The effect of neonatal hyperbilirubinemia on the auditory brainstem response

Auditory brainstem response (ABR) testing was performed on 30 babies in the Premature Baby Center of Kyoto University Hospital as soon after birth as possible. In cases of hyperbilirubinemia of more than 15.0 mg/dl, ABR testing was performed at least twice. In four babies with total bilirubin concentrations of more than 18.0 mg/dl at some point, abnormal ABRs were seen. These abnormalities normalized with a decrease in serum total bilirubin concentration in two of the four cases, but in the other two the abnormalities showed no change. The cause and significance of this difference are not known, but ABR is a simple and useful method for assessing the neurotoxic effects of bilirubin on the nervous system.