Brodsky M C, Haslwanter T, Kori A A, Straumann D
Department of Ophthalmology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Binocul Vis Strabismus Q. 2000;15(4):325-30.
To determine whether volitional effort on the part of the subject can influence the results of the Bielschowsky Head Tilt Test.
Bielschowsky Head Tilt testing was performed in five normal subjects. Vertical amplitudes were measured with prism alternate cover testing when the head tilt was voluntary (volitionally maintained in a tilted position by the subject), forced (restrained in the tilted position by the examiner while the patient actively resisted) and active (restrained in a tilted position by the examiner with the subject actively trying to increase the tilt). Three-dimensional scleral search coil recordings were performed in three additional normal subjects using the same paradigm to determine the effect of volition on the torsional positions of the eyes.
No vertical deviation of the eyes was detectable with prism alternate cover testing in any position of tilt, regardless of whether the tilt was voluntary, forced, or active. Volitional attempts to tilt the head were preceded by a transient ipsiversive torsional movement of the measured eye, which was quickly followed by a normal ocular counterroll. Following completion of the counterroll, the position of the eyes was constant for any position of head tilt, regardless of whether the tilt was forced, active, or voluntary.
Anticipatory torsional movements of the eyes are evoked by an attempted volitional head movement in the roll plane and its associated innervation to the cervical musculature. However, these volitional movements do not alter the final torsional position of the eyes, which is a function of the degree of head tilt and the normal ocular counterroll. These anticipatory torsional movements do not influence the results of the Bielschowsky Head Tilt Test clinically by prism alternate cover testing.
确定受试者的自主努力是否会影响拜尔绍夫斯基头倾试验的结果。
对5名正常受试者进行拜尔绍夫斯基头倾试验。当头部倾斜为自主（受试者自主保持在倾斜位置）、强制（检查者将患者限制在倾斜位置，同时患者积极抵抗）和主动（检查者将患者限制在倾斜位置，受试者积极试图加大倾斜度）时，用棱镜交替遮盖试验测量垂直幅度。另外3名正常受试者采用相同模式进行三维巩膜搜索线圈记录，以确定自主意识对眼睛扭转位置的影响。
无论倾斜是自主、强制还是主动，在任何倾斜位置用棱镜交替遮盖试验均未检测到眼睛的垂直偏差。在自主尝试倾斜头部之前，被测眼会出现短暂的同侧扭转运动，随后很快出现正常的眼反向旋转。反向旋转完成后，无论头部倾斜是强制、主动还是自主，眼睛在任何头部倾斜位置的位置都是恒定的。
在横滚平面上试图自主移动头部及其对颈部肌肉组织的相关神经支配会引发眼睛的预期扭转运动。然而，这些自主运动不会改变眼睛的最终扭转位置，而最终扭转位置是头部倾斜程度和正常眼反向旋转的函数。通过棱镜交替遮盖试验，这些预期扭转运动在临床上不会影响拜尔绍夫斯基头倾试验的结果。
