Reliability of hearing screening in high-risk neonates: Comparative study of otoacoustic emission, automated and conventional auditory brainstem response

Newborn Hearing Screening Results for Infants With Prenatal Opioid Exposure in Southern Appalachia

PURPOSE

Infants prenatally exposed to opioids exhibit withdrawal symptomology that introduce physiological noise and can impact newborn hearing screening results. This study compared the referral rate and physiological noise interpreted by number of trials rejected due to artifact on initial newborn hearing screenings of infants with prenatal opioid exposure (POE) and infants with no opioid exposure (NOE). Furthermore, within the POE group, it examined the relationship of referral rates with severity of withdrawal symptomology, and with maternal and infant risk factors.

METHOD

This study used a retrospective cohort design of electronic medical records from six delivery hospitals in South-Central Appalachia. Newborn hearing screenings were conducted using automated auditory brainstem response (ABR) for 334 infants with POE and 226 infants with NOE. Severity of withdrawal symptomology was measured using the Modified Finnegan Neonatal Abstinence Scoring Tool, which includes observation of behaviors that introduce physiological noise.

RESULTS

There was no significant difference in newborn hearing screening referral rate between infants with POE and infants with NOE. Referral rate was not affected by maternal or infant risk factors. Infants with POE had statistically significant higher artifact (defined as rejected ABR sweeps) than infants with NOE. There was a strong positive correlation between Finnegan scores and artifact but not referral rates. Sensitivity and specificity analysis indicated artifact decreased substantially after Day 4 of life.

CONCLUSIONS

Referral rates of infants with POE were similar to those of infants with NOE. Nevertheless, the withdrawal symptomology of infants with POE introduces physiological noise reflected as artifact on ABR, which can affect efficiency of newborn hearing screenings.

Comparison of Otoacoustic Emission (OAE) and Brainstem Evoked Response Audiometry (BERA) in High Risk Infants and Children under 5 Years of Age for Hearing Assessment in Western India: A Modification in Screening Protocol

There are very few studies from India, which have compared Otoacoustic Emission (OAE) and Brainstem Evoked Response Audiometry (BERA) as a screening modality for detection of hearing loss in children. With the aim of establishing some guidelines regarding the protocols for hearing loss assessment and preventive measures, the present study has been undertaken to compare OAE with BERA done simultaneously, in the diagnosis of paediatric hearing loss, and also to study associated risk factors for hearing loss in children of Rural Central India. Prospective observational study was carried out on 100 children (200ears) in age group of 0-5 years. Selection was based on the inclusion and exclusion criteria. In all the 100 children detailed history was taken from the parents and were subjected to distortion product otoacoustic emissions (DPOAE). Irrespective of the pass or refer result children were subjected for BERA test. The interpretation of OAE and BERA test was as follows. Both the results of OAE refer and BERA fail were considered as confirmed HL, OAE pass and BERA fail were considered as children having Auditory Neuropathy (AN), OAE refer and BERA pass were considered as children at risk of permanent hearing loss (HL), OAE pass and BERA pass were considered as children with no evidence of HL. In the present study the male to female ratio was 1.32:1. Of the total 100 children 80% children showed presence of any one or more than one risk factors. In our study, eclampsia [7%] followed by multiparity [6%] and oligohydramnios [5%] were the most common risk factors in prenatal period. Maximum number of infants in AN profile were with Low Apgar score, children exposed to ototoxic medications, non-syndromic cardiac disorders in children [25.8% each]. Maximum number of infants in Confirmed HL profile were with congenital syndromes/ear anomalies [41.86%] followed by other risk factors. In our study, both OAE and BERA test were comparable and statistically significant with p value of 0.0001. OAE has a high specificity and positive predictive value of 93.33% and 97.22% respectively and it has a low sensitivity and negative predictive value of 67.74% and 45.65% respectively. In a developing country like India were universal screening protocols are not followed large number of children may be missed and may present late when it affects child's communication abilities. Hence, we need to modify our screening test and implement high risk screening even in the absence of any hearing or speech complaints.

Continuous positive airway pressure treatment may negatively affect auditory maturation in preterm infants

AIM

Nasal continuous positive airway pressure (CPAP) devices generate loud noise, which might harm auditory function and maturation. The function of auditory pathways can be examined by using brainstem auditory evoked potential (BAEP) and brainstem audiometry (BA) recordings. Our objective was to study whether CPAP treatment during the neonatal period is associated with abnormalities in BAEP and BA recordings.

METHODS

Included in this retrospective study were preterm infants (birth weight ≤1500 g and/or gestational age ≤32 weeks) born between 2002 and 2006 with a comprehensive clinical background and follow-up data, including the duration of CPAP treatment (n = 162). BAEP and BA were recorded near the mean corrected age of one month. The following variables from BAEP and BA examinations were analysed: latencies of BAEP components I, III, V, interpeak intervals (IPI) I-V, I-III, III-V (ms), amplitude I and V (µV), amplitude ratio I/V and BA thresholds.

