Abstract: Background　Alzheimer's disease is accompanied by cognitive decline in preclinical stage，but it is not clear at which stage the significant changes in different cognitive domains appear.Objective　To explore the characteristics of cognitive function changes in different stages of preclinical Alzheimer's disease，to provide evidence for early identification and intervention of cognitive impairment.Methods　Elderly subjects were recruited to participate in cognitive function screening at the Health Management Center，the Second Affiliated Hospital of Fujian Traditional Chinese Medical University from April to June 2019，among whom 34 were found with normal cognitive function（NC group），29 with subjective cognitive decline（SCD group），and 34 with mild cognitive impairment（MCI group） were included for neuropsychological tests，which included Fuzhou version of Montreal Cognitive Assessment（MoCA-F），Lawton Instrumental Activities of Daily Living scale （Lawton-IADL），Geriatric Depression Scale-15（GDS-15），Boston Naming Test（BNT），Rey Auditory Verbal Learning Test（RAVLT），Stroop Color and Word Test （SCWT）.Results　There was no significant difference in the mean score of Lawton-IADL or GDS-15 among the groups（P>0.05）.The mean MoCA score differed significantly across the groups（P<0.001），in particular，MCI group had lower mean MoCA score than other groups（P<0.05）.The mean scores of BNT，RAVLT immediate recall and RAVLT delayed recall varied significantly across the groups（P<0.001），in particular，they were much lower in MCI group were all lower than those of NC and SCD groups （P<0.05）.There was no significant difference in the number of words read correctly in three groups（P>0.05）.The time required to name color，time needed to read words，time needed to name color-words，number of color named correctly and number of color-words named correctly varied significantly across the groups（P<0.05）.Compared with NC group，MCI group took longer time to name color，name color-words and read words，and had less number of correctly named color（P<0.05），and SCD group took longer time to read words，and had less number of correctly named color-words（P<0.05）.MCI group had the least number of correctly named color-words （P<0.05）.Conclusion　Attention and executive function decreased significantly in SCD stage，while language ability and memory function decreased significantly in MCI stage，suggesting that the decline of different cognitive domains may occur in different stages of Alzheimer's disease in preclinical stage.Therefore，clinicians should pay necessary attention to attention and executive function in SCD stage and to language ability and memory function in MCI stage.

Key words: Preclinical Alzheimer's disease, Subjective cognitive decline, Mild cognitive impairment, Cognition

摘要： 背景　阿尔茨海默病临床前期伴随认知功能下降，但各细分认知领域的显著改变具体出现在哪个阶段，目前尚不清楚。目的　探讨阿尔茨海默病临床前期不同阶段的认知领域变化特征，为认知障碍的早期识别与干预提供依据。方法　于2019年4—6月在福建中医药大学附属第二人民医院健康管理中心招募老年受试者参与认知功能筛查，共纳入34例认知正常老年人（NC组）、29例主观认知下降患者（SCD组）和34例轻度认知障碍患者（MCI组）进行神经心理学测试，包括福州版蒙特利尔认知评估量表（MoCA）、工具性日常生活能力量表（Lawton-IADLs）、简版老年抑郁量表（GDS-15）、Boston命名测验（BNT）、Rey听觉词语学习测验（RAVLT）、Stroop色词测验（SCWT）。结果　三组Lawton-IADLs、GDS-15得分比较，差异均无统计学意义（P>0.05）；三组MoCA得分比较，差异有统计学意义（P<0.001）；其中MCI组MoCA得分低于NC组和SCD组（P<0.05）。三组BNT、RAVLT即时回忆、RAVLT延迟回忆得分比较，差异均有统计学意义（P<0.001）；其中MCI组BNT、RAVLT即时回忆、RAVLT延迟回忆得分均低于NC组和SCD组（P<0.05）。三组Stroop字正确数比较，差异无统计学意义（P>0.05）；三组Stroop颜色耗时数、字耗时数、色字耗时数、颜色正确数、色字正确数比较，差异均有统计学意义（P<0.05）；其中MCI组Stroop颜色耗时数、字耗时数、色字耗时数均长于NC组，颜色正确数少于NC组（P<0.05）；SCD组Stroop字耗时数长于NC组，色字正确数少于NC组（P<0.05）；MCI组Stroop色字正确数少于NC组和SCD组（P<0.05）。结论　在主观认知下降阶段，注意力与执行功能出现明显下降；在轻度认知障碍阶段则出现语言能力和记忆功能明显下降。提示阿尔茨海默病临床前期不同认知领域的下降可能出现在不同阶段，临床上应给予主观认知下降患者注意力与执行功能必要的关注，对轻度认知障碍患者应当注意语言能力和记忆功能的变化。

关键词: 阿尔茨海默病临床前期, 主观认知下降, 轻度认知障碍, 认知