Diagnostic Auditory Brainstem Response Research Articles

The outcomes of an audiological management programme for neonates with hyperbilirubinaemia.

Hyperbilirubinaemia is a contributing condition to the prevalence of neonatal hearing loss. Because of its pathophysiology, the use of Otoacoustic Emissions (OAE) and Automated Auditory Brainstem Response (AABR) testing is essential in diagnosing hearing loss. Two-tier screening models are typically used in developing world contexts; however, a combined approach to testing (using both tests) should be used for early detection. Blood serum levels should also be monitored to determine how they impact audiological test results. To determine the outcomes of using a combined testing approach of both OAE and Auditory Brainstem Response (ABR) for both screening and diagnostic testing of neonates with hyperbilirubinaemia and studying the relationship between the test results and the serum bilirubin levels. A cross-sectional, comparative design was utilised. Forty neonates were tested (80 ears). Neonates underwent hearing screening and diagnostic testing (ABR and/or AABR and DPOAE tests). The study was conducted at a hospital in South Africa. One-third (32.5%) of the neonates had comorbidities. Screening results indicated that the AABR test could identify more cases of abnormalities than DPOAEs (p= 0.001). Participants with a serum level greater than 10 mg/dL presented with abnormal diagnostic ABR test results while passing the DPOAE test (p 0.001). Combined use of ABR and DPOAE testing yielded a greater identification of auditory pathology than using either test alone. Serum bilirubin levels can be used as an indicator for combination testing.Contribution:Combined use of ABR and DPOAE testing leads to greater identification of auditory pathology.

Evaluating the feasibility of a tele-diagnostic auditory brainstem response service in a rural context.

There is a noticeable gap in access to audiology services in South Africa, and the gap is intensified in rural areas. Often, primary healthcare (PHC) facilities have an unequal ratio of audiologists to patients in need. Telehealth can expand the range of hearing healthcare services. This study aimed to determine whether, for infants, tele-diagnostic Auditory Brainstem Response (ABR) assessment results conducted within a mobile clinic van are comparable to face-to-face diagnostic ABR results in rural Winterveldt, Pretoria North, South Africa. The study utilised a quantitative, prospective cross-sectional comparative within-subject design. Each participant received both face-to-face and mobile tele-diagnostic ABR tests, which were then compared to evaluate the feasibility of mobile tele-diagnostic ABR testing. The Student's t-test was used to determine whether there was a difference between face-to-face and tele-diagnostic tests, and Bland -Altman plots were used to assess the level of agreement between the ABR testing results. There was a strong correlation (p 0.001) between face-to-face and mobile tele-diagnostic ABR test results for both neurological and audiological ABR tests. The study found that there was no statistical significance between face-to-face and tele-diagnostic ABR measures; additionally, the results were within clinically acceptable and normative measures. Tele-diagnostic ABR offered within a mobile clinic van is feasible as it produces similar and clinically acceptable results when compared to the traditional assessment method.Contribution:This feasibility study is a positive indicator that tele-diagnostic ABR testing through a mobile clinic van may be considered to accelerate the delivery of hearing healthcare services to the infant population in rural communities.

Availability of resources for paediatric hearing care in a South African province.

Unavailability of healthcare resources can lead to poor patient outcomes. The latter is true for infants with hearing loss and require early hearing detection and intervention (EHDI). To determine the availability and distribution of resources for EHDI in state hospitals in the Eastern Cape (EC) province, South Africa. Sixteen state hospitals (nine district, four regional and three tertiary hospitals). Descriptive cross-sectional survey completed between July 2022 and October 2022. Thirteen hospitals had audiologists (n= 4) or speech therapists and audiologists (n= 9). Specific to equipment, 10 hospitals had a screening otoacoustic emissions or automated auditory brainstem response, 8 hospitals had diagnostic middle ear analysers and only 3 hospitals had diagnostic auditory brainstem response and/or auditory steady state response. Twelve hospitals did not have visual response audiometry (VRA) and 94% had no hearing aid verification systems. Budget allocations were uneven, with only 10 hospitals, i.e., 4 districts, all regional and 2 tertiary hospitals being allocated varying amounts. Subsequently, only 50% provided newborn hearing screening, 56% provided diagnostic evaluations and 14 hospitals fitted hearing aids. Results revealed a limited and uneven distribution of resources, which negatively impacted the provision of EHDI. Even distribution of healthcare resources and further research aimed at strengthening hearing health services is recommended as these could potentially improve equitable access to EHDI and the overall quality of healthcare provided.Contribution:This study highlights the need for even distribution of resources and strengthening of health systems, especially in the dawn of the National Health Insurance.

