A multisite study to examine the efficacy of the otoacoustic emission/automated auditory brainstem response newborn hearing screening protocol: introduction and overview of the study

Diagnostic accuracy of CE Chirp

OBJECTIVE

There has been an increase in the use of the CE-Chirp stimulus in automated auditory brainstem response (AABR) equipment for neonatal hearing screening. The purpose of this study is to evaluate the diagnostic accuracy of the LS CE-Chirp-evoked auditory brainstem response (ABR) compared to the click-evoked ABR for the identification of different degrees and configurations of sensorineural (SNHL) hearing loss.

METHOD

49 ears with mild to moderate SNHL were assessed: 16 ears with rising SNHL and 33 ears with sloping high frequency SNHL. Behavioural pure tone thresholds were obtained at 125-8000 Hz and ABR thresholds were measured using the click and LS CE-Chirp stimuli respectively. Click- and LS CE-Chirp-evoked thresholds were compared with each other and with behavioural pure tone average at 500, 1000, 2000 Hz (PTA), high frequency average at 2000, 4000, 8000 Hz (HFA) and low frequency average at 250, 500, 1000 Hz (LFA). Diagnostic accuracy of the two ABR stimuli was also compared by using ROC curves.

RESULTS

Differences between click- and LS CE Chirp-evoked ABR, and behavioural thresholds were not statistically significant (p > 0.05). The highest significant correlations for ABR using clicks to behavioural thresholds was found at 2000 and 4000 Hz, whereas, the highest correlation for LS CE-Chirp ABRs to behavioural thresholds was found at 1000, 2000 and 4000 Hz (r > 0.7, p < 0.001). A very strong, positive correlation was found between both click (r = 0.805, p < 0.001) and LS CE-Chirp (r = 0.825, p < 0.001) and the behavioural PTA. LS CE-Chirp ABR thresholds were closer to mid and low frequency thresholds than the click ABR while the click-evoked thresholds were in closer proximity to HFA. Sensitivity and specificity and false negative rates were identical. Diagnostic accuracy of the LS CE-Chirp ABR was equal to or better than click for low (area under the curve (AUC) = 0.83), mid (AUC = 0.89) and high frequency hearing losses (AUC = 0.73). However, scatterplots indicated more frequent underestimation of behavioural pure tone thresholds at mid and high frequencies with the LS CE-Chirp than for the click ABR.

CONCLUSION

The diagnostic accuracy of the LS CE Chirp-evoked ABR is equivalent or better than the click-evoked ABR. The importance of ongoing surveillance and consideration of ABR screening protocols is consequently emphasized.

Prevalence of Hearing Loss Among a Representative Sample of Canadian Children and Adolescents, 3 to 19 Years of Age

Supplemental Digital Content is available in the text.

Objectives:

There are no nationally representative hearing loss (HL) prevalence data available for Canadian youth using direct measurements. The present study objectives were to estimate national prevalence of HL using audiometric pure-tone thresholds (0.5 to 8 kHz) and or distortion product otoacoustic emissions (DPOAEs) for children and adolescents, aged 3 to 19 years.

Design:

This cross-sectional population-based study presents findings from the 2012/2013 Canadian Health Measures Survey, entailing an in-person household interview and hearing measurements conducted in a mobile examination clinic. The initial study sample included 2591 participants, aged 3 to 19 years, representing 6.5 million Canadians (3.3 million males). After exclusions, subsamples consisted of 2434 participants, aged 3 to 19 years and 1879 participants, aged 6 to 19 years, with valid audiometric results. Eligible participants underwent otoscopic examination, tympanometry, DPOAE, and audiometry. HL was defined as a pure-tone average >20 dB for 6- to 18-year olds and ≥26 dB for 19-year olds, for one or more of the following: four-frequency (0.5, 1, 2, and 4 kHz) pure-tone average, high-frequency (3, 4, 6, and 8 kHz) pure-tone average, and low-frequency (0.5, 1, and 2 kHz) pure-tone average. Mild HL was defined as >20 to 40 dB (6- to 18-year olds) and ≥26 to 40 dB (19-year olds). Moderate or worse HL was defined as >40 dB (6- to 19-year olds). HL in 3- to 5-year olds (n = 555) was defined as absent DPOAEs as audiometry was not conducted. Self-reported HL was evaluated using the Health Utilities Index Mark 3 hearing questions.

