Screening and prevention of hearing loss in children

Rescuing Auditory Temporal Processing with a Novel Augmented Acoustic Environment in an Animal Model of Congenital Hearing Loss

Congenital sensorineural hearing loss (SNHL) affects thousands of infants each year and results in significant delays in speech and language development. Previous studies have shown that early exposure to a simple augmented acoustic environment (AAE) can limit the effects of progressive SNHL on hearing sensitivity. However, SNHL is also accompanied by hearing loss that is not assessed on standard audiological examinations, such as reduced temporal processing acuity. To assess whether sound therapy may improve these deficits, a mouse model of congenital SNHL was exposed to simple or temporally complex AAE. The DBA/2J mouse strain develops rapid, base to apex, progressive SNHL beginning at birth and is functionally deaf by six months of age. Hearing sensitivity and auditory brainstem function was measured using otoacoustic emissions, auditory brainstem response (ABR) and extracellular recording from the inferior colliculus (IC) in mice following exposure to 30 d of continuous AAE. Peripheral function and sound sensitivity in auditory midbrain neurons improved following exposure to both types of AAE. However, exposure to a novel, temporally complex AAE more strongly improved a measure of temporal processing acuity, neural gap-in-noise detection in the auditory midbrain. These experiments suggest that targeted sound therapy may be harnessed to improve hearing outcomes for children suffering from congenital SNHL.

Value of Newborn Hearing Screening on Early Intervention in the Saudi Population and Review of International Records

Background

Hearing impairment is found to be the most prevalent disabling condition worldwide. Early diagnosis is crucial to avoid speech and language delays and to ensure the best performance results after cochlear implant (CI) surgery. Universal newborn hearing screening is a way to recognize newborns with a hearing impairment with or without risk factors. In this article, we have studied the effect of the newborn hearing screening program on early presentation to a healthcare center and, hence, early intervention in patients with congenital hearing loss, and reviewed the international numbers.

Objectives

The objective of this study was to determine whether neonatal hearing screening in Saudi Arabia helped prelingually deaf children to present earlier or not.

Design

Retrospective cross-sectional review

Setting

King Abdullah Ear Specialist Center (KAESC), Riyadh, Saudi Arabia

Subjects and methods

We included all patients who presented to the CI committee for the first time at KAESC, between March 2016 and March 2018, and met the inclusion criteria. Data were retrieved through phone calls and patient files. The sample size was 242.

Main outcomes

The timing difference between those who were screened positive for hearing loss at birth versus patients who were screened negative or not screened at all.

Results

By far, patients who were screened positive for hearing loss presented earlier (p-value >0.001) to a healthcare center than those who were not screened at all or screened negative for hearing loss and they finished the journey to CI 17 months earlier than those who were not screened. On the other hand, those who were screened negative were not found to present later than those who were not screened.

Conclusion

Going with the international trend, screening was found to have a significant positive effect on age at presentation, diagnosis, hearing aid fitting, surgery, and, hence, performance after implantation. Testing false negative on screening did not show a significant further delay when compared to those who were not screened.

Genetic screening revealed usher syndrome in a paediatric Chinese patient

Introduction

Usher syndrome is the most common cause of hereditary deaf-blindness. Three clinical subtypes have been classified. Usher syndrome type I is the most severe subtype characterized by congenital severe-to-profound hearing loss, retinitis pigmentosa and vestibular dysfunction.

Methods

One family was analyzed and the analysis included the combination of a custom capture/next-generation sequencing panel of 180 known deafness gene, Sanger sequencing and bioinformatics approaches.

Results

Compound heterozygous mutations in the MYO7A gene: a known missense mutation c.494C>T (p.Thr165Met) and a novel missense mutation c.6113G>A (p.Gly2038Glu) were identified in a proband. This Chinese hearing-impaired child was misdiagnosed as non-syndromic hearing loss which was later changed to the diagnosis of Usher syndrome type I after comprehensive audiometric, vestibular and ophthalmological examinations at 9 years old.

Conclusions

Due to the features of genetic heterogeneity and variation in clinical manifestation, molecular diagnosis and ophthalmological examinations by skilled ophthalmologists with knowledge of Usher syndrome should be suggested as a routine assessment which may improve the accuracy and reliability of etiological diagnosis for hearing loss.

Management challenges of congenital & early onset childhood hearing loss in a sub-Saharan African country

BACKGROUND

Hearing impairment is a hidden human disability with potentially catastrophic and age long consequences. This study highlighted the challenges associated with the management of congenital and early onset childhood hearing loss in a sub-Saharan African country.

METHODS

A retrospective descriptive study of children seen between January 2008 and December 2013 RESULT: A total of 223 children consisting of 124 (55.6%) males with (M:F) of 1.3:1. Age ranged 1-15 years (mean±SD; 6.39±4.37 years) and age group 1-5 years constituted the largest proportion (56.5%). Congenital causes, febrile illness and hypoxia were the leading causes of HI. Over 93% had moderately severe to profound hearing loss and 64.6% had delayed speech development. Majority (99.3%) with congenital/perinatal onset of HL had significantly delayed speech development and 99.3% of HL due to ototoxicity and infective causes had peri/post lingual speech impairment. Larger percentage of patients presented late; 16.6% of patients with congenital/perinatal onset of HL presented within the first year, >41% presented after the fifth year. Less than 5% had hearing aid fitted and patients with profound hearing impairment were referred for cochlear implant

CONCLUSION

The burden of congenital and early onset hearing impairment is high and management outcomes are unsatisfactory in our locality, Challenges associated with managing such children were discussed, and suggestions/strategies for better management and outcome were made.

Hearing aid use in Finnish children--impact of hearing loss variables and detection delay

OBJECTIVE

The aim was to study the factors contributing to the mode of hearing aid use in children, with special emphasis on hearing loss variables and detection delay.

METHODS

The subjects were 328 children and adolescents (58.5% boys, 41.5% girls) aged 1-18 years with hearing loss of > or =30 dB HL in the better ear fitted with hearing aid(s). The study was cross-sectional analysing the mode of using the aid binaurally/unilaterally or not at all.

RESULTS

The children with hearing-impairment ranging from 50 to 90 dB HL used more regularly their hearing aids. In the subjects with hearing loss > or =80 dB HL the presence of measurable hearing threshold at 4 kHz related significantly to the acceptance of amplification (p=0.027). In 19% of the subjects hearing aid was discarded. Bilateral amplification was used in 38%. Unilateral use was the prevailing mode (44%). The younger the children (p=0.000) and the worse their hearing loss (p=0.008), the more regular their bilateral use was. Early detection of hearing loss and early hearing aid fitting promoted binaural hearing aid use (p=0.004). A marked asymmetry in pure tone thresholds was a significant audiological reason for fixed unilateral hearing device use (38%, p=0.001).

CONCLUSIONS

The study shows that early detection of hearing loss and early habilitation of hearing increase bilateral use of hearing device and decrease the number of nonusers. Furthermore, residual unaided hearing at 4 kHz significantly improves the use of device.

Initiators in processes leading to hearing loss identification in Finnish children

The objective was to examine processes leading to the diagnosis of hearing loss in children. The subjects were 328 children (hearing loss >30 dB HL) fitted with hearing aids in Helsinki University Central Hospital. The risk factor initiated hearing loss detection in 31%, whereas parental suspicion accounted for 26% and hearing screening at the well-baby clinics for 20% of the subjects. Parents were foremost to suspect hearing loss at the age spoken language normally emerges (1.5-3.4 years). Screening was equally effective irrespective of the severity of hearing loss. Parents with misgivings of hearing impairment in their child should have compliant access to audiological units.