Hearing Loss and Risk Factors in Very Low Birth Weight Infants.

The incidence of sensorineural hearing loss (SNHL) is still high in very low birth weight (VLBW) infants. The purpose of our study was to provide the prevalence rates of SNHL and to analyze the risk factors of hearing impairment and changes in hearing thresholds in a cohort of VLBW infants. A retrospective observational study was conducted in our neonatal intensive care unit (NICU) from 2012 to 2016. All VLBW infants included were screened by transient evoked otoacoustic emissions (TEOAEs) and diagnostic auditory brainstem response (ABR). In total, we enrolled 316 infants and SNHL was diagnosed in 68, leading to an early incidence of 21.5% as 36 infants out of 68 improved. Finally, SNHL was confirmed in 20 patients (6.3%) who needed hearing aids. They were significantly smaller, sicker, had longer hospitalizations, and received more ototoxic therapies. Logistic regression analysis showed that gestational age (GA) influenced the association between drugs and SNHL. The results underlined how the total exposure to antibiotics is significantly associated with SNHL, even after GA correction. In conclusion, GA, birth weight and, above all, the length and complexity of NICU stay quantify the risk of SNHL and should be considered at the individual level for parent counseling.

Evaluation of an Investigational Hearing Screening Device (HeLe) to Demonstrate Acoustic Brainstem Response among Normal-hearing Adults.

This pilot human trial demonstrates the ability of the investigational newborn hearing screening device to provide acoustic stimulation to produce evoked potentials, as well as its ability to capture and acquire auditory evoked potentials, especially the auditory brainstem response (ABR) wave V. This pilot study also demonstrates the ease of recognizing and identifying ABR waves in the graphical presentation of the evoked potentials over time. Fourteen normal-hearing adults or a total of twenty-eight (28) normal-hearing adult ears underwent auditory brainstem response testing using the investigational hearing screening device. A commercially available auditory brainstem response detection device was used to confirm that the acquired ABR waves of the investigational device are normal. The ABR waves displayed by the investigation device were also reviewed by the clinical audiologists to determine their recognizability and identifiability. The pilot trial demonstrates the ability of the investigational newborn hearing screening device in providing acoustic stimulation to produce evoked potentials, and in acquiring and capturing ABR waves, specifically the wave V, among normal-hearing adult ears. The clinical audiologists recognized and identified the ABR wave V among the evoked potentials at 40dB, 60dB, and 80dB acoustic stimulation. About eighty-nine percent (89.2%) of all ears tested had identifiable and recognizable wave V upon acoustic stimulation at 40dB. The investigational hearing screening device: (1) can provide acoustic stimulation to produce evoked potentials, (2) can accurately capture and acquire these evoked potentials, (3) can present these evoked potentials in a voltage per time graphical display which an audiologist and trained HCP can easily read and interpret (diagnostic ABR), and (4) can present wave V auditory brainstem potentials that can be easily identified by an audiologist and trained HCP (screening ABR).

Incidence of Hearing Loss in Corpus Callosum Agenesis.

Congenital corpus callosum agenesis (CCA) is one of the congenital anomalies in newborns, which usually presents with syndromic features. It can be asymptomatic or have variable neurological deficits. Some studies demonstrated that hearing loss can occur in patients with CCA; however, the exact prevalence remains unclear. Therefore, we aimed to investigate the prevalence of hearing loss in CCA using data from newborn hearing screening in a single tertiary referral center. A total of 126 patients with CCA combined with hearing loss diagnosed at our hospital from November 2005 to November 2022 were retrospectively included in our study. All patients had at least one screening or diagnostic auditory brainstem response result. Brain ultrasonography and magnetic resonance imaging were used to diagnose CCA. Among 126 patients, 93 had automated auditory brainstem response within a month from birth. Of the 93 patients, 20 (21.5%) had a "refer" result in the screening tests in at least one ear. The final incidence of hearing loss in patients with CCA was 16.1%. We observed no hearing loss in 22 patients with isolated CCA. Patients with CCA have a higher incidence of hearing loss. However, this is likely related to the concurrent condition of patients. CCA seems not to be a risk factor for hearing loss.

