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.

Central Deafness Associated with a Midbrain Lesion

Central deafness has been linked historically to bihemispheric involvement of the temporal lobe, with more recent findings suggesting that compromise of other cortical and subcortical structures can also result in this disorder. The present investigation extends our understanding of the potential anatomical correlates to central deafness by demonstrating that bilateral involvement of an auditory structure within the midbrain can additionally result in this condition. Our subject was a 21-year-old male with a subarachnoid bleed affecting both inferior colliculi. Significant auditory deficits were noted for the middle and late auditory evoked potentials, while electrophysiologic measures of the periphery indicated normal function. The patient was enrolled in a rehabilitation program for approximately 14 weeks. Although initially unresponsive to sounds, the patient regained most of his auditory abilities during the 10 months he was followed. This case documents the range of auditory deficits that may be associated with damage to the inferior colliculi, and it profiles a hierarchical recovery of auditory function consistent with test findings.

A case of cortical deafness and loss of vestibular and somatosensory sensations caused by cerebrovascular lesions in bilateral primary auditory cortices, auditory radiations, and postcentral gyruses - complete loss of hearing despite normal DPOAE and ABR

CONCLUSION

A right-handed 38-year-old man's complete loss of hearing could be diagnosed as cortical deafness caused by cerebral vascular lesions in bilateral auditory cortices.

OBJECTIVE

The aim of this case report was to study the pathophysiology of a particular patient who manifested deafness without residual hearing and lost somatosensory sensation, vestibular sensation, and articulation ability after a right internal carotid-posterior communicating artery (IC-PC) aneurysm and subarachnoidal hemorrhage.

METHODS

MRI, aphasia and neurological tests, subjective and objective audiometry, and vestibular function tests were performed.

RESULTS

The neurological test revealed system loss of somatosensory sensation with normal motor function and articulation ability. Brain imaging revealed extensive infarction in the bilateral primary auditory cortices, postcentral gyruses, and the bilateral partial third frontal gyruses. Pure-tone audiometry of both ears revealed off-the-scale results and speech audiometry demonstrated 0% maximum speech discrimination. However, objective audiometry showed normal distortion product otoacoustic emissions (DPOAE) and normal auditory brainstem response (ABR). The patient showed 0% perception of environmental, speech, and music sounds in both ears. He was unable to feel vestibular sensation despite normal caloric nystagmus. He showed no damage to his larynx or articulation organs.

Performance of hearing skills in children with auditory neuropathy spectrum disorder using cochlear implant: a systematic review

Introduction

Currently, there are no doubts about the benefits of cochlear implants for the development of children with severe or profound hearing loss. However, there is still no consensus among researchers and professionals regarding the benefits for the improvement of hearing skills in children with auditory neuropathy spectrum disorder using cochlear implants.

Objective

Review the available evidence in the literature to answer the following: “What is the performance of hearing skills in children with auditory neuropathy spectrum disorder using cochlear implants?”

Methods

Systematic review of the literature through electronic database consultation, considering publications in the period 2002–2013.

Results

Twenty-two studies met the criteria and were included in the systematic review.

Conclusion

The analyzed studies demonstrated that after cochlear implant surgery, individuals with auditory neuropathy spectrum disorder improved their performance of hearing skills and had similar performance to that of children with sensorineural hearing loss using cochlear implant.

Preliminary performance of cochlear implants in post-lingual patients with auditory neuropathy

CONCLUSIONS

Auditory restoration can be obtained by using cochlear implants (CIs) in post-lingual patients with auditory neuropathy (AN). However, improvements in postoperative speech recognition for these patients varied.

OBJECTIVES

The primary purpose of this study was to assess the postoperative performances of two post-lingual AN patients after receiving CIs.

METHODS

Two post-lingual AN patients received unilateral CIs and the efficacy of the implants was then evaluated. One patient was female with bilateral mid-severe hearing loss and received an implant at age 28 years. The second patient was male with severe hearing loss and he received an implant at age 15 years. The postoperative performance for both patients was evaluated.

