Testing of visual dependency on body sway and its application to balance rehabilitation

我们检查了15例视觉眩晕综合征（VVS）患者。VVS被诊断为由特定的视觉环境引发的头晕或不平衡。男性9名，女性6名，平均年龄43岁，年龄范围25 - 69岁。视觉环境包括看电视或电脑显示器（5例）、在隧道中开车（4例）、在超市中行走（4例）和穿过人群（2例）。这些结果表明，含有光流的特定视觉环境会引起VVS患者的头晕。因此，我们认为VVS患者对身体摇摆的视觉依赖性增加。然后，我们开发了一种新的装置来产生光流刺激，以评估视觉对身体摇摆的依赖。闭着眼睛和睁开眼睛的摇摆路径之比被称为Romberg比率，它显示了静态视觉对身体摇摆的依赖。健康志愿者和VVS患者的Romberg比率均增加。另一方面，在有光流刺激和没有光流刺激的情况下，摇摆路径的比值对身体摇摆表现出动态的视觉依赖性。这一比例在部分VVS患者中显著增加，但在其他VVS患者和健康志愿者中没有明显增加。这些结果表明，对身体摇摆的动态视觉依赖的增加是VVS发展的重要机制

We examined 15 patients with visual vertigo syndrome (VVS). VVS was diagnosed as having dizziness or imbalance triggered by the specific visual environments. There were 9 men and 6 women and their mean age was 43 years, range 25 to 69. The visual environments consisted of looking at TV or computer display (5 patients), driving car in the tunnel (4 patients), walking in supermarkets (4 patients) and walking through a crowd (2 patients). These findings indicate that the specific visual environments containing optical flow induced dizziness in VVS patients. Therefore, it is suggested that visual dependency on body sway is increased in VVS patients. We then developed a new device to produce optical flow stimulation to evaluate visual dependency on body sway. The ratio between sway path with eyes closed and eyes open is called the, Romberg ratio, which showed static visual dependency on, body sway. The Romberg ratio was increased in both healthy volunteers and VVS patients. On the other hand, the ratio between sway path with and without optical flow stimulation showed dynamic visual dependency on body sway. The ratio was markedly increased in some VVS patients, but not in other VVS patients and healthy volunteers. These findings suggested that the increased dynamic visual dependency on body sway is an important mechanism of the development of VVS