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Gary Rance - One of the best experts on this subject based on the ideXlab platform.
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Auditory Neuropathy in a patient with hemochromatosis.
Journal of otology, 2016Co-Authors: Gary Rance, Donella ChisariAbstract:Abstract Objective To evaluate the Auditory function of an individual with genetically confirmed hemochromatosis. Methods A 57 year old male with mildly impaired sound detection thresholds underwent a range of behavioural, electroacoustic and electrophysiologic assessments. These included the recording of otoacoustic emissions and Auditory brainstem responses, measurement of monaural temporal resolution and evaluation of binaural speech processing. Findings for this patient were subsequently compared with those of 80 healthy controls with similar audiometric thresholds. Results The patient showed the three cardinal features of Auditory Neuropathy, presenting with evidence of normal cochlear outer hair cell function, disrupted neural activity in the Auditory nerve/brainstem and impaired temporal processing. His functional hearing ability (speech perception) was significantly affected and suggested a reduced capacity to use localization cues to segregate signals in the presence of background noise. Conclusion We present the first case of an individual with hemochromatosis and Auditory Neuropathy. The findings for this patient highlight the need for careful evaluation of Auditory function in individuals with the disorder.
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chapter 28 Auditory Neuropathy
Handbook of Clinical Neurology, 2015Co-Authors: Arnold Starr, Gary RanceAbstract:Neural disorders of the Auditory nerve are associated with particular disorders of Auditory perceptions dependent on processing of acoustic temporal cues. These include: (1) speech perception; (2) localizing a sound's origin in space; and (3) identifying sounds in background noise. Auditory Neuropathy (AN) is a consequence of: (1) presynaptic disorders affecting inner hair cell ribbon synapses; (2) postsynaptic disorders of Auditory nerve dendrites; and (3) postsynaptic disorders of Auditory nerve axons. The etiologies of these disorders are diverse, similar to other cranial or peripheral neuropathies. The pathologies cause attenuated and dyssynchronous Auditory nerve discharges. Therapies and management of patients with AN are reviewed.
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Binaural speech processing in individuals with Auditory Neuropathy
Neuroscience, 2012Co-Authors: Gary Rance, Monique M. Ryan, Peter Carew, Louise A. Corben, Eppie M. Yiu, Johanna Tan, Martin B. DelatyckiAbstract:Auditory Neuropathy disrupts the neural representation of sound and may therefore impair processes contingent upon inter-aural integration. The aims of this study were to investigate binaural Auditory processing in individuals with axonal (Friedreich ataxia) and demyelinating (Charcot-Marie-Tooth disease type 1A) Auditory Neuropathy and to evaluate the relationship between the degree of Auditory deficit and overall clinical severity in patients with neuropathic disorders. Twenty-three subjects with genetically confirmed Friedreich ataxia and 12 subjects with Charcot-Marie-Tooth disease type 1A underwent psychophysical evaluation of basic Auditory processing (intensity discrimination/temporal resolution) and binaural speech perception assessment using the Listening in Spatialized Noise test. Age, gender and hearing-level-matched controls were also tested. Speech perception in noise for individuals with Auditory Neuropathy was abnormal for each listening condition, but was particularly affected in circumstances where binaural processing might have improved perception through spatial segregation. Ability to use spatial cues was correlated with temporal resolution suggesting that the binaural-processing deficit was the result of disordered representation of timing cues in the left and right Auditory nerves. Spatial processing was also related to overall disease severity (as measured by the Friedreich Ataxia Rating Scale and Charcot-Marie-Tooth Neuropathy Score) suggesting that the degree of neural dysfunction in the Auditory system accurately reflects generalized neuropathic changes. Measures of binaural speech processing show promise for application in the neurology clinic. In individuals with Auditory Neuropathy due to both axonal and demyelinating mechanisms the assessment provides a measure of functional hearing ability, a biomarker capable of tracking the natural history of progressive disease and a potential means of evaluating the effectiveness of interventions.
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Auditory Neuropathy dys synchrony and its perceptual consequences
Trends in Amplification, 2005Co-Authors: Gary RanceAbstract: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.
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Auditory Neuropathy/Dys-synchrony and Its Perceptual Consequences:
Trends in amplification, 2005Co-Authors: Gary RanceAbstract: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.
Liang Zong - One of the best experts on this subject based on the ideXlab platform.
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Temperature sensitive Auditory Neuropathy.