RESULTS

After using the CI for 6 months, the hearing ability of both subjects was improved by the CI with an average post-implant threshold of 35 dB and 44 dB, respectively. The woman made significant progress in speech recognition with an open-set spondee recognition score of 55% and sentence recognition in quiet score of 90%. Sentence recognition in noise scores were 94% (SNR = +10 dB), 88% (SNR = +5 dB), and 80% (SNR = 0 dB). The boy achieved improved recognition scores for monosyllables (40%) and disyllables (26%), but poor sentence recognition both in quiet (0%) and in noise (0%).

[Auditory neuropathy (auditory neuropathy spectrum disorders): the approaches to diagnostics and rehabilitation]

Auditory neuropathies (auditory neuropathy spectrum disorders, ANSD) may be a consequence of dysfunction of inner hair cells and/or of synapses between these cells and auditory nerve fibers. Another cause of these disorders is supposed to be pathological changes in the auditory nerve itself. The outcome of the rehabilitative treatment of the patients presenting with this disorder depends on the quality of diagnosis and precise location of the pathological process. The present study involved 82 patients with auditory neuropathies. The audiological data obtained in the course of this work were compared with the results of other authors published during the recent years. The objective audiological examination included electrocochleography, registration of auditory brainstem response (ABR) and otoacoustic emission of short-latency and long-latency evoked auditory nerve action potentials. High-amplitude cochlear microphonic and transient evoked otoacoustic emission (TEOAE) potentials were recorded in 82 patients. In 17 (20.7%) patients, otoacoustic emission disappeared in the course of time even though the microphonic potential remained stable. It was shown that the results of electrical acoustic correction in the patients exhibiting long-latency evoked auditory action potentials and positive ABR to electrical stimulation (positive promontory test) were better than in the remaining cases. The outcome of cochlear implantation to a large extent depended on the localization of the pathological process. Specifically, the results of the treatment of the patients with high-amplitude summation potentials, prolonged latency, and positive auditory action potentials in response to electrical stimulation (typical of pre-synaptic localization of the pathological process) were better than in the patients with normal summation potentials, pathological auditory nerve action potentials, TEOAE, and negative ABR to electrical stimulation (indicative of post-synaptic localization of the pathological process). In the latter group of patients, the results of cochlear implantation were far from being satisfactory. It is concluded that additional information facilitating categorization of the pathological process can be obtained by the identification of the genetic mutations responsible for the development of auditory neuropathies.

Inter-trial coherence as a marker of cortical phase synchrony in children with sensorineural hearing loss and auditory neuropathy spectrum disorder fitted with hearing aids and cochlear implants

OBJECTIVE

Although brainstem dys-synchrony is a hallmark of children with auditory neuropathy spectrum disorder (ANSD), little is known about how the lack of neural synchrony manifests at more central levels. We used time-frequency single-trial EEG analyses (i.e., inter-trial coherence; ITC), to examine cortical phase synchrony in children with normal hearing (NH), sensorineural hearing loss (SNHL) and ANSD.

METHODS

Single trial time-frequency analyses were performed on cortical auditory evoked responses from 41 NH children, 91 children with ANSD and 50 children with SNHL. The latter two groups included children who received intervention via hearing aids and cochlear implants. ITC measures were compared between groups as a function of hearing loss, intervention type, and cortical maturational status.

RESULTS

In children with SNHL, ITC decreased as severity of hearing loss increased. Children with ANSD revealed lower levels of ITC relative to children with NH or SNHL, regardless of intervention. Children with ANSD who received cochlear implants showed significant improvements in ITC with increasing experience with their implants.

CONCLUSIONS

Cortical phase coherence is significantly reduced as a result of both severe-to-profound SNHL and ANSD.

