Dale R T, Kirby A W, Jampel R S
Am J Ophthalmol. 1978 Mar;85(3):400-6. doi: 10.1016/s0002-9394(14)77738-4.
We observed a brother and sister with Friedreich's ataxia during steady fixation. They both had abnormal eye movements consisting of randomly occurring, small amplitude, conjugate horizontal saccades away from the fixation target. The saccades were followed by maintenance of this eccentric position for a brief period, and finally, a corrective saccade back to the original position. Electro-oculographic recordings showed these eye movements to be square wave jerks. They had an amplitude ranging from 1.5 to 10.7 degrees and a duration averaging less than 200 msec. Square wave jerks were also superimposed on pursuit movements in both patients. Square wave jerks are an additional ocular finding that may signify chronic cerebellar dysfunction. More specifically, they are an additional neuro-ophthalmological finding that may be observed in Friedreich's ataxia.
我们观察了一对患有弗里德赖希共济失调的兄妹在稳定注视期间的情况。他们都有异常的眼球运动，表现为随机出现的、小幅度的、共轭水平扫视，偏离注视目标。扫视之后会在这个偏心位置短暂维持，最后有一个回到原始位置的矫正扫视。眼电图记录显示这些眼球运动为方波急跳。它们的幅度在1.5至10.7度之间，持续时间平均小于200毫秒。两名患者的追踪运动中也叠加有方波急跳。方波急跳是一种额外的眼部表现，可能预示着慢性小脑功能障碍。更具体地说，它们是在弗里德赖希共济失调中可能观察到的一种额外的神经眼科表现。
