Albert Szent-Györgyi Clinical Center, Department of Neurology, University of Szeged, Szeged, Hungary.
J Alzheimers Dis. 2013;36(1):119-28. doi: 10.3233/JAD-122431.
Several recent studies have indicated that white matter is affected in Alzheimer's disease (AD). Diffusion tensor imaging is a tool by which the white matter microstructure can be examined in vivo, and might offer a possibility for the identification of the pattern of white matter disintegration in AD. In the current analysis, we made use of a novel model-free analysis approach of linked independent component analysis to identify a motif of diffusion parameter alterations exemplifying AD. Analysis of the diffusion data of 16 AD patients and 17 age-matched healthy subjects revealed six independent components, two of which demonstrated differences between the patients and controls. Component #0 was dominated by axial diffusivity, but significant alterations in fractional anisotropy and mean and radial diffusivity were also detected. Alterations were found in regions of crossing of major white matter pathways, such as forceps, corona radiate, and superior longitