Abstract: Objective Diffusion tensor imaging (DTI) technique with voxel-based analysis was applied to analyze the differences of whole-brain fractional anisotropy (FA) in an attempt to find out the characteristic changes of white matter in amnesic mild cognitive impairment (aMCI) patients. Methods According to the diagnostic criteria of aMCI and individual neuropsychological tests (verbal memory, similarity, perceptive, connection A, graphics memory, etc.), 16 aMCI patients received brain DTI and voxel-based analysis were compared with the normal cognitive (NC) function subjects (control group) by differences of whole-brain FA value. Results 1) The overall rating of Mini-Mental State Examination (MMSE) in the control group was 28.69 ± 1.03, higher than 27.50 ± 1.65 of the aMCI group (t = 1.278, P = 0.035). 2) The overall rating of Montreal Cognitive Assessment (MoCA) in the control group was 25.85 ± 1.52, higher than 22.50 ± 1.91 of the aMCI group (t = 0.900, P = 0.000). 3) The number of Verbal Fluency in control group was 19.08 ± 4.92, which was more than 15.14 ± 4.66 of the aMCI group (t = 0.012，P = 0.043). 4) The scores of vocabulary memory, delayed vocabulary recall, word recognition, graphic recall were 5.54 ± 0.88, 5.15 ± 1.77, 9.15 ± 1.07 and 14.69 ± 2.25, respectively, higher than those of the aMCI group 3.98 ± 1.07, 2.14 ± 1.23, 7.00 ± 2.04 and 10.57 ± 2.31 (P = 0.000, for all). 5) The FA value in the left middle frontal gyrus and right middle frontal gyrus white matter of the aMCI group was significantly lower than that of the control group. The difference was statistically significant (P < 0.001, for all). Conclusion White matter lesion (WML) of frontal lobe may be involved in the early pathophysiological processes of aMCI, and may be a new evidence for the early non-invasive diagnosis of aMCI.

Key words: Cognition disorders, Leukoencephalopathy, progressive multifocal, Neuropsychological tests, Magnetic resonance imaging

摘要： 目的   通过扩散张量成像（DTI）和基于体素的分析方法进行全脑部分各向异性（FA）差异性分析，尝试发现遗忘型轻度认知损害（aMCI）患者脑白质的特征性改变。方法   根据遗忘型轻度认知损害诊断标准和单项神经心理学测验（词表记忆、相似性、领悟力、连线A、图形自由回忆等），16 例遗忘型轻度认知损害患者接受头部DTI，所得影像资料行基于体素的分析，并与认知功能正常者（对照组）比较全脑FA 值差异性。结果   （1）对照组简易智能状态检查量表总评分为28.69 ± 1.03，高于aMCI 组的27.50 ± 1.65（t = 1.278，P = 0.035）。（2）对照组蒙特利尔认知评价量表总评分为25.85 ± 1.52，高于aMCI 组的22.50 ± 1.91（t = 0.900，P = 0.000）。（3）对照组词语流畅性词汇数目为（19.08 ± 4.92）个，多于aMCI 组的（15.14 ± 4.66）个（t = 0.012，P = 0.043）。（4）对照组词表记忆、延迟词表回忆、词语辨认、图形自由回忆测验评分分别为5.54 ± 0.88、5.15 ± 1.77、9.15 ± 1.07 和14.69 ± 2.25，高于aMCI 组的3.98 ± 1.07、2.14 ± 1.23、7.00 ± 2.04 和10.57 ± 2.31（均P = 0.000）。（5）aMCI 组左侧额中回、右侧额中回白质区FA 值显著低于对照组，差异有统计学意义（均P < 0.001）。结论   额叶白质病变可能参与遗忘型轻度认知损害的早期病理生理学过程。

关键词: 认知障碍, 脑白质病, 进行性多灶性, 神经心理学测验, 磁共振成像