Audiological Profile of Adult Persons with Auditory Neuropathy Spectrum Disorders

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Background and Objectives

The auditory profile of a large number of persons with late onset auditory neuropathy spectrum disorder (ANSD) is recently described in the Indian context. The purpose of study was 1) to profile data on routine audiological parameters, cortical evoked potentials, and temporal processing, 2) to analyze the benefit from hearing aids for persons with ANSD, and 3) to understand the association between benefit from hearing aids and auditory profile.

Subjects and Methods

Thirty-eight adults with late onset ANSD and a matched group of 40 normally hearing adults participated in the study. Basic audiological tests, recording of cortical evoked potentials, and temporal processing tests were carried out on both groups of participant while only persons with ANSD were fitted with hearing aid.

Results

Subjects in the two groups were significantly different on all the audiological parameters. ANSD group seemed to benefit from hearing aids variably. The mean amplitude of N2 was significantly different between normally-hearing participants and patients with ANSD.

Conclusions

Residual temporal processing, particularly amplitude modulation detection seems to be associated with benefit from hearing aids in patients with ANSD.

Related collections

Most cited references 39

Record: found
Abstract: found
Article: not found

Hair cell synaptic ribbons are essential for synchronous auditory signalling.

Rémy Pujol, Alexander Egner, Tobias Moser … (2005)

Hearing relies on faithful synaptic transmission at the ribbon synapse of cochlear inner hair cells (IHCs). At present, the function of presynaptic ribbons at these synapses is still largely unknown. Here we show that anchoring of IHC ribbons is impaired in mouse mutants for the presynaptic scaffolding protein Bassoon. The lack of active-zone-anchored synaptic ribbons reduced the presynaptic readily releasable vesicle pool, and impaired synchronous auditory signalling as revealed by recordings of exocytic IHC capacitance changes and sound-evoked activation of spiral ganglion neurons. Both exocytosis of the hair cell releasable vesicle pool and the number of synchronously activated spiral ganglion neurons co-varied with the number of anchored ribbons during development. Interestingly, ribbon-deficient IHCs were still capable of sustained exocytosis with normal Ca2+-dependence. Endocytic membrane retrieval was intact, but an accumulation of tubular and cisternal membrane profiles was observed in ribbon-deficient IHCs. We conclude that ribbon-dependent synchronous release of multiple vesicles at the hair cell afferent synapse is essential for normal hearing.

0 comments Cited 135 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Auditory neuropathy.

Rebecca L. Hood, Daniel Starr, T Picton … (1996)

Ten patients presented as children or young adults with hearing impairments that, by behavioural and physiological testing, were compatible with a disorder of the auditory portion of the VIII cranial nerve. Evidence of normal cochlear outer hair cell function was provided by preservation of otoacoustic emissions and cochlear microphonics in all of the patients. Auditory brainstem potentials showed evidence of abnormal auditory pathway function beginning with the VIII nerve: the potentials were absent in nine patients and severely distorted in one patient. Auditory brainstem reflexes (middle ear muscles; crossed suppression of otoacoustic emissions) were absent in all of the tested patients. Behavioural audiometric testing showed a mild to moderate elevation of pure tone threshold in nine patients. The extent of the hearing loss, if due to cochlear receptor damage, should not have resulted in the loss of auditory brainstem potentials. The shape of the pure tone loss varied, being predominantly low frequency in five patients, flat across all frequencies in three patients and predominantly high frequency in two patients. Speech intelligibility was tested in eight patients, and in six was affected out of proportion to what would have been expected if the pure tone loss were of cochlear origin. The patients were otherwise neurologically normal when the hearing impairment was first manifest. Subsequently, eight of these patients developed evidence for a peripheral neuropathy. The neuropathy was hereditary in three and sporadic in five. We suggest that this type of hearing impairment is due to a disorder of auditory nerve function and may have, as one of its causes, a neuropathy of the auditory nerve, occurring either in isolation or as part of a generalized neuropathic process.

0 comments Cited 67 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Perceptual consequences of disrupted auditory nerve activity.

Ying Y. Kong, H. Michalewski, Arnold Starr … (2005)

Perceptual consequences of disrupted auditory nerve activity were systematically studied in 21 subjects who had been clinically diagnosed with auditory neuropathy (AN), a recently defined disorder characterized by normal outer hair cell function but disrupted auditory nerve function. Neurological and electrophysical evidence suggests that disrupted auditory nerve activity is due to desynchronized or reduced neural activity or both. Psychophysical measures showed that the disrupted neural activity has minimal effects on intensity-related perception, such as loudness discrimination, pitch discrimination at high frequencies, and sound localization using interaural level differences. In contrast, the disrupted neural activity significantly impairs timing related perception, such as pitch discrimination at low frequencies, temporal integration, gap detection, temporal modulation detection, backward and forward masking, signal detection in noise, binaural beats, and sound localization using interaural time differences. These perceptual consequences are the opposite of what is typically observed in cochlear-impaired subjects who have impaired intensity perception but relatively normal temporal processing after taking their impaired intensity perception into account. These differences in perceptual consequences between auditory neuropathy and cochlear damage suggest the use of different neural codes in auditory perception: a suboptimal spike count code for intensity processing, a synchronized spike code for temporal processing, and a duplex code for frequency processing. We also proposed two underlying physiological models based on desynchronized and reduced discharge in the auditory nerve to successfully account for the observed neurological and behavioral data. These methods and measures cannot differentiate between these two AN models, but future studies using electric stimulation of the auditory nerve via a cochlear implant might. These results not only show the unique contribution of neural synchrony to sensory perception but also provide guidance for translational research in terms of better diagnosis and management of human communication disorders.

0 comments Cited 61 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): J Audiol Otol

Journal ID (iso-abbrev): J Audiol Otol

Journal ID (publisher-id): JAO

Title: Journal of Audiology & Otology

Publisher: The Korean Audiological Society

ISSN (Print): 2384-1621

ISSN (Electronic): 2384-1710

Publication date (Print): December 2016

Publication date (Electronic): 30 November 2016

Volume: 20

Issue: 3

Pages: 158-167

Affiliations

Department of Speech-Language Pathology & Audiology, National Institute of Mental Health & Neurosciences, Bangalore, India.

Author notes

Address for correspondence: Mannarukrishnaiah Jayaram, PhD. Department of Speech-Language Pathology & Audiology, National Institute of Mental Health & Neurosciences, Hosur main road, Bangalore 560029, India. Tel: +91 80 26995569, Fax: +91 80 26564830, drmjay16@ 123456gmail.com

Article

DOI: 10.7874/jao.2016.20.3.158

PMC ID: 5144811

PubMed ID: 27942602

SO-VID: 72ccd810-3b75-4592-a561-42f2cc2d3947

License:

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

History

Date received : 29 June 2016

Date revision received : 20 July 2016

Date accepted : 03 August 2016

Comments

Comment on this article

scite_

Cited by 4

See all cited by

Most referenced authors 283

See all reference authors

Audiological Profile of Adult Persons with Auditory Neuropathy Spectrum Disorders

Read this article at

Abstract

Background and Objectives

Subjects and Methods

Results

Conclusions

Related collections

Biomarkers for Inflammatory Lung Disease

Most cited references 39

Hair cell synaptic ribbons are essential for synchronous auditory signalling.

Auditory neuropathy.

Perceptual consequences of disrupted auditory nerve activity.

Author and article information

Journal

Affiliations

Author notes

Article

History

Categories

Comments

Comment on this article

Similar content 423

Cited by 4

Most referenced authors 283