Vannini Patrizia, Amariglio Rebecca, Hanseeuw Bernard, Johnson Keith A, McLaren Donald G, Chhatwal Jasmeer, Pascual-Leone Alvaro, Rentz Dorene, Sperling Reisa A
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02114, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02114, USA; Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02114, USA; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA.
Neuropsychologia. 2017 May;99:343-349. doi: 10.1016/j.neuropsychologia.2017.04.002. Epub 2017 Apr 3.
While loss of insight of cognitive deficits, anosognosia, is a common symptom in Alzheimer's disease dementia, there is a lack of consensus regarding the presence of altered awareness of memory function in the preclinical and prodromal stages of the disease. Paradoxically, very early in the Alzheimer's disease process, individuals may experience heightened awareness of memory changes before any objective cognitive deficits can be detected, here referred to as hypernosognosia. In contrast, awareness of memory dysfunction shown by individuals with mild cognitive impairment (MCI) is very variable, ranging from marked concern to severe lack of insight. This study aims at improving our mechanistic understanding of how alterations in memory self-awareness are related to pathological changes in clinically normal (CN) adults and MCI patients. 297 CN and MCI patients underwent PiB-PET (Positron Emission Tomography using Pittsburgh Compound B) in vivo amyloid imaging. Amyloid burden was estimated from Alzheimer's disease vulnerable regions, including the frontal, lateral parietal and lateral temporal, and retrosplenial cortex. Memory self-awareness was assessed using discrepancy scores between subjective and objective measures of memory function. A set of univariate analysis of variance were performed to assess the relationship between self-awareness of memory and amyloid pathology. Whereas CN individuals harboring amyloid pathology demonstrated hypernosognosia, MCI patients with increased amyloid pathology demonstrated anosognosia. In contrast, MCI patients with low amounts of amyloid were observed to have normal insight into their memory functions. Altered self-awareness of memory tracks with amyloid pathology. The findings of variability of awareness may have important implications for the reliability of self-report of dysfunction across the spectrum of preclinical and prodromal Alzheimer's disease.
虽然对认知缺陷缺乏洞察力（即疾病感缺失）是阿尔茨海默病痴呆的常见症状，但对于该疾病临床前和前驱阶段记忆功能意识改变的存在，目前尚未达成共识。矛盾的是，在阿尔茨海默病进程的很早阶段，个体可能在任何客观认知缺陷被检测到之前就经历对记忆变化的高度意识，这里称为超疾病感缺失。相比之下，轻度认知障碍（MCI）个体表现出的对记忆功能障碍的意识差异很大，从明显关注到严重缺乏洞察力。本研究旨在增进我们对记忆自我意识改变如何与临床正常（CN）成年人和MCI患者的病理变化相关的机制理解。297名CN和MCI患者接受了匹兹堡化合物B正电子发射断层扫描（PiB-PET）活体淀粉样蛋白成像。从包括额叶、外侧顶叶、外侧颞叶和压后皮质在内的阿尔茨海默病易损区域估计淀粉样蛋白负荷。使用记忆功能主观和客观测量之间的差异分数评估记忆自我意识。进行了一组方差分析以评估记忆自我意识与淀粉样蛋白病理之间的关系。携带淀粉样蛋白病理的CN个体表现出超疾病感缺失，而淀粉样蛋白病理增加的MCI患者表现出疾病感缺失。相比之下，观察到淀粉样蛋白含量低的MCI患者对其记忆功能有正常的洞察力。记忆自我意识的改变与淀粉样蛋白病理相关。意识变异性的发现可能对临床前和前驱期阿尔茨海默病全谱中功能障碍自我报告的可靠性具有重要意义。
