© Borgis - New Medicine 3/1999, s. 54-55
Joanna Ratyńska, Małgorzata Mueller-Malesińska, Krzysztof Kochanek, Henryk Skarżyński
Application of OAE and ABR techniques in neonatal screening and diagnostics of hearing impairment in newborns and infants
From the Institute of Physiology and Pathology of Hearing, Warsaw
Director: Prof. Henryk Skarżyński, MD, DSc
ABR and OAE techniques have become a standard in the hearing screening of newborns and infants. ABR is also the basic test when establishing a diagnosis of hearing loss in a child. Based on their own experience the authors discuss the applicability of ABR and OAE tests in newborns and infants and present the difficulties that may be encountered when screening children at different ages.
Registration of otoacoustic emissions (OAE) and auditory brainstem evoked potentials (ABR) have become a standard in neonatal hearing screening and are used worldwide. These methods are recommended as the tools in neonatal hearing screening programms (3, 4).
For over 10 years, ABR has been a „golden standard” in neonatal hearing screening. The sensitivity and specificity of this test are close to 100%. In neonatal hearing screening, 2 modes are applied: conventional ABR using intensity sequences, and automated ABR. In the conventional method, the threshold of wave V is investigated. In full-term newborns the threshold is 30 dB nHL. The test outcome is assessed subjectively by the tester. In the automated mode, both the registration process and evaluation of the result are performed automatically. In the automated mode, the presence of wave V is usually assessed for only one intensity level (most commonly 35 dB nHL). The advantages of ABR as a screening test are its high sensitivity and specificity, and the possibility of assessing both the sensory part and a substantial portion of the neural part of the auditory pathway. The disadvantages of ABR are the relatively long duration of the test, and subjective assessment of the result when using the conventional mode. ABR is also a basic method in establishing a diagnosis of hearing loss in a child.
The second most popular hearing screening tool in newborns and infants is otoacoustic emission. In hearing screening programmes, two kinds of emissions are used. They are transiently evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE). Most screening programmes use TEOAE, but recently DPOAE has become more and more popular. The advantages of the OAE test are its high sensitivity and simplicity. The disadvantage is the high susceptibility of the test result to environmental noises or internal noise produced by the child. OAE is not correct for identifying retrocochlear lesions. However, pure retrocochlear hearing loss is relatively infrequent in the newborn population (according to White, no more than 1% of all hearing impaired children, or 3 cases in 100000 persons in the whole population) (7).
The aim of this study is to discuss the applicability of OAE and ABR techniques in newborn and infant screening for hearing loss, based on the experience of the Department of Audiology of the Institute of Physiology and Pathology of Hearing in Warsaw.
Material and methods
Powyżej zamieściliśmy fragment artykułu, do którego możesz uzyskać pełny dostęp.
Płatny dostęp tylko do jednego, POWYŻSZEGO artykułu w Czytelni Medycznej
(uzyskany kod musi być wprowadzony na stronie artykułu, do którego został wykupiony)
Płatny dostęp do wszystkich zasobów Czytelni Medycznej