry, and out-patient cochlear implant electrically evoked auditory brainstem response testing (at 12 months). RESULTS: Patients with better waveforms on transtympanic electrically evoked auditory brainstem response testing showed superior performance after one year of implant use. Neural response telemetry and electrically evoked auditory brainstem response measures improved in all patients. CONCLUSION: Inferences related to cochlear implantation outcomes can be based on the waveform of transtympanic electrically evoked auditory brainstem responses. Robust transtympanic electrically evoked auditory brainstem responses suggest better performance. Improvements in electrically evoked auditory brainstem responses and neural response telemetry over time indicate that electrical stimulation is favourable in auditory neuropathy spectrum disorder patients. These measures provide an objective way to monitor changes and progress in auditory pathways following cochlear implantation.

Cochlear implantation in patient with Charcot-Marie-Tooth disease.

Two patients with auditory neuropathy spectrum disorder (ANSD) considered to be associated with Charcot-Marie-Tooth (CMT) are reported. In case 1, a 23-year-old man presented with progressive bilateral sensorineural hearing loss (SNHL) from 10 years of age and was diagnosed with ANSD. He was later diagnosed with CMT by neurological testing. In case 2, a 16-year-old girl, the younger sister of the patient in case 1, presented with progressive SNHL with similar auditory findings since 6 years of age as those of her brother. Both cases underwent bilateral cochlear implantation. In case 1, the maximum discrimination score improved to 45% 24 months after the first side of cochlear implantation from 5% before the surgery. In case 2, the score was 5% 10 months after cochlear implant (CI) surgery from 0% before the surgery. CI treatment for CMT patients has been considered difficult because of both failure in synchronization of nerve conduction due to demyelination and axonal failure of the auditory nerve. Though slower progress compared to the average subset of patients receiving CI was seen, significant improvement was gradually observed in the present patients after bilateral cochlear implantations. CI is thus a viable option for rehabilitation of SNHL in CMT patients.

Cortical deafness of following bilateral temporal lobe stroke.

Cortical deafness is an extremely rare clinical manifestation that originates mainly from bilateral cortical lesions in the primary auditory cortex. Its main clinical manifestation is the bilateral sudden loss of hearing. Diagnosis is difficulty due to its rarity and similarity with other language and communication disorders, such as Wernicke's aphasia, auditory agnosia or verbal deafness. Herein, we present a case report of a young woman with a sudden bilateral loss of auditory comprehension. Initially, a psychiatric nature of the disorder was considered, but the persistence of the symptoms, lead to the diagnosis of cortical deafness secondary to bilateral ischemic lesions in both temporal lobes. Progressive improvement occurred and three months after the initial manifestations she manifested pure verbal deafness. Cortical deafness usually has a poor functional prognosis, with limited therapeutic options. Rehabilitation and speech therapy is recommended to improve the chance of patients achieving communication skills.

[Retrospective analysis of auditory neuropathy patients after cochlear implantation].

Objectives: To study an effects on hearing ability and speech performance of the patients with auditory neuropathy (AN) after cochlear implantation (CI). Methods: Thirty-five AN patients (26 males and 9 females) after CI in our center since 2007 were chosen, including 5 postlingual patients (implanted age from 14.3 to 38.6 years old) and 30 prelingual patients (implanted age from 1.1 to 13.7 years old). Hearing sensitivity and speech performance were estimated via following methods: (1) implanted hearing thresholds by sound field audiometry; (2) speech audiometry, including monosyllable, disyllable and sentences recognition test by computer-controlled software and sentence recognition test under noise condition (signal to noise ratio=+ 10dB); (3) Mandarin Early Speech Perception test (MESP), Mandarin Pediatric Speech Intelligibility test (MPSI), MAIS, or IT-MAIS for prelingual AN implantees. Results: The average implanted hearing threshold (250-4 000 Hz) was (41.1±11.7) dBHL in 22 AN implantees, while those prelingual implantees was (39.1±10.9) dBHL, and (44.9±12.3) dBHL in postlingual implantees. Speech audiometry were implemented in four of 5 postlingual AN implantees, the results showed increasing tendency in monosyllable recognition scores, dramatic individual variation in computer-controlled disyllable and sentences recognition test, and poor scores (<30%) in speech recognition test in noise condition. Four of 30 prelingual implantees reconstruct their speech recognition ability within 1-3 years after switch-on, characterized as recognition scores (>60%) in monosyllable, disyllable and sentences. The one of prelingual implantee gained recognition scores of speech in noise within 1 year after switch-on. MAIS or IT-MAIS were implemented in twenty-five prelingual implantees, the average score in these patients was 28.6±11.7. Conclusion: Cochlear implant can improve the hearing thresholds of AN patients, however, the improvement in speech performance presented significant variations among the implanted individuals.

Speech Perception in Quiet and in Noise Condition in Individuals with Auditory Neuropathy Spectrum Disorder.

OBJECTIVE: The study investigated the effect of noise on syllable perception in individuals with Auditory Neuropathy Spectrum Disorder (ANSD) and compared that with the normal hearing individuals. MATERIALS AND METHODS: A total of 54 participants were considered, out of which 26 individuals were diagnosed with ANSD and 28 with normal hearing sensitivity. Syllable identification and discrimination were assessed in both the groups in quiet as well as +10 dB SNR. RESULTS: All the individuals with ANSD performed poorer on syllable identification and syllable discrimination tasks compared to individuals with normal hearing. Information transfer and d-prime analyses revealed that noise affects the perception of voicing information in individuals with ANSD compared to place and manner information. Among the consonants tested, /pa/ was more resistant to noise. CONCLUSION: Noise had deleterious effects on speech perception in individuals with ANSD. Low-frequency information appears to be more susceptible to the effects of noise in individuals with ANSD.

Effectiveness of low-cut modified amplification strategy and channel-free hearing aid in individuals with auditory neuropathy spectrum disorder.

OBJECTIVE: The present study attempted to compare the aided benefit using low-cut modified amplification and channel-free hearing aids in individuals with auditory neuropathy spectrum disorder (ANSD). It was also attempted to determine these effects in good and poor performers with ANSD. DESIGN: Cross-sectional within group pretest, post-test design. STUDY SAMPLE: Twenty-five individuals with acquired ANSD were selected for the study. The study sample included 11 males and 14 females between the age ranges of 17-40 years (mean age of 24.6 years). RESULTS: The results of the repeated measures analysis of variance (ANOVA) showed that aided benefit was significantly higher with the channel-free hearing aid. Mixed ANOVA results showed that the improvement was more in good performers than poor performers with ANSD. Multiple regression analyses showed that speech identification scores are a strong predictor of aided benefit. CONCLUSIONS: The results of the present study suggest that channel-free hearing aids and low-cut modified amplification can be used as an efficient alternative technique during hearing aid fitting for individuals with ANSD. However, further evidence-based studies on a larger group are essential to validate the results.

Auditory Performance and Electrical Stimulation Measures in Cochlear Implant Recipients With Auditory Neuropathy Compared With Severe to Profound Sensorineural Hearing Loss.

