Effect of neonatal hyper bilirubinemia on brain stem auditory evoked response

Abstract

Introduction: Neonatal hyperbilirubinemia is a major cause of morbidity in neonates. The long term neurological sequel can be prevented and reversed by timely and aggressive management of hyperbilirubinemia. Brain stem auditory evoked response (BAER) is an assessment tool to help predictimpeding bilirubin neurotoxicity. This study was conducted to evaluate the effect of hyperbilirubinemia on auditory system of newborn and the effect of therapy on BAER. Materials and Methods: In this case control study, 50 term neonates with hyperbilirubinemia (total serum bilirubin > 15 mg/dl) were included in the study group and 25 normal term neonates were taken as controls. Baseline BAER was recorded in study group before therapy and after therapy. Results were compared with controls and intra group comparison was also done. Continuous data with normal distribution was analysed by student t-test, and categorical data was analysed using chi-square test. Results: Most common BAER abnormality noted in jaundiced neonates was prolonged latency of wave V (42%) andprolonged inter wave interval I–V (32%). Significant increase in the absolute latencies of waves III and V was noted in hyperbilirubinemic neonates as compared to controls (p<0.05). I-III and I-V inter-peak latencies were also significantly prolonged in neonates with hyper bilirubinemia (p<0.05). There was significant improvement in the latency of wave III and wave V, I – III inter- peak latency and I – V inter-peak latency after treatment (P<0.05). Conclusion: Results of our study demonstrate the importance of early ABR screening as an efficient tool for monitoring the neonates at risk of bilirubin neurotoxicity. Diagnosing the early changes in ABR caused by hyperbilirubinemia before appearance of clinical abnormality will help prevent bilirubin neurotoxicity.