Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, 100053, China.
Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China.
Mol Neurodegener. 2020 Sep 22;15(1):55. doi: 10.1186/s13024-020-00395-3.
Subjective cognitive decline (SCD) is regarded as the first clinical manifestation in the Alzheimer's disease (AD) continuum. Investigating populations with SCD is important for understanding the early pathological mechanisms of AD and identifying SCD-related biomarkers, which are critical for the early detection of AD. With the advent of advanced neuroimaging techniques, such as positron emission tomography (PET) and magnetic resonance imaging (MRI), accumulating evidence has revealed structural and functional brain alterations related to the symptoms of SCD. In this review, we summarize the main imaging features and key findings regarding SCD related to AD, from local and regional data to connectivity-based imaging measures, with the aim of delineating a multimodal imaging signature of SCD due to AD. Additionally, the interaction of SCD with other risk factors for dementia due to AD, such as age and the Apolipoprotein E (ApoE) ɛ4 status, has also been described. Finally, the possible explanations for the inconsistent and heterogeneous neuroimaging findings observed in individuals with SCD are discussed, along with future directions. Overall, the literature reveals a preferential vulnerability of AD signature regions in SCD in the context of AD, supporting the notion that individuals with SCD share a similar pattern of brain alterations with patients with mild cognitive impairment (MCI) and dementia due to AD. We conclude that these neuroimaging techniques, particularly multimodal neuroimaging techniques, have great potential for identifying the underlying pathological alterations associated with SCD. More longitudinal studies with larger sample sizes combined with more advanced imaging modeling approaches such as artificial intelligence are still warranted to establish their clinical utility.
主观认知下降 (SCD) 被认为是阿尔茨海默病 (AD) 连续体的首发临床症状。对 SCD 人群进行研究对于了解 AD 的早期病理机制和识别 SCD 相关生物标志物非常重要，这些标志物对于 AD 的早期检测至关重要。随着正电子发射断层扫描 (PET) 和磁共振成像 (MRI) 等先进神经影像学技术的出现，越来越多的证据揭示了与 SCD 症状相关的结构和功能脑改变。在这篇综述中，我们总结了与 AD 相关的 SCD 的主要影像学特征和关键发现，从局部和区域数据到基于连接的影像学测量，旨在描绘 AD 所致 SCD 的多模态影像学特征。此外，还描述了 SCD 与 AD 所致痴呆的其他危险因素（如年龄和载脂蛋白 E (ApoE) ε4 状态）之间的相互作用。最后，还讨论了导致 SCD 个体的神经影像学发现不一致和异质性的可能解释，以及未来的方向。总的来说，文献表明在 AD 背景下 SCD 存在 AD 特征区域的优先易损性，支持了这样一种观点，即 SCD 个体与轻度认知障碍 (MCI) 和 AD 所致痴呆患者具有相似的脑改变模式。我们得出结论，这些神经影像学技术，特别是多模态神经影像学技术，在识别与 SCD 相关的潜在病理改变方面具有很大的潜力。仍需要更多的纵向研究，样本量更大，并结合更先进的成像建模方法（如人工智能），以确定其临床应用价值。