RESULTS

In the adjusted analysis, a longer CPAP treatment leads to longer latencies of BAEP component III (p = 0.01) and V (p = 0.02) in the right ear.

CONCLUSION

CPAP treatment may impair the auditory maturation and processing mediated via the dominant right ear. The hearing and neurodevelopment of the children who are treated with CPAP should be followed.

Auditory brainstem response in preterm infants with bilirubin encephalopathy

AIM

To clarify auditory brainstem response (ABR) in preterm infants with bilirubin encephalopathy and the relationships between ABR and clinical variables.

METHOD

We retrospectively reviewed the ABR waveforms of 56 preterm infants with BE and graded them as "no response", "abnormal interwave separation", or "normal". Patient backgrounds, the peak total bilirubin level, the bilirubin/albumin ratio, verbal communication ability, and newborn hearing screening test results from an automated ABR evaluation had been collected during an earlier nationwide survey.

RESULTS

The frequency of abnormal ABR findings decreased with age. Verbal communication tended to be poorer in patients with more severe ABR abnormalities. ABR findings improved in 7 of 29 infants with available serial ABR data. Both gestational age and the peak total bilirubin level were relatively lower in patients with than in those without improved ABR findings. Newborn hearing screening using automated ABR evaluation yielded data consistent with manual ABR findings in 16 of 20 patients who underwent both examinations.

CONCLUSIONS

ABR abnormalities in preterm infants with bilirubin encephalopathy may improve over time, especially in those with a lower gestational age and peak total bilirubin level. Newborn hearing screening using automated ABR may fail to detect abnormalities in some infants.

Screening Programs for Hearing Assessment in Newborns and Children

Objective In this study, we aimed to assess the incidence of hearing loss in the pediatric population through otoacoustic emission (OAE) and brainstem evoked response audiometry (BERA) and to analyze the possible etiological factors responsible for it. Material and methods A retrospective observational study was conducted in the Otolaryngology (ENT) and Gynecology and Obstetrics Departments at the Jinnah Postgraduate Medical Centre and National Institute of Child Health in Karachi, Pakistan between July 2019 and October 2019. The convenient sampling technique was used to select the patients. The final sample size consisting of newborns and children was 108. Initially, screening procedures were undertaken for newborns to detect permanent or fluctuating, bilateral or unilateral, and sensory or conductive hearing loss, averaging 30-40 dB or more in the frequency region, which indicated potential issues related to speech recognition (approximately 500-4,000 Hz). The screening of newborns involved the use of non-invasive, objective physiologic measures that included OAEs and/or auditory brainstem response (ABR). The children with hearing impairment then underwent BERA; thereafter, further investigations were performed to confirm the defects found on BERA testing. Results Of the 108 cases, 96 had normal hearing on OAE screening, and 12 were found to have hearing loss on the OAE test. Further testing was carried out on BERA for 12 cases that had been detected to have hearing loss on OAE, and BERA showed normal hearing for five cases whereas seven were found to have hearing loss. Of the seven patients with hearing loss on the BERA test, five were diagnosed with cochlear deafness, and two had retrocochlear deafness. Conclusion Our present study concludes that in order to avoid any hearing problems in infants, OAE hearing screening and diagnostic BERA screening programs should be carried out in all the hospitals of Pakistan to assess newborn hearing at an early age.

Neonatal brainstem auditory function associates with early receptive language development in preterm children

AIM

To study whether auditory function measured with brainstem auditory evoked potential and brainstem audiometry recordings in the neonatal period associates with language development 1 year later in preterm infants.

METHODS

This retrospective study included 155 preterm infants (birthweight ≤1500 g and/or birth ≤32 gestational weeks) born between 2007 and 2012 at the Turku University Hospital. Auditory function was recorded in neonatal period. Information of language development was gathered at the mean corrected age of 1 year by using the Finnish version of the MacArthur Communicative Development Inventory.

RESULTS

Slower auditory processing (longer interpeak interval, IPI I-V) in the right ear in the neonatal brainstem auditory evoked potential recording associated with smaller receptive lexicon size at 1 year (P = .043). Infants with longer IPI I-V were more likely to have a deviant (≤17 words) receptive lexicon size (P = .033). The absence of a contralateral response with right ear stimulation increased the risk for deviant lexicon size (P = .049).

CONCLUSION

The results suggest that impaired auditory function in the neonatal period in preterm infants may lead to a poorer receptive language outcome 1 year later. Auditory pathway function assessment provides information for the identification of preterm children at risk for weak language development.

Accuracy of otoacoustic emissions, and automated and diagnostic auditory brainstem responses, in high-risk infants

Objectives

This study aimed to compare the diagnostic reliabilities of transient evoked otoacoustic emissions, automated auditory brainstem responses and brainstem auditory evoked responses for detecting hearing loss, and to use the information regarding hearing level of automated auditory brainstem responses for planning rehabilitation.