Risk Factors Associated with Newborn Hearing Impairment in the Neonatal ICU of a Tertiary Hospital

Introduction: Hearing impairment has a devastating, detrimental, and adverse impact on the development of the newborn. Unfortunately, this hidden disability remains undetected for many newborns until it is too late to prevent undesirable and often irreversible damage. It has long been recognized that undiagnosed hearing loss, even a mild loss at birth, can negatively affect speech and language development, Resulting in poor academic achievement and social-emotional development. According to WHO 2009, newborns in the NICU are 10-20 times at higher risk of developing hearing loss. The risk factors associated with newborn hearing impairment vary from country to country and even within countries. There has been a paucity of studies on this topic from Bangladesh. This study was done to identify the risk factors associated with newborn hearing impairment in the study place. The objective of the study: To identify risk factors associated with newborn hearing impairment in the study group.
 Methodology: A prospective observational study was conducted in the department of neonatology, BSMMU. After taking consent from the parents/guardians, a thorough history of these newborns, including particulars of the neonates, family history of hearing loss, treatment history, antenatal, natal, and postnatal history, was recorded in a data collection form. Newborn admitted to the NICU during the study period was the study population. The newborn who meet the inclusion criteria was screened with Transient Evoked Otoacoustic Emissions (TEOAE) close to discharge from the NICU or before one month of age. A second screen was done with TEOAE again after one month of 1st screen but prior to 3 months of postnatal age if referred in 1st screen. Diagnostic Auditory Brain stem Response (ABR) was made to confirm the hearing impairment, and it was done prior to 3 months of postnatal age if referred in both the 1st and 2nd screens. Data were analyzed by statistical package for social sciences (SPSS) version 20.
 Results: 426 valid recordings from 493 newborns admitted in the NICU enrolled consecutively constitute the basis of this study. 14 newborns were found to have hearing impairment among 426 newborns. APGAR ≤ 6 at 5 minutes (odds ratio 20.34, p-value 0.01), TORCH infection (odds ratio 0.64, p-value 0.01), IUGR odds ratio 8.92, p-value 0.02) were independent significant risk factors for hearing impairment.
 Conclusion: APGAR ≤ 6 at 5 minutes, TORCH infection, and IUGR are independent significant risk factors for newborn hearing impairment. Newborns in NICU with these risk factors should have mandatory audiological evaluation.
 TAJ 2022; 35: No-2: 59-65

Enhanced Place Specificity of the Parallel Auditory Brainstem Response: A Modeling Study.

While each place on the cochlea is most sensitive to a specific frequency, it will generally respond to a sufficiently high-level stimulus over a wide range of frequencies. This spread of excitation can introduce errors in clinical threshold estimation during a diagnostic auditory brainstem response (ABR) exam. Off-frequency cochlear excitation can be mitigated through the addition of masking noise to the test stimuli, but introducing a masker increases the already long test times of the typical ABR exam. Our lab has recently developed the parallel ABR (pABR) paradigm to speed up test times by utilizing randomized stimulus timing to estimate the thresholds for multiple frequencies simultaneously. There is reason to believe parallel presentation of multiple frequencies provides masking effects and improves place specificity while decreasing test times. Here, we use two computational models of the auditory periphery to characterize the predicted effect of parallel presentation on place specificity in the auditory nerve. We additionally examine the effect of stimulus rate and level. Both models show the pABR is at least as place specific as standard methods, with an improvement in place specificity for parallel presentation (vs. serial) at high levels, especially at high stimulus rates. When simulating hearing impairment in one of the models, place specificity was also improved near threshold. Rather than a tradeoff, this improved place specificity would represent a secondary benefit to the pABR's faster test times.

Expanding the Role of Educational Audiologists After a Failed Newborn Hearing Screening: A Quality Improvement Study.

Purpose Lack of timely and proximal access to diagnostic hearing evaluation using auditory brainstem response (ABR) testing hampers the effectiveness of Early Hearing Detection and Intervention (EHDI) programs in the United States. This study measured the impact of a state-based quality-improvement (QI) project that provided diagnostic ABR equipment and training to educational audiologists distributed throughout Iowa in regional special education centers. Method We used de-identified administrative data generated by the state EHDI program to analyze markers of access to early hearing health care for infants in a preproject condition ("Baseline") compared to the implementation of diagnostic ABRs at the regional special education centers ("QI Project"). Results Our findings revealed that the QI Project was associated with improvements in timeliness of first hearing evaluation, distance traveled for first hearing evaluation, and likelihood of receiving on-guideline audiology care during the first hearing evaluation. Conclusions Following the onset of the QI Project, infants and their families had greater access to initial hearing evaluation after failed newborn hearing screening. This improvement could have cascading effects on timeliness of later intervention among those with confirmed permanent childhood hearing loss.

The difference between Chirp & Click stimulation in Diagnostic Auditory Brainstem Response in assessment of hearing among age group between 1-10 years Iraqi children

Background: Aim: To compare the response of human auditory brain stem evoked by clicks stimuli and chirps. Patients and Methods: A study of cross-sectional design was chosen to evaluate the objective of the study. Children between 1-10 years were enrolled from the attendants of the Dept. of Surgery and Audiology, Al-Jamhoori Teaching Hospital, Ministry of Health /Nineveh health Directorate, and the outpatient clinics in al-alwiyah teaching hospital for children and done in the privet clinics of the researchers. The data collection extended over the period from 2019 January to 2020 August. A total number of 70 children involved in the study according to the parents’ complaints, full history taken and the clinical examination by otoscopy. The probable conductive problem excluded by using the Tympanometry. Moreover, free field test was done before chirp and click. Paired t-test was used for the statistical analysis. Results: The males represent (44.3%) and the females (55.7%). The mean age of children included was 49 months ± 27.7 SD. Wave V of the chirp shows lower latency means in all intensities in comparison with that of click stimuli. While waves I and III, show longer latency as the intensity go down, but the differences between chirp and click are insignificant. Wave V amplitudes getting lower values as the intensity decreasing in both chirp and click and become significantly higher than that of click. Wave I and III show decreasing amplitudes with the decreasing intensity in both chirp and click, with higher amplitudes in click in comparing with that of chirp, which are insignificant statistically down to below 70 dBnHL. Conclusions: The chirp stimuli are highly significant and more efficient from the click in the detection of hearing loss among the children regarding both latency and amplitude particularly at wave V.

Analysis of the Risk Factors Associated with Hearing Loss of Infants Admitted to a Neonatal Intensive Care Unit: A 13-Year Experience in a University Hospital in Korea.

Early detection of hearing loss in neonates is important for normal language development, especially for infants admitted to the neonatal intensive care unit (NICU) because the infants in NICU have a higher incidence of hearing loss than healthy infants. However, the risk factors of hearing loss in infants admitted to the NICU have not been fully acknowledged, especially in Korea, although they may vary according to the circumstances of each country and hospital. In this study, the risk factors of hearing loss in NICU infants were analyzed by using the newborn hearing screening (NHS) and the diagnostic auditory brainstem response (ABR) test results from a 13-year period. A retrospective chart review was performed using a list of NICU infants who had performed NHS from 2004 to 2017 (n = 2404) in a university hospital in Korea. For the hearing loss group, the hearing threshold was defined as 35 dB nHL or more in the ABR test performed in infants with a ‘refer’ result in the NHS. A four multiple number of infants who had passed the NHS test and matched the age and gender of the hearing loss group were taken as the control group. Various patient factors and treatment factors were taken as hearing loss related variables and were analyzed and compared. From the 2404 infants involved, the prevalence of hearing loss was 1.8% (n = 43). A comparison between the hearing loss group (n = 43) and the control group (n = 172) revealed that history of sepsis, peak total bilirubin, duration of vancomycin use, days of phototherapy, and exposure to loop-inhibiting diuretics were significantly different, and can be verified as significant risk factors for hearing loss in NICU infants.

Status of early hearing detection and intervention in South Korea: a nationwide population-based study of national infant health checkup

The aim of this study was to evaluate the status of early hearing detection and intervention after newborn hearing screening (NHS) in South Korea. A retrospective review of Korean national health insurance service data of all infants receiving the 4-month old national infant health checkup between 2010 and 2016 from a nationwide population-based database was conducted. Based on the results of the NHS-administered hearing questionnaires as part of the national infant health checkup, individuals were classified into “pass” (1,730,615 infants) or “refer” (10,941 infants) groups. Next, an analysis was conducted of age and the frequencies of tracking audiologic tests and surgeries of the middle ear (ME) and cochlear implants (CI). Diagnostic auditory brainstem response and audiometry, and surgeries of ME and CI were significantly performed more and earlier in the refer group compared with the pass group. For infants in the pass group who were presumed to have delayed or acquired hearing loss, the time of the first audiology tests and CI surgery was significantly delayed compared to those in the refer group; the average ages for first CI were 37 and 52 months in the refer group and pass group, respectively. Therefore, for early detection of delayed-onset hearing loss, regular hearing screening programs should be considered throughout the preschool ages.

