Abstract
Introduction
Whether the severity of bilirubin neurotoxicity is closely related to the level of total serum bilirubin (TSB) remains to be determined.
Materials and methods
We studied the amplitudes of brainstem auditory evoked response (BAER) components in 83 term neonates with TSB >10 mg/dL to detect any differences in bilirubin ototoxic effect on the amplitudes between different levels of TSB.
Results and discussion
Compared to age-matched normal controls, the amplitudes of BAER waves III and V were reduced significantly (P<0.01 and 0.001). The V/I and V/III amplitude ratios were also decreased significantly (P<0.001 and 0.01). Although all amplitudes tended to be lower at higher TSB levels than at lower levels, none of the amplitudes correlated significantly with the level of TSB. Neither the V/I amplitude ratio nor the V/III amplitude ratio correlated with the TSB. No significant differences were found in any BAER wave amplitudes among the TSB levels 11–15, 16–20 and >20 mg/dL. In the comparison of amplitude data between any two of the three TSB levels, only wave V amplitude showed significant difference between TSB levels 11–15 and >20 mg/dL (P < 0.05).
Conclusion
BAER wave amplitudes were significantly reduced in neonates with hyperbilirubinemia. However, there was no close correlation between the degree of amplitude reduction and the level of TSB. These results indicate that bilirubin toxicity to the neonatal brain is not closely related to the level of TSB.
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Abbreviations
- BAER:
-
brainstem auditory evoked response
- nHL:
-
normal hearing level
- TSB:
-
total serum bilirubin
References
Amin SB, Ahlfors C, Orlando MS et al (2001) Bilirubin and serial auditory brainstem responses in premature infants. Pediatrics 107:664–670. doi:10.1542/peds.107.4.664
Boo NY, Oakes M, Lye MS et al (1994) Risk factors associated with hearing loss in term neonates with hyperbilirubinaemia. J Trop Pediatr 40:194–197
Chiappa KH (1990) Brainstem auditory evoked potentials: Methodology. In: Chiappa KH (ed) Evoked potentials in clinical medicine. Raven, New York, pp 173–221
Dennery PA, Seidman DS, Stevenson DK (2001) Neonatal hyperbilirubinaemia. N Engl J Med 344:581–590. doi:10.1056/NEJM200102223440807
Funato M, Tamai H, Shimada S et al (1994) Vigintiphobia, unbound bilirubin, and auditory brainstem responses. Pediatrics 93:50–53
Funato M, Teraoka S, Tamai H et al (1996) Follow-up study of auditory brainstem responses in hyperbilirubinemic newborns treated with exchange transfusion. Acta Paediatr Jpn 38:17–21
Gupta AK, Mann SB (1998) Is auditory brainstem response a bilirubin neurotoxicity marker? Am J Otolaryngol 19:232–236. doi:10.1016/S0196-0709(98)90123-5
Gustafson PA, Boyle DW (1995) Bilirubin index: a new standard for intervention? Med Hypotheses 45:409–416. doi:10.1016/0306-9877(95)90213-9
Hansen TWR, Paulsen O, Gjerstad L et al (1988) Short-term exposure to bilirubin reduces synaptic activation in rat transverse hippocampal slices. Pediatr Res 23:453–456. doi:10.1203/00006450-198802000-00018
Hansen TWR, Bratlid D, Walaas SI (1988) Bilirubin decreases phosphorylation of synapsin I, a synaptic vesicle-associated neuronal phosphoprotein, in intact synaptosomes from rat cerebral cortex. Pediatr Res 23:219–223. doi:10.1203/00006450-198802000-00018
Hung KL (1989) Auditory brainstem responses in patients with neonatal hyperbilirubinaemia and bilirubin encephalopathy. Brain Dev 11:297–301
Jiang ZD, Brosi DM, Wilkinson AR (2002) Auditory neural responses to click stimuli of different rates in the brainstem of very preterm babies at term. Pediatr Res 51:454–459. doi:10.1203/00006450-200204000-00009
Jiang ZD, Shao XM, Wilkinson AR (2006) Changes in BAER amplitudes after perinatal asphyxia during the neonatal period in term infants. Brain Dev 28:554–559. doi:10.1016/j.braindev.2006.03.004
Jiang ZD, Chen C, Liu TT et al (2007) Changes in BAER wave latencies in term neonates with hyperbilirubinaemia. Pediatr Neurol 37:35–41. doi:10.1016/j.pediatrneurol.2007.03.006
Kountakis SE, Skoulas I, Phillips D et al (2002) Risk factors for hearing loss in neonates: a prospective study. Am J Otolaryngol 23:133–137. doi:10.1053/ajot.2002.123453
Newman TB, Liljestrand P, Jeremy RJ et al (2006) Outcomes among newborns with total serum bilirubin levels of 25 mg per deciliter or more. N Engl J Med 354:1889–1900. doi:10.1056/NEJMoa054244
Newton V (2001) Adverse perinatal conditions and the inner ear. Semin Neonatol 6:543–551. doi:10.1053/siny.2001.0076
Sano M, Kaga K, Kitazumi E et al (2005) Sensorineural hearing loss in patients with cerebral palsy after asphyxia and hyperbilirubinemia. Int J Pediatr Otorhinolaryngol 69:1211–1217. doi:10.1016/j.ijporl.2005.03.014
Shapiro SM (2003) Bilirubin toxicity in the developing nervous system. Pediatr Neurol 29:410–421. doi:10.1016/j.pediatrneurol.2003.09.011
Shi HB, Kakazu Y, Shibata S et al (2006) Bilirubin potentiates inhibitory synaptic transmission in lateral superior olive neurons of the rat. Neurosci Res 55:161–170. doi:10.1016/j.neures.2006.02.015
Smith CM, Barnes GP, Jacobson CA et al (2004) Auditory brainstem response detects early bilirubin neurotoxicity at low indirect bilirubin values. J Perinatol 24:730–732. doi:10.1038/sj.jp.7211164
Soares I, Collet L, Delorme C et al (1989) Are click-evoked BAEPs useful in case of neonate hyperbilirubinaemia? Int J Pediatr Otorhinolaryngol 117:231–237. doi:10.1016/0165-5876(89)90050-5
Streletz LJ, Graziani LJ, Branca PA et al (1986) Brainstem auditory evoked potentials in fullterm and preterm newborns with hyperbilirubinemia and hypoxemia. Neuropediatrics 17:66–71. doi:10.1055/s-2008-1052503
Wilkinson AR, Jiang ZD (2006) Brainstem auditory evoked response in neonatal neurology. Semin Fetal Neonatal Med 11:444–451. doi:10.1016/j.siny.2006.07.005
Wong V, Chen WX, Wong KY (2006) Short- and long-term outcome of severe neonatal nonhemolytic hyperbilirubinemia. J Child Neurol 21:309–315. doi:10.1177/08830738060210040301
Acknowledgements
This research was supported by Deafness Research and WellChild, UK. Dr Rong Yin participated in collecting and analysing part of the data.
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We have no financial relationships relevant to this article to disclose.
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Jiang, Z.D., Brosi, D.M. & Wilkinson, A.R. Changes in BAER wave amplitudes in relation to total serum bilirubin level in term neonates. Eur J Pediatr 168, 1243–1250 (2009). https://doi.org/10.1007/s00431-008-0919-3
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DOI: https://doi.org/10.1007/s00431-008-0919-3