Results:

The primary study outcome indicates that 7.7% of Canadian youth, aged 6 to 19, had any HL, for one or more pure-tone average. Four-frequency pure-tone average and high-frequency pure-tone average HL prevalence was 4.7 and 6.0%, respectively, whereas 5.8% had a low-frequency pure-tone average HL. Significantly more children/adolescents had unilateral HL. Mild HL was significantly more common than moderate or worse HL for each pure-tone average. Among Canadians, aged 6 to 19, less than 2.2% had sensorineural HL. Among Canadians, aged 3 to 19, less than 3.5% had conductive HL. Absent DPOAEs were found in 7.1^E% of 3- to 5-year olds, and in 3.4^E% of 6- to 19-year olds. Among participants eligible for the hearing evaluation and excluding missing data cases (n = 2575), 17.0% had excessive or impacted pus/wax in one or both ears. Self-reported HL in Canadians, aged 6 to 19, was 0.6 E% and 65.3% (aged 3 to 19) reported never having had their hearing tested. E indicates that a high sampling variability is associated with the estimate (coefficient of variation between 16.6% and 33.3%) and should be interpreted with caution.

Conclusions:

This study provides the first estimates of audiometrically measured HL prevalence among Canadian children and adolescents. A larger proportion of youth have measured HL than was previously reported using self-report surveys, indicating that screening using self-report or proxy may not be effective in identifying individuals with mild HL. Results may underestimate the true prevalence of HL due to the large number excluded and the presentation of impacted or excessive earwax or pus, precluding an accurate or complete hearing evaluation. The majority of 3- to 5-year olds with absent DPOAEs likely had conductive HL. Nonetheless, this type of HL which can be asymptomatic, may become permanent if left untreated. Future research will benefit from analyses, which includes the slight HL category, for which there is growing support, and from studies that identify factors contributing to HL in this population.

Accuracy of school screenings in the identification of minimal sensorineural hearing loss

PURPOSE

The goal of this study was to investigate how the use of a 25 dB HL referral criterion in school screenings affects the identification of hearing loss categorized as minimal sensorineural hearing loss (MSHL).

METHOD

A retrospective study applied screening levels of 20 and 25 dB HL at 1000, 2000, and 4000 Hz in each ear to previously obtained pure-tone thresholds for 1,475 school-age children. In a separate prospective study, 1,704 children were screened at school under typical conditions, and a subsample had complete audiological evaluations. Referral rates, sensitivity, and specificity were calculated for each screening level.

RESULTS

Referral rates varied by grade and criterion level, with comparable results between the two data sets. In both studies, when the screening level increased, the sensitivity to MSHL declined markedly, whereas specificity increased in the prospective study.

CONCLUSIONS

Screening at 25 dB yields poor sensitivity to MSHL. Converging evidence from these diverse populations supports using the 20 dB level to help identify MSHL. Multistage screening is recommended to limit referral rates. Even at 20 dB HL, cases of MSHL may be missed. Audiologists should encourage parents, educators, and speech–language pathologists to refer children suspected of hearing difficulty for complete audiological evaluations even if they pass school screenings.

Cochleopathy in Egyptian adolescents with Type 1 diabetes mellitus

BACKGROUND

Diabetic neuropathy is recognized as the most common clinical picture of nervous system disorders caused by diabetes mellitus (DM). Although peripheral and autonomic nervous system involvements are frequently encountered, data about the incidence of central diabetic neuropathies is limited.