SIGNIFICANCE

ITC provides a window into the brain oscillations underlying the averaged cortical auditory evoked response. Our results provide a first description of deficits in cortical phase synchrony in children with SNHL and ANSD.

The uses of overlap: carer-child interaction involving a nine-year-old boy with auditory neuropathy

The subject of this single case study, Ricky, is a nine-year-old boy with a profound hearing loss arising from auditory neuropathy. Despite cochlear implantation at the age of two, his receptive language skills remain very restricted and his speech is unintelligible. Techniques of interactional linguistics are used to analyse recordings of Ricky and his mother during shared book reading. Both participants display competences in managing turn-taking and overlapping talk that enable them to progress the book-reading activity, to talk spontaneously on topically related matters and also to handle issues of phonetic and linguistic repair. Instances of both competitive and non-competitive overlap reveal that Ricky has access to interactionally important prosodic skills. The study thus reinforces the need, when assessing a child's potential to understand and use spoken language, to examine the child's talk from an interactional perspective. It further indicates that overlapping talk is not necessarily a problem; indeed it can be part of a solution to issues of interpersonal understanding that routinely arise in the course of talk-in-interaction.

[Idiopathic generalized epilepsies with absence seizures with valproic acid treatment: neuropsychological disorders]

AIM

To analyze the neuropsychological profile of children with absence seizures treated with valproate.

SUBJECTS AND METHODS

Sample of 34 children from 7 to 12 years with absence seizures treated with valproate (median dose: 30 mg/kg/day) and 28 controls. We get the neuropsychological profile by applying the Wechsler Intelligence Scale for Children-Revised (WISC-R) and Luria-DNI Battery.

RESULTS

Children with absence seizures manifest verbal IQ significantly lower (p < 0.05) than the control group but within normal. The neuropsychological profile Luria-DNI is significantly lower (p < 0.05) than the control group in all areas except in regulation verbal, kinesthetic, visual perception, comprehension and understanding simple grammar. This is a serious deterioration profile in the areas of logical memory, short-term memory, arithmetic, numerical structure, reading, writing, naming, and articulation. Children with absence seizures have a significant memory deficit. Memory profile measured with the Luria-DNI Battery and the WISC-R appears generally deteriorated when compared with the control group (p < 0.001) although there is a paradoxical preservation of shape memory. The short-term auditory and visual memory and logical memory are particularly affected. In the epileptic group, the attentional profile (estimated by the 'third factor of the WISC-R') is generally deteriorated when compared with the control group.

CONCLUSIONS

We consider in children with this diagnosis and treatment, the neuropsychological profile described to strengthen deficient neuropsychological and psychoeducational areas. Above, we claim the need, in the consultations of neuropediatrics, the neuropsychlogists to ensure the systematic analysis of neuropsychological and cognitive difficulties both at the time of the diagnosis and follow-up of epilepsy.

Open set speech perception with auditory brainstem implant?

OBJECTIVE

Only a small percentage of auditory brainstem implant (ABI) recipients treated for neurofibromatosis type 2 (NF2) have proved capable of identifying words using only the sound from the ABI. Recently, the ABI was applied to a series of patients with no cochlear nerve or with cochlear disorders that could not benefit from a cochlear implant (i.e., cochlear nerve aplasia or posttraumatic avulsion) or whose benefit was or would be severely compromised. A significant number of these patients have proven capable of understanding speech, including effortless telephone use. In the present study, a series of psychophysical tests were administered to determine the cause of the difference in performance between tumor (T) and nontumor (NT) ABI patients.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Twenty patients with ABIs participated in the investigation. Ten were NF2 patients and 10 NT subjects. Patient ages ranged from 24 to 61 years. Eleven were males and nine females.

INTERVENTION

Auditory rehabilitation in auditory disconnection caused by cochlea or cochlear nerve disorders.

RESULTS

There was a significant correlation between modulation detection thresholds and speech understanding and a significant difference in modulation detection between T and NT patients.

