Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK.
Janssen Prevention Center, Leiden, The Netherlands.
J Alzheimers Dis. 2018;66(2):587-600. doi: 10.3233/JAD-180101.
Despite the progressive nature of Alzheimer's disease and other dementias, it is observed that many individuals that are diagnosed with mild cognitive impairment (MCI) in one clinical assessment, may return back to normal cognition (CN) in a subsequent assessment. Less frequently, such 'back-transitions' are also observed in people that had already been diagnosed with later stages of dementia. In this study, an analysis was performed on two longitudinal cohort datasets provided by 1) the Alzheimer's Disease Neuroimaging Initiative (ADNI) and 2) the National Alzheimer's Coordinating Centre (NACC). The focus is on the observed improvement of individuals' clinical condition recorded in these datasets to explore potential associations with different factors. It is shown that, in both datasets, transitions from MCI to CN are significantly associated with younger age, better cognitive function, and the absence of ApoE ɛ4 alleles. Better cognitive function and in some cases the absence of ApoE ɛ4 alleles are also significantly associated with transitions from types of dementia to less severe clinical states. The effect of gender and education is not clear-cut in these datasets, although highly educated people who reach MCI tend to be more likely to show an improvement in their clinical state. The potential effect of other factors such as changes in symptoms of depression is also discussed. Although improved clinical outcomes can be associated with many factors, better diagnostic tools are required to provide insight into whether such improvements are a result of misdiagnosis, and if they are not, whether they are linked to improvements in the underlying neuropathological condition.
尽管阿尔茨海默病和其他痴呆症是进行性疾病，但观察到许多在一次临床评估中被诊断为轻度认知障碍（MCI）的个体，在随后的评估中可能会恢复正常认知（CN）。不太常见的是，在已经被诊断为痴呆症后期的个体中也观察到这种“回退”。在这项研究中，对两个纵向队列数据集进行了分析，这些数据集分别来自 1）阿尔茨海默病神经影像学倡议（ADNI）和 2）国家阿尔茨海默病协调中心（NACC）。研究重点是观察到的个体临床状况改善，以探索与不同因素的潜在关联。结果表明，在这两个数据集，从 MCI 到 CN 的转变与年龄较小、认知功能较好和没有 ApoE ɛ4 等位基因显著相关。在某些情况下，认知功能较好且没有 ApoE ɛ4 等位基因也与从痴呆类型向更轻的临床状态的转变显著相关。在这些数据集中，性别和教育的影响并不明确，尽管达到 MCI 的高学历者更有可能改善他们的临床状况。还讨论了其他因素的潜在影响，如抑郁症状的变化。尽管改善的临床结果可能与许多因素有关，但需要更好的诊断工具来深入了解这些改善是否是误诊的结果，如果不是，它们是否与潜在神经病理学状况的改善有关。