OBJECTIVES: The aim of the study was to compare auditory and speech outcomes and electrical parameters on average 8 years after cochlear implantation between children with isolated auditory neuropathy (AN) and children with sensorineural hearing loss (SNHL). DESIGN: The study was conducted at a tertiary, university-affiliated pediatric medical center. The cohort included 16 patients with isolated AN with current age of 5 to 12.2 years who had been using a cochlear implant for at least 3.4 years and 16 control patients with SNHL matched for duration of deafness, age at implantation, type of implant, and unilateral/bilateral implant placement. All participants had had extensive auditory rehabilitation before and after implantation, including the use of conventional hearing aids. Most patients received Cochlear Nucleus devices, and the remainder either Med-El or Advanced Bionics devices. Unaided pure-tone audiograms were evaluated before and after implantation. Implantation outcomes were assessed by auditory and speech recognition tests in quiet and in noise. Data were also collected on the educational setting at 1 year after implantation and at school age. The electrical stimulation measures were evaluated only in the Cochlear Nucleus implant recipients in the two groups. Similar mapping and electrical measurement techniques were used in the two groups. Electrical thresholds, comfortable level, dynamic range, and objective neural response telemetry threshold were measured across the 22-electrode array in each patient. Main outcome measures were between-group differences in the following parameters: (1) Auditory and speech tests. (2) Residual hearing. (3) Electrical stimulation parameters. (4) Correlations of residual hearing at low frequencies with electrical thresholds at the basal, middle, and apical electrodes. RESULTS: The children with isolated AN performed equally well to the children with SNHL on auditory and speech recognition tests in both quiet and noise. More children in the AN group than the SNHL group were attending mainstream educational settings at school age, but the difference was not statistically significant. Significant between-group differences were noted in electrical measurements: the AN group was characterized by a lower current charge to reach subjective electrical thresholds, lower comfortable level and dynamic range, and lower telemetric neural response threshold. Based on pure-tone audiograms, the children with AN also had more residual hearing before and after implantation. Highly positive coefficients were found on correlation analysis between T levels across the basal and midcochlear electrodes and low-frequency acoustic thresholds. CONCLUSIONS: Prelingual children with isolated AN who fail to show expected oral and auditory progress after extensive rehabilitation with conventional hearing aids should be considered for cochlear implantation. Children with isolated AN had similar pattern as children with SNHL on auditory performance tests after cochlear implantation. The lower current charge required to evoke subjective and objective electrical thresholds in children with AN compared with children with SNHL may be attributed to the contribution to electrophonic hearing from the remaining neurons and hair cells. In addition, it is also possible that mechanical stimulation of the basilar membrane, as in acoustic stimulation, is added to the electrical stimulation of the cochlear implant.

Performance-Intensity Function and Aided Improvement in Individuals With Late-Onset Auditory Neuropathy Spectrum Disorder.

OBJECTIVES: The purpose of the study was to explore the effect of intensity on speech perception in individuals with late-onset auditory neuropathy spectrum disorder (ANSD) by obtaining their performance-intensity (PI) function. Additionally, the study investigated the effect of PI function on aided speech perception. It was hypothesized that speech perception abilities of individuals with ANSD vary with intensity and may provide information regarding their aided performance. DESIGN: A factorial research design was used to obtain the PI function and aided performance. Thirty individuals with late-onset ANSD in the age range of 14 to 42 years were evaluated. All the participants had bilateral mild to moderately-severe symmetrical hearing loss and were naive hearing aid users. A PI function was obtained for each participant for phonemically-balanced words. Further, aided performance was evaluated for binaural digital hearing aids fitted using the National Acoustic Laboratories-Non-linear 1 method. RESULTS: It was found that the sensation level at which maximum word recognition scores were obtained varied across the participants. However, the majority of the participants had maximum scores below 30 dB SL. A large number of participants had a rollover PI function where the word recognition scores deteriorated with increase in presentation level. However, a few individuals demonstrated improvement in word recognition scores with increase in presentation level. Rollover index calculated from the PI function clearly demarcated those who had improved speech perception with hearing aids from those who did not. It was found that those with a rising pattern had aided speech identification scores that were significantly higher than their unaided scores. No such difference was found in those with a rollover. Further, aided benefit calculated by obtaining the difference between the aided and unaided scores was significantly higher in those with a rising PI function than those with a rollover function. CONCLUSIONS: The word recognition scores of individuals with ANSD varied with sensation level. This implies that obtaining the word recognition scores at a single presentation level may not accurately represent the speech perception abilities of those with ANSD. Further, a PI function helps differentiate those individuals with ANSD who benefit from hearing aids from those who do not.