CONCLUSIONS

The difference in modulation detection between the two groups suggests a difference in the survival of specific cells in the cochlear nucleus that support modulation. The pattern of results indicates a separate pathway of auditory processing that is specialized for modulated sounds, and that pathway is critical for speech understanding. In NF2 patients, the tumor and surgery may selectively damage this pathway, resulting in poor speech recognition with prosthetic stimulation.

Auditory neuropathy/dys-synchrony and its perceptual consequences

Auditory neuropathy/dys-synchrony is a form of hearing impairment in which cochlear outer hair cell function is spared but neural transmission in the auditory pathway is disordered. This condition, or group of conditions with a common physiologic profile, accounts for approximately 7% of permanent childhood hearing loss and a significant (but as yet undetermined) proportion of adult impairment. This paper presents an overview of the mechanisms underlying auditory neuropathy/dys-synchrony-type hearing loss and the clinical profile for affected patients. In particular it examines the perceptual consequences of auditory neuropathy/dys-synchrony, which are quite different from those associated with sensorineural hearing loss, and considers currently available, and future management options.

Auditory learning as a cause and treatment of central dysfunction

Conductive hearing loss produced by middle ear disease (MED) is very prevalent in the first 5 years of childhood. Both MED in children and prolonged ear plugging in animals lead to a binaural hearing impairment that persists beyond the duration of the peripheral impairment. However, after cessation of the MED, or removal of the ear plug, binaural hearing gradually improves. We suggest here that this improvement is a passive form of auditory learning. We also show that active auditory learning, through repetition of discrimination tasks, can accelerate performance increments, both after hearing loss and in unimpaired individuals. A more detailed understanding of auditory learning holds out the prospect of improving rehabilitation strategies for the language- and hearing-impaired.

Brainstem electronic implants for bilateral anacusis following surgical removal of cerebello pontine angle lesions

The multichannel auditory brainstem implant (ABI) has been used successfully to treat deafness in individuals with neurofibromatosis type II. The device has been implanted in nearly 150 recipients worldwide, and clinical trials with the device are approaching completion. The implantation and fitting of the multichannel ABI differ significantly from cochlear implantation, and the processes are illustrated in a series of case studies. Performance data also are included from recipients with up to 7 years experience.

Auditory brainstem implant in auditory rehabilitation of patients with neurofibromatosis type 2: Hannover programme

An auditory brainstem implant (ABI) is indicated for patients suffering from bilateral neural deafness. The most affected patients are those with neurofibromatosis type 2 (NF2). An implantation is possible either at the same time as, or after, surgical removal of an acoustic neuroma. This paper demonstrates the results of eight out of 11 patients with NF2, seven of whom received an ABI after tumour removal. Pre-operatively, all of them were deaf. Post-operatively, the first fitting served to determine the individual stimulation parameters for each electrode. The stimulation-dependent side-effects were eliminated by reducing the stimulus intensity without causing negative effects on the hearing with the ABI. Only in one case was an open set understanding achieved within the first year. However, all patients had a better speech understanding when they combined their hearing with the ABI and their lip-reading abilities. There is no correlation between the performance with ABI and the tumour size or the duration of deafness.

[Active electronic hearing implants for middle and inner ear hearing loss--a new era in ear surgery. II: Current state of developments]

