Newborn auditory follow-up

Because hearing is a key component in the infant's development of speech, language, and cognition, early detection of infant hearing loss is critically important. The routine evaluation of hearing should include the identification of parental concerns regarding infant hearing as well as the assessment and diagnosis of infants with potential hearing impairment. Identification of hearing loss should be followed by early interventions to prevent developmental delays. This article promotes universal screening of newborn hearing. The article also provides a review of the embryogenesis of hearing and includes a breakdown of risks for hearing loss, recommendations for auditory testing, and suggestions for follow-up, early intervention, and support for families of infants with hearing impairment.     

State programs for universal newborn hearing screening

Published reports of several statewide and hospital-based systems for universal newborn hearing screening demonstrate that successful large-scale programs that appropriately identify infants with hearing loss in the earliest months of life can be developed. These programs are characterized by nursery-based screening rates of 95% or higher, referral rates of 6% or less, and reasonable per-infant costs. Less data are available regarding the outcome of these screening programs in ensuring confirmation of hearing loss by 3 months of age and initiation of intervention by 6 months of age. The results of the MDNC survey provide important information on the status of newborn hearing screening, audiologic assessment, and intervention services in 16 states. The survey reveals that hospitals have initiated universal newborn hearing screening programs using appropriate technology but that confirmation of hearing loss, fitting of amplification, and enrollment in early intervention are often delayed beyond the JCIH recommendations. Several factors might contribute to late confirmation of hearing loss and delayed amplification and intervention. First, as shown in the Colorado report, lack of a mandatory statewide system for tracking and reporting may delay transition of infants and families from screening to diagnosis, and diagnosis to intervention. In addition, many states lack a centralized system for reporting confirmed hearing loss. Successful statewide programs for universal newborn hearing screening, audiologic diagnosis, and early intervention depend on data-reporting strategies that facilitate transition of infants and families through a system of care. Second, lack of understanding about the urgent need for intervention in the earliest months of life may hinder referral to early intervention programs. Recent data from Colorado's universal newborn hearing screening program reveals that infants who are deaf or who have hearing losses achieve significantly better language development outcomes if intervention begins before age 6 months than infants whose intervention begins after 6 months of age. Hopefully, as these data become more widely available, the compelling need for early intervention will facilitate transition into these services. Although universal newborn hearing screening programs are increasing rapidly, states have not yet developed the coordinated systems for linking universal newborn hearing screening programs to audiologic diagnostic services and audiologic diagnostic services to early intervention programs. Key issues impeding development of these systems may be lack of tracking and reporting systems, lack of standardized guidelines for screening, diagnostic audiologic assessment, hearing aid fitting for very young infants, and lack of understanding about the compelling need for intervention in the earliest months of life. Development of complete systems of care must become a priority for universal newborn hearing screening to provide its ultimate benefit.     

Identification of SLC26A4 gene mutations in Iranian families with hereditary hearing impairment

Mutations in the SLC26A4 gene at the DFNB4 locus are responsible for Pendred syndrome and non-syndromic hereditary hearing loss (DFNB4). This study included 80 nuclear families with two or more siblings segregating presumed autosomal recessive hearing loss. All deaf persons tested negative for mutations in GJB2 at the DFNB1 locus and were, therefore, screened for autozygosity by descent (ABD) using short tandem repeat polymorphisms (STRPs) that flanked SLC26A4. In 12 families, homozygosity for STRPs suggested possible ABD in this genomic region. Affected individuals in five families had a positive perchlorate discharge test. Sequence analysis of SLC26A4 identified ten mutations in eight families (T420I, 1197delT, G334V, R409H, T721M, R79X, S448L, L597S, 965insA and L445W), of which, four are novel (T420I, G334V, 965insA and R79X). These results imply that Pendred syndrome is the most prevalent form of syndromic hereditary hearing loss in Iran.     