Management of children with auditory neuropathy spectrum disorder (ANSD) / Tratamento de crianças com espectro da neuropatia auditiva (ENA)

ABSTRACT INTRODUCTION: ANSD is a challenging problem. OBJECTIVE: To present our experience on management of the children with ANSD with respect to clinical data. METHODS: This retrospective study included all children younger than 16 years of age who applied to the department between 2005 and 2013 (with the exception of newborn hearing screening NHS referrals). The data were derived from pure tone, OAEs and ABR tests, and further medical risk factors of the subjects were evaluated. RESULTS: ANSD was recognized in 74 ears of 40 children (B/U: 34/6) among 1952 children with SNHL (2.04%) detected among 9520 applicants to the department (0.42%). The clinical tests revealed that hearing loss greater than 15 dB was present in both ears of 38 cases. The degree of hearing loss was profound in 48% children, severe in 12% children, moderate in 28% children, mild in 10% children and normal in 5% children. ABRs were absent/abnormal in 37/3 ears and CMs were detected in all. Acoustic reflexes were absent in all ears. Rehabilitation was managed by CI and hearing aids in 15 and 23 cases, respectively. FM system was given to two cases displaying normal hearing but poor speech discrimination in noisy environments. CONCLUSION: ANSD is a relatively challenging problem for the audiology departments because of its various clinical features and difficulties in management. Our patients with ANSD most commonly displayed profound hearing loss. The number of overlooked cases may be minimized by performing ABR and OAE in every case referred with the suspicion of hearing loss.

Resumo Introdução: Espectro da neuropatia auditiva ainda é uma condição clínica desafiadora. Objetivo: Apresentar nossa experiência no tratamento de crianças com espectro da neuropatia auditiva em relação aos dados clínicos. Método: Este estudo retrospectivo incluiu crianças menores de 16 anos de idade que deram entrada no departamento entre 2005 e 2013 (com exceção de encaminhamentos para triagem auditiva neonatal). Foram avaliados os dados obtidos a partir dos exames de audiometria tonal, emissões otoacústicas (EOA), potencial evocado auditivo de tronco encefálico (ABR) e outros fatores de risco. Resultados: Das 1.952 crianças com perda auditiva neurossensorial (2,04%) detectadas dentre os 9.520 candidatos que deram entrada no departamento (0,42%), espectro da neuropatia auditiva foi reconhecida em 74 orelhas de 40 crianças (B/U: 34/6). Os testes clínicos revelaram que uma perda auditiva superior a 15 dB estava presente em ambas as orelhas em 38 casos. O grau de perda auditiva das crianças era profundo em 48%, grave em 12%, moderado em 28%, leve em 10%, e normal em 5%. ABR estava ausente/anormal em 37/3 orelhas e microfonia coclear foi detectado em todas as crianças. Reflexos acústicos estavam ausentes em todas as orelhas. A reabilitação foi tratada com implante coclear e aparelhos auditivos em 15 e 23 casos, respectivamente. Um sistema FM foi utilizado em dois casos que apresentavam audição normal, mas discriminação deficiente da fala em ambientes ruidosos. Conclusão: Espectro da neuropatia auditiva é um problema desafiador para os departamentos de audiologia, devido às suas várias características clínicas e dificuldades no tratamento. Em nossos pacientes a perda auditiva profunda foi a mais frequente. O número de casos negligenciados pode ser diminuído com a realização dos exames ABR e EOA em todos os casos encaminhados com suspeita de perda auditiva.

Electrically Evoked Auditory Event-Related Responses in Patients with Auditory Brainstem Implants: Morphological Characteristics, Test-Retest Reliability, Effects of Stimulation Level, and Association with Auditory Detection.