Earlier Intervention for Medically Fragile Pediatric Inpatient Population

Earlier Intervention for Medically Fragile Pediatric Inpatient Population

Analysis of the effectiveness of coupon-mediated newborn hearing screening program through comparison of two government-funded pilot projects in South Korea

ObjectiveThe aims of this study are to compare the results of two government-funded newborn hearing screening (NHS) pilot programs and evaluate the feasibility and the effectiveness of the coupon-mediated NHS program in Korea. MethodsWe retrospectively analyzed the database of the NHS center of the Ministry of Health and Welfare (MHW) from 2007 to 2013. Before the NHS was covered by national health insurance in 2018, the MHW conducted two types of NHS pilot programs. For the first pilot program, the MHW initiated an area based universal newborn hearing screening (UNHS) program which initially included 16 in 2007 and then spreading to 32 administrative areas in 2008 for all newborns in the pilot areas regardless of income level. The second pilot program was an offshoot of the continuing expansion of the first pilot program, which was a nationwide coupon-mediated NHS program for low-income families from 2009. The hearing loss (HL) was defined as a threshold of 40 dB nHL or worse on the auditory brainstem response (ABR) test. In both NHS pilot programs, the government financially supported the cost of the first NHS test and one ABR test for an infant who did not pass NHS test. ResultsDuring the 1st NHS pilot program, 29.8% of the target neonates were screened which was 3.9% of total births; during the 2nd NHS pilot program 81.1% of the target neonates were screened which was 8.8% of total births. Documented diagnostic ABR tests were performed in 12.4% of referred infants in the 1st program and 33.5% in the 2nd program. The prevalence of HL was 0.11% in the 1st program and 0.15% in the 2nd program. In the 2nd NHS coupon-mediated program, the NHS was performed on average 5.4 ± 8.7 days after birth, and the diagnostic ABR test in the referred infants were performed on 61.3 ± 45.0 days after birth. There was no comparable recorded data in the 1st NHS pilot program. ConclusionsThis study suggests that the coupon-mediated NHS pilot program may be a worthwhile government-led NHS project for the proper tracking and accurate statistics. This program helped formulate UNHS national health insurance policies. However, to become a successful UNHS program, the governmental supports for both timely interventions and the inauguration of a web tracking system are mandatory.

Comparison of newborn hearing screening results between well babies and neonates admitted to the neonatal intensive care unit for more than 5 days: Analysis based on the national database in Korea for 9 years.

ObjectiveThe purpose of this cohort study is to compare newborn hearing screening (NHS) results between healthy newborns and neonates who were admitted to the neonate intensive care unit (NICU) for more than 5 days based on the national database for 9 years. Ultimately, we’ve tried to analyze the associated factors necessary to manage the national NHS program according to the group, which would help to establish policy to effectively detect and support hearing impaired children and which would help to control qualities.MethodsThe Ministry of Health and Welfare (MHW) introduced a nationwide coupon-mediated program for the low-income class since 2009. The coupon consisted of two parts, the screening part and the confirming parts with the same unique number, and the MHW supported the cost of one screening test and one diagnostic auditory brainstem response (ABR) test for infants who did not pass from the screening test. We have analyzed the screening test performing rate, the referral rate according to the screening methods or institutions, the prevalence of hearing loss, and the average age of hearing loss diagnosis. Hearing loss was defined as any hearing impairment either unilateral or bilateral with the hearing threshold ≥ 40 dB nHL on the diagnostic ABR test, irrespective of its etiology.ResultsA total of 524,371 newborns were enrolled in the study, and 506,634 (96.6%) neonates were in the “well-baby group (WBG)”, while 17,737 (3.4%) were in the “high-risk group (HRG)”. The referral rate of the screening test was 1.5% in average, 1.3% in the WBG, and 7.5% in the HRG. The referral rates varied according to the screening methods and screening institutions. The adjusted prevalence of HL was 5.6/1,000 in average, 4.6/1,000 in the WBC, and 28.8/1,000 in the HRG. The screening tests were performed 4.3 ± 6.7 days after birth and the diagnostic tests were done 62.7 ± 37.5 days after birth in WBG. In HRG, dates were 17.7 ± 19.3 days and 97.6 ± 51.4 days, respectively.ConclusionsThe prevalence of hearing loss in infants who were hospitalized in NICU for more than 5 days was about seven times higher than that in healthy newborns. However, different referral rates were noted depending on both institutions and the screening methods. These differences need to be addressed in order to improve our program and ensure that all neonates with hearing loss, especially neonates with high risk factor, are detected and appropriately referred for the treatment.

