Subjective cognitive decline (SCD) has been proposed as a preclinical stage of Alzheimer's disease (AD). Neuroimaging studies have suggested early AD-like structural brain alterations in SCD subjects compared to healthy controls. However, there is substantial heterogeneity in the results, which might depend on whether SCD samples were drawn from the community or from memory clinics. Here we reviewed brain atrophy, assessed through structural magnetic resonance imaging, separately for SCD-community and clinic-based samples. SCD-community samples show a more consistent pattern of atrophy, involving the hippocampus and temporal and parietal cortices. Similarly, in SCD-clinic samples the temporo-parietal cortex showed early vulnerability, however these studies reported a more heterogeneous atrophy pattern. Overall, these studies suggest both commonalities and differences in brain atrophy patterns between SCD clinical and community samples. In SCD-community, the temporal cortex is involved, while SCD-clinical exhibited a more complex pattern of atrophy, which may be related to a more heterogeneous sample reporting neuropsychiatric symptoms along with preclinical AD.

已经提出主观认知下降（SCD）作为阿尔茨海默氏病（AD）的临床前阶段。神经影像学研究表明，与健康对照组相比，SCD受试者的早期AD样结构性大脑改变。但是，结果中存在很大的异质性，这可能取决于SCD样本是从社区还是从记忆诊所中提取的。在这里，我们回顾了通过结构磁共振成像评估的脑萎缩，分别针对SCD社区和基于临床的样本。SCD社区样本显示出更一致的萎缩模式，涉及海马以及颞叶和顶叶皮质。同样，在SCD诊所的样本中，颞顶叶皮层显示出较早的脆弱性，但是这些研究报告了更加异质的萎缩模式。总体，这些研究表明，SCD临床样本和社区样本之间的脑萎缩模式既有共性，又有差异。在SCD社区中，颞皮质参与其中，而SCD-临床表现出更复杂的萎缩模式，这可能与报告临床前AD的神经精神病症状的样本更加多样化有关。