正常人多焦视觉诱发电位的特征

The characteristics of multifocal visual evoked potential in healthy individuals

目的 探讨正常人多焦视觉诱发电位 (multifocal visual evoked potential,mf- VEP)的特征 ,为其临床应用提供正常参考值。 方法 应用 VERIS Science TM 4 .0视觉诱发反应图像系统对 37例正常人 70只眼进行 mf- VEP检测。刺激图形为包含 6 0个小块的飞镖盘 ,对应的视角为 2 5°,m-系列长度为 2 1 4-1,电极记录采用跨枕部双极记录法 ,放大器的放大倍数为 10 0 K,通频带为 3～ 10 0 Hz,通过 VERIS软件分析 mf- VEP的二阶一次反应 ,并对不同刺激视野区域的 mf- VEP分为上下 1/ 2视野、4个象限视野组以及按年龄 (≥ 5 0岁和 <5 0岁组 )、性别和眼别等分组进行比较。 结果 mf- VEP潜伏期和振幅反应密度在上下 1/ 2视野差异有显著性的意义 (P均 <0 .0 5 ) ;4个象限视野分组比较 ,差异有显著性的意义 (P<0 .0 5 ) ;≥ 5 0岁和 <5 0岁年龄组组间比较 ,部分视野分区潜伏期延长 (P<0 .0 5 ) ;女性潜伏期短于男性 ,差异有显著性的意义 (P均 <0 .0 5 ) ;双眼的潜伏期和振幅反应密度在各视野分区无明显差别 (P均 >0 .0 5 ) ,具有一定的对称性。 结论 正常人 mf- VEP具有一定的特征 ,能客观地反映不同视野部位的视觉诱发反应 ,可为临床应用提供正常参考值。

Objective To investigate the characteristics of multifocal visual evoked potential (mf-VEP) in healthy individuals, and provide normal reference values for its clinical application. Methods The mf-VEP of 37 healthy individuals (70 eyes) were examined by VERIS Science TM 4.0. The visual stimulus was a dart board with patterns consisted of 60 patches spanning a 25° visual field. The length of m-sequence was 2 14-1. The results were recorded by bipolar occipital straddle. The signal was amplified 100 K and was put through a band-pass filter between 3 and 100 Hz. The first slice of the second order kernel was analyzed by VERIS software. The summed responses of fields with different stimulus were analyzed and compared according to different ages, genders and eyes. Results The latencies and response densities of amplitude had statistically significant differences both in dimidiate and quartered field(P <0 05). The latencies in ≥50 year group were much more delayed in some sectors of the visual field than those in < 50 year group(P<0.05). The latencies of women were shorter than those of men(P <0.05). There was no obvious difference of latencies and response densities of amplitude in each field sectors between both eyes(P>0.05). Conclusions The mf-VEP of healthy individuals can reflect the VEP at different field locations objectively with its specific physiological characteristics, which may provide normal reference values for its clinical application.