Ito Ken, Karino Shotaro, Murofushi Toshihisa
Department of Otolaryngology, Faculty of Medicine, University of Tokyo, Tokyo, Japan. itoken@
Acta Otolaryngol. 2007 Jan;127(1):57-61. doi: 10.1080/00016480600740597.
The present study demonstrated the robustness of VEMP testing with toneburst stimuli, since it is hardly affected by head position, i.e. base or tonic excitation levels of the saccule and inferior vestibular nerve. However, the small but highly significant difference found in latency should not be neglected: the gravitational axis in the upright position may have some special effect on tonic excitation of the saccule.
To evaluate the effect of head positions on vestibular evoked myogenic potentials (VEMPs) with toneburst stimuli.
VEMPs were recorded with short tonebursts of 500 Hz in 14 normal subjects in 5 head positions (upright, nose up, ear up, nose down, and ear down). The three parameters analyzed were: 1) latency of p13, 2) latency of n23, and 3) corrected amplitude of p13-n23 (CA p13-n23).
One-way repeated measures ANOVA showed significant effects on both p13 (p=0.0245) and n23 (p<0.0001) latencies, but not on CA p13-n23. Bonferroni's post hoc test demonstrated that there were significant differences in n23 latency between the upright position and all other head positions leaning on the bed.
本研究证明了短纯音刺激下前庭诱发肌源性电位（VEMP）测试的稳健性，因为它几乎不受头部位置的影响，即球囊和前庭下神经的基础或紧张性兴奋水平。然而，潜伏期存在的虽小但高度显著的差异不容忽视：直立位时的重力轴可能对球囊的紧张性兴奋有一些特殊影响。
评估头部位置对短纯音刺激下前庭诱发肌源性电位（VEMPs）的影响。
对14名正常受试者在5种头部位置（直立、头向上、耳向上、头向下和耳向下）下记录500Hz短纯音刺激诱发的VEMPs。分析的三个参数为：1）p13潜伏期，2）n23潜伏期，3）p13 - n23校正幅度（CA p13 - n23）。
单向重复测量方差分析显示，对p13潜伏期（p = 0.0245）和n23潜伏期（p < 0.0001）均有显著影响，但对CA p13 - n23无显著影响。Bonferroni事后检验表明，直立位与所有其他靠在床上的头部位置之间的n23潜伏期存在显著差异。
