ABSTRACT
Brainstem auditory evoked responses (BAER) were longitudinally recorded prospectively in 18 term infants with neonatal hyperbilirubinemia (NHB) (total serum bilirubin > 15 mg/dl). Seven neonates had abnormal BAER. Wave complex IV-V was absent in eight recordings in NHB group while they were normal in the control group (p < 0.001). Prolongation of latency of waves I and V and interwave conduction time (wave I-V) occurred in jaundiced infants especially when unconjugated serum bilirubin level rose above 22 mg/dl. The abnormalities in BAER reversed to normal in all seven neonates after exchange blood transfusion indicating transient nature of bilirubin toxicity to the brain. All seven neonates in the study and control group had normal hearing, development quotient and were free of neurological sequelae on follow up for one year.
Subject(s)
Audiometry, Evoked Response , Case-Control Studies , Evoked Potentials, Auditory, Brain Stem/physiology , Exchange Transfusion, Whole Blood , Humans , Hyperbilirubinemia/physiopathology , India , Infant, Newborn , Prospective StudiesABSTRACT
Auditory brainstem evoked responses (ABER) were recorded to provide normative data regarding the latency values, brainstem conduction times in term neonates and infants up to 24 months of age. The mean latency for wave I - 1.86 +/- 0.11 m sec, wave III - 5.11 +/- 0.31 m sec, wave V - 7.10 +/- 0.30 m sec progressively decreased at birth to wave I - 1.64 +/- 0.17 m sec, wave III - 4.40 +/- 0.27 m sec, wave V - 6.15 +/- 0.21 m sec at 12 months of age by stimulus strength of 75 decibels at a rate 20 clicks/sec. Interwave conduction times improved to I-III - 2.76 +/- 0.29 m sec, I-V - 4.51 +/- 0.29 m sec, III-V - 1.75 +/- 0.17 m sec at 12 months from I-III - 3.25 +/- 0.26 m sec, I-V - 5.23 +/- 0.23 m sec, III-V - 1.99 +/- 0.35 m sec at birth.