Crane Benjamin T, Tian Jun-Ru, Demer Joseph L
Department of Surgery, Division of Otolaryngology, University of California, Los Angeles, California 90095-7002, USA.
Invest Ophthalmol Vis Sci. 2007 May;48(5):2076-83. doi: 10.1167/iovs.06-1219.
With the head upright and stationary, ocular torsion is confined by Listing's Law (LL), so that three-dimensional eye rotational axes form Listing's plane (LP). During head rotation, the vestibulo-ocular reflex violates LL by driving ocular torsion opposite to head torsion, sometimes out of LP. Saccades originating from non-Listing's initial torsional positions remain in a plane offset from, but parallel to, the original LP. The present study was conducted to determine whether whole-body yaw alters the position and orientation of LP.
Eight normal subjects and six with unilateral vestibular deafferentation (UVD) underwent binocular eye and head movement recordings with 3-D magnetic search coils. Visual fixations were used to define LP, after which subjects underwent whole-body yaw rotation of 30 degrees or 70 degrees , at peak accelerations from 125 deg/s(2) to 2800 deg/s(2). Gaze during rotation was either central or 20 degrees up. After rotation, a dynamic LP (DLP) was defined during fixations.
Orientation and thickness of the DLP did not vary significantly from the previously defined LP; however, DLP was offset an average of 4 degrees +/- 4 degrees (mean +/- SD), 87% of head torsion relative to LP. Stimulus intensity, UVD, and starting vertical gaze direction had no effect on DLP offset or orientation. The DLP torsional offset declined toward the original LP with a time constant of approximately 1 minute, suggesting mediation by neural integration.
Yaw rotation can cause stable torsional offsets in the location of Listing's Plane.
头部保持直立且静止时，眼扭转受利斯定律（LL）限制，使得三维眼旋转轴形成利斯平面（LP）。头部旋转时，前庭眼反射会违反利斯定律，驱动眼扭转方向与头部扭转方向相反，有时会超出利斯平面。从非利斯初始扭转位置发起的扫视运动保持在一个与原始利斯平面偏移但平行的平面内。本研究旨在确定全身偏航是否会改变利斯平面的位置和方向。
8名正常受试者和6名单侧前庭传入神经切断术（UVD）患者使用三维磁性搜索线圈进行双眼和头部运动记录。通过视觉注视来定义利斯平面，之后受试者进行30度或70度的全身偏航旋转，峰值加速度范围为125度/秒²至2800度/秒²。旋转过程中的注视方向要么是中央注视，要么是向上20度注视。旋转后，在注视期间定义动态利斯平面（DLP）。
动态利斯平面的方向和厚度与先前定义的利斯平面相比无显著差异；然而，动态利斯平面平均偏移了4度±4度，相对于利斯平面的头部扭转角度为87%。刺激强度、单侧前庭传入神经切断术以及起始垂直注视方向对动态利斯平面的偏移或方向均无影响。动态利斯平面的扭转偏移以约1分钟的时间常数向原始利斯平面衰减，提示存在神经整合介导作用。
偏航旋转可导致利斯平面位置出现稳定的扭转偏移。
