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

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