OBJECTIVE: This study aimed to (1) characterize morphological characteristics of the electrically evoked cortical auditory event-related potentials (eERPs) and explore the potential association between onset eERP morphology and auditory versus nonauditory stimulation; (2) assess test-retest reliability of onset eERPs; (3) investigate effects of stimulation level on onset eERPs; and (4) explore the feasibility of using the onset eERP to estimate the lowest stimulation level that can be detected for individual stimulating electrodes in patients with auditory brainstem implants (ABIs). DESIGN: Study participants included 5 children (S1 to S5) and 2 adults (S6 to S7) with unilateral Cochlear Nucleus 24M ABIs. Pediatric ABI recipients ranged in age from 2.6 to 10.2 years (mean: 5.2 years) at the time of testing. S6 and S7 were 21.2 and 24.6 years of age at the time of testing, respectively. S6 and S7 were diagnosed with neurofibromatosis II (NF2) and implanted with an ABI after a surgical removal of the tumors. All pediatric subjects received ABIs after being diagnosed with cochlear nerve deficiency. The lowest stimulation level that could be detected (behavioral T level) and the estimated maximum comfortable level (C level) was measured for individual electrodes using clinical procedures. For electrophysiological measures, the stimulus was a 100-msec biphasic pulse train that was delivered to individual electrodes in a monopolar-coupled stimulation mode at stimulation levels ranging from subthreshold to C levels. Electrophysiological recordings of the onset eERP were obtained in all subjects. For studies evaluating the test-retest reliability of the onset eERP, responses were measured using the same set of parameters in two test sessions. The time interval between test sessions ranged from 2 to 6 months. The lowest stimulation level that could evoke the onset eERP was defined as the objective T level. RESULTS: Onset eERPs were recorded in all subjects tested in this study. Inter- and intrasubject variations in morphological characteristics of onset eERPs were observed. Onset eERPs with complex waveforms were recorded for electrodes that evoked nonauditory sensations, based on feedback from subjects, as well as for electrodes without any indications of nonauditory stimulations. Onset eERPs in patients with ABIs demonstrated good test-retest reliability. Increasing stimulation levels resulted in increased eERP amplitudes but showed inconsistent effects on response latencies in patients with ABIs. Objective and behavioral T levels were correlated. CONCLUSIONS: eERPs could be recorded in both non-NF2 and NF2 patients with ABIs. eERPs in both ABI patient groups show inter- and intrasubject variations in morphological characteristics. However, onset eERPs measured within the same subject in this study tended to be stable across study sessions. The onset eERP can potentially be used to estimate behavioral T levels in patients with ABIs. Further studies with more adult ABI recipients are warranted to investigate whether the onset eERP can be used to identify electrodes with nonauditory stimulations.

Performance of Cochlear Implants in Pediatric Patients with Auditory Neuropathy Spectrum Disorder.

OBJECTIVE: To describe the performance and results of CIs (cochlear implant) in patients with AN (auditory neuropathy) and to present a medical literature review. MATERIALS AND METHODS: Retrospective chart review of patients with AN who were treated with CI. The mesh terms used for the review in the Pubmed and Scopus databases were as follows: "hearing loss, cochlear implants, rehabilitation of persons with hearing impairment, auditory neuropathy". STATISTICAL ANALYSES: The Mann-Whitney test was performed. RESULTS: The sample consisted of 10 patients. The mean age at surgery was 4.3 years, range 2-16 years. The average length of CI use was 5.2 years. The comparison of hearing levels before and after CI use showed a significant improvement in all patients, with p<0.05. All of them also reported an increase in overall satisfaction 1 year after the procedure. A CI is the standard treatment for the hearing rehabilitation of patients with severe profound hearing loss who do not benefit from conventional hearing aids. There are diseases such as AN that also invoke a discussion in the literature regarding CI benefits. CONCLUSION: Individuals with an demonstrated a significant gain in hearing levels and language use with CI.

Speech perception in users of hearing aid with auditory neuropathy spectrum disorder.

