Epidemiology of Permanent Childhood Hearing Loss in Glasgow, 1985–1994

Universal neonatal hearing screening and delayed hearing loss or late-developmental hearing loss

OBJECTIVE

To determine the percentage of children with permanent bilateral postnatal hearing loss in order to study its incidence, related risk factors, diagnosis and treatment.

METHODS

Retrospective study to collect data on children diagnosed with hearing loss outside the neonatal period in the Hearing Loss Unit of the Hospital Universitario Central de Asturias, from April 2014 to April 2021.

RESULTS

52 cases met the inclusion criteria. The detection rate of congenital hearing loss in the neonatal screening programme in the same study period was 1.5 children per thousand newborns per year, adding postnatal hearing loss results in a rate of infant bilateral hearing loss of 2.7 children per thousand (55.5% and 44.4% respectively). Thirty-five children presented risk factors for hearing loss, of which 23 were at retrocochlear risk. The mean age at referral was 91.9 (18-185) months. Hearing aid fitting was indicated in 44 cases (84.6%). Cochlear implantation was indicated in eight cases (15.4%).

DISCUSSION

Although congenital hearing loss accounts for the majority of childhood deafness, postnatal hearing loss has a significant incidence. This may be mainly due to: (1) that hearing impairment may arise in the first years of life, (2) that mild hearing loss as well as hearing loss in severe frequencies are undetectable by neonatal screening in some cases, (3) that some children may have false negative results.

CONCLUSION

postnatal hearing loss requires identification of risk factors and long-term follow-up of children with hearing loss, as it needs to be detected and treated early.

Genetic screening as an adjunct to universal newborn hearing screening: literature review and implications for non-congenital pre-lingual hearing loss

Objective: Universal newborn hearing screening (UNHS) uses otoacoustic emissions testing (OAE) and auditory brainstem response testing (ABR) to screen all newborn infants for hearing loss (HL), but may not identify infants with mild HL at birth or delayed onset HL. The purpose of this review is to examine the role of genetic screening to diagnose children with pre-lingual HL that is not detected at birth by determining the rate of children who pass UNHS but have a positive genetic screening. This includes a summary of the current UNHS and its limitations and a review of genetic mutations and screening technologies used to detect patients with an increased risk of undiagnosed pre-lingual HL.Design: Literature review of studies that compare UNHS with concurrent genetic screening.Study sample: Infants and children with HLResults: Sixteen studies were included encompassing 137,895 infants. Pathogenic mutations were detected in 8.66% of patients. In total, 545 patients passed the UNHS but had a positive genetic screening. The average percentage of patients who passed UNHS but had a positive genetic screening was 1.4%.Conclusions: This review demonstrates the positive impact of concurrent genetic screening with UNHS to identify patients with pre-lingual HL.

A new hearing screening system for preschool children

OBJECTIVES

This study aimed to investigate the practical application of Smart Hearing, a new hearing screening system for preschool children.

METHODS

The screening system was applied to 6288 preschool children. The system auto-tested hearing thresholds at three frequencies: 1kHz, 2kHz, and 4kHz; a 30dB hearing level (HL) was the critical intensity for passing. Children with positive results were referred for audiological evaluation (pure tone audiometry, tympanometry and distortion product otoacoustic emissions assessment, etc.). To evaluate the test accuracy, 312 children (5%) were randomly selected to receive audiology assessment.

RESULTS

In this study, 582 children (9.3%) tested positive in the screening, and the referral rate of the four age groups from 3 to 6 years old was 18.8%, 11.9%, 6.5% and 4.0%, respectively. A total of 463 children underwent audiological assessment, of which 12 cases (1.91‰; 95% CI: 0.83‰, 2.99‰) were diagnosed with permanent hearing loss, and 75 cases (1.19%; 95% CI: 0.92%, 1.46%) were diagnosed with temporary conductive hearing loss. No mixed hearing loss was found in this study. The specificity of the system was 92.6% and the sensitivity was only 37.5%.

CONCLUSIONS

This screening system is suitable for the universal hearing screening of preschool children above 4 years old, and further improvements of the system are needed to increase its sensitivity.

