HP01: Usefulness of auditory brainstem evoked response in the assessment of bilirubin-induced auditory toxicity in infants with jaundice: A case-control study

Abstract

To assess ABR alterations due to hyperbilirubinemia in jaundiced infants compared to a control group. Background: Bilirubin-induced neurotoxicity has predilection to specific areas of the brain including the auditory pathway structures. These latter are assessed by auditory brainstem evoked response (ABR). Methods: This was a retrospective study including two groups: jaundiced infants (G1) and age-matched (p>0.05) infants without jaundice (G2). All infants underwent ABR on each ear to screen deafness. Responses obtained at 90 dB were studied. Responses of G2 were normal. The Mann-Whitney U test was used to compare the responses between the two groups. Results: Twenty infants (40 ears) were included with a mean age of 33.5±13 months. G1 and G2 included 18 and 20 ears, respectively. Wave-I latency was significantly more prolonged in G1 (1.71±0.2 ms) compared to G2 (1.56±0.1 ms) with p=0.02. There was no difference in I-III interpeak interval (IPL). The III-V IPL was significantly increased in G1 (2.04±0.1 ms) compared to G2 (1.92±0.1 ms) with p=0.04. I-V IPL was more prolonged in G1. Discussion: Both peripheral and central auditory pathways may be altered in infants with jaundice. Bilirubin-induced toxicity may affect the inner part of the ear. The central dysfunction may occur at the brainstem level between the bulbo-protuberant junction and the inferior colliculus. This may be due to the hyperbilirubinemia-induced changes in the central synaptic transmission. Conclusion: Hyperbilirubinemia-induced auditory toxicity can occur at different levels of the auditory pathway. Therefore, there is a need for an early ABR assessment in jaundiced infants.