Plasticity in the vestibule-ocular reflex and its application for rehabilitation for the patients with peripheral vestibular disorders

为了阐明外周前庭疾病患者训练过程中的光学参数，我们研究了正弦偏离垂直轴旋转(OVAR)在评估健康受试者耳石功能(n=8)和前庭-眼反射(VOK)可塑性(n=9)方面的作用。在正弦向下OVAR中，所有受试者在0.8 Hz时的OVAR与0.8 Hz时的地球垂直轴关系(EVAR)相比，VOR增益均显著降低(p&lt；0.05)。在可塑性实验中，7名受试者在0.3赫兹和30°波幅下进行x2适应实验，在两次实验中，VOR增益稳步增加。其余2名受试者中有1名在所有三次试验中VOR增益均下降，另一名受试者在3次试验中VOR增益增加，在2次试验中VOR增益下降。在0.3 Hz、80°波幅(峰值速度：28°/S)的x2适应实验中，相同刺激条件下的增益变化百分比((Pre-Pre)/Pre)为133%，0.4 Hz(峰值速度：37°/S)的增益变化百分率为100%。在0.1 Hz、60°振幅时，增益变化为65%(峰值速度：18%/S)；在0.2 Hz、60°振幅时，增益变化为%(峰值速度：37°/S)。在XL适应实验(30°，0.3赫兹)中，在相同条件下，增益百分比变化为-62%，0.1赫兹和60°幅值时为50%，0.2赫兹和60°幅值时为-30%。在其他频率下，VOR增益没有变化，受试者不适应0.1 Hz和30°幅度。在X2适应实验中，对于较快的头部角加速，VOR增益增加较大，从而得出结论，VOR增益机制可以为VOR设置非常不同的增益状态，这些状态在头部加速度方面非常相似。

To elucidate the optical parameters in the training procedure for the patients with peripheral vestibular disorders, we investigated the usefulness of the sinusoidal off-vertical axis rotation (OVAR) to evaluate the otolith function in the healthy subjects (n=8), plasticity in the vestibule-ocular reflex (VOK) (n=9).In the sinusoidal nose-down OVAR, all subjects showed significant VOR gain reduction (p<0.05) in the OVAR at 0.8Hz compared with earth vertical axis relation (EVAR) at 0.8Hz. We concluded that the sinusoidal nose-down OVAR at 0.8Hz may evaluate the otolith function without discomfort for the patients with otolith disorders.In the plasticity experiments, 7 of the subjects who participated in the x2 adaptation experiment at 0.3 Hz and 30° amplitude showed a steady increase of VOR gain within a couple of trials. One of the remaining 2 subjects showed a decrease in VOR gain in all the three trials, and *ther subject showed a VOR gain increase in three trials and decrease in 2 trials. In the x2 adaptation experiment at 0.3 Hz and 80° amplitude (peak velocity : 28°/s), the percentage gain change ((post-pre)/pre) was 133% at the same stimulation and 100% at 0.4 Hz (peak velocity : 37°/s). The gain change was 65% at 0.1 Hz and 60° amplitude (peak velocity : 18%/s), and 64% at 0.2 Hz and 60° amplitude (peak velocity : 37° /s). In the xl adaptation experiment (30° at 0.3 Hz), the percentage gain change was -62% under the same conditions, 50% at 0.1 Hz and 60° amplitude, and -30% at 0.2 Hz and 60° amplitude. No change of VOR gain was observed at other frequencies, and the subject was not adapted at 0.1 Hz and 30° amplitude. The larger VOR gain increase in the x2 adaptation experiment for the faster head angular acceleration leads to the conclusion that the VOR gain mechanism can set very different gain states for the VOR that are quite similar in terms of the head acceleration.