Vestibular function and balance performance in children with sensorineural hearing loss.

OBJECTIVE: Balance difficulties are common in children with sensorineural hearing loss (SNHL). For some of these children, concomitant vestibular deficits may impact postural control. This study aimed to explore vestibular function, functional balance and postural control, and the relationship between these measures in children with SNHL. DESIGN: Cross-sectional study quantifying peripheral vestibular function (vestibular evoked myogenic potentials [VEMP], video head impulse test), functional balance (Bruininks-Oseretsky Test of Motor Proficiency [BOT]) and postural control (static posturography with modified sensory inputs). The relationship between the degree of vestibular impairment, functional balance and postural control was explored. STUDY SAMPLE: Eleven with SNHL, and 11 with normal sound detection (NSD) between 5 and 12 years of age. RESULTS: Children with SNHL had varying degrees of vestibular dysfunction and differences in overall balance performance. Across all children, greater degrees of vestibular impairment were associated with significantly poorer functional balance and postural control performance for complex standing conditions (BOT percentile rank p = 0.001; compliant surface eyes open [EO]: p = 0.027; compliant surface eyes closed: p = 0.048). CONCLUSIONS: Vestibular dysfunction in children with SNHL was variable. Vestibular impairment predicted poorer functional balance performance and postural control abilities, including differences in postural sway patterns.

Acoustic change complex for assessing speech discrimination in normal-hearing and hearing-impaired infants.

OBJECTIVE: This study examined (1) the utility of a clinical system to record acoustic change complex (ACC, an event-related potential recorded by electroencephalography) for assessing speech discrimination in infants, and (2) the relationship between ACC and functional performance in real life. METHODS: Participants included 115 infants (43 normal-hearing, 72 hearing-impaired), aged 3-12 months. ACCs were recorded using [szs], [uiu], and a spectral rippled noise high-pass filtered at 2 kHz as stimuli. Assessments were conducted at age 3-6 months and at 7-12 months. Functional performance was evaluated using a parent-report questionnaire, and correlations with ACC were examined. RESULTS: The rates of onset and ACC responses of normal-hearing infants were not significantly different from those of aided infants with mild or moderate hearing loss but were significantly higher than those with severe loss. On average, response rates measured at 3-6 months were not significantly different from those at 7-12 months. Higher rates of ACC responses were significantly associated with better functional performance. CONCLUSIONS: ACCs demonstrated auditory capacity for discrimination in infants by 3-6 months. This capacity was positively related to real-life functional performance. SIGNIFICANCE: ACCs can be used to evaluate the effectiveness of amplification and monitor development in aided hearing-impaired infants.

Auditory Dysfunction Among Individuals With Neurofibromatosis Type 1.

Importance: Neurofibromatosis type 1 (NF1) affects hearing through disruption of central auditory processing. The mechanisms, functional severity, and management implications are unclear. Objective: To investigate auditory neural dysfunction and its perceptual consequences in individuals with NF1. Design, Setting, and Participants: This case-control study included children and adults with NF1 and control participants matched on age, sex, and hearing level. Patients were recruited through specialist neurofibromatosis and neurogenetic outpatient clinics between April and September 2019. An evaluation of auditory neural activity, monaural/binaural processing, and functional hearing was conducted. Diffusion-weighted magnetic resonance imaging (MRI) data were collected from a subset of participants (10 children with NF1 and 10 matched control participants) and evaluated using a fixel-based analysis of apparent fiber density. Main Outcomes and Measures: Type and severity of auditory dysfunction evaluated via laboratory testing and questionnaire data. Results: A total of 44 participants (18 [41%] female individuals) with NF1 with a mean (SD) age of 16.9 (10.7) years and 44 control participants (18 [41%] female individuals) with a mean (SD) age of 17.2 (10.2) years were included in the study. Overall, 11 participants (25%) with NF1 presented with evidence of auditory neural dysfunction, including absent, delayed, or low amplitude electrophysiological responses from the auditory nerve and/or brainstem, compared with 1 participant (2%) in the control group (odds ratio [OR], 13.03; 95% CI, 1.59-106.95). Furthermore, 14 participants (32%) with NF1 showed clinically abnormal speech perception in background noise compared with 1 participant (2%) in the control group (OR, 20.07; 95% CI, 2.50-160.89). Analysis of diffusion-weighted MRI data of participants with NF1 showed significantly lower apparent fiber density within the ascending auditory brainstem pathways. The regions identified corresponded to the neural dysfunction measured using electrophysiological assessment. Conclusions and Relevance: The findings of this case-control study could represent new neurobiological and clinical features of NF1. Auditory dysfunction severe enough to impede developmental progress in children and restrict communication in older participants is a common neurobiological feature of the disorder.