OBJECTIVE

Our study aimed to detect early asymptomatic auditory impairment whether at the level of outer hair cells (OHCs), inner hair cells (IHCs) and or olivo-cochlear bundle and the relationship between these abnormalities and other variables such as diabetes duration, degree of the metabolic control, or presence of microvascular complications.

SUBJECTS AND METHODS

Seventy five adolescents with Type 1 DM and thirty three healthy controls participated in the study. Duration of DM, glycated hemoglobin (HbA1c) levels, microvascular complications were analyzed. All underwent basic audiological assessment to ensure normal hearing and normal middle ear function. Other tests comprised: transiently evoked otoacoustic emissions (TEOAEs) testing OHCs, TEOAEs with contralateral suppression (testing the integrity of olivo-cochlear bundle) and threshold equalizing noise (TEN) testing IHCs as evidenced by dead regions within the cochlea.

RESULTS

Early asymptomatic OHCs involvement as reflected by partial pass in 33.3% of cases with diminished suppression as compared to 9.1% control group. Eleven patients (7.33%) showed positive TEN Test reflecting resistance of IHCs to hyperglycemic injury. Diabetic patients had significantly higher amplitude on TEOAEs with noise suppression when compared to controls (P=0.002). The mean difference in amplitude of TEOAEs before and after suppression was significantly higher in diabetics with microvascular complications when compared to diabetic children without complications at all frequencies (P<0.001 for all). Duration of diabetes and microvascular complications (nephropathy, peripheral and autonomic neuropathy) were not correlated with the lack of suppression except for retinopathy (P=0.02). In contrast, poor metabolic control was associated with poor suppression (r=-0.443, P=0.001).

CONCLUSIONS

Cochleopathy can be detected in a relatively high proportion of subjects with Type 1 diabetes in spite of a normal audiometric hearing threshold. It should be considered as early manifestation of diabetic neuropathy which is related to the degree of metabolic control and retinopathy independent of other microvascular complications.

PEATE automático em recém nascidos de risco: estudo da sensibilidade e especificidade

OBJETIVO: verificar a sensibilidade e especificidade do teste de potencial evocado auditivo de tronco encefálico em equipamento automático (PEATEa), comparando-o ao teste de potencial evocado auditivo de tronco encefálico em equipamento diagnóstico (PEATE) em um programa de triagem auditiva neonatal em neonatos de risco. MÉTODO: foram avaliados 186 neonatos, 83 nascidos a termo e 103 pré-termo, sendo 88 do sexo masculino e 98 feminino. A triagem constou de emissões otoacústicas evocadas por estímulos transientes (EOAT), PEATEa e ao PEATE na mesma semana. RESULTADOS: dos 186 neonatos avaliados, 156 (83,9%) apresentaram audição normal. A perda condutiva foi encontrada em 9 neonatos (4,8%),sendo 7 bilaterais e 2 unilaterais. A perda auditiva coclear foi observada em 5 neonatos (2,7%) sendo um unilateral. Alteração central foi obtida em 11 neonatos (5,9%) e um neonato foi diagnosticado como espectro da neuropatia auditiva -ENA(0,5%).Em 4 casos houve atraso maturacional na avaliação inicial com normalização das respostas no mês seguinte Comparando-se os resultados do PEATEa com o PEATE, observou-se alta sensibilidade ( superior a 99%) para identificação de perda coclear,condutiva, central, atraso maturacional e ENA .A especificidade do PEATEa foi de 100% para ENA, mediana para perda coclear (75% na OD e 60% na OE), e para alterações centrais (54,5%OD e 63,6% OE). Para identificação de perdas condutivas (inferior a 43%). CONCLUSÃO: o PEATEa foi eficaz na identificação das neuropatias auditivas com elevada especificidade e sensibilidade. Contudo, falsos negativos foram observados para perdas cocleares, condutivas, para alterações centrais e atraso maturacional.