Study of auditory brain stem response in newborns treated from unconjugated hyperbilirubinemia started in the first day of life

Background Neonatal jaundice remains a very common presentation in newborn babies, especially during the first week of life. Serious morbidities and long-term sequelae are seen in babies with delayed diagnosis and intervention. A timely and early decision-making workout would make the outcome better. First-hour-of-life presenting icterus is a worrisome sign, and hence, a swift intervention is much needed. Aim To compare the auditory brain stem response results between healthy newborns and newborns managed from pathological unconjugated hyperbilirubinemia started in the first day of life. Patients and methods A case–control study was conducted at the neonatal intensive care unit of Alexandria University Maternity Hospital on 55 full-term newborns; 30 were cases who had pathological unconjugated hyperbilirubinemia in the first day of life using Queensland Clinical Guideline: neonatal jaundice 2017, and 25 were controls who had no pathological jaundice and were healthy. The exclusion criteria were considered. Diagnostic auditory brain stem response tests were done at the Audiology Unit in Outpatient clinics at Alexandria Main University Hospital by an audiologist for each ear of the case group within 7 days of complete management and were made for each ear of the controls group from 7 to 15 days of age. Results The study found no significant difference between both studied groups regarding latency, amplitude of waves I, III, and V, V/I amplitude ratio, and interpeak interval between waves I–III, III–V, and I–V at intensity of 70 dBnHL on both right and left ears. Conclusions Early identification and management of newborns with early-onset pathological hyperbilirubinemia using Queensland Clinical Guidelines: Neonatal jaundice 2017 can protect them from the acute bilirubin encephalopathy and auditory neuropathy spectrum disorder.

Results of a Government-supported Newborn Hearing Screening Pilot Project in the 17 Cities and Provinces from 2014 to 2018 in Korea.

BackgroundThe aim of this study was to present and analyze, for the first time, the results of a government-supported nationwide newborn hearing screening (NHS) pilot project in the 17 major cities and provinces of Korea.MethodsWe analyzed a nationwide NHS database of 344,955 newborns in the pilot project from 2014 to 2018. The government supported the cost of one NHS and one diagnostic auditory brainstem response (ABR) test. Hearing loss (HL) was defined as ≥ 40 dB nHL on either side of the ABR threshold test.ResultsMost NHS tests were performed in the maternity clinics (91.5%). In regions with lack of maternity clinics, the screening rate of local clinics was high (Jeju: 31.1% and Sejong: 12.9%). In most regions, automated ABR was mainly used for screening test (89.7%), but Gangwon (32.7%), Jeju (31.0%), and Jeonbuk (29.6%) performed more NHS tests using (automated) otoacoustic emissions than other regions. The mean referral rate was 1.5%, but the overall diagnostic ABR rate was low at 18.5%. The referral rates of Busan (0.6%) and Gyeongnam (0.9%) were lower than 1%, and Jeju's referral rate was 7.3%. Prevalence of HL including unilateral HL was 0.12%.ConclusionDepending on the cities and provinces, there were significant differences in the screening rates and referral rates by hospital type and NHS method. For successful early hearing detection and intervention (EHDI) and quality control, it will be necessary to support and manage EHDI according to regional NHS's characteristics and ensure that the whole country conducts EHDI as standard.

Comparison of distortion product otoacoustic emission (DPOAE) and automated auditory brainstem response (AABR) for neonatal hearing screening in a hospital with high delivery rate

