Improving the efficiency of Auditory Brainstem Responses in newborns, using a 60clicks/s stimulation rate.

Recent evidence suggests that Auditory Brainstem Responses (ABR), in neonates with risk factors for neurological damage, may show auditory brainstem abnormalities, even in patients with normal hearing. To compare the recording and diagnostic accuracy of neonatal Auditory Brainstem Responses (ABR), using 10 and 60clicks/s stimulation rates, two groups of neonates were prospectively studied: 30 healthy full-term neonates, with no peri- or postnatal complications; and 30 high-risk newborns with two or more of the following conditions: hyperbilirubinemia, use of ototoxic drugs, birth weight inferior to 1500g, perinatal sepsis, intraventricular hemorrhage, and/or mechanical ventilation. Correlation between ABR trials, recording duration, and the absolute and interpeak latencies of ABR waves I, III and V, were measured. ROC-curve analysis assessed the diagnostic accuracy of both stimulation rates. The correlations between ABRs trials were significantly higher at 60clicks/s than at 10clicks/s (F(1,116)=14.5, p<0.0002). Recording duration at 60clicks/s was significantly lower (t=20.9, p<0.0001). ROC-curve comparisons showed increased diagnostic accuracy at the stimulation rate of 60clicks/s, for waves I (D=2.04, p=0.04), V (D=2.02, p=0.04), interpeak latencies III-V (D=2.2, p=0.02), and I-V (D=2.86, p=0.004). In neonates, the use of 60clicks/s stimulation rate permits a substantial shortening of the ABR recording, with greater diagnostic accuracy and replicability.