Sound-conduction effects on distortion-product otoacoustic emission screening outcomes in newborn infants: test performance of wideband acoustic transfer functions and 1-kHz tympanometry

OBJECTIVE

Universal newborn hearing screening (UNHS) test outcomes can be influenced by conditions affecting the sound conduction pathway, including ear canal and/or middle ear function. The purpose of this study was to evaluate the test performance of wideband (WB) acoustic transfer functions and 1-kHz tympanometry in terms of their ability to predict the status of the sound conduction pathway for ears that passed or were referred in a UNHS program.

DESIGN

A distortion-product otoacoustic emission (DPOAE) test was used to determine the UNHS status of 455 infant ears (375 passed and 80 referred). WB and 1-kHz tests were performed immediately after the infant's first DPOAE test (day 1). Of the 80 infants referred on day 1, 67 infants were evaluated again after a second UNHS DPOAE test the next day (day 2). WB data were acquired under ambient and tympanometric (pressurized) ear canal conditions. Clinical decision theory analysis was used to assess the test performance of WB and 1-kHz tests in terms of their ability to classify ears that passed or were referred, using DPOAE UNHS test outcomes as the "gold standard." Specifically, performance was assessed using previously published measurement criteria and a maximum-likelihood procedure for 1-kHz tympanometry and WB measurements, respectively.

RESULTS

For measurements from day 1, the highest area under the receiver operating characteristic curve was 0.87 for an ambient WB test predictor. The highest area under the receiver operating characteristic curve among several variables derived from 1-kHz tympanometry was 0.75. In general, ears that passed the DPOAE UNHS test had higher energy absorbance compared with those that were referred, indicating that infants who passed the DPOAE UNHS had a more acoustically efficient conductive pathway.

CONCLUSIONS

Results showed that (1) WB tests had better performance in classifying UNHS DPOAE outcomes than 1-kHz tympanometry; (2) WB tests provide data to suggest that many UNHS referrals are a consequence of transient conditions affecting the sound conduction pathway; (3) WB data reveal changes in sound conduction during the first 2 days of life; and (4) because WB measurements used in the present study are objective and quick it may be feasible to consider implementing such measurements in conjunction with UNHS programs.

Triagem auditiva neonatal: um estudo na cidade de Curitiba - PR

OBJETIVO: verificar a prática de Triagem Auditiva Neonatal na cidade de Curitiba-PR. MÉTODOS: inicialmente foi realizado um levantamento do número de maternidades e/ou hospitais com maternidades existentes na cidade de Curitiba, mediante a consulta no Cadastro Nacional de Estabelecimentos de Saúde. Constatou-se a existência de um total de 59 hospitais cadastrados, sendo que três destes são maternidades e 18 são hospitais com maternidade. A partir do levantamento feito, foi estabelecido um contato com o profissional responsável por cada uma das instituições, sendo questionado quanto à existência de um programa de Triagem Auditiva Neonatal e para aqueles que o apresentavam foi entregue um questionário a fim de obter informações a respeito do referido serviço. RESULTADOS: constatou-se que apenas 23,8% das maternidades realizam Triagem Auditiva Neonatal, sendo que destas, 20% é universal para neonatos a termo e 80% universal para neonatos de alto risco. A triagem em todos os serviços é realizada com Emissões Otoacústicas Evocadas por Estímulo Transiente. CONCLUSÃO: mediante o estudo realizado verificou-se que a lei número 14588 - 22/12/2004 não está sendo rigorosamente cumprida. Apesar da demanda aliada à importância da detecção precoce, a Triagem Auditiva Neonatal não é realizada em todas as maternidades existentes e mesmo naquelas nas quais há um fonoaudiólogo e a triagem auditiva é realizada, esta não é universal.

Quantitative and Qualitative Follow-Up Outcomes From a Preschool Audiologic Screening Program: Perspectives Over a Decade

Purpose

This investigation reports on quantitative and qualitative follow-up information obtained from a preschool audiologic screening program covering a 10-year period (1995 to 2004).

