不同刺激声骨导眼肌前庭诱发肌源性电位特征分析

Characteristics of Vestibular Myogenic Evoked Potentials in Vocal Bones Stimulated by Different Frequencies

目的分析不同刺激声骨导诱发的眼肌前庭诱发肌源性电位(bone conducted ocular vestibular evoked myogenic potential,BC-oVEMP)特征,分析其反应阈、潜伏期和振幅,探讨其最佳刺激声,并获得正常值范围,为临床诊断前庭疾病提供参考。方法分别用500、1000、2000 Hz短纯音及短声对20例(40耳)正常青年人进行BC-oVEMP测试,刺激声起始强度为仪器每个频率可输出的最大峰值等效力级(force level,FL),以5 dB FL为步阶测试至阈值,分别记录其n1-p1潜伏期、振幅、波间期,得出其对称性和振幅比。结果在最大输出强度下,500、1000、2000 Hz短纯音及短声四种刺激声诱发的BC-oVEMP n1-p1引出率分别为100.0%、85.0%、42.50%及52.50%;反应阈分别为127.63±4.76、130.89±3.06、114.94±2.54、117.25±3.98 dB FL;n1波潜伏期分别为10.14±0.62、11.80±1.66、13.61±0.81、12.52±0.82 ms;p1波潜伏期分别为15.65±1.09、16.08±1.61、17.59±0.98、16.32±0.54 ms;n1-p1振幅分别为12.14±5.85、2.80±1.82、2.69±1.14、2.85±1.78μV。结论500、1000、2000 Hz短纯音及短声四种骨导刺激声均可诱发出眼肌前庭诱发肌源性电位;在最大输出强度下500 Hz短纯音BC-oVEMP引出率和振幅最高,为最佳刺激声,便于椭圆囊及其传导通路的相关疾病诊断。

Objective The aim of this study was to obtain the threshold,latency and amplitude of bone conduction ocular vestibular evoked myogenic potential(BC-oVEMP),and provide the normal range of values for clinical diagnosis of vestibule.Methods BC-oVEMP tests were performed on twenty(forty ears)normal young adults with four different stimuli at 500 Hz,1000 Hz,2000 Hz tone burst and click.The initial intensity of the test was the maximum peak force level(FL)of each frequency,with 5dB FL as the step until to the threshold.The latency and amplitude of n1,p1,wave interval of n1-p1 were recorded respectively.Results①The n1 and p1 extraction rates of BC-oVEMP induced by 500 Hz,1000 Hz,2000 Hz tone burst and click were 100.0%,85.0%,42.50%and 52.50%respectively at the maximum output intensity of each frequency.②At the maximum output intensity of each frequency,the latencies of n1 induced by the four different stimuli were 10.14±0.62 ms,11.80±1.66 ms,13.61±0.81 ms,and 12.52±0.82 ms.The latencies of p1 were 15.65±1.09 ms,16.08±1.61 ms,17.59±0.98 ms,and 16.32±0.54 ms.The amplitudes of n1-p1 were 12.14±5.85μV,2.80±1.82μV,2.69±1.14μV,and 2.85±1.78μV.Conclusion For the highest extraction rates and amplitude at the maximum output intensity,500 Hz tone burst was the best stimuli for BC-oVEMP among the four different stimuli.It was important for diagnosis of related diseases of vestibule.