Levy-Hollister syndrome

The Levy-Hollister syndrome is an autosomal dominant disorder characterized by lacrimal malformations, simple cup-shaped ears, hearing loss, hypodontia and enamel dysplasia, and upper limb malformations. Renal anomalies have been noted variably. Two families with this disorder have been described previously. Recently, a third family with the Levy-Hollister syndrome was evaluated. Unusual features present in this family included bilateral nasolacrimal duct fistulas, radial aplasia, and unusual dermal ridge patterns. Early recognition of this disorder should prompt investigation for renal anomalies and/or hearing loss. It should also lead to consideration of surgical attempts to correct the lacrimal abnormalities or conductive hearing loss, thereby reducing the long-term morbidity in affected patients.     

Genetic deafness:the primary cause of sensorineural hearing loss in children]

Genetically-transferred hearing impairments account for more than 50% of cases of pediatric sensorineural hearing defects. Multiple clinical aspects are involved in genetic hearing impairment, including the involvement of other organs, genetic inheritance, and the degree and age at onset of hearing loss. Diagnosis relies on family history, on the systematic investigation of the symptomatology including an associated syndrome, and audiometry testing in parents and siblings. Analysis of the connexin 26 gene is also indicated, as it is frequently involved in this disorder. Further genetic analysis in affected families will aid in detecting other as yet unidentified genes responsible for hearing impairment.     

Thiamine-responsive megaloblastic anaemia: a cause of syndromic diabetes in childhood

Thiamine-responsive megaloblastic anaemia (TRMA) is a rare autosomal recessive condition, characterized by megaloblastic anaemia, non-autoimmune diabetes mellitus, and sensorineural hearing loss. We describe three infants with TRMA from two consanguineous Pakistani families, who were not known to be related but originated from the same area in Pakistan. All children were homozygous, and the parents were heterozygous for a c.196G>T mutation in the SLC19A2 gene on chromosome 1q23.3, which encodes a high-affinity thiamine transporter. The result is an abnormal thiamine transportation and vitamin deficiency in the cells. Thiamine in high doses (100-200 mg/d) reversed the anaemia in all our patients. Two patients discontinued insulin treatment successfully after a short period, while the third patient had to continue with insulin. The hearing loss persisted in all three children. The diagnosis of TRMA should be suspected in patients with syndromic diabetes including hearing loss and anaemia, even if the latter is only very mild and, particularly, in the case of consanguinity.     

儿童保健门诊语音障碍儿童初诊现状分析

目的 了解儿童保健科医生对语音障碍（SSD）的认识。方法 收集并分析2017年1月至2019年5月期间初次就诊并诊断为SSD的506例儿童的临床资料。结果 506例SSD儿童中，90.5% SSD儿童病史中描述发育行为相关表现；97.6%完善发育行为评估，以筛查性智能及发育测试为主（485/506，95.8%）。116例（22.9%）共患神经发育障碍性疾病，最常见的为语言障碍、全面发育迟缓和智力障碍，45.7%（53/116）发育行为相关病史中未记录异常表现。家属自觉听力异常儿童的神经发育障碍性疾病发生率高于家属自觉听力正常儿童，体查时对声源反应异常儿童的神经发育障碍性疾病发生率高于对声源反应正常儿童（P < 0.05）。506例SSD儿童中，病史中及体查时未关注听力的比例分别达33.2%、31.2%。92例（18.2%）完善诊断性听力测试，听力损失检出率为12%（11/92）。11例听力损失儿童病史中，3例既往听力筛查通过，3例家属自觉听力正常，7例体查时对声源反应正常。结论 SSD儿童易共患神经发育障碍性疾病，关注交流表现有助于其诊断，但病史询问易遗漏，应结合发育行为评估。SSD儿童的神经心理发育状况得到了儿童保健医师的关注，发育行为评估完成率高，但目前以筛查性智能发育测试为主。SSD儿童听力损失检出率高，儿童保健医生对其听力损失问题认识不足，诊断性听力测试未得到重视，临床不应以既往听力筛查结果或生活场景中儿童对声源的反应评估听力水平。     

Universal newborn hearing screening

The present statement reviews the evidence for universal newborn hearing screening (UNHS). A systematic review of the literature was conducted using Medline and using search dates from 1996 to the third week of August 2009. The following search terms were used: neonatal screening AND hearing loss AND hearing disorders. The key phrase "universal newborn hearing screening" was also searched. The Cochrane Central Register of Controlled Trials and systematic reviews was searched. Three systematic reviews, one controlled non-randomized trial and multiple cohort studies were found. It was determined that there was satisfactory evidence to support UNHS. The results of the available literature are consistent and indicate clear evidence that without UNHS, delayed diagnosis leads to significant harm for children and their families; with UNHS, diagnosis and intervention occur earlier; earlier intervention translates to improved language outcomes; and in well-run programs, there is negligible harm from screening.     

