Yang Qing, Wang Tao, Su Ning, Xiao Shifu, Kapoula Zoi
IRIS group, UMR 8194, CNRS, Hôpital Européen Georges Pompidou, University Paris V, 20 rue Leblanc, 75015, Paris, France.
Age (Dordr). 2013 Aug;35(4):1287-98. doi: 10.1007/s11357-012-9420-z. Epub 2012 May 11.
Saccadic impairment in Alzheimer's disease (AD) was found in horizontal saccades. The present study extends investigation to vertical saccades in a large number of subjects, including AD and amnestic mild cognitive impairment (aMCI). We examined both horizontal and vertical saccades in 30 healthy elderly, 18 aMCI, and 25 AD. Two tasks were used: gap (fixation target extinguishes prior to target onset) and overlap (fixation stays on after target onset). Eye movements were recorded with the Eyeseecam system. (1) Robust gap effect (shorter latencies in gap than in overlap) exists for AD and aMCI patients as for healthy elderly; (2) abnormal long latency of saccades in gap and overlap tasks for AD relative to healthy elderly and aMCI patients; (3) longer latency for aMCI patients than for healthy elderly for the overlap task; (4) significant correlation between scores of Mini-Mental State Examination (MMSE) and latencies of saccades considering the AD group only; (5) higher coefficient of variation in latency for AD patients than for healthy elderly and for aMCI patients; (6) variability of accuracy and speed is abnormally higher in AD patients than in aMCI and healthy elderly. Abnormalities of latency and latency-accuracy-speed variability reflect deficits of cerebral areas involved in the triggering and execution of saccades; latency of saccades can be used as follow-up test for aMCI and AD patients with its significant correlation with the changes of MMSE scores.
在阿尔茨海默病（AD）患者中发现水平扫视存在眼跳障碍。本研究将调查范围扩大到大量受试者的垂直扫视，包括AD患者和遗忘型轻度认知障碍（aMCI）患者。我们对30名健康老年人、18名aMCI患者和25名AD患者进行了水平和垂直扫视检查。使用了两项任务：间隙任务（注视目标在靶标出现前熄灭）和重叠任务（靶标出现后注视仍保留）。用Eyeseecam系统记录眼动。（1）AD患者和aMCI患者与健康老年人一样，存在明显的间隙效应（间隙任务中的潜伏期比重叠任务中的短）；（2）与健康老年人和aMCI患者相比，AD患者在间隙和重叠任务中的扫视潜伏期异常延长；（3）在重叠任务中，aMCI患者的潜伏期比健康老年人长；（4）仅考虑AD组时，简易精神状态检查表（MMSE）得分与扫视潜伏期之间存在显著相关性；（5）AD患者潜伏期的变异系数高于健康老年人和aMCI患者；（6）AD患者准确性和速度的变异性比aMCI患者和健康老年人异常更高。潜伏期以及潜伏期-准确性-速度变异性的异常反映了参与扫视触发和执行的脑区功能缺陷；扫视潜伏期可作为aMCI和AD患者的随访测试指标，因为它与MMSE得分的变化显著相关。