Active hearing implants have been developed to varying degrees for conductive hearing loss as well as for sensorineural hearing loss. Implants for conductive hearing loss match impedance transformation by the middle ear. They will be referred to as ITI (impedance transformation implants). Three partial ITIs have been developed for routine clinical use: the Swedish transcutaneous BAHA, the American subcutaneous AUDIANT, and the Japanese P-MEI. Of greater importance with respect to the number of patients are electronic implants for sensorineural hearing loss. These implants are designed to replace parts of the function of the cochlea amplifier (CA). Therefore, in this study, they will be called CAI (cochlea amplifier implant). The CAI consist of four parts: (1) transducer, (2) microphone, (3) control unit, and (4) battery. A CAI for routine clinical use does not yet exist. Two transducer principles have thus far been developed for use in CAIs: the electromagnetic (EM) and the piezoelectric (PE) principle. Most of the transducers that have been described are EM transducers. The American Maniglia implant and the American floating mass transducer have been tested in humans. Both belong to the category of high energy consuming (HEC) implants with a limited frequency range that does not contain the whole speech spectrum. This is in contrast to the Canadian electromagnetic Fredrickson-HEC implant which is capable of transmitting broad band signals of up to 10 kHz. All ot he HEC-EM transducers lack an implantable microphone and an implantable battery. The German CAI, one of the piezoelectrical implants, was recently implanted acutely in humans. It consists of a piezoelectrical, ossicle coupled, low energy consuming (LEC) transducer, as well as an implantable microphone. It allows a broadband signal of up to 10 kHz, yet at a considerably lower level of energy.

Audiological deficits in brain-injured children and adolescents

A retrospective chart review of 62 children aged 2 to 18.5 years admitted over a 4-year period to a brain injury rehabilitation unit was performed. Glasgow Coma Scales were not always recorded at the referring institutions, but all but three of the children in the series experienced a period of unresponsiveness to the environment for a period of at least one hour. Available Glasgow Coma scores at the time of injury ranged from 3 to 13. Maximum coma duration was 3 months. All children received an audiological evaluation. Sixteen per cent of the children had conductive hearing losses, 13% had sensorineural hearing loss, and 16% had central auditory processing problems. Three of these children were found to have combined losses, one with both conductive and sensorineural hearing loss, and two with sensorineural hearing loss and central auditory processing problems. Of the five patients with the most severe injuries and prolonged comas, none had hearing deficits. Twenty-five of the 62 patients, or 40%, had hearing deficits, of which 15 are known to persist.

Educational evaluation. The first step toward understanding and remediation of central auditory disorders

Of all the problems experienced by children with learning disabilities, a language disorder may be the most detrimental to school performance. Because the problems of a child with a language disorder are frequently not recognized until he begins school, it is important that the educational clinician, teacher, related professional, and parents understand what a central auditory disorder is, that it may manifest itself as language disorder, and the way it can academically and emotionally affect a child. Evaluation and identification of a child with a central auditory disorder is vital at an early stage of development; however, testing, while it appears simple, is an extremely complex process and is not always exact. Therefore, the educational clinician must be skilled and understand the frailties which exist in the test instrument and the testing situation. It must be remembered, also, that testing in only part of the diagnostic procedure. Organized, perceptive classroom observations are essential. These must be followed by multidisciplinary meetings that generate remedial procedures and directions to be taken by parents and teachers. Finally, parents must be accepted by professionals as reasonable, concerned, and able to offer knowledgeable insight into their child's learning problems. If a language disorder is suspected, professional help should be sought immediately. Truth is better than fiction or fantasy in helping a child become a happy, adjusted, productive human being.

Audiological rehabilitation of patients with brainstem disorders

A brief account is given of the course of rehabilitation of three patients with severe brainstem injuries. Particular use has been made of synthetic speech pattern assessment procedures which have been integrated into the management model of Goldstein and Stephens (1981). The use of speech stimuli of controllable simplicity has two main clinical benefits: the early course of re-acquisition can be examined analytically, second, aspects of speech receptive and productive rehabilitation can be facilitated. Re-acquisition of perceptive ability in some of these patients may follow a progression from simple to complex acoustic pattern contrasts and this may provide an effective basis for future techniques of rehabilitation.

Hearing aid performance relative to site of lesion

This study investigated hearing aid acceptance and use as functions of the probable site of a lesion: conductive, cochlear, neural, and central as determined by an audiometric test battery. Results indicate significantly better acceptance of aids in conductive and cochlear disorders than in more central neural and central disorders.