Methods

A total of 144 high-risk infants (288 ears) completed the 3 hearing tests. The sensitivity and specificity of otoacoustic emissions and automated auditory brainstem responses were compared using the chi-square test.

Results

Automated auditory brainstem response was the most reliable test of hearing levels, with a sensitivity of 91.7 per cent and specificity of 92.1 per cent; the sensitivity of otoacoustic emissions was 78.7 per cent and the specificity was 88.8 per cent.

Conclusion

Automated auditory brainstem responses have acceptably high sensitivity and specificity. Additionally, the hearing level from automated auditory brainstem responses can help the screeners explain to the parents the importance of further diagnosis and rehabilitation.

Impact of Brain Injury on Processing of Emotional Prosodies in Neonates

Being able to appropriately process different emotional prosodies is an important cognitive ability normally present at birth. In this study, we used event-related potential (ERP) to assess whether brain injury impacts the ability to process different emotional prosodies (happy, fear, and neutral) in neonates; whether the ERP measure has potential value for the evaluation of neurodevelopmental outcome in later childhood. A total of 42 full-term neonates were recruited from the neonatology department of Peking University First Hospital from June 2014 to January 2015. They were assigned to the brain injury group (n = 20) or control group (n = 22) according to their clinical manifestations, physical examinations, cranial images and routine EEG outcomes. Using an oddball paradigm, ERP data were recorded while subjects listened to happy (20%, deviation stimulus), fearful (20%, deviation stimulus) and neutral (80%, standard stimulus) prosodies to evaluate the potential prognostic value of ERP indexes for neurodevelopment at 30 months of age. Results showed that while the mismatch responses (MMRs) at the frontal lobe were larger for fearful than happy prosody in control neonates, this difference was not observed in neonates with brain injuries. This finding suggests that perinatal brain injury may influence the cognitive ability to process different emotional prosodies in neonatal brain; this deficit could be reflected by decreased MMR amplitudes in response to fearful prosody. Moreover, the decreased MMRs at the frontal lobe was associated with impaired neurodevelopment at 30 months old.

Newborn hearing screening protocols and their outcomes: A systematic review

OBJECTIVE

To conduct a review of the most current research in objective measures used within newborn hearing screening protocols with the aim of exploring the actual protocols in terms of the types of measures used and their frequency of use within a protocol, as well as their outcomes in terms of sensitivity, specificity, false positives, and false negatives in different countries worldwide.

METHODS

A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Electronic databases such as PubMed, Google Scholar and Science Direct were used for the literature search. A total of 422 articles were identified, of which only 15 formed part of the current study. The 15 articles that met the study's criteria were reviewed. Pertinent data and findings from the review were tabulated and qualitatively analysed under the following headings: country; objective screening and/or diagnostic measures; details of screening protocol; results (including false positive and negative findings, sensitivity and/or specificity), conclusion and/or recommendations. These tabulated findings were then discussed with conclusions and recommendations offered.

RESULTS

Findings reported in this paper are based on a qualitative rather than a quantitative analysis of the reviewed data. Generally, findings in this review revealed firstly, that there is a lack of uniformity in protocols adopted within newborn hearing screening. Secondly, many of the screening protocols reviewed consist of two or more tiers or stages, with transient evoked otoacoustic emissions (TEOAEs) and automated auditory brainstem response (AABR) being most commonly used. Thirdly, DPOAEs appear to be less commonly used when compared to TEOAEs. Lastly, a question around routine inclusion of AABR as part of the NHS protocol remains inconclusively answered.

CONCLUSIONS

There is sufficient evidence to suggest that the inclusion of AABR within a NHS programme is effective in achieving better hearing screening outcomes. The use of AABR in combination with OAEs within a test-battery approach or cross-check principle to screening is appropriate, but the inclusion of AABR to facilitate appropriate referral for diagnostic assessment needs to be systematically studied.

Outcomes of Automated Auditory Evoked Potential Performed in Different Settings and the Factors Associated with Referred Cases

Introduction  For the population with risk factors for hearing loss, the first option to assess the hearing status is the performance of the automated brainstem auditory evoked potential (BAEP) test because of its efficacy in identifying retrocochlear hearing loss. Objective  To verify the outcomes of automated BAEP performed in different settings as well as the factors associated with the prevalence of hearing impairment. Methods  Cross-sectional study conducted from October of 2014 to May of 2015. The sample consisted of 161 infants with at least one risk factor for hearing loss who underwent automated BAEP during the hospital stay or at the outpatient clinic. After 30 days, the altered cases were referred for BAEP diagnosis. Results  One hundred and thirty-eight infants (86%) had a result of "pass" and 23 (14%) of "failure" in the automated BAEP. There was no statistically significant difference in the rate of "referred" results between examinations performed in different settings. The infants' ages did not influence the number of abnormal cases. All of the 23 infants who presented a "referred" result in the automated BAEP, unilateral or bilateral, were sent for BAEP diagnosis, and out of these, 9 (39%) remained with at least some degree of alteration. The average age of diagnosis was 2.7 months. Conclusion  The results of the automated BAEP were similar when performed during hospitalization or after discharge. Neither the age at the examination nor the gender of the patient influenced the prevalence of hearing loss.

