皮层听觉诱发电位在听力评估中的应用

Hearing Assessment by Complex Wave N1-P2 of Cortical Auditory Evoked Potentials

目的探讨短纯音刺激皮层听觉诱发电位(cortical auditory evoked potentials,CAEP)对听力评估的价值。方法受试者为听力正常成人19例(36耳),感音神经性聋成人患者21例(21耳),以500、1000、2000和4000 Hz短纯音作为刺激声,在醒觉状态下颅顶电极记录CAEP的N1-P2复合波,分析N1-P2阈值与纯音听阈的相关性,以及两者差值在不同人群中的差异。结果所有受试者四个测试频率的N1-P2阈值与对应频率纯音听阈值的相关系数依次为0.971、0.967、0.958、0.955,呈显著的线性相关;听力正常组36耳500、1000、2000和4000 Hz的N1-P2阈值上限(95%置信区间)依次为32、27、32、39 dB SPL,即正常人阈值上限为32.5 dB SPL;正常人N1-P2阈值与纯音听阈的差值依次为18.9±6.1、11.6±5.9、13.3±7.0、18.7±8.3 dB;感音神经性聋患者两者差值依次为10.3±6.0、6.8±8.9、6.5±9.5、12.9±11.4 dB,四个测试频率的差值在两组人群中的差异均有统计学意义(P<0.05)。结论听力正常人短纯音CAEP的N1-P2平均阈值小于32.5 dB SPL;N1-P2阈值与对应频率纯音听阈相关性非常好,听力评估中使用N1-P2阈值预测听力时应注意刺激声的校准及校正值的使用。

Objective To explore the application value of cortical auditory evoked potentials(CAEP)with tone burst stimulus in hearing assessment.Methods A total of 19 adults with normal hearing and 21 adults with sensorineural hearing loss were included in the study.Tone burst at 500 Hz,1000 Hz,2000 Hz and 4000 Hz were used as stimuli.The complex wave N1-P2 of CAEP was recorded by the scalp vertex electrode in arousal and vigilance state.The relationship between N1-P2 thresholds and pure tone audiometry,thresholds and the magnitude of discrepancy between thresholds obtained by CAEP and by pure-tone audiometry(PTA)of the two groups were analyzed.Results The correlation coefficients between N1-P2 thresholds and PTA at 500,1000,2000 and 4000 Hz test frequencies were 0.971,0.967,0.958 and 0.955 respectively,showing a significant linear correlation.The upper limit of N1-P2 thresholds(95%confidence interval)of the four test frequencies in 36 ears of normal hearing group were 32,27,32 and 39 dB SPL respectively,that is,the upper limit of threshold in normal people was 32.5 dB SPL.The difference of N1-P2 thresholds and PTA in normal hearing group were 18.9±6.1,11.6±5.9,13.3±7.0 and 19.7±8.3 dB,respectively.The difference values of the two thresholds in patients with sensorineural hearing loss were 10.3±6.0,6.8±8.9,6.5±9.5 and 12.9±11.4 dB respectively.The difference of the subtractive values between the two groups was statistically significant(P<0.001).Conclusion The N1-P2 average threshold of tone burst CAEP in normal hearing people is lower than 32.5 dB SPL.The N1-P2 threshold has a good correlation with PTA at the corresponding frequency.When N1-P2 threshold is used to predict the level of hearing loss,attention should be paid to the calibration of stimulus sound and the use of correction values.