PURPOSE: To analyze speech perception in children with pre-lingual hearing loss with auditory neuropathy spectrum disorder users of bilateral hearing aid. METHODS: This is a descriptive and exploratory study carried out at the Research Center Audiological (HRAC/USP). The study included four children aged between 8 years and 3 months and 12 years and 2 months. Lists of monosyllabic words, two syllables, nonsense words and sentences, the Infant Toddler-Meaningful Auditory Integration Scale (IT-MAIS) and the Meaningful Use of Speech Scale (MUSS), hearing, and language categories were used. All lists were applied in acoustic booth, with speakers, in free field, in silence. RESULTS: The results showed an average 69.5% for the list of monosyllabic words, 87.75% for the list of two-syllable words, 89.92% for the list of nonsense syllables, and 92.5% for the list of sentences. CONCLUSION: The therapeutic process that includes the use of bilateral hearing aid was extremely satisfactory, since it allowed the maximum development of auditory skills.

Percepção de fala em deficientes auditivos pré-linguais com desordem do espectro da neuropatia auditiva usuários de aparelho auditivo de amplificação sonora / Speech perception in users of hearing aid with auditory neuropathy spectrum disorder

RESUMO Objetivo: Analisar a percepção de fala em crianças portadoras de deficiência auditiva pré-lingual com desordem do espectro da neuropatia auditiva (DENA) usuárias de aparelho de amplificação sonora individual (AASI) bilateral. Métodos: Trata-se de um estudo descritivo e exploratório realizado no Centro de Pesquisas Audiológicas da Sessão de Implante Coclear do Hospital de Reabilitação de Anomalias Craniofaciais (HRAC/USP). Foram avaliadas 4 crianças com idade variando entre 8 anos e 3 meses e 12 anos e 2 meses. Foram utilizados: listas de palavras monossílabas, dissílabas, palavras sem sentido e sentenças, Escala de Integração Auditiva Significativa para Crianças Pequenas (IT-MAIS) e Questionário de Avaliação da Linguagem Oral (MUSS), categorias de linguagem e audição. Todas as listas foram aplicadas em cabine acústica, à viva-voz, em campo livre, no silêncio. Resultados: Os resultados apresentaram média de 69,5% para a lista de palavras monossílabas, 87,75% para a lista de palavras dissílabas, 89,92% para a lista de sílabas sem sentido e 92,5% para a lista de sentenças. Conclusão: O processo terapêutico aplicado, que incluiu o uso do AASI bilateral, foi extremamente satisfatório, uma vez que possibilitou o desenvolvimento máximo das habilidades auditivas.

ABSTRACT Purpose: To analyze speech perception in children with pre-lingual hearing loss with auditory neuropathy spectrum disorder users of bilateral hearing aid. Methods: This is a descriptive and exploratory study carried out at the Research Center Audiological (HRAC/USP). The study included four children aged between 8 years and 3 months and 12 years and 2 months. Lists of monosyllabic words, two syllables, nonsense words and sentences, the Infant Toddler-Meaningful Auditory Integration Scale (IT-MAIS) and the Meaningful Use of Speech Scale (MUSS), hearing, and language categories were used. All lists were applied in acoustic booth, with speakers, in free field, in silence. Results: The results showed an average 69.5% for the list of monosyllabic words, 87.75% for the list of two-syllable words, 89.92% for the list of nonsense syllables, and 92.5% for the list of sentences. Conclusion: The therapeutic process that includes the use of bilateral hearing aid was extremely satisfactory, since it allowed the maximum development of auditory skills.

Management of children with auditory neuropathy spectrum disorder (ANSD).

