Garcia-Ptacek S, Eriksdotter M, Jelic V, Porta-Etessam J, Kåreholt I, Manzano Palomo S
Servicio de Neurología, Hospital Clínico San Carlos, Madrid, España; Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Estocolmo, Suecia.
Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Estocolmo, Suecia; Department of Geriatric Medicine, Karolinska University Hospital, Karolinska Institutet/Stockholm University, Estocolomo, Suecia.
Neurologia. 2016 Oct;31(8):562-71. doi: 10.1016/j.nrl.2013.02.007. Epub 2013 Apr 17.
Neurodegeneration in Alzheimer disease (AD) begins decades before dementia and patients with mild cognitive impairment (MCI) already demonstrate significant lesion loads. Lack of information about the early pathophysiology in AD complicates the search for therapeutic strategies.Subjective cognitive impairment is the description given to subjects who have memory-related complaints without pathological results on neuropsychological tests. There is no consensus regarding this heterogeneous syndrome, but at least some of these patients may represent the earliest stage in AD.
We reviewed available literature in order to summarise current knowledge on subjective cognitive impairment.
Although they may not present detectable signs of disease, SCI patients as a group score lower on neuropsychological tests than the general population does, and they also have a higher incidence of future cognitive decline. Depression and psychiatric co-morbidity play a role but cannot account for all cognitive complaints. Magnetic resonance imaging studies in these patients reveal a pattern of hippocampal atrophy similar to that of amnestic mild cognitive impairment and functional MRI shows increased activation during cognitive tasks which might indicate compensation for loss of function. Prevalence of an AD-like pattern of beta-amyloid (Aβ42) and tau proteins in cerebrospinal fluid is higher in SCI patients than in the general population.
Memory complaints are relevant symptoms and may predict AD. Interpatient variability and methodological differences between clinical studies make it difficult to assign a definition to this syndrome. In the future, having a standard definition and longitudinal studies with sufficient follow-up times and an emphasis on quantifiable variables may clarify aspects of early AD.
阿尔茨海默病（AD）中的神经退行性变在痴呆出现前数十年就已开始，轻度认知障碍（MCI）患者已表现出显著的病变负荷。缺乏关于AD早期病理生理学的信息使得寻找治疗策略变得复杂。主观认知障碍是指那些有与记忆相关主诉但神经心理学测试无病理结果的受试者。对于这种异质性综合征尚无共识，但至少其中一些患者可能代表AD的最早阶段。
我们回顾了现有文献，以总结关于主观认知障碍的当前知识。
尽管主观认知障碍（SCI）患者可能没有可检测到的疾病迹象，但作为一个群体，他们在神经心理学测试中的得分低于一般人群，并且未来认知衰退的发生率也更高。抑郁和精神共病起了一定作用，但不能解释所有的认知主诉。对这些患者的磁共振成像研究显示出与遗忘型轻度认知障碍相似的海马萎缩模式，功能磁共振成像显示在认知任务期间激活增加，这可能表明对功能丧失的代偿。SCI患者脑脊液中β-淀粉样蛋白（Aβ42）和tau蛋白的AD样模式患病率高于一般人群。
记忆主诉是相关症状，可能预测AD。患者间的变异性以及临床研究之间的方法学差异使得难以给这个综合征下定义。未来，拥有一个标准定义以及足够随访时间并强调可量化变量的纵向研究可能会阐明早期AD的各个方面。
