Frequency-following response among neonates with progressive moderate hyperbilirubinemia.

OBJECTIVE

To evaluate the feasibility of auditory monitoring of neurophysiological status using frequency-following response (FFR) in neonates with progressive moderate hyperbilirubinemia, measured by transcutaneous (TcB) levels.

STUDY

DESIGN

ABR and FFR measures were compared and correlated with TcB levels across three groups. Group I was a healthy cohort (n = 13). Group II (n = 28) consisted of neonates with progressive, moderate hyperbilirubinemia and Group III consisted of the same neonates, post physician-ordered phototherapy.

RESULT: FFR amplitudes in Group I controls (TcB = 83.1 ± 32.5µmol/L; 4.9 ± 1.9 mg/dL) were greater than Group II (TcB = 209.3 ± 48.0µmol/L; 12.1 ± 2.8 mg/dL). After TcB was lowered by phototherapy, FFR amplitudes in Group III were similar to controls. Lower TcB levels correlated with larger FFR amplitudes (r = -0.291, p = 0.015), but not with ABR wave amplitude or latencies.

CONCLUSION

The FFR is a promising measure of the dynamic neurophysiological status in neonates, and may be useful in tracking neurotoxicity in infants with hyperbilirubinemia.