Abstract: AbstractObjectiveTo study brainstem function at term in preterm infants who have a hypoxic history using brainstem auditory evoked potentials (BAEP) to click stimuli of different repetition rates.MethodsStudy group included 39 preterm infants (gestational age 29w~36w) with a hypoxic history.The controls were 30 preterm infants (gestational age 29w~36w) without any complication.The BAEP was recorded at the repetition rates of 21.1,51.1 and 91.1/sec for these babies between 37 to 42 weeks of postconceptional age.The latencies and amplitudes of wavesⅠ、Ⅲ、and Ⅴ and the interpeak intervals of Ⅰ~Ⅲ、Ⅲ~Ⅴ andⅠ~Ⅴ were analyzed.ResultsIn preterm infants with a hypoxic history,the latency of wave Ⅴ and Ⅲ~Ⅴ interpeak interval increased at 21.1/sec,compared with the controls.At 51.1/sec and 91.1/sec,these changes became more significant,and the latency of Ⅲ,amplitude of Ⅴ and the Ⅰ~Ⅲ、Ⅰ~Ⅴ interpeak intervals were also significantly different from the controls.ConclusionThere are some abnormalities in brainstem auditory function at term in preterm infants who have a hypoxic history.The increase in click rate can enhance the detection of BAEP abnormalities.

Key words: Hypoxia , Click rate, Preterm infant

摘要： 目的通过分析不同刺激速率下的脑干听觉诱发电位变化，观察有缺氧病史的早产儿在纠正胎龄足月时的脑功能状态。方法2002年7月至2004年7月复旦大学儿科医院新生儿科收治的早产儿，缺氧组：39例，有缺氧病史，除外其它听力及脑损伤高危因素；对照组：30例，无缺氧病史，无其他听力损伤高危因素。两组于纠正胎龄37~42周时进行脑干听觉诱发电位检查，声刺激速率为21.1/s、51.1/s和91.1/s，分析Ⅰ、Ⅲ、Ⅴ波的潜伏期、振幅、峰间期等参数，进行t检验。结果在60dBnHL刺激强度下，随刺激速率增加，各组Ⅰ、Ⅲ、Ⅴ波的潜伏期、峰间期均逐渐延长，振幅下降。在常规21.1/s时，缺氧组仅表现为Ⅴ波潜伏期和Ⅲ~Ⅴ峰间期延长；随刺激速率增加，不仅上述差异更加显著，而且Ⅲ波潜伏期、Ⅴ波振幅及Ⅰ~Ⅲ、Ⅰ~Ⅴ峰间期也表现出差异。结论有缺氧病史的早产儿在纠正胎龄足月时脑干功能仍存在异常，提高刺激速率有助于异常的检出，为更好地研究新生儿脑干功能状态及发育规律提供了新的方法。

关键词: 脑干听觉诱发电位, 刺激速率, 早产儿, 缺氧