The Effects of Amplitude Normalization and EMG Targets on cVEMP Interaural Amplitude Asymmetry
The Effects of Amplitude Normalization and EMG Targets on cVEMP Interaural Amplitude Asymmetry
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DOI：
10.1097/aud.0b013e31827ad792
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发表时间：
2013-07-01
期刊：
影响因子：
3.7
通讯作者：
DeLong, Andrew P.
中科院分区：
文献类型：
--
作者：
McCaslin, Devin L.;Jacobson, Gary P.;DeLong, Andrew P.
目的：本研究的目的是确定使用紧张性肌电图（EMG）活动的视觉反馈或使用振幅标准化技术是否会显著降低耳和神经功能完好的儿童和成人的颈前庭诱发肌源性电位（cVEMP）P13-N23耳间振幅不对称数据的变异性。设计：共有97名儿童和成人受试者，作者记录了使用和不使用EMG目标和振幅归一化技术的cVEMP。这四个条件是：（1）常规记录（条件1），（2）具有EMG目标的常规记录（条件2），（3）与条件1相同，添加了采集后振幅归一化技术，以及（4）与条件2相同，添加了采集后振幅归一化技术。测量P13-N23的绝对峰-峰振幅、P13的绝对潜伏期和P13-N23的左右振幅不对称性。P13-N23振幅和波幅、全波整流EMG活动的均方根（RMS）和RMS EMG活动的标准差均无显著差异，并且没有被要求确保他们的紧张性EMG活动超过视觉目标（即，表示>50 μ V RMS EMG）。cVEMP波形的振幅标准化未能显著降低振幅不对称性data.Conclusions的变异性：激活胸锁乳突肌，患者处于半卧位，头部远离受刺激的耳朵，头部抬高（即，最佳激活技术）足以在所有年龄的受试者中产生具有可接受的变异量的最高振幅cVEMP。组数据表明，使用视觉目标和振幅正常化程序并没有显着降低cVEMP耳间振幅不对称措施的变异性。然而，在孤立的情况下，振幅正常化将异常cVEMP转换为正常cVEMP，尽管也发生了相反的情况，这表明这些技术可能有利于接受不太完美的测试程序的患者子集。
Objectives: The purpose of this investigation was to determine whether the use of visual feedback of tonic electromyographic (EMG) activity, or the use of amplitude normalization techniques would reduce significantly the variability in cervical vestibular evoked myogenic potential (cVEMP) P13-N23 interaural amplitude asymmetry data in otologically and neurologically intact children and adults.Design: There were 97 subjects, both pediatric and adult, from whom the authors recorded cVEMPs with and without the use of an EMG target and amplitude normalization techniques. The four conditions were: (1) conventional recording (condition 1), (2) conventional recording with an EMG target (condition 2), (3) same as condition 1, with the addition of postacquisition amplitude normalization techniques, and (4) same as condition 2, with the addition of postacquisition amplitude normalization techniques. The absolute peak to peak amplitude of positive-negative response (P13-N23), absolute latency of P13, and the left or right amplitude asymmetry of P13-N23 were measured.Results: Neither P13-N23 amplitudes nor latencies, neither mean root mean square (RMS) of the full wave rectified EMG activity, nor the standard deviation of the RMS EMG activity differed significantly when subjects were, and were not, asked to ensure their tonic EMG activity exceeded a visual target (i.e., representing >50 mu V RMS EMG). Amplitude normalization of the cVEMP waveforms failed to reduce significantly the variability in the amplitude asymmetry data.Conclusions: Activating the sternocleidomastoid muscle with the patient in a semirecumbent position, with head turned away from the stimulated ear and head elevated (i.e., an optimal activation technique) was sufficient to produce the highest amplitude cVEMPs with an acceptable amount of variability in subjects of all ages. Group data suggested that the use of visual targets and amplitude normalization routines did not reduce significantly the variability in cVEMP interaural amplitude asymmetry measures. However, in isolated cases amplitude normalization converted an abnormal cVEMP into a normal cVEMP although the reverse occurred as well, suggesting that these techniques may be beneficial for a subset of patients receiving a less than perfectly administered test procedure.