Department of Experimental Psychology, University of Bristol, Clifton, Bristol, UK.
J Alzheimers Dis. 2011;24(1):151-60. doi: 10.3233/JAD-2010-101818.
In the study of Alzheimer's disease, a multidisciplinary research approach has identified significant abnormality in several areas of visual and visual attention-related brain function in addition to those typically measured as part of clinical diagnosis. This raises the possibility that a similar approach applied to amnestic mild cognitive impairment (aMCI) will increase our understanding of its theoretical and clinical constructs, particularly if functions whose integrity is heterogeneous with respect to etiological outcome can be found. In this study we examined visual search performance (the brain's ability to search effectively throughout the environment for a particular object) in aMCI compared to healthy aging. Cross-sectionally, visual search performance in aMCI was significantly poorer than in healthy aging, with greater intra-group performance heterogeneity in the aMCI compared to the healthy older adult group. This outcome illustrates that although individuals within an aMCI group ostensibly have the same condition they can differ substantially with respect to the integrity of aspects of brain function. Such findings may have implications for the clinical management of the individual patient. The results from the longitudinal aspect of this study also illustrate how heterogeneity in the performance of brain operations other than memory in aMCI may help to inform the likelihood of their developing dementia, as those patients who were diagnosed with dementia within 2.5 years of baseline measurement showed significantly poorer visual search performance compared to those who did not.
在阿尔茨海默病的研究中，除了那些通常作为临床诊断一部分来衡量的领域外，多学科的研究方法还发现了与视觉和视觉注意力相关的大脑功能的几个区域的显著异常。这就提出了一种可能性，即类似的方法应用于遗忘型轻度认知障碍 (aMCI) 将增加我们对其理论和临床结构的理解，特别是如果可以发现与病因结果相关的功能具有完整性的异质性。在这项研究中，我们比较了 aMCI 与健康衰老个体的视觉搜索表现（大脑在环境中有效搜索特定物体的能力）。从横截面上看，aMCI 的视觉搜索表现明显差于健康衰老，与健康老年人组相比，aMCI 组的组内表现异质性更大。这一结果表明，尽管 aMCI 组中的个体表面上具有相同的疾病，但他们在大脑功能的完整性方面可能存在很大差异。这些发现可能对个体患者的临床管理产生影响。本研究纵向部分的结果还说明了 aMCI 中除记忆以外的大脑操作表现的异质性如何有助于告知其发展为痴呆的可能性，因为那些在基线测量后 2.5 年内被诊断为痴呆的患者的视觉搜索表现明显差于那些没有被诊断为痴呆的患者。
