ABSTRACT

Introduction: Mild cognitive impairment (MCI) is known to be heterogeneous in its cognitive features and course of progression. Whilst memory impairment is characteristic of amnestic MCI (aMCI), cognitive deficits other than memory can occur in both aMCI and non-amnestic MCI (naMCI) and accurate assessment of the subtypes of MCI is difficult for clinicians without the application of extensive neuropsychological testing. In this study, we examine metrics derived from recording of reflexive and voluntary saccadic eye movements as a potential alternative method for discriminating between subtypes and assessing cognitive functions in MCI.

Method: A total of 29 MCI patients and 29 age- and education-matched healthy controls (HCs) participated in the cross-sectional study. We recorded horizontal and vertical pro-saccades and anti-saccade responses. All the participants also completed a comprehensive neuropsychological tests battery.

Results: Significant differences in saccadic eye movement were found between the subtypes of MCI and HCs. Patients with aMCI had a higher percentage of short latency “express” saccades than HCs. We found strong associations between saccadic reaction times and cognitive domains, including executive functions and attention. The mini-mental state examination (MMSE) was also found to correlate with uncorrected errors in the anti-saccade task.

Conclusions: The increased proportion of saccades in the express latency range in aMCI may be indicative of problems with cognitive inhibitory control in these patients. A focus on this and other saccade metrics in the preclinical and prodromal stages of dementia may help to predict the clinical progression of the disease and direct interventions for the management of MCI. The clinical significance of saccadic eye movement impairments in MCI is not yet fully understood and should be investigated in further studies using larger samples.

摘要

简介：众所周知，轻度认知障碍 (MCI) 在其认知特征和进展过程中具有异质性。虽然记忆障碍是遗忘型 MCI (aMCI) 的特征，但在 aMCI 和非遗忘型 MCI (naMCI) 中都可能发生记忆以外的认知缺陷，如果不应用广泛的神经心理学测试，临床医生很难准确评估 MCI 的亚型。在这项研究中，我们检查了从反射性和自愿性扫视眼运动的记录中得出的指标，作为区分亚型和评估 MCI 认知功能的潜在替代方法。

方法：共有 29 名 MCI 患者和 29 名年龄和教育匹配的健康对照 (HC) 参与了横断面研究。我们记录horizo​​nta升和垂直亲眼跳和反扫视反应。所有参与者还完成了全面的神经心理学测试。

结果：在 MCI 和 HC 亚型之间发现扫视眼球运动的显着差异。aMCI 患者的短潜伏期“表达”眼跳的百分比高于 HC。我们发现扫视反应时间与认知领域（包括执行功能和注意力）之间存在很强的关联。还发现小型精神状态检查 (MMSE) 与反眼跳任务中未纠正的错误相关。

结论：aMCI 中快速潜伏期范围内的眼跳比例增加可能表明这些患者的认知抑制控制存在问题。在痴呆的临床前和前驱阶段关注这个和其他扫视指标可能有助于预测疾病的临床进展和直接干预 MCI 的管理。MCI 中扫视眼运动障碍的临床意义尚不完全清楚，应在使用更大样本的进一步研究中进行调查。