RÉSUMÉ
@#Alzheimer's disease (AD) is a progressive irreversible neurodegenerative disease,and its prevalence rate is increasing rapidly as the population ages. Most patients with AD are diagnosed after the age of 65 years,and compared with late-onset Alzheimer's disease (LOAD),approximately 5%~10% of patients with AD develop cognitive impairment before the age of 65 years and are defined as early-onset Alzheimer's disease (EOAD). Although LOAD,typical amnestic EOAD,and atypical EOAD share the same molecular pathology of the accumulation of β-amyloid and tau,they tend to have heterogeneous clinical manifestations. EOAD is frequently misdiagnosed or delayed due to atypical clinical manifestations,and it often has rapid progression and a short survival time;therefore,it is crucial to understand the characteristics of EOAD for early diagnosis and treatment. Different clinical phenotypes of AD appear to have selective vulnerability in certain brain regions,which may help to explain such heterogeneity. This review analyzes the recent research advances in the structural,functional,and molecular imaging of typical amnestic EOAD and atypical EOAD and investigates the feasibility and effectiveness of imaging indicators as a noninvasive marker,so as to provide new ideas for the diagnosis of EOAD.