Hearing research, 2016Co-Authors: Qiujing Zhang, Lan Lan, Wei Shi, Linyi Xie, Fen Xiong, Cui Zhao, Zifang Yin, Liang ZongAbstract:Temperature sensitive Auditory Neuropathy is a very rare and puzzling disorder. In the present study, we reported three unrelated 2 to 6 year-old children who were diagnosed as Auditory Neuropathy patients who complained of severe hearing loss when they had fever. Their hearing thresholds varied from the morning to the afternoon. Two of these patients' hearing improved with age, and one patient received positive results from cochlear implant. Genetic analysis revealed that these three patients had otoferlin (OTOF) homozygous or compound heterozygous mutations with the genotypes c.2975_2978delAG/c.4819C>T, c.4819C>T/c.4819C>T, or c.2382_2383delC/c.1621G>A, respectively. Our study suggests that these gene mutations may be the cause of temperature sensitive Auditory Neuropathy. The long term follow up results suggest that the hearing loss in this type of Auditory Neuropathy may recover with age.
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screening mutations of otof gene in chinese patients with Auditory Neuropathy including a familial case of temperature sensitive Auditory Neuropathy
BMC Medical Genetics, 2010Co-Authors: Dayong Wang, Liang Zong, Yichen Wang, Dominique Weil, Ya Li Zhao, Shao Qi Rao, Qiong Liu, Huan Ming Yang, Yan Shen, Cindy BenedictalderferAbstract:Background Mutations in OTOF gene, encoding otoferlin, cause DFNB9 deafness and non-syndromic Auditory Neuropathy (AN). The aim of this study is to identify OTOF mutations in Chinese patients with non-syndromic Auditory Neuropathy.
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Screening mutations of OTOF gene in Chinese patients with Auditory Neuropathy, including a familial case of temperature-sensitive Auditory Neuropathy
BMC Medical Genetics, 2010Co-Authors: Dayong Wang, Liang Zong, Yichen Wang, Dominique Weil, Ya Li Zhao, Shao Qi Rao, Qiong Liu, Huan Ming Yang, Yan Shen, Cindy Benedict-alderferAbstract:Background Mutations in OTOF gene, encoding otoferlin, cause DFNB9 deafness and non-syndromic Auditory Neuropathy (AN). The aim of this study is to identify OTOF mutations in Chinese patients with non-syndromic Auditory Neuropathy. Methods 73 unrelated Chinese Han patients with AN, including one case of temperature sensitive non-syndromic Auditory Neuropathy (TS-NSRAN) and 92 ethnicity-matched controls with normal hearing were screened. Forty-five pairs of PCR primers were designed to amplify all of the exons and their flanking regions of the OTOF gene. The PCR products were sequenced and analyzed for mutation identification. Results Five novel possibly pathogenic variants (c.1740delC, c.2975_2978delAG, c.1194T>A, c.1780G>A, c.4819C > T) were identified in the group of 73 AN patients, in which two novel mutant alleles (c.2975_2978delAG + c.4819C > T) were identified in one Chinese TS-NSRAN case. Besides, 10 non-pathogenic variants of the OTOF gene were found in AN patients and controls. Conclusions Screening revealed that mutations in the OTOF gene account for AN in 4 of 73(5.5%) sporadic AN patients, which shows a lower genetic load of that gene in contrast to the previous studies based on other populations. Notably, we found two novel mutant alleles related to temperature sensitive non-syndromic Auditory Neuropathy. This mutation screening study further confirms that the OTOF gene contributes to ANs and to TS-NSRAN.
Arnold Starr - One of the best experts on this subject based on the ideXlab platform.
