不同月龄婴儿的ABR正常值分析

Normal Values of Auditory Brainstem Responses for Infants of Different Ages

目的获取6月龄内婴儿的听性脑干反应（auditory brainstem response，ABR）正常值范围并分析其特点。方法2006年5月至2008年5月对听力正常、出生40天～7月龄的60例婴儿进行ABR检测，根据平均年龄分为A（6周龄）、B（3月龄）、C（6月龄）组，每组20例（40耳）；对照组为听力正常的成人20例（40耳），平均年龄25．2岁。对各组的ABR结果进行统计分析。结果各组100dB nHL ABR的波Ⅰ、Ⅲ、Ⅴ潜伏期的正常值范围分别为：A组：1．49±0．08、4．42±0．16、6．61±0．25ms；B组：1．47±0.07、4．35±0．20、6．50±0．25ms；C组：1．45±0．07、4．17±0．15、6．32±0．22ms；对照组：1．45±0．07、3．79±0．11、5．49±0．20ms；三组婴儿80dB nHL ABR的波Ⅰ、Ⅲ、Ⅴ潜伏期的正常值范围分别为：A组：1．63±0．08、4．52±0．17、6．74±0．26ms；B组：1．64±0．11、4．44±0．20、6．67±0．26ms；C组：1．60±0．11、4．27±0．16、6．43±0．24ms。随刺激声强度降低，ABR各波潜伏期延长。各月龄组婴儿的波Ⅲ、Ⅴ潜伏期、Ⅰ-Ⅲ、Ⅰ—V波间期均比成人延长．且随婴儿月龄增加逐渐缩短，但6月龄时仍未达到成人水平。各月龄组ABR反应阈差异无统计学意义。结论不同月龄婴儿的波Ⅰ潜伏期与成人相近；各月龄婴儿的ABR反应阈无明显差异，且与成人相近。

Objective To find the normal range and features for auditory brainstem responses （ABR） of infants within six months, and the basic parameters for identifying the hearing impaired infants. Methods May 2006 to May 2008, 60 normal infants and 20 normal adults received the ABR tests. The infants were divided into three groups： group A （6 weeks）, group B （3 months） and group C （6 months）. Each group consisted of 20 infants （40 ears） and the ABR data were statistically analyzed. Results At 100 dB nHL, the wave Ⅰ , Ⅲ , Ⅴ latencies of ABR for 6-week infants respectively were 1.49±0.08 ms, 4.42±0.16 ms and 6.61±0.25 ms, for 3-month infants, 1.47±0.07 ms, 4. 35±0.20 ms and 6. 50±0.25 ms, for 6-month infants, 1.45±0.07 ms, 4. 17±0.15 ms and 6. 32±0. 22 ms. At 80dB nHL, thewave Ⅰ, Ⅲ, Ⅴ latencies of ABR for 6 week infants were 1. 63±0. 08 ms, 4. 52±0.17 ms and 6.74±0.26 ms,respectively, for 3-month infants, 1.64±0.11 ms, 4.44±0.20 ms and 6.67±0.26 ms, for 6 month infants, 1.60±0.11 ms, 4.27±0.16 ms and 6.43±0.24 ms. As the intensity of stimulating signals decreased, the peak latency of ABR became more delayed. The peak latencies of Ⅲ , Ⅴ waves and interval peak latencies of Ⅰ - Ⅲ and -Ⅴ waves for the infants were more delayed than those for adults, and became shorter with the increase of the infants＇ ages, but they failed to reach aduhs＇ levels even for 6-month infants. However, the length of wave Ⅰ of ABR for infants of different months was close to that for adults. The thresholds of ABR for the infants of different ages were not significantly different, all being close to the values for adults. Conclusion This study has analyzed the ABR wave features for the infants of three ages and this can help to define the reference ranges for the infants and to provide the parameters for early diagnosis of hearing loss among the infants.