Gap-task模式下反射性视觉诱导性眼扫动的左侧皮层控制机制

Left cortical control of reflexive visually-guided saccades with the gap-task

目的 研究 gap task模式下反射性视觉诱导性眼扫动的左侧皮层控制机制。 方法 以左侧额叶脑梗死患者、左侧顶叶脑梗死患者与正常受试者为研究对象 ,按照 gap task模式测定左右眼扫动速度及潜伏期 ,并观察眼动波形 ,通过组间对照以探讨该模式眼扫动的皮层控制机制。结果 左侧顶叶病变患者出现双向启动延迟 ,但以右向眼动的受累更为显著 ;左侧顶叶与额叶病变均会引起右向眼扫动准确性下降。结论 对于 gap task模式下反射性视觉诱导性眼扫动 ,左侧顶叶可以启动双向眼动 ,并表现出支配向右侧的眼球运动优势 ,额叶则不参与启动过程 ;左侧顶叶与额叶共同参与调节向对侧的眼球运动幅度 ,以保证眼扫动的准确性。

Objective To study the left cortical control of reflexive visually-guided saccades with the gap-task.Methods All 84 subjects were engaged in our study, who included 60 normal subjects, 11 subjects with infarction of the left frontal lobe, 13 subjects with infarction of the left parietal lobe. The latency and velocity were measured under gap-task paradigms. Saccades latency and velocity in the patient group were compared with those of the control group by Student's t-test.Results There was no effect in saccades latency for subjects with frontal lesions. The bilateral latency of subjects with the left parietal was significant longer and the rightward latency was longer than the leftward. In 11 cases with left frontal lesion, 8 cases showed rightward dysmetria. In 13 subjects with parietal lesion, 11 cases showed rightward dysmetria. Conclusions For gap-task visual saccades, left parietal lobe triggers bilateral saccades and obviously in opposite ward saccades; left frontal and parietal lobe control the accuracy of contralateral saccades by regulating the saccades amplitude.