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Auditory Neuropathy — neural and synaptic mechanisms
Nature Reviews Neurology, 2016Co-Authors: Tobias Moser, Arnold StarrAbstract:Sensorineural hearing impairment is the most common form of hearing loss, and encompasses pathologies of the cochlea and the Auditory nerve. Hearing impairment caused by abnormal neural encoding of sound stimuli despite preservation of sensory transduction and amplification by outer hair cells is known as 'Auditory Neuropathy'. This term was originally coined for a specific type of hearing impairment affecting speech comprehension beyond changes in audibility: patients with this condition report that they “can hear but cannot understand”. This type of hearing impairment can be caused by damage to the sensory inner hair cells (IHCs), IHC ribbon synapses or spiral ganglion neurons. Human genetic and physiological studies, as well as research on animal models, have recently shown that disrupted IHC ribbon synapse function — resulting from genetic alterations that affect presynaptic glutamate loading of synaptic vesicles, Ca^2+ influx, or synaptic vesicle exocytosis — leads to hearing impairment termed 'Auditory synaptopathy'. Moreover, animal studies have demonstrated that sound overexposure causes excitotoxic loss of IHC ribbon synapses. This mechanism probably contributes to hearing disorders caused by noise exposure or age-related hearing loss. This Review provides an update on recently elucidated sensory, synaptic and neural mechanisms of hearing impairment, their corresponding clinical findings, and discusses current rehabilitation strategies as well as future therapies. Auditory Neuropathy impairs speech comprehension severely, beyond the extent that would be expected on the basis of increased threshold of audibility Auditory Neuropathy encompasses a range of disease mechanisms that typically disrupt the synaptic encoding and/or neural transmission of Auditory information in the cochlea and Auditory nerve Auditory synaptopathy, impaired sound encoding at the synapses between inner hair cells and spiral ganglion neurons, results from genetic defects or insults such as exposure to loud noise Advanced physiological and psychophysical testing combined with molecular genetic analysis facilitate diagnostics of Auditory synaptopathy and Neuropathy Although traditional hearing aids often do not provide substantial benefit for patients with Auditory synaptopathy or Neuropathy, cochlear implants can provide effective hearing rehabilitation depending on the site(s) of disorder In Auditory Neuropathy, sensory transduction and amplification is preserved, but abnormal neural encoding of sound stimuli impairs speech comprehension severely, beyond what would be expected on the basis of increased threshold of audibility. Here, Moser and Starr provide an overview of the mechanisms of Auditory Neuropathy, including Auditory synaptopathy. Moreover, the authors provide a brief guide to physiological and psychophysical tests for the clinical diagnosis of the disorders, discuss the strategies for hearing rehabilitation, and provide an outlook on future therapies.
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chapter 28 Auditory Neuropathy
Handbook of Clinical Neurology, 2015Co-Authors: Arnold Starr, Gary RanceAbstract:Neural disorders of the Auditory nerve are associated with particular disorders of Auditory perceptions dependent on processing of acoustic temporal cues. These include: (1) speech perception; (2) localizing a sound's origin in space; and (3) identifying sounds in background noise. Auditory Neuropathy (AN) is a consequence of: (1) presynaptic disorders affecting inner hair cell ribbon synapses; (2) postsynaptic disorders of Auditory nerve dendrites; and (3) postsynaptic disorders of Auditory nerve axons. The etiologies of these disorders are diverse, similar to other cranial or peripheral neuropathies. The pathologies cause attenuated and dyssynchronous Auditory nerve discharges. Therapies and management of patients with AN are reviewed.
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Auditory Neuropathy a new perspective on hearing disorders
2001Co-Authors: Yvonne S Sininger, Arnold StarrAbstract:Auditory Neuropathy: An Historical and Current Perspective. Patients with Auditory Neuropathy: Who Are They and What Can They Hear. The Neurology of Auditory Neuropathy. Models of Auditory Neuropathy Based on Inner Hair Cell Damage. Pathophysiology of Auditory Neuropathy. Anatomy of the Human Cochlea and Auditory Nerve, Primary Cochlear Neuronal Degeneration. Psychoacoustics and Speech Perception in Auditory Neuropathy. The Genetics of Auditory Neuropathy. Auditory Neuropathy (Auditory Dys-synchrony) Disables Efferent Suppression of Otoacoustic Emissions. Cochlear Implantation of Patients with Auditory Neuropathy. Amplification and Rehabilitation Strategies for Patients with Auditory Neuropathy.
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The varieties of Auditory Neuropathy.
Journal of basic and clinical physiology and pharmacology, 2000Co-Authors: Arnold Starr, Yvonne S Sininger, H. PrattAbstract:Auditory Neuropathy (AN) was initially described as impairment of Auditory neural function, with preserved cochlear hair cell function. In this report, 67 patients with audiological and neurophysiological criteria for hearing loss due to Auditory Neuropathy are described. Reviewing this large body of patients, AN appears to consist of a number of varieties, with different etiologies and sites affected. All varieties share a relatively spared receptor function, and an impaired neural response, with diminished ability to follow fast temporal changes in the stimulus, but different varieties in this general scheme can be distinguished. Analyses of the clinical features indicate that Auditory neuropathies vary in several measures including age of onset, presence of peripheral Neuropathy, etiology, and behavioral and physiological measures of Auditory function. The sites affected along the peripheral Auditory pathway may include dysfunction of the outer hair cells, the synapse between hair cell and Auditory nerve, and the Auditory nerve fibers, with myelin as well as axonal impairments contributing to the disorder.
