3-Dimentional analysis for the vertical semicircular canal- and the otolithic-ocular reflexes and those influences to the spatial orientation

摆动旋转试验，倾斜头位。对正常人和良性阵发性位置性眩晕(BPPV)患者进行向后60°左右旋转45°。旋转360°，频率0.1赫兹(最大速度114°/秒)。我们通过这一测试程序评估垂直半规管的兴奋性。利用红外摄像机和个人计算机系统对诱发的眼震进行分析。当头部向后倾斜60°，然后向右旋转，第一摆向右旋转时，所有受试者均可见向上顺时针旋转的眼球震颤。当头部向左旋转45°时，可见向下顺时针旋转的眼球震颤。随着第一次摆动向左旋转，所有眼球震颤的方向都颠倒了。可以想象，当头部向右旋转45°时，由向右旋转引起的向上和顺时针旋转的眼球震颤表示为…左后半规管兴奋较多，左旋向下及逆时针旋转眼球震颤提示右前半规管兴奋。当头部向左旋转45°时，右旋出现的向下和顺时针旋转的眼球震颤代表左前半规管的兴奋；向左旋转的向上和逆时针旋转的眼球震颤代表右后半规管的兴奋。通过分析旋转试验引起的眼球震颤来确定BPPV的发病率。对于眩晕患者，前半规管眼球震颤与后半规管眼震的最大慢相眼速(MX SPEV)差异有统计学意义(P&lt；0.05)。患耳后半规管的兴奋性低于前半规管。尽管如此。眩晕、眼球震颤消失后，兴奋性的差异有所改善。目前的结果表明，BPPV病例的后半规管功能有所恶化，这表明机械性(按质量倾倒)和器质性(外周终末器官)参与了发病。在本研究中，在头部与直立位置成30°角前倾的情况下，主观视觉垂直(SVV)在有或没有旋转刺激的情况下都是正常的。外周半规管对SVV无明显影响。在旋转刺激条件下，SVV在刺激后管时发生偏向，尤其是偏向于刺激后管的对侧。我们得出结论，垂直半规管影响空间方位，如SVV。较少

Pendular rotation test in a head-tilted position. 60° backward and rotated 45° either to the right or left, was performed in normal healthy subjects and patients with benign paroxysmal positional vertigo (BPPV). They were rotated 360° at the frequency of 0.1 Hz (the maximal speed=114°/sec). We evaluated the excitability of vertical semicircular canals by this test procedure. Using an infra-red CCD camera and a personal computer system, evoked nystagmus was analyzed. When the head was tilted backward in 60°, and then rotated to the right, and with the first pendullar rotation was given to his right, upward and clockwise rotatory nystagmus was seen in all subjects. When the head was rotated 45° to the left, downward, clockwise rotatory nystagmus was seen. With the first pendullar rotation to the left, all nystagmic directions were reversed. It is conceivable that when the head was rotated 45° rightward, upward and clockwise rotatory nystagmus evoked by the rightward rotation was represen … More ting excitation of the left posterior semicircular canal, and downward and counterclockwise rotatory nystagmus by the leftward rotation was indicating excitation of the right anterior semicircular canal. When the head was rotated 45° leftward, downward and clockwise rotatory nystagmus by the rightward rotation should represent excitation of the left anterior semicircular canal, and upward and counterclockwise rotatory nystagmus in the leftward rotation indicated excitation of the right posterior semicircular canal. The morbidity of BPPV was determined by analyzing nystagmus elicited by the rotation test. So far as the patients had vertigo, we found a statistically significant difference (P<0.05) in the maximal slow-phase eye velocity (mx SPEV) between nystagmus from the anterior semicircular canal and nystagmus from the posterior semicircular canal. The excitability of the posterior semicircular canal in the affected ear was lower than that of the anterior semicircular canal. Nevertheless. while vertigo and nystagmus disappeared, the difference of the excitability was improved. The present result indicates some functional deterioration of the posterior semicircular canal in BPPV cases, which suggests a mechanical (dumping by mass) and organic (peripheral end organ) participation in causing morbidity. Regarding the present study, in the head tilted forward at an angle of 30° from the upright position, subjective visual vertical (SVV) was normal on the both conditions with and without the rotatory stimulus. It seems that the lateral semicircular canal doesn't influence SVV.On the other hand, SVV was deviated during the posterior canal excited on the condition with the rotatory stimulus, especially, which was much deviated on the opposite side to the excited posterior canal. We conclude that the vertical semicircular canal influences the spatial orientation such as the SVV. Less