Kanayama R, Bronstein A M, Shallo-Hoffmann J, Rudge P, Husain M
MRC Human Movement and Balance Unit, National Hospital for Neurology and Neurosurgery, London, UK.
J Neurol Neurosurg Psychiatry. 1994 Sep;57(9):1081-4. doi: 10.1136/jnnp.57.9.1081.
Saccades under four specific test conditions (visually guided, visually remembered, vestibular remembered, and cervical remembered) were studied in a 38 year old man with ocular dysmetria due to an angioma of the dorsal cerebellar vermis. The aim of the study was to investigate if the saccadic disorder was specific to certain subsets of saccades elicited by different sensory modalities. The experiments showed that initial saccades were equally hypermetric in all four conditions and that final eye position was normal in all memory guided saccade tests. Eye movements differed after the initial saccade, however. Whereas corrective saccades were seen in most visually guided and visually remembered experiments, postsaccadic centripetal drifts were documented in non-visual (vestibular and cervical) remembered saccades. These results indicate that the cerebellar vermis modulates the amplitude of the initial saccade (pulse size of saccadic innervation) independently of the saccadic task. The finding that post-saccadic drift never occurred when saccades were programmed using visual positional information suggests that the dorsal vermis may participate in the process of pulse step integration of saccades elicited by memorised vestibulo-cervical information.
对一名38岁因小脑蚓部背侧血管瘤导致眼球运动失调的男性，研究了在四种特定测试条件下（视觉引导、视觉记忆、前庭记忆和颈部记忆）的扫视运动。本研究的目的是调查扫视障碍是否特定于由不同感觉模式引发的某些扫视子集。实验表明，在所有四种条件下初始扫视均同等地过度度量，并且在所有记忆引导扫视测试中最终眼位均正常。然而，初始扫视之后的眼动有所不同。在大多数视觉引导和视觉记忆实验中可看到矫正扫视，而在非视觉（前庭和颈部）记忆扫视中记录到扫视后向心漂移。这些结果表明，小脑蚓部独立于扫视任务调节初始扫视的幅度（扫视神经支配的脉冲大小）。当使用视觉位置信息对扫视进行编程时未出现扫视后漂移这一发现表明，蚓部背侧可能参与由记忆的前庭 - 颈部信息引发的扫视的脉冲步长整合过程。
