Air and bone-conduction frequency-specific auditory brainstem response in neonates with normal hearing

Purpose to determine the minimum response and the latency of V wave in the Frequency-specific auditory brainstem responses (FS-ABR) in normal hearing neonates at the frequencies: 0.5, 1, 2 and 4 kHz by air and bone conduction and to determine normative values. Methods normal hearing neonates were assessed with FS-ABR at 0.5, 1, 2 and 4 kHz, air and bone conduction. Twelve ears were assessed in each frequency, totalizing 18 neonates. Results analysis considered the latency and the presence of wave V until 20 dB nHL in air and bone conduction, for four intensities. Results it was observed an increase of wave V latency with the decrease of intensity, and greater latencies at lower frequencies in both air and bone conduction. Nevertheless, there was no difference between the latencies at 0.5 and 1 kHz with strong intensity stimuli in both conditions, contrasting to literature findings. Considering air conduction, wave V was present at 0,5 kHz at 30 dB nHL in all ears and at 1 kHz 11 ears (91,66%) presented it at 20 dB nHL. All subjects (100%) presented responses to the other frequencies at 20 dBn HL. Considering bone conduction, all subjects presented wave V at 20 dB nHL in all frequencies. Conclusion the found values can be used in clinical practice in order to guide the differential diagnosis of hearing loss, complementing the evaluation as for hearing neonates.

研究目的：明确正常听力新生儿在0.5、1、2及4 kHz频率下，采用气导与骨导方式检测时，频率特异性听觉脑干反应（Frequency-specific auditory brainstem responses, FS-ABR）中V波的最小反应阈值与潜伏期，并建立其正常值参考范围。
方法：针对0.5、1、2及4 kHz频率，采用气导与骨导方式，对正常听力新生儿实施FS-ABR检测。本研究共纳入18名新生儿，各频率下共评估12耳。
结果：分析涵盖气导与骨导两种检测方式下，4种刺激强度直至20 dB 正常听力级（dB nHL）时的V波潜伏期与可引出情况。结果显示，随着刺激强度降低，V波潜伏期延长；且在气导与骨导两种方式中，低频段的V波潜伏期均更长。不过，在高强度刺激下，0.5 kHz与1 kHz频段的潜伏期无显著差异，这与既往文献报道结果不符。就气导检测而言，所有受试耳在0.5 kHz频率、30 dB nHL刺激下均可引出V波；在1 kHz频率下，11耳（占比91.66%）在20 dB nHL刺激下可引出V波。其余频率在20 dB nHL刺激下，所有受试者（100%）均可引出相应反应。就骨导检测而言，所有受试者在所有频率、20 dB nHL刺激下均可引出V波。
结论：本研究所得的FS-ABR V波相关参数值可应用于临床实践，用于辅助新生儿听力损失的鉴别诊断，完善新生儿听力评估体系。