Reducing Listening-Related Stress in School-Aged Children with Autism Spectrum Disorder.

High levels of stress and anxiety are common in children with Autism Spectrum Disorder (ASD). Within this study of school-aged children (20 male, 6 female) we hypothesised that functional hearing deficits (also pervasive in ASD) could be ameliorated by auditory interventions and that, as a consequence, stress levels would be reduced. The use of Ear-Level Remote Microphone devices and Classroom Amplification systems resulted in significantly improved listening, communication and social interaction and a reduction in physiologic stress levels (salivary cortisol) in both one-on-one and group listening situations.

Auditory neuropathy in a patient with hemochromatosis.

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.

Auditory neuropathy in individuals with Type 1 diabetes.

Peripheral neuropathy is a major consequence of diabetes mellitus with up to 50 % of patients showing clinically significant neural injury during the disease course. Hearing loss (as defined by impaired sound detection thresholds) is a recognized symptom of DM, but the possibility of auditory neuropathy (AN) has not been explored in this population. This pilot study investigated peripheral auditory function, auditory processing and speech perception in individuals with Type 1 diabetes mellitus (T1DM) and compared the findings with measures of vestibular function, ocular pathology/visual acuity and overall neurologic profile. Ten adults with T1DM and ten matched controls underwent a battery of tests which included: audiometry, otoacoustic emissions, auditory brainstem responses, temporal processing measures and speech perception. Six of the ten T1DM participants showed electrophysiologic evidence of AN and impaired functional hearing. Furthermore, auditory capacity was correlated with both visual acuity and degree of somatic peripheral neuropathy. This pilot investigation revealed functional-hearing deficits severe enough to impact upon everyday communication. Should the findings be confirmed by larger studies, auditory evaluation may form an important part of the management regimen for individuals with T1DM. This may be especially important for those with DM-related eye conditions, as deficits across multiple sensory modalities can have multiplicative detrimental effects on quality-of-life.

Auditory processing deficits in individuals with primary open-angle glaucoma.

OBJECTIVE: The high energy demand of the auditory and visual pathways render these sensory systems prone to diseases that impair mitochondrial function. Primary open-angle glaucoma, a neurodegenerative disease of the optic nerve, has recently been associated with a spectrum of mitochondrial abnormalities. This study sought to investigate auditory processing in individuals with open-angle glaucoma. DESIGN/STUDY SAMPLE: Twenty-seven subjects with open-angle glaucoma underwent electrophysiologic (auditory brainstem response), auditory temporal processing (amplitude modulation detection), and speech perception (monosyllabic words in quiet and background noise) assessment in each ear. A cohort of age, gender and hearing level matched control subjects was also tested. RESULTS: While the majority of glaucoma subjects in this study demonstrated normal auditory function, there were a significant number (6/27 subjects, 22%) who showed abnormal auditory brainstem responses and impaired auditory perception in one or both ears. CONCLUSIONS: The finding that a significant proportion of subjects with open-angle glaucoma presented with auditory dysfunction provides evidence of systemic neuronal susceptibility. Affected individuals may suffer significant communication difficulties in everyday listening situations.

Auditory perception in individuals with Friedreich's ataxia.

INTRODUCTION: Friedreich's ataxia (FRDA) is an inherited ataxia with a range of progressive features including axonal degeneration of sensory nerves. The aim of this study was to investigate auditory perception in affected individuals. METHODS: Fourteen subjects with genetically defined FRDA participated. Two control groups, one consisting of healthy, normally hearing individuals and another comprised of subjects with sensorineural hearing loss, were also assessed. Auditory processing was evaluated using structured tasks designed to reveal the listeners' ability to perceive temporal and spectral cues. Findings were then correlated with open-set speech understanding. RESULTS: Nine of 14 individuals with FRDA showed evidence of auditory processing disorder. Gap and amplitude modulation detection levels in these subjects were significantly elevated, indicating impaired encoding of rapid signal changes. Electrophysiologic findings (auditory brainstem response, ABR) also reflected disrupted neural activity. Speech understanding was significantly affected in these listeners and the degree of disruption was related to temporal processing ability. Speech analyses indicated that timing cues (notably consonant voice onset time and vowel duration) were most affected. CONCLUSION: The results suggest that auditory pathway abnormality is a relatively common consequence of FRDA. Regular auditory evaluation should therefore be part of the management regime for all affected individuals. This assessment should include both ABR testing, which can provide insights into the degree to which auditory neural activity is disrupted, and some functional measure of hearing capacity such as speech perception assessment, which can quantify the disorder and provide a basis for intervention.