Fox C R, Paige G D
Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri.
J Vestib Res. 1990;1(2):153-60.
Effective interpretation of vestibular inputs to postural control requires that orientation of head on body is known. Postural stability might deteriorate when vestibular information and neck information are not properly coupled, as might occur with vestibular pathology. Postural sway was assessed in unilateral vestibulopathic patients before and acutely, 1, 4, and 18+ months after unilateral vestibular ablation (UVA) as well as in normal subjects. Postural equilibrium with eyes closed was quantified as scaled pk-pk sway during 20 s trials in which the support surface was modulated proportionally with sway. Subjects were tested with the head upright and facing forward, turned 45 degrees right, and 45 degrees left. Equilibrium was uninfluenced by head orientation in normal subjects. In contrast, patients after UVA showed both a general reduction in stability and a right/left head orientation-dependent asymmetry. These abnormalities adaptively recovered with time. It is concluded that vestibular inputs to postural control are interpreted within a sensory-motor context of head-on-body orientation.
要有效地解读前庭输入对姿势控制的作用，就需要知道头部在身体上的方位。当前庭信息和颈部信息未正确耦合时，姿势稳定性可能会变差，比如在前庭病变时就可能出现这种情况。对单侧前庭病变患者在单侧前庭神经切断术（UVA）前、术后即刻、1个月、4个月和18个月以上，以及正常受试者进行姿势摆动评估。闭眼时的姿势平衡通过在20秒试验中测量缩放后的峰峰值摆动来量化，试验中支撑面会根据摆动成比例地调整。受试者分别在头部直立向前、向右转45度和向左转45度的情况下接受测试。在正常受试者中，平衡不受头部方位的影响。相比之下，UVA术后的患者不仅稳定性普遍下降，而且存在与头部左右方位相关的不对称性。这些异常会随着时间自适应恢复。研究得出结论，前庭对姿势控制的输入是在头部相对于身体方位的感觉运动背景下进行解读的。