Hearing level in children with Down syndrome at the age of eight

This study examines the prevalence of hearing loss in children with Down syndrome at the age of 8. All children were examined in the ENT-departments of public hospitals in Norway and the study population consisted of children born in Norway in 2002 with Down syndrome. Hearing loss was defined as pure-tone air-conduction reduction by on average more than 25 dB HL in the best hearing ear. A cross sectional clinical and audiological population based study was chosen as study design. Hearing loss more than 25 dB HL in the best hearing ear was found in 17/49 children (35%). Mild hearing loss was found in 13 children (26%), moderate in 3 (6%) children and severe hearing loss in 1 child (2%). Conductive hearing loss was found in 8 children (16%), 9 children (18%) had a sensory-neural hearing loss, and mixed hearing loss was found in 3 children. Mean hearing level among boys and girls were 30.0 dB HL (SD 15.7) and 25.5 dB HL (SD13.7) respectively, a non-significant difference (p=0.139). In conclusion this study indicates that both conductive and sensorineural hearing loss, is still common in children with Down syndrome children at the age of eight and as much as two thirds of the children may have a bilateral impairment. The study population was under diagnosed in terms of hearing loss and thus our findings underline the importance of continuous audiological follow up of this group of children throughout childhood.

Screening for delayed-onset hearing loss in preschool children who previously passed the newborn hearing screening

OBJECTIVE

The goal of this study was to investigate the prevalence of delayed-onset hearing loss in preschool children who previously passed newborn hearing screening in Shanghai, China.

METHODS

Between October 2009 and September 2010, 21,427 preschool children were enrolled from five areas of Shanghai, who had passed newborn hearing screening. Children were screened for delayed-onset hearing loss with pediatric audiometers. Children with positive results in initial and re-screening tests were assessed audiologically and for risk indicators according to the Year 2007 Statement of the American Joint Committee on Infant Hearing (JCIH).

RESULTS

During the study period, 445 children (2.08%) were referred for audiologic assessment; 16 (0.75/1000, 95% CI 0.38-1.12) had permanent delayed-onset hearing loss. Of these, five (0.23/1000) had bilateral moderate hearing loss; seven (0.33/1000) had mild bilateral hearing loss; and four (0.19/1000) had unilateral moderate or mild hearing loss. JCIH risk indicators were established for six children (6/16, 37.5%), including parental concern regarding speech and language developmental delay, neonatal intensive care unit with assisted ventilation or hyperbilirubinemia, recurrent otitis media with effusion, craniofacial malformation, and family history (n=1 for each). The remaining ten (62.5%) had no related risk factors.

CONCLUSIONS

A significant proportion of preschool children have undiagnosed delayed-onset hearing loss. Hearing screening in preschool is recommended for an early detection.

Universal newborn hearing screening and postnatal hearing loss

OBJECTIVE

The goal of this study was to determine the percentage of children who have a postnatal permanent childhood hearing impairment (PCHI) and the percentage thereof who have risk indicators for a postnatal hearing loss.

METHODS

Data were drawn retrospectively from the clinical charts of children who had bilateral PCHI (>40 dB hearing level, better ear, unaided) and had undergone universal newborn hearing screening (UNHS) between 1995 and 2000 in various Austrian hospitals. A hearing loss was recognized as postnatal when a child passed UNHS but was later found to have a hearing impairment. The presence of risk indicators, as suggested by the Year 2000 Statement of the American Joint Committee on Infant Hearing (JCIH), was assessed by reviewing the children's clinical charts.

RESULTS

Of a total of 105 children with bilateral PCHI, 23 (22%) showed postnatal impairment. After correction of this number for underascertainment, postnatal impairment was estimated to account for 25% of all bilateral PCHI at age 9 years. Risk indicators were found in 17 children but did not fully correspond to those proposed by the JCIH. The risk factors found were a family history of hearing loss (3 children), meningitis (2), craniofacial malformation (2), persistent pulmonary hypertension (1), congenital cytomegaly infection (1), extracorporeal membrane oxygenation (1), recurrent otitis media with effusion (1), and, in addition to the JCIH list, ototoxic therapy (5), and birth before 33rd gestational week (2) (1 child had a combination of the last 2). Six children showed no risk indicators for the postnatal hearing loss.

CONCLUSIONS

Our findings suggest that approximately 25% of bilateral childhood hearing loss is postnatal, which supports the leading role of UNHS in detecting PCHI. Provisions for also identifying postnatal cases nevertheless are justified. Because in some of these children no risk indicators are detectable and in others the hearing deterioration starts after age 3 years, audiologic monitoring of at-risk children up to this age may not be sufficient. Additional methods, such as hearing screening at nursery schools or schools, are recommended.