Method

The audiologic screening consisted of a hearing (pure tone) and tympanometry screening. A total of 34,979 children, 3 to 5 years of age, were screened.

Results

Eighteen percent (6,337) of the children were referred for further hearing and/or medical ear evaluation. Of 1,421 follow-up responses received, 93% complied with the follow-up recommendations while 7% did not. Of 1,316 children in the follow-up group, outer and/or middle ear disorder in one or both ears was medically confirmed for 37%. Unilateral or bilateral hearing loss was diagnosed in 18% as conductive (12%), sensorineural (1%), mixed (0.4%), or unspecified (5%). Overall, hearing loss and/or otologic disorder was confirmed in 49% of the follow-up group, suggesting a prevalence of 1.8% in a preschool-age population. A small ( n = 32) sample of unsolicited comments indicated that physicians most influenced noncompliance with hearing evaluation follow-up.

Conclusions

The quantitative hearing and otologic follow-up outcome data affirm the importance of audiologic screening in the preschool population. Qualitative data suggest that some physicians may not be advocating appropriate screening follow-up services.

Is Gentamicin Ototoxic to the Fetus?

BACKGROUND

Gentamicin is used in pregnancy to treat infections that cause complications to the mother and fetus if left untreated. In 2003, Schering, the manufacturer of Garamycin Injectable, amended the product monograph in the Compendium of Pharmaceuticals and Specialties to state that gentamicin should be avoided in pregnancy due to cases of "total irreversible bilateral congenital deafness" in babies exposed to gentamicin in utero. Because we have identified, after an intensive literature search, only two cases over many years of availability, it is questionable whether the outcome can be attributed to drug use rather than other factors.

OBJECTIVES

The main objective of this study was to determine whether any infant exposed in utero to intravenous gentamicin and born between January 2002 and April 2006 at Victoria General Hospital demonstrated audiologic deficits on routine hearing testing. Such testing has been universally available since late 2001. Our secondary objectives were to examine patterns of gentamicin use, including indication, dosage, duration, and to determine whether or not monitoring of serum gentamicin levels was done.

METHODS

Women who had received gentamicin were identified through pharmacy records and their charts reviewed for factors that might contribute to fetal deafness including substance abuse, use of other potentially ototoxic medications, genetic predisposition, and intrauterine infections. We reviewed audiology test result and the infants' charts for potential confounding factors, including prematurity, low birth weight, low Apgar scores, anoxia, hyperbilirubinemia, sepsis, and meningitis.

RESULTS

Fifty-two charts were reviewed, 40 of which documented live births. There was no case of hearing loss documented. Of the eight fetal losses, six (11.5%) were preterm births before viability, and two were elective terminations. Pyelonephritis was the main indication for gentamicin use (48%), followed by chorioamnionitis (31%) and other miscellaneous indications (21%). Three times daily dosing was used for a mean duration of 2.7 +- 2.3 days, resulting in an average cumulative dose of 764 +- 600 mg gentamicin. The average gestational age at exposure was 28 weeks. Maternal serum gentamicin levels were obtained in 72.5% of cases, and no trough level was above 2 mg/L. Other potentially ototoxic medications were administered to the mother in 17.5% of pregnancies, and to 17.5% of babies in the immediate newborn period. With the exception of one infant who died before additional testing could be carried out, all the infants passed hearing tests, 89% on initial screening.

CONCLUSION

In utero exposure to gentamicin did not cause an increase in audiologic impairment in the infants tested in this cohort.

