Ishikawa Kumiko, Nagai Takayuki, Yamada Yuko, Negi Akira, Nakamura Makoto
Division of Ophthalmology, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Doc Ophthalmol. 2011 Feb;122(1):29-37. doi: 10.1007/s10633-010-9252-z. Epub 2010 Nov 18.
The purpose of this study was to establish optimal conditions for recording multifocal visual evoked potentials (mVEPs) in Japanese individuals, whose skull frame presumably differs from Caucasians. The scalp point that was extended from the calcarine fissure was identified using magnetic resonance imaging scans of 200 subjects. MVEPs were recorded from 56 individuals using three single channels and combinations of vertical and horizontal channels. Five electrodes were placed at the inion, 4 cm above the inion, 2.5 cm below the inion, 4 cm to the left or 4 cm to the right of the inion. The signal-to-noise ratio (SNR) was obtained by measuring the root-mean-square (RMS) amplitude of a signal window (45-150 ms) from each of 60-local responses that was divided by the average of the 60 RMS amplitudes of the noise window (325-430 ms). Receiver operating characteristic (ROC) analyses were performed based on the proportion of mVEP responses that exceeded a specific SNR criterion, calculated for both the signal window and the noise window. The position of the calcarine fissure relative to the inion was significantly lower than the value reported for Caucasians. The ROC analyses disclosed that bi-channel combinations (one vertical and one horizontal) had significantly better performance to discriminate signal from noise in 60-local mVEP responses compared to any single channel and performed similarly to the tri-channel combination. Two sets of perpendicular channels should be simultaneously used in recording mVEP responses from Japanese people, among whom skull frame characteristics differ from those observed in Caucasians.
本研究的目的是为头骨结构可能与高加索人不同的日本人建立记录多焦视觉诱发电位（mVEPs）的最佳条件。通过对200名受试者进行磁共振成像扫描，确定了从距状裂延伸出的头皮点。使用三个单通道以及垂直和水平通道的组合，对56名个体记录了mVEPs。五个电极分别置于枕外隆凸、枕外隆凸上方4厘米处、枕外隆凸下方2.5厘米处、枕外隆凸左侧4厘米处或枕外隆凸右侧4厘米处。信噪比（SNR）通过测量每个60个局部反应的信号窗口（45 - 150毫秒）的均方根（RMS）振幅，并除以噪声窗口（325 - 430毫秒）的60个RMS振幅的平均值来获得。基于超过特定SNR标准的mVEPs反应比例进行了受试者操作特征（ROC）分析，该比例是针对信号窗口和噪声窗口分别计算的。距状裂相对于枕外隆凸的位置明显低于报道的高加索人的值。ROC分析表明，与任何单通道相比，双通道组合（一个垂直通道和一个水平通道）在区分60个局部mVEPs反应中的信号与噪声方面具有显著更好的性能，并且与三通道组合表现相似。在记录头骨结构特征与高加索人不同的日本人的mVEPs反应时，应同时使用两组垂直通道。