Early childhood hearing loss: a frequently overlooked cause of speech and language delay

The explosion of information regarding the genetics of hearing loss, the extraordinary effectiveness of early intervention, and the widespread practice of universal newborn hearing screening make for exciting times for those who serve young children who are deaf or hard-of-hearing and their families. These rapid changes in the knowledge base and practice standards also require the cooperation and help of pediatricians to enable children to take full advantage of available opportunities to optimize development of early communication.     

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.     

The relationship between language development and behaviour problems in children with hearing loss

Background:  There are well-replicated findings that link poor development on a range of communication skills with increased behavioural problems. This paper examines this relationship in children with hearing loss.
Method:  One hundred and twenty children with hearing loss (67 boys, 53 girls) and 63 hearing children (37 boys, 26 girls) with a mean age of 8 years from eight districts in Southern England were assessed for receptive and expressive language skills. The relationships between these measures and an aggregate of parent- and teacher-reported behaviour problems in the children were investigated.
Results:  Children with hearing loss had higher levels of behaviour problems compared to hearing children. Once the language abilities of children with hearing loss are taken into account, the negative effects of hearing loss on behaviour disappear.
Conclusions:  Behaviour problems are found more commonly in children with hearing loss and the level of behaviour problems is highest amongst those children with hearing loss with the least developed language capabilities.     

Differential diagnosis between Pendred and pseudo-Pendred syndromes: clinical, radiologic, and molecular studies

The disease gene for Pendred syndrome has been recently characterized and named PDS. It codes for a transmembrane protein called pendrin, which is highly expressed at the apical surface of the thyroid cell and functions as a transporter of chloride and iodide. Pendrin is also expressed at the inner ear level, where it appears to be involved in the maintenance of the endolymph homeostasis in the membranous labyrinth, and in the kidney, where it mediates chloride-formate exchange and bicarbonate secretion. Mutations in the PDS gene and the consequent impaired function of pendrin leads to the classic phenotype of Pendred syndrome, i.e. dyshormonogenic goiter and congenital sensorineural hearing loss. In the present study, we performed a detailed clinical, radiologic, and molecular analysis of six families presenting with clinical diagnosis of Pendred syndrome. In two families a homozygous pattern for PDS mutations was found, whereas the affected members of the other four families were compound heterozygotes. One family did not harbor PDS mutations. Among the four novel mutations described, one is a transversion in exon 2 (84C>A), leading to the substitution S28R. Two other novel mutations lie in exon 4 (398T>A) and in exon 16 (1790T>C), leading to the substitutions S133T and L597S, respectively. The fourth novel mutation (1614+1G>A) is located in the first base pair of intron 14, probably affecting the splicing of the PDS gene. Clinically, all patients had goiter with positive perchlorate test, hypothyroidism, and severe or profound sensorineural hearing loss. In all the individuals harboring PDS mutations, but not in the family without PDS mutations, inner ear malformations, such as enlargement of the vestibular aqueduct and of the endolymphatic duct and sac, were documented. The pseudo-Pendred phenotype exhibited by the family without PDS mutations is likely caused by an autoimmune thyroid disease associated with a sensorineural hearing loss of different origin.     

NICU高危新生儿早期的听力研究

目的　探讨新生儿重症监护室 (NICU)中重症患儿及高危儿与听力障碍或丧失相关的危险因素及其发病率。方法　对 1999年 12月～ 2 0 0 1年 8月 ,入住我院NICU的 2 4 8例听力障碍高危儿 ,在病情稳定后或出院前用听性脑干反应进行听力评价。结果　全部受检患儿中有 72例呈阳性结果 ,该组新生儿初次检查听力异常的发生率为 2 9 0 3% ,其中 3例系重度以上听力障碍。听力障碍的发生率在窒息组为 4 0 0 0 % ;高胆红素血症组为 2 6 37% ;早产儿组为 34 0 9% ,出生体重 <15 0 0g者阳性率尤高 ;接受机械通气组为 4 0 0 0 % ;应用耳毒性药物组为 4 1 30 %。结论　在NICU住院的新生儿中 ,存在较多与听力障碍有关的高危因素 ,该组新生儿听力障碍的发生率较正常活产新生儿明显增高。所以 ,高危新生儿从NICU出院前应常规进行听力检查。     