Characteristic findings of auditory brainstem response and otoacoustic emission in the Bronx waltzer mouse

Auditory brainstem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs) were evaluated serially from 1 to 22 months in Bronx waltzer homozygotes (bv/bv), heterozygotes (+/bv) and control (+/+) mice, which were differentiated by means of PCR of marker DNA (D5Mit209). The wave IV threshold of the click-evoked ABR was higher than the DPOAE threshold with the DP growth method in each bv/bv, although the two thresholds were almost the same in the +/+ group. The DP value at 2f(1) - f(2) in the bv/bv showed an apparent decrease at 2 to 3 months of age with 80 dB SPL stimulation using f(2) frequency 7996 Hz and frequency ratio f(2)/f(1) = 1.22, compared to control or heterozygote mice. It was characteristic that the 2f(2) - f(1) DP signal-to-noise ratio (SNR) value was more preserved from 80 to 60 dB SPL than the 2f(1) - f(2) DP value at f(2) frequency 7996 Hz in most bv/bv, however, control mice showed almost the same levels of 2f(1) - f(2) and 2f(2) - f(1) SNR value at both f(2) frequencies of 6006 and 7996 Hz. The preservation of a substantial 2f(2) - f(1) DP suggested that it would be generated basal to the primary-tone place on the basilar membrane and there might be a reflection of the unique function of the remaining outer hair cells in the Bronx waltzer mice. These findings suggest that combination of ABR with DPOAE could offer useful information about differentiating the mechanism of hair cell dysfunction of the hereditary hearing impairment in the clinical fields.

A Multisite Study to Examine the Efficacy of the Otoacoustic Emission/Automated Auditory Brainstem Response Newborn Hearing Screening Protocol

Purpose: This article examines whether changes in hearing screening practices are warranted based on the results of the recent series of studies by J. L. Johnson, K. R. White, J. E. Widen, J. S. Gravel, B. R. Vohr, M. James, T. Kennalley, A. B. Maxon, L. Spivak, M. Sullivan-Mahoney, Y. Weirather, and S. Meyer (Johnson, White, Widen, Gravel, James, et al., 2005; Johnson, White, Widen, Gravel, Vohr, et al., 2005; White et al., 2005; Widen et al., 2005) that found a significant number of infants who passed an automated auditory brainstem response (A-ABR) screening after failing an initial otoacoustic emission (OAE) screening later were found to have permanent hearing loss in one or both ears.

Method: Similar to the approach used by F. H. Bess and J. Paradise (1994), this article addresses the public health tenets that need to be in place before screening programs, or in this case, a change in screening practice (use of a 2-step screening protocol) can be justified.

Results: There are no data to suggest that a 2-step OAE/A-ABR screening protocol should be avoided.

Conclusion: Research is needed before any change in public policy and practice surrounding current early hearing detection and intervention programs could be supported.

A Multisite Study to Examine the Efficacy of the Otoacoustic Emission/Automated Auditory Brainstem Response Newborn Hearing Screening Protocol

Purpose: This 3rd of 4 articles on a study of the efficacy of the 2-stage otoacoustic emission/automated auditory brainstem response (OAE/A-ABR) newborn hearing screening protocol describes (a) the behavioral audiometric protocol used to validate hearing status at 8–12 months of age, (b) the hearing status of the sample, and (c) the success of the visual reinforcement audiometry (VRA) protocol across 7 sites.

Method: A total of 973 infants who failed OAE but passed A-ABR, in one or both ears, during newborn screening were tested with a VRA protocol, supplemented by tympanometry and OAE screening at age 8–12 months.

Results: VRA audiograms (1.0, 2.0, and 4.0 kHz) were obtained for 1,184 (82.7%) of the 1,432 study ears. Hearing loss was ruled out in another 100 ears by VRA in combination with OAE, for a total of 88.7% of the study sample. Permanent hearing loss was identified in 30 ears of 21 infants. Sites differed in their success with the VRA protocol.

Conclusions: Continued monitoring of hearing beyond the newborn period is an important component of early detection of hearing loss. Using a structured protocol, VRA is an appropriate test method for most, but not all, infants. A battery of test procedures is often needed to adequately delineate hearing loss in infants. Examiner experience appears to be a factor in successful VRA.