The Relationship Between Hospital Construction and High-Risk Infant Auditory Function at NICU Discharge: A Retrospective Descriptive Cohort Study

PURPOSE

To describe the difference in auditory function at neonatal intensive care unit (NICU) discharge between high-risk infant cases exposed to hospital construction during NICU stay and those not exposed.

BACKGROUND

Noise produced by routine NICU caregiving exceeds recommended intensity. As California hospitals undergo construction to meet seismic safety regulations, vulnerable neonates are potentially exposed to even higher levels of noise. Ramifications are unknown.

METHODS

Retrospective data-based descriptive cohort design was used to compare high-risk infant auditory function at NICU discharge between hospital construction exposed and unexposed groups.

SAMPLE SIZE

N = 540 infant cases (243 construction exposed and 297 unexposed controls).

INCLUSION CRITERIA

Infant cases born and discharged from the study site NICU in the year 2010 (unexposed) and year 2015 (exposed) and received a newborn hearing screening by automated auditory brainstem evoked response (ABER) prior to discharge with results reported. Infant cases excluded: hearing screen results by ABER unavailable, potentially confounding characteristics (congenital infection, major anomalies including cleft lip and/or palate), and transferred into or out of the study site.

INSTRUMENTATION

ABER.

ANALYSIS

descriptive statistics (SPSS Version 24.0), hypothesis testing, correlation, and logistic regression.

RESULTS

The difference in auditory function at NICU discharge between high-risk infant cases exposed to hospital construction noise and those unexposed was statistically insignificant, χ² = 1.666, df = 4, p = .1968, 95% confidence interval [-0.635, 2.570].

CONCLUSIONS

More research is needed to better understand whether hospital construction exposure during NICU admission negatively affects high-risk infant auditory function. Findings may catalyze theory development, future research, and child health policy.

Neonatal Cortical Auditory Evoked Potentials Are Affected by Clinical Conditions Occurring in Early Prematurity

PURPOSE

Cortical auditory evoked potentials may serve as an early indicator of developmental problems in the auditory cortex. The aim of the study was to determine the effect on neonatal cortical auditory processing of clinical conditions occurring in early prematurity.

METHODS

Sixty-seven preterm infants born at 29 weeks mean gestational age (range, 23-34 weeks) were recorded at a mean postconception age of 35 weeks, before discharge from the third level neonatal intensive care unit. The average of 330 responses to standard 1000 Hz pure tones delivered in an oddball paradigm was recorded at frontal location. Data of 45 of 67 recruited premature infants were available for analysis. Mean amplitudes calculated from the data points of 30 milliseconds centered on P1 and N2 peaks in the waveforms of each subject were measured. The effect of perinatal clinical factors on cortical auditory evoked responses was evaluated.

RESULTS

The amplitude of P1 component was significantly lower in infants with bronco-pulmonary dysplasia (P = 0.004) and retinopathy of prematurity (P = 0.03). The multivariate analysis, done to evaluate the relative weight of gestational age and bronco-pulmonary dysplasia and/or retinopathy of prematurity on cortical auditory evoked potentials components, showed an effect of clinical factors on P1 (P = 0.005) and of gestational age on N2 (P = 0.02).

CONCLUSIONS

Cortical auditory processing seems to be influenced by clinical conditions complicating extremely preterm birth.

Prevalence and referral rates in neonatal hearing screening program using two step hearing screening protocol in Chennai - A prospective study

OBJECTIVE

To estimate the prevalence and referral rates in well born and high risk babies using two step hearing screening protocol with Distortion Product Otoacoustic Emissions (DPOAE) and Automated Auditory Brainstem Response (AABR).

METHOD

A prospective study was carried out on 1405 neonates (983 well born babies and 422 high risk babies) who were screened during May 2013 to January 2015 at Institute of Obstetrics and Gynecology, Madras Medical College, Chennai. All neonates were screened using two step screening protocol. They were initially tested with DPOAE. Referred babies in DPOAE were screened with AABR subsequently.

RESULTS

Among 1405 (100%) neonates 983 (69.96%) were well born babies and 422 (30.03%) were high risk babies. Total referral rate in DPOAE was found to be 311 (22.13%) among which 195 (13.87%) were well born babies and 116 (8.25%) were high risk babies. Out of 311 babies 31 (2.20%) babies were referred in AABR screening. In 31 babies referred in AABR 11(0.78%) were from well born group and 20 (1.42%) were from the high risk group. Further diagnostic evaluation of these babies, 2 (0.14%) were confirmed to have hearing loss. This study reveals, the prevalence of congenital hearing loss in our population is 1.42 per 1000 babies.

