High-stimulation-rate ABR predicts persistent auditory pathway dysfunction in neonates with severe hyperbilirubinemia: a 6-month longitudinal study

Objective This study aims to analyze high-stimulation-rate auditory brainstem response (ABR) outcomes in neonates diagnosed with hyperbilirubinemia (NH) and assess its clinical relevance. Methods This study utilized a prospective longitudinal cohort design. It included ABR tests conducted at 11.1 and 51.1 stimulations per second, alongside serum total bilirubin (TSB) measurements for 28 neonates (56 ears) with severe NH, 28 neonates (56 ears) with mild-to-moderate NH, and 28 neonates (56 ears) from a healthy control group (CG) during their hospital stay. We compared the differences among these groups. Additionally, ABR tests at both high and low stimulation rates were administered to neonates with severe and mild-to-moderate NH at ages 3 and 6 months to compare both inter-group and intra-group variations. Results (1) During hospitalization, interpeak latency (IPL) differences between waves I and V (ΔIPL I-V) at high (51.1 stimulations per second) and low (11.1 stimulations per second) stimulation rates showed that the severe NH group exhibited longer ΔIPL I-V compared to the healthy CG ( p < 0.05) and the mild-to-moderate NH group ( p < 0.05). The mild-to-moderate group also demonstrated longer ΔIPL I-V compared to the CG ( p < 0.05). Correlation analysis between TSB and ΔIPL I-V in neonates with NH during hospitalization revealed no significant correlation in the CG ( r = 0.203, p = 0.300) and the mild-to-moderate group ( r = 0.116, p = 0.558), but a positive correlation in the severe group ( r = 0.712, p < 0.05). (2) At 3 months, the ΔIPL I-V in the severe group was notably longer than that in the mild-to-moderate group ( p < 0.05). This pattern persisted at 6 months ( p < 0.05). (3) Within-group comparisons showed that in the severe group, ΔIPL I-V was shorter at both 3 and 6 months than during hospitalization ( p < 0.05), with no significant changes between these two ages ( p > 0.05). In the mild-to-moderate group, ΔIPL I-V remained unchanged across all examined periods ( p > 0.05). Conclusion High-stimulation-rate ABR is a potent tool for detecting auditory deficits in neonates with NH. Neonates with severe NH exhibit persistent auditory abnormalities, whereas those with mild-to-moderate conditions display only transient alterations. These findings underscore the value of high-stimulation-rate ABR in the early identification of neonates at high risk, recommending its incorporation into routine follow-up protocols for those with severe NH.