INTRODUCTION: ANSD is a challenging problem. OBJECTIVE: To present our experience on management of the children with ANSD with respect to clinical data. METHODS: This retrospective study included all children younger than 16 years of age who applied to the department between 2005 and 2013 (with the exception of newborn hearing screening NHS referrals). The data were derived from pure tone, OAEs and ABR tests, and further medical risk factors of the subjects were evaluated. RESULTS: ANSD was recognized in 74 ears of 40 children (B/U: 34/6) among 1952 children with SNHL (2.04%) detected among 9520 applicants to the department (0.42%). The clinical tests revealed that hearing loss greater than 15dB was present in both ears of 38 cases. The degree of hearing loss was profound in 48% children, severe in 12% children, moderate in 28% children, mild in 10% children and normal in 5% children. ABRs were absent/abnormal in 37/3 ears and CMs were detected in all. Acoustic reflexes were absent in all ears. Rehabilitation was managed by CI and hearing aids in 15 and 23 cases, respectively. FM system was given to two cases displaying normal hearing but poor speech discrimination in noisy environments. CONCLUSION: ANSD is a relatively challenging problem for the audiology departments because of its various clinical features and difficulties in management. Our patients with ANSD most commonly displayed profound hearing loss. The number of overlooked cases may be minimized by performing ABR and OAE in every case referred with the suspicion of hearing loss.

Auditory nerve disease and auditory neuropathy spectrum disorders.

In 1996, a new type of bilateral hearing disorder was discerned and published almost simultaneously by Kaga et al. [1] and Starr et al. [2]. Although the pathophysiology of this disorder as reported by each author was essentially identical, Kaga used the term "auditory nerve disease" and Starr used the term "auditory neuropathy". Auditory neuropathy (AN) in adults is an acquired disorder characterized by mild-to-moderate pure-tone hearing loss, poor speech discrimination, and absence of the auditory brainstem response (ABR) all in the presence of normal cochlear outer hair cell function as indicated by normal distortion product otoacoustic emissions (DPOAEs) and evoked summating potentials (SPs) by electrocochleography (ECoG). A variety of processes and etiologies are thought to be involved in its pathophysiology including mutations of the OTOF and/or OPA1 genes. Most of the subsequent reports in the literature discuss the various auditory profiles of patients with AN [3,4] and in this report we present the profiles of an additional 17 cases of adult AN. Cochlear implants are useful for the reacquisition of hearing in adult AN although hearing aids are ineffective. In 2008, the new term of Auditory Neuropathy Spectrum Disorders (ANSD) was proposed by the Colorado Children's Hospital group following a comprehensive study of newborn hearing test results. When ABRs were absent and DPOAEs were present in particular cases during newborn screening they were classified as ANSD. In 2013, our group in the Tokyo Medical Center classified ANSD into three types by following changes in ABRs and DPOAEs over time with development. In Type I, there is normalization of hearing over time, Type II shows a change into profound hearing loss and Type III is true auditory neuropathy (AN). We emphasize that, in adults, ANSD is not the same as AN.

Temporal Response Properties of the Auditory Nerve in Implanted Children with Auditory Neuropathy Spectrum Disorder and Implanted Children with Sensorineural Hearing Loss.