CONCLUSION

Using two step protocol especially AABR along with DPOAE at the initial level of testing significantly reduces referral rates in new born screening programs. Also AABR decreases the false positive responses hence increasing the efficiency of screening program.

Hearing impairment and its risk factors by newborn screening in north-western India

Background

To screen the newborn by Transient evoked Otoacoustic emission and to assess the incidence of hearing damage and associated risk factors.

Method

This longitudinal prospective observational study was conducted at a tertiary care hospital in India. A total of 415 babies were included in the study. All the newborns were evaluated with Transient evoked Otoacoustic emission (TEOAE) which was done by age of 1–3 days. Auditory brain stem response audiometry (AABR) was performed at the age of three months for confirming the hearing loss in the neonates those who failed the TEOAE screening. For infants proven to have significant hearing loss in one or both ears, were denoted to an ear, nose, and throat specialist for further evaluation & rehabilitation.

Results

Out of total 415 babies included in the study, 22 neonates showed abnormal TEOAE examination. Out of these 22 neonates, hearing loss was confirmed in 18 (82 %) subjects. by AABR. The following antenatal and post-natal risk factors were associated with hearing loss: ante-partum bleeding, history of maternal blood transfusion, fetal distress, prematurity, severe birth asphyxia, NICU admission for more than 24 h and Apgar score less than five at 5 min.

Conclusion

Late identification of hearing loss presents a substantial public health burden. Early recognition and intervention prior to 6 months of age has a significant positive impact on development. A high incidence of hearing impairment seen in our study neonatal population warrants the urgent implementation of universal hearing screening of all the newborn infants in India. NICU infants admitted for more than 24 h are to have an auditory brainstem response (AABR) included as part of their screening so that neural hearing loss will not be missed.

Auditory neuropathy in late preterm infants treated with phototherapy for hyperbilirubinemia

OBJECTIVE

To evaluate the prevalence of auditory neuropathy (AN) in late preterms treated with phototherapy for hyperbilirubinemia.

DESIGN

Prospective observational study comprising late preterms treated with phototherapy for hyperbilirubinemia. Newborns were screened with combined transient-evoked otoacoustic emissions (TEOAEs) / automated auditory brainstem responses (AABR). Infants who failed screening underwent diagnostic (ABR). Infants were all re-evaluated with AABR at one year.

STUDY SAMPLE

Eighty-five infants with a mean serum total bilirubin concentration of 22.3 ± 1.76 mg/dl; severe-hyperbilirubinemia (SH), and 102 infants with a mean serum total bilirubin concentration of 18.6 ± 1.26 mg/dl; non-severe hyperbilirubinemia (NSH) were included.

RESULTS

From 85 late preterms with SH, six (7.1%) failed screening and underwent diagnostic ABR for six weeks. AN was diagnosed in two (2%) infants with SH. Four (3.9%) of the 102 controls with NSH demonstrated failure at TEOAE/AABR. No AN was diagnosed in the control group at the diagnostic ABR. No statistically significant difference was found between infants treated with phototherapy for SH and NSH with regard to AN/AD either in the postnatal period or at one year. No correlation was found between serum bilirubin levels and ABR latencies or thresholds.

CONCLUSIONS

AN (2%) in late preterms treated with phototherapy for severe-hyperbilirubinemia was not higher than in those with non-severe hyperbilirubinemia.

Failure of hearing screening in high-risk neonates does not increase parental anxiety

OBJECTIVE

The aim of this study was to determine whether a failure of neonatal hearing screening affected the anxiety level of parents of high-risk infants.

METHODS

Two hundred and eighty-eight parents of infants included in the neonatal hearing screening protocol of our Institution were tested with the Spielberger State-Trait Anxiety Inventory and with an open-question questionnaire investigating parents' attitude to hearing problems in their child, done at the time of audiological follow-up. 105 were parents of high-risk infants who had been discharged from neonatal intensive care unit (NICU) and 183 of low-risk infants discharged from well-baby nursery.

RESULTS

No differences in anxiety levels were seen between parents of high-risk infants passing and failing neonatal hearing screening using homogeneous case-control pairs. Additionally, no differences in the level of anxiety were found between parents of high- and low-risk infants failing neonatal auditory screening.

CONCLUSIONS

Failure of neonatal auditory screening does not affect the anxiety levels of parents of high-risk infants at post discharge from NICU. This finding is a key factor to be considered when evaluating the costs and benefits of tests for universal neonatal hearing screening.

Triagem auditiva neonatal com emissões otoacusticas e reflexo cocleo-palpebral: estudo da sensibilidade e especificidade

OBJETIVO: analisar a especificidade e sensibilidade da TAN com emissões otoacústicas evocadas por estimulo transiente (EOAT) associadas à pesquisa do reflexo cócleo-palpebral (RCP), comparando-os aos resultados do Potencial Evocado Auditivo de Tronco Encefalico (PEATE). MÉTODO: a casuística do presente estudo foi composta por 369 RN de risco para deficiência auditiva que foram submetidos à triagem com a captação das emissões otoacústicas evocadas por estímulo transiente e pesquisa do reflexo cócleo- palpebral. Os resultados foram comparados aos resultados do Potencial Evocado Auditivo de Tronco Encefalico (PEATE). RESULTADOS: a incidência do tipo da perda auditiva na população geral foi de 4RN (1,1%) com perda coclear, 22 (5,9%) com perda condutiva, 2 (0,5%) com espectro da neuropatia auditiva (ENA), 14 (3,8%) com alteração central e 15 (4,1%) com atraso de maturação da via auditiva. A TAN mostrou 100% de sensibilidade e 94,6% de especificidade na detecção de alterações cocleares e espectro da neuropatia auditiva; 77,3% de sensibilidade e 94,6% de especificidade na detecção de alterações condutivas e 42,9% de sensibilidade e 94,6% de especificidade na detecção de alterações centrais. Todos os achados evidenciaram diferenças estatisticamente significantes em relação aos neonatos auditivamente normais. CONCLUSÃO: este protocolo de TAN mostrou-se eficaz na detecção de RN com alterações de cocleares e espectro da neuropatia auditiva com sensibilidade e especificidade elevadas.

Performance of two hearing screening protocols in NICU in Shanghai

OBJECTIVE

To study the sensitivity and specificity of targeted neonatal hearing screening for the single-session distortion product otoacoustic emissions (DPOAE) technique and the combined DPOAE/automated auditory brain-stem response (AABR) technique.

METHODS

3000 high-risk newborns were studied at Children's Hospital of Fudan University. They were required to take two different screening procedures separately. The first procedure consisted of DPOAE alone and the second consisted of DPOAE combined with the AABR. Based upon the etiology in high-risk babies, they were divided into four groups. In group I there were 670 very-low-birth-weight (VLBW) newborns (1340 ears), and in group II there were 890 preterm babies (1780 ears). 850 babies (1700 ears) suffered from hyperbilirubinemia in group III, whereas 790 babies (1580 ears) with asphyxia were in group IV. The babies in groups II, III, and IV came from the neonatal intensive-care unit (NICU) of our hospital. The study protocols consisted of the DPOAE alone and DPOAE combined with AABR hearing screening at an age of less than 1 month, and a diagnostic stage at the age of 2 months.

RESULTS

With single-session DPOAE screening, the referral rate (8% of the NICU babies), the false-positive rate (4.96%) and the false-negative rate (0.8%) were higher. The different etiologies in NICU babies had significantly different referral rates (F-test, p<0.01). A 4.46% referral rate of hyperbilirubinemi babies was much lower. The combined DPOAE/AABR screening technique revealed a referral rate of 5.03%, a false-positive rate of 2% and a false-negative rate of 0.06%. The false-positive rate was well below the suggested 3% of the American Academy of Pediatric. Comparisons of the referral rate, false-positive rate and false-negative rate of two hearing screening protocols (DPOAE alone and combined DPOAE/AABR) revealed significant differences (t-test, p<0.05, p<0.01, p<0.01). 91 infants (3.03% of the NICU babies) who failed the combined DPOAE/AABR screening were confirmed on hearing impairment. Of 22 babies who passed DPOAE screening but failed the AABR screening had a severe to profound hearing loss based on classic ABR. These patients (24% of the NICU babies with hearing losses) with hyperbilirubinemia and asphyxia problems at newborn stage were diagnosed as auditory neuropathy based on evaluations of DPOAE screening passed, abnormal ABR and absent middle-ear muscle reflexes (MMR).

CONCLUSION

Our study demonstrates the use of a combination of DPOAE and AABR testing ensures high sensitivity and acceptable specificity, and predict the AN profile in NICU babies. Our efforts identified 22 NICU babies with auditory neuropathy who hopefully will benefit from early remediation of their hearing deficit.

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.

Are gentamicin and/or vancomycin associated with ototoxicity in the neonate? A retrospective audit

BACKGROUND

Aminoglycoside-induced ototoxicity has been reported in neonates but its incidence is poorly defined, whereas vancomycin-induced ototoxicity has not been reported in neonates.

OBJECTIVE

To compare hearing test results in infants in a neonatal intensive care unit (NICU) who were or were not treated with extended interval gentamicin dosing and/or standard vancomycin dosing.

METHOD

A database of otoacoustic emissions (OAE), over a 5-year period of NICU admissions, was combined with databases of gentamicin and vancomycin dosing to compare patients treated or not treated with these antibiotics.

RESULTS

A total of 2,347 OAE results was available. OAE failure rates were: no gentamicin and no vancomycin (noGnoV), 7% (85/1,233); gentamicin but no vancomycin (GnoV), 4% (42/949); vancomycin but no gentamicin (VnoG), 22% (9/41) and gentamicin and vancomycin (GandV), 14% (17/124). Compared to noGnoV there was a decreased risk of OAE failure in GnoV (p = 0.022, OR 0.64, 95% CI 0.44-0.94) and an increased risk in VnoG (p = 0.003, OR 3.46, 95% CI 1.54-7.75) and GandV, (p = 0.006, OR 2.20, 95% CI 1.26-3.83).

CONCLUSIONS

Gentamicin, as used and evaluated in this audit, showed no evidence of an increased risk of ototoxicity; what was observed was a statistically significant decrease in OAE failure rate. Vancomycin, by contrast, was associated with ototoxicity.

Auditory processing during sleep in preterm infants: An event related potential study

Auditory processing during sleep was investigated in premature infants by auditory event related potentials (AERPs). Twenty-six premature infants (mean GA 30 week- range 25-35) admitted to a neonatal intensive care unit were studied, prior to discharge, in active and quiet sleep at a mean post-conceptional age of 35 weeks. Infant state was determined by behavioral observation according to standard criteria. An auditory odd-ball paradigm was used with frequently occurring 'standard' tones at 1000Hz and infrequent 'deviant' tones at 2000Hz. Waveforms were recorded at Fz, Cz, Pz, T3 and T4 scalp locations. Measurements were performed in 18 patients because 8 preterm infants were excluded since they had less than the required artifact-free deviant trials in each sleep state. The responses to standard tones were equally recorded in both active and quiet sleep, but auditory responses to deviant tones consisting of an increased frontal negativity in the time period from 200 to 300ms after the stimulus were recorded only in active sleep. A significant effect of electrode placement, for frontal location by sleep condition and sleep condition by 50ms time windows was shown by repeated measures analyses of variance. The significance of these findings on evoked potential methodology in preterm infants admitted to neonatal intensive care unit is discussed.

Bilateral loss of cortical somatosensory evoked potential at birth predicts cerebral palsy in term and near-term newborns

Bilateral loss of cortical somatosensory evoked potential (SEP) is considered the single best indicator of adverse outcome in acute encephalopathy of adult patients and older children. This study determines whether the presence or absence of the neonatal cortical SEP can predict cerebral palsy at two years in survivors of neonatal encephalopathy scored according to Sarnat criteria. We also compare SEPs with visual evoked potentials (VEPs), the EEG and neonatal neurological status. Fifty-nine neonates admitted to the neonatal intensive care unit had SEP, VEP and EEG recordings analysed according to the presence (n=37, 63%) or absence (n=22, 37%) of neonatal encephalopathy (score >or=1). Cortical SEP was always present in the perinatal period in those surviving without major neurological disability, while it was bilaterally absent in all but one patient with a subsequent diagnosis of cerebral palsy. Multivariate analysis using the logistic regression model showed that bilateral loss of cortical SEP and Sarnat Score correctly classified the neurological outcome in all patients. Bilateral absence of cortical SEP indicates early identification of neonates at risk of cerebral palsy indicating that EPs have a clinical role in the workup of neonatal encephalopathy.

Impairment of perinatal hypoxia-ischemia to the preterm brainstem

Hypoxia-ischemia is a major perinatal problem that results in severe damage to the newborn brain. This study assessed functional integrity of the brainstem at term in preterm infants after perinatal hypoxia-ischemia to shed light on the influence of hypoxia-ischemia on the preterm brainstem. We recruited sixty-eight preterm infants after perinatal hypoxia-ischemia, ranging in gestation 28-35 weeks. Brainstem evoked response was studied at term age (37-42 weeks postconceptional age) with 91-910/s clicks using the maximum length sequence technique. Compared with healthy preterm infants, the preterm infants after perinatal hypoxia-ischemia showed a significant increase in I-V interval at very high rates 455 and 910/s of clicks (P<0.05, 0.05). III-V interval and III-V/I-III interval ratio also increased significantly at 455 and 910/s (P<0.05-0.01). The slope of III-V interval-rate function was significantly steeper than in the healthy preterm infants (P<0.05). Compared with normal term controls, the preterm infants after hypoxia-ischemia showed similar, but slightly more significant, abnormalities. The differences between the preterm infants after hypoxia-ischemia and the healthy preterm and term infants generally increased with increasing click rate. These results demonstrated that central components of brainstem auditory evoked response were abnormal at very high click rates in the preterm infants after perinatal hypoxia-ischemia. Click rate-dependent change in the more central part of the brainstem is also abnormal. Apparently, functional integrity of the brainstem, mainly in the more central part, is impaired. Hypoxic-ischemic damage to the preterm brainstem is unlikely to completely recover within a relatively short period after the insult, which is of clinical importance.

Neurodevelopmental outcome in preterm histological chorioamnionitis

The role of histological chorioamnionitis in neonatal neurological outcome is not yet fully understood. The present study aimed to assess the neurodevelopmental outcome of preterm babies born after pregnancy complicated by histological chorioamnionitis. Clinical data were prospectively collected for consecutive premature neonates born before 32 weeks of gestation, admitted to Neonatal Intensive Care Unit of Padua University from January 1998 to December 2001. Placental histology was performed. Outcome at 18 months of corrected age was evaluated by a standardized postal parental questionnaire. Among 104 placentas examined, 41 (39.4%) were diagnosed with histological chorioamnionitis. Reply to the postal questionnaire was available from 76.1% of the families. The relative risk of disability in vision, hearing, speech and motor development was higher in the histological chorioamnionitis than in the non-histological chorioamnionitis group, with statistical significance in speech delay (relative risk 2.37; 95% confidence interval: 1.33-4.22) and hearing loss (relative risk 2.76; 95% confidence interval:1.64-4,64). To our knowledge this is the first report suggesting preterm histological chorioamnionitis as a possible risk factor for hearing loss and speech delay.

Infant hearing screening

PURPOSE OF REVIEW

Infant hearing screening has progressed markedly over the past year. Although uncommon in the past, now almost 95% of infants in the United States are screened for hearing loss. Recent literature has expanded on several important components of hearing screening.

RECENT FINDINGS

A major revision of the American Academy of Pediatrics policy statement on infant hearing screening was published. This statement identifies a number of important principles and guidelines for infant hearing screening. Improvements in diagnostic techniques have been described including the need for auditory brainstem response screening in premature infants. Risk factors for congenital-hearing loss have been updated. An etiologic diagnosis for infants with hearing loss is increasingly possible with advances in genetics and molecular diagnosis. Finally, several articles provide further information on optimizing follow-up and diagnostic testing as well as early intervention.

SUMMARY

Despite the challenges still present in infant hearing screening, screening continues to identify infants at a very young age, and improve the early communication skills of infants with hearing loss through early diagnosis and early intervention.

The frequency of auditory neuropathy detected by universal newborn hearing screening program

OBJECTIVE

Auditory neuropathy/auditory dyssynchrony (AN/AD) has become a well-accepted clinical entity. The combined use of oto-acoustic emissions (OAEs) and auditory brainstem response (ABR) testing in the universal newborn hearing screening (UNHS) has led to the easy recognition of this disorder. Although, we are now able to diagnose AN/AD reliably, little is known about its epidemiology, etiology, and especially the frequency of its occurrence. The primary goal of this study was to determine the frequency of AN/AD in the Western Anatolian region of Turkey. The secondary goal was to compare the detection rate of AN/AD before and after the implementation of the UNHS in the audiology department of Dokuz Eylul University Hospital.

METHOD

Between 2005 and 2007, among the 23,786 newborns who were screened by automated click evoked oto-acoustic emissions (a-CEOAE) and automated auditory brainstem responses (a-ABRs), 2236 were referred to our department. All necessary audiological tests were performed for all the referred newborns. Among them, babies with deficient or abnormal ABR in combination with normal OAEs were considered as having AN/AD. These babies were evaluated with additional diagnostic audiological tests. Furthermore, comparison of the incidence of children diagnosed with AN/AD before and after the implementation of UNHS in our audiology department was also performed.

RESULTS

Among the referred newborns, 65 had abnormal or deficient ABR test results. Ten of these 65 newborn babies (mean diagnostic age: 5.7 months) with hearing impairment showed electrophysiological test results that were consistent with AN/AD. The frequency of AN/AD in these 65 children with hearing loss was 15.38%. Moreover, the frequency of AN/AD within UNHS was found to be 0.044%. Seven of the 10 babies with AN/AD had hyperbilirubinemia as a risk factor, which is a high rate to be emphasized. On the other hand, the retrospective investigation of children diagnosed with AN/AD in the same audiology department between 1999 and 2005 (i.e. before the implementation of UNHS) revealed only 7 children, with an average diagnostic age of 34 months.

CONCLUSION

After implementing the UNHS, the incidence of AN/AD in the audiology department increased from 1.16 to 4.13. Furthermore, the age of diagnosis of AN/AD decreased from 34 months to 5.7 months. This study shows that AN/AD, when screened, is a comparatively common disorder in the population of hearing-impaired infants. While newborn hearing screening provides early detection of babies with hearing loss, it also helps to differentiate AN/AD cases when the screening is performed with both a-ABR and automated oto-acoustic emission (a-OAE) tests. Thus, the routine combined use of a-ABR and a-OAE tests in UNHS programs, especially for the high-risk infants, can provide better detection of newborns with AN/AD. Furthermore, hyperbilirubinemia is merely an association and maybe etiologically linked.