The Current Status of Auditory Brainstem Response Testing in Neonatal Populations

Abstract

SummaryThe use of auditory brainstem response (ABR) for assessment of hearing in the neonate has not been without challenge. Although numerous articles have appeared, agreement regarding the utility of neonatal ABR testing does not exist. In review of the current studies and commentaries, a clear majority are favorable to neonatal ABR testing. These studies along with current test procedures are discussed. (38); procedures for the assessment of that potential were initiated. Since 1975, the research reported in the literature has grown exponentially each year. In spite of the large and increasing amount of research reported, sever! issues have remained unresolved, viz., the applicability, reliability, and validity of neonatal ABR testing. In fact, because of these and other factors, some authors have begun to seriously question using ABR with neonates (13,35,42).. The need for early identification of infants with hearing loss is apparent. Normal language, learning, and social skill acquisition is contingent upon hearing. Although the incidence of hearing impairment in the general neonatal population is relatively low (0,26%) (41), in NICU neonates the incidence is considerably higher (2-10%) (16, 39). Furthermore, the improved survival rate of neonates born weighing less than 1500 g (19, 31) has increased the pool of infants in which a high incidence of hearing impairment is seen (16). Because the need for early identification of hearing loss does exist and the current procedures that could identify hearing impairment in the neonate are open to question (ABR), a critical review of ABR testing is in order. The purpose of this article is to summarize the current ABR literature, both pro and con, and to draw conclusions regarding its use based on the literature and the experience of the writer. The summary will not attempt to review early ABR literature primarily due to excellent reviews that are already published. The interested reader, however, would find Downs (13) very thorough.The current literature pertinent to ABR testing of neonates and NICU populations is discussed and from several aspects (5)(6)(7) II,12,17,20,25,34,36,47). Weber (47) The influence of various factors on the ABR have been explored

Neonatal hearing screening

“…Approximately 1 child in every 1000 live births suffers from a serious congenital hearing impairment [7,29]. The prevalence of hearing impairment is much higher among the population of neonatal intensive care units with figures of 1% reported in Great Britain [7,9], 1.5% in the Netherlands [47] and 2% in the USA [6].…”

“…The conventional auditory brainstem evoked response is the gold standard which is used for testing hearing [6,13,20]. The use of auditory brainstem responses (ABR) was first reported by Jewett et al in 1970 [21].…”

Newborn Auditory Brainstem Evoked Responses (ABRs): Prenatal and Contemporary Correlates

“…By contrast, researchers in two of the six studies found evidence of peripheral delays as indicated by prolonged latencies of Wave I (Nakamura et al, 1985;Streletz et al, 1986). In three studies, investigators looked specifically at the question of threshold elevation and found no relation with elevated bilirubin levels (Cox et al, 1984;Lenhardt et al, 1984;Roberts et al, 1982), although Cox and Roberts did not measure the ABR at peak bilirubin levels.…”

“…Since the description of ABRs (Jewett & Williston, 1971), the procedure has been widely used in the evaluation of auditory nerve integrity in children. Thus, in the absence of reliable behavioral audiometric methods for newborns, the technique has become popular as a hearing screening test for neonatal intensive care (NICU) survivors (Cox, 1984). This has led to the use of the ABR to evaluate hearing in populations that are not testable using traditional methods.…”

Brainstem Acoustic Evoked Responses: Maturational Aspects from Cochlea to Midbrain

“…Brainstem acoustic evoked potentials (BAEP) to different stimulus intensities have proved to be a reliable tool in the early diagnosis of hearing impairment in high-risk infants (1,2,3,5,15,17,18). Abnormalities ofwaveform and prolongation of interpeak latencies are objective indicators of brainstem involvement in various neuropediatric diseases, for example in post-asphyxiated children, dysraphic malformations or during neurointensive treatment (3,7,8,13,19 (4,10,11,14,15,17,20).…”