Hearing loss in infants with persistent fetal circulation

Infants with the diagnosis of persistent fetal circulation were evaluated for hearing loss. From Jan 1, 1982, to Jan 1, 1984, 28 infants with this diagnosis were retrospectively identified, and 18 were evaluated by formal audiologic testing. Additionally, 22 infants were prospectively followed by serial auditory evaluation from Jan 1, 1984, to Jan 1, 1986. Of the 40 infants evaluated, 21 were identified as having hearing impairment (52.5%), 14 of whom required hearing aids. For 82% of those retrospectively identified hearing-impaired infants who required hearing aids, parental concern was expressed for their lack of hearing acuity. This factor could have aided in the earlier recognition of these infants' impairment. Among those infants followed prospectively, formal audiologic testing, in some cases serially, was needed to diagnose a progressive hearing loss that was expressed at 6 to 8 months after discharge from the neonatal intensive care unit. Perinatal factors associated with the development and management of persistent fetal circulation were identified and compared in infants with confirmed hearing loss and those with normal hearing. Variables related to those infants with hearing loss were as follows: degree of alkalosis, duration of ventilation, and possibly use of furosemide. We concluded from these results that infants with persistent fetal circulation have an extremely high incidence of sensorineural hearing loss and suggest serial formal audiologic evaluations to aid in detection of hearing-impaired infants.     

Otoacoustic emissions as a screening test for hearing impairment in children recovering from acute bacterial meningitis

OBJECTIVES: To study the efficacy of otoacoustic emissions (OAEs) as a screening test for hearing impairment in children with acute bacterial meningitis. Hearing tests were performed before discharge from the hospital in an attempt to improve coverage and avoid delays in the diagnosis of postmeningitic hearing loss. METHODS: Children with bacterial meningitis were recruited from 21 centers. In the 48 hours before discharge from the hospital, all patients underwent a thorough audiologic assessment consisting of transient evoked OAEs, auditory brainstem responses (ABRs), otoscopy, and tympanometry. Hearing loss was defined as ABR threshold >/=30 dB. The results of OAE screening were compared with the gold standard of ABR threshold. RESULTS: Of 124 children recruited, we were able to perform both OAEs and ABRs on 110 children. Seven (6.3%) of the 110 children had ABR threshold >/=30 dB; 2 had sensorineural hearing loss and 5 had conductive hearing loss. At follow-up, hearing loss persisted in both cases of sensorineural hearing loss and no new cases were identified. All 7 children with hearing loss failed the OAE screening test. Ninety-four children with normal hearing thresholds passed the test, and 9 failed. Thus, the screening test had a sensitivity of 1.00 (95% confidence interval, 0.59 to 1.00), a specificity of 0.91 (0.85 to 0.97), a positive predictive value of 0. 44 (0.20 to 0.70), and a negative predictive value of 1.00 (0.96 to 1.00). CONCLUSIONS: OAE screening in children recovering from meningitis was found to be feasible and effective. The test was highly sensitive and reasonably specific. Inpatient OAE screening should allow early diagnosis of postmeningitic hearing loss and prompt auditory rehabilitation.     

Hearing impairment in children: early diagnosis is essential]

Diagnosis of hearing impairment is possible during the first days of life. Hearing tests are noninvasive and should not be delayed when hearing loss is suspected. Among children's hearing impairments, conductive hearing loss is the most frequent; it is generally acquired and reversible. At the opposite pole, sensorineural hearing loss has more severe consequences because it is irreversible and often present from birth. Early diagnosis and treatment are necessary in all cases to prevent speech delay. In cases with sensorineural hearing impairment, hearing aid fitting, or even cochlear implantation, and intensive speech therapy will help deaf children learn speech, with the view of optimal social and professional integration.     