IntroductionCongenital hearing loss is one of the commonest congenital anomalies. Neonatal hearing screening aims to detect congenital hearing loss early and provide prompt intervention for better speech and language development. The two recommended methods for neonatal hearing screening are otoacoustic emission (OAE) and automated auditory brainstem response (AABR). ObjectiveTo study the effectiveness of distortion product otoacoustic emission (DPOAE) and automated auditory brainstem response (AABR) as first screening tool among non-risk newborns in a hospital with high delivery rate. MethodA total of 722 non-risk newborns (1444 ears) were screened with both DPOAE and AABR prior to discharge within one month. Babies who failed AABR were rescreened with AABR ± diagnostic auditory brainstem response tests within one month of age. ResultsThe pass rate for AABR (67.9%) was higher than DPOAE (50.1%). Both DPOAE and AABR pass rates improved significantly with increasing age (p-value<0.001). The highest pass rate for both DPOAE and AABR were between the age of 36–48 h, 73.1% and 84.2% respectively. The mean testing time for AABR (13.54 min ± 7.47) was significantly longer than DPOAE (3.52 min ± 1.87), with a p-value of <0.001. ConclusionsOAE test is faster and easier than AABR, but with higher false positive rate. The most ideal hearing screening protocol should be tailored according to different centre.

Implementation and evaluation of a rural community-based pediatric hearing screening program integrating in-person and tele-diagnostic auditory brainstem response (ABR)

BackgroundIn an attempt to reach remote rural areas, this study explores a community-based, pediatric hearing screening program in villages, integrating two models of diagnostic ABR testing; one using a tele-medicine approach and the other a traditional in-person testing at a tertiary care hospital.MethodsVillage health workers (VHWs) underwent a five day training program on conducting Distortion Product Oto Acoustic Emissions (DPOAE) screening and assisting in tele-ABR. VHWs conducted DPOAE screening in 91 villages and hamlets in two administrative units (blocks) of a district in South India. A two-step DPOAE screening was carried out by VHWs in the homes of infants and children under five years of age in the selected villages. Those with ‘refer’ results in 2nd screening were recommended for a follow-up diagnostic ABR testing in person (Group A) at the tertiary care hospital or via tele-medicine (Group B). The overall outcome of the community-based hearing screening program was analyzed with respect to coverage, refer rate, follow-up rate for 2nd screenings and diagnostic testing. A comparison of the outcomes of tele-versus in-person diagnostic ABR follow-up was carried out.ResultsSix VHWs who fulfilled the post training evaluation criteria were recruited for the screening program. VHWs screened 1335 children in Group A and 1480 children in Group B. The refer rate for 2nd screening was very low (0.8%); the follow-up rate for 2nd screening was between 80 and 97% across the different age groups. Integration of tele-ABR resulted in 11% improvement in follow-up compared to in-person ABR at a tertiary care hospital.ConclusionsNon-availability of audiologists and limited infrastructure in rural areas has prevented the establishment of large scale hearing screening programs. In existing programs, considerable challenges with respect to follow-up for diagnostic testing was reported, due to patients being submitted to traveling long distance to access services and potential wage losses during that time. In this program model, integration of a tele-ABR diagnostic follow-up improved follow-up in comparison to in-person follow-up. VHWs were successfully trained to conduct accurate screenings in rural communities. The very low refer rate, and improved follow-up rate reflect the success of this community-based hearing screening program.

Hyperbilirubinemia and Follow-up Auditory Brainstem Responses in Preterm Infants.

Objectives. Neonatal hyperbilirubinemia is considered one of the most common causative factors of hearing loss. Preterm infants are more vulnerable to neuronal damage caused by hyperbilirubinemia. This study aimed to evaluate the effect of hyperbilirubinemia on hearing threshold and auditory pathway in preterm infants by serial auditory brainstem response (ABR). In addition, we evaluate the usefulness of the unconjugated bilirubin (UCB) level compared with total serum bilirubin (TSB) on bilirubin-induced hearing loss.Methods. This study was conducted on 70 preterm infants with hyperbilirubinemia who failed universal newborn hearing screening by automated ABR. The diagnostic ABR was performed within 3 months after birth. Follow-up ABR was conducted in patients with abnormal results (30 cases). TSB and UCB concentration were compared according to hearing threshold by ABR.Results. The initial and maximal measured UCB concentration for the preterm infants of diagnostic ABR ≥40 dB nHL group (n=30) were statistically higher compared with ABR ≤35 dB nHL group (n=40) (P=0.031 and P=0.003, respectively). In follow-up ABR examination, 13 of the ABR ≥40 dB nHL group showed complete recovery, but 17 had no change or worsened. There was no difference in bilirubin level between the recovery group and non-recovery group.Conclusion. UCB is a better predictor of bilirubin-induced hearing loss than TSB in preterm infants as evaluated by serial ABR. Serial ABR testing can be a useful, noninvasive methods to evaluate early reversible bilirubin-induced hearing loss in preterm infants.