OBJECTIVE: This study aimed to (1) characterize temporal response properties of the auditory nerve in implanted children with auditory neuropathy spectrum disorder (ANSD), and (2) compare results recorded in implanted children with ANSD with those measured in implanted children with sensorineural hearing loss (SNHL). DESIGN: Participants included 28 children with ANSD and 29 children with SNHL. All subjects used cochlear nucleus devices in their test ears. Both ears were tested in 6 children with ANSD and 3 children with SNHL. For all other subjects, only one ear was tested. The electrically evoked compound action potential (ECAP) was measured in response to each of the 33 pulses in a pulse train (excluding the second pulse) for one apical, one middle-array, and one basal electrode. The pulse train was presented in a monopolar-coupled stimulation mode at 4 pulse rates: 500, 900, 1800, and 2400 pulses per second. Response metrics included the averaged amplitude, latencies of response components and response width, the alternating depth and the amount of neural adaptation. These dependent variables were quantified based on the last six ECAPs or the six ECAPs occurring within a time window centered around 11 to 12 msec. A generalized linear mixed model was used to compare these dependent variables between the 2 subject groups. The slope of the linear fit of the normalized ECAP amplitudes (re. amplitude of the first ECAP response) over the duration of the pulse train was used to quantify the amount of ECAP increment over time for a subgroup of 9 subjects. RESULTS: Pulse train-evoked ECAPs were measured in all but 8 subjects (5 with ANSD and 3 with SNHL). ECAPs measured in children with ANSD had smaller amplitude, longer averaged P2 latency and greater response width than children with SNHL. However, differences in these two groups were only observed for some electrodes. No differences in averaged N1 latency or in the alternating depth were observed between children with ANSD and children with SNHL. Neural adaptation measured in these 2 subject groups was comparable for relatively short durations of stimulation (i.e., 11 to 12 msec). Children with ANSD showed greater neural adaptation than children with SNHL for a longer duration of stimulation. Amplitudes of ECAP responses rapidly declined within the first few milliseconds of stimulation, followed by a gradual decline up to 64 msec after stimulus onset in the majority of subjects. This decline exhibited an alternating pattern at some pulse rates. Further increases in pulse rate diminished this alternating pattern. In contrast, ECAPs recorded from at least one stimulating electrode in six ears with ANSD and three ears with SNHL showed a clear increase in amplitude over the time course of stimulation. The slope of linear regression functions measured in these subjects was significantly greater than zero. CONCLUSIONS: Some but not all aspects of temporal response properties of the auditory nerve measured in this study differ between implanted children with ANSD and implanted children with SNHL. These differences are observed for some but not all electrodes. A new neural response pattern is identified. Further studies investigating its underlying mechanism and clinical relevance are warranted.

Auditory neuropathy spectrum disorder (ANSD) and cochlear implantation.

We discuss issues related to cochlear implantation in children with auditory neuropathy spectrum disorder (ANSD). We describe the varied nature of this disease category including the numerous potential causes of auditory neuropathy. The most prevalent etiology for infants with ANSD is associated with prolonged neonatal intensive care unit (NICU) stay. We discuss the potential contribution of cochlear hypoxia to this etiology. The second part of this review describes in detail our own experience at the Hospital for Sick Children in Toronto, with cochlear implantation of children diagnosed with ANSD. We outline the detection, diagnosis, and referral routes for our patients. We provide an overview of our "standard operation procedures" regarding candidacy, and discuss some of the special considerations that need to be applied to children with ANSD. This includes decisions to implant children with better audiometric thresholds that are standard in non-ANSD patients, concerns about the possibility of spontaneous remission and the appropriate timing of implantation. Finally we review an extensive published literature in outcomes after cochlear implantation (CI) in ANSD. This is not a systematic review but rather an exercise to distill out some important reoccurring themes and the general consensus of opinion to date. Our conclusion is that the hearing loss category ANSD, together with its numerous co-morbidities, is far too heterogeneous to make definitive statements about prognosis with CI.

Cortical development and neuroplasticity in Auditory Neuropathy Spectrum Disorder.

Cortical development is dependent to a large extent on stimulus-driven input. Auditory Neuropathy Spectrum Disorder (ANSD) is a recently described form of hearing impairment where neural dys-synchrony is the predominant characteristic. Children with ANSD provide a unique platform to examine the effects of asynchronous and degraded afferent stimulation on cortical auditory neuroplasticity and behavioral processing of sound. In this review, we describe patterns of auditory cortical maturation in children with ANSD. The disruption of cortical maturation that leads to these various patterns includes high levels of intra-individual cortical variability and deficits in cortical phase synchronization of oscillatory neural responses. These neurodevelopmental changes, which are constrained by sensitive periods for central auditory maturation, are correlated with behavioral outcomes for children with ANSD. Overall, we hypothesize that patterns of cortical development in children with ANSD appear to be markers of the severity of the underlying neural dys-synchrony, providing prognostic indicators of success of clinical intervention with amplification and/or electrical stimulation. This article is part of a Special Issue entitled .