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Temporal and speech processing deficits in Auditory Neuropathy
NeuroReport, 1999Co-Authors: Fan Gang Zeng, Sandy Oba, Smita Garde, Yvonne Sininger, Arnold StarrAbstract:Auditory Neuropathy affects the normal synchronous activity in the Auditory nerve, without affecting the amplification function in the inner ear. Patients with Auditory Neuropathy often complain that they can hear sounds, but cannot understand speech. Here we report psychophysical tests indicating that these patients' poor speech recognition is due to a severe impairment in their temporal processing abilities. We also simulate this temporal processing impairment in normally hearing listeners and produce similar speech recognition deficits. This study demonstrates the importance of neural synchrony for Auditory perceptions including speech recognition in humans. The results should contribute to better diagnosis and treatment of Auditory Neuropathy.
Dayong Wang - One of the best experts on this subject based on the ideXlab platform.
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screening mutations of otof gene in chinese patients with Auditory Neuropathy including a familial case of temperature sensitive Auditory Neuropathy
BMC Medical Genetics, 2010Co-Authors: Dayong Wang, Liang Zong, Yichen Wang, Dominique Weil, Ya Li Zhao, Shao Qi Rao, Qiong Liu, Huan Ming Yang, Yan Shen, Cindy BenedictalderferAbstract:Background Mutations in OTOF gene, encoding otoferlin, cause DFNB9 deafness and non-syndromic Auditory Neuropathy (AN). The aim of this study is to identify OTOF mutations in Chinese patients with non-syndromic Auditory Neuropathy.
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Screening mutations of OTOF gene in Chinese patients with Auditory Neuropathy, including a familial case of temperature-sensitive Auditory Neuropathy
BMC Medical Genetics, 2010Co-Authors: Dayong Wang, Liang Zong, Yichen Wang, Dominique Weil, Ya Li Zhao, Shao Qi Rao, Qiong Liu, Huan Ming Yang, Yan Shen, Cindy Benedict-alderferAbstract:Background Mutations in OTOF gene, encoding otoferlin, cause DFNB9 deafness and non-syndromic Auditory Neuropathy (AN). The aim of this study is to identify OTOF mutations in Chinese patients with non-syndromic Auditory Neuropathy. Methods 73 unrelated Chinese Han patients with AN, including one case of temperature sensitive non-syndromic Auditory Neuropathy (TS-NSRAN) and 92 ethnicity-matched controls with normal hearing were screened. Forty-five pairs of PCR primers were designed to amplify all of the exons and their flanking regions of the OTOF gene. The PCR products were sequenced and analyzed for mutation identification. Results Five novel possibly pathogenic variants (c.1740delC, c.2975_2978delAG, c.1194T>A, c.1780G>A, c.4819C > T) were identified in the group of 73 AN patients, in which two novel mutant alleles (c.2975_2978delAG + c.4819C > T) were identified in one Chinese TS-NSRAN case. Besides, 10 non-pathogenic variants of the OTOF gene were found in AN patients and controls. Conclusions Screening revealed that mutations in the OTOF gene account for AN in 4 of 73(5.5%) sporadic AN patients, which shows a lower genetic load of that gene in contrast to the previous studies based on other populations. Notably, we found two novel mutant alleles related to temperature sensitive non-syndromic Auditory Neuropathy. This mutation screening study further confirms that the OTOF gene contributes to ANs and to TS-NSRAN.
Qiujing Zhang - One of the best experts on this subject based on the ideXlab platform.
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Temperature sensitive Auditory Neuropathy.
Hearing research, 2016Co-Authors: Qiujing Zhang, Lan Lan, Wei Shi, Linyi Xie, Fen Xiong, Cui Zhao, Zifang Yin, Liang ZongAbstract:Temperature sensitive Auditory Neuropathy is a very rare and puzzling disorder. In the present study, we reported three unrelated 2 to 6 year-old children who were diagnosed as Auditory Neuropathy patients who complained of severe hearing loss when they had fever. Their hearing thresholds varied from the morning to the afternoon. Two of these patients' hearing improved with age, and one patient received positive results from cochlear implant. Genetic analysis revealed that these three patients had otoferlin (OTOF) homozygous or compound heterozygous mutations with the genotypes c.2975_2978delAG/c.4819C>T, c.4819C>T/c.4819C>T, or c.2382_2383delC/c.1621G>A, respectively. Our study suggests that these gene mutations may be the cause of temperature sensitive Auditory Neuropathy. The long term follow up results suggest that the hearing loss in this type of Auditory Neuropathy may recover with age.