Genetic causes of nonsyndromic hearing loss

Explosive progress is being made in genetic studies of hearing and deafness from the clinical and basic research perspectives. Greater than half of hearing loss is estimated to have a genetic basis. Recent studies of hearing and deafness have identified a dozen genes that cause nonsyndromic hearing disorders. Deafness can be inherited in an autosomal recessive, autosomal dominant, X-linked, or mitochondrial manner. Mutations in one gene, connexin 26 (encoding the gap junction protein beta 2), may be responsible for half of all autosomal recessive nonsyndromic deafness. With new mandates for hearing screening programs for newborns in many states, for the first time, the new information on the genetics of hearing loss can be used to diagnose the cause of hearing loss in some children and to understand better the molecular biology of hearing.     

Factors influencing the efficacy of universal newborn hearing screening

The debate surrounding the issue of universal hearing screening is being carried out on several levels. Although little disagreement exists over the educational, vocational, and quality-of-life benefits that would result from early identification and timely intervention of congenital hearing loss, the pragmatic issues, such as the effectiveness and the cost benefits associated with universal screening, cannot be ignored. This means that sensitivity, specificity, prevalence, and predictive value remain important factors. Determining the number of infants born with hearing loss in the United States each year, the prevalence issue is key to calculating the predictive value of newborn hearing screening. Emerging from current studies is that estimates of prevalence in the universal newborn population vary from 0.9 in 1000 for permanent bilateral hearing loss of more than 35 dB, to 3.24 in 1000 for bilateral hearing loss, to 5.95 in 1000 when unilateral and moderate hearing loss infants are counted. By comparison, the incidence of hearing loss in the NICU or at-risk population is accepted as high, somewhere between 2% and 4% or 20 to 40 in 1000. Incidence in the NICU varies depending on admission policies and level of care. In general, however, by screening the NICU and targeted at-risk populations, estimated to make up 10% to 16% of the newborn population, half or more of all newborns with severe to profound educationally disabling hearing loss are identified. Data from several well-conducted clinical studies, dating back to the first studies on the use of ABR to screen in the NICU, provide ample justification for the recommendation that all infants admitted to an NICU for longer than 24 hours should be screened for hearing impairment regardless of whether they have any of the at-risk indicators for hearing loss. In the author's opinion, screening in the NICU should be modeled on the operator-controlled ABR protocol outlined by Galambos and colleagues, with the addition that every ABR fail be screened by OAE before discharge. Unlike the targeted NICU population, the question remains for well infants, is sufficient clinical data or evidence available to justify screening all well newborns, specifically those with none of the at-risk for hearing loss indicators cared for in the well-infant nursery and who are discharged home within 24 or 48 hours? With the steady increase in the number of hospital-based universal newborn hearing screening programs implemented since the NIH Consensus Statement, additional data should become available to help resolve several outstanding issues, including prevalence and the predictive value of the various test protocols currently in use or proposed.     

The efficacy of early identification and intervention for children with hearing impairment

From these findings, the inevitable conclusion is that identification of hearing loss by 6 months of age, followed by appropriate intervention, is the most effective strategy for the normal development of language in infants and toddlers with hearing loss. Identification of hearing loss by 6 months can only be accomplished through universal newborn hearing screening. Some questions that arise as a result of these studies include: What can one conclude from the finding that the language skills of children with mild hearing losses are no better than those with greater losses? If the finding holds up, it indicates a great need for investigations into biobehavior theories of language acquisition and into the part played by the prenatal 4 months of hearing. And it also shows a need for answering the question, When does a hearing loss begin?, because it certainly seems that all hearing losses are similar in their outcomes. Can the findings from these studies be used to benefit normally hearing children who are at risk for language delays as a result of limited language environments? Such children suffer from auditory deprivation just as surely as those with hearing losses. If the language skills of the latter children can be brought to normal range by early intervention, the same strategy may help high-risk populations. The efficacy of early intervention is just as valid for these children as it is for the children with hearing impairment. Now that the benefits of early identification of children with congenital hearing loss have been demonstrated, these benefits should be extended to all children who are at risk for language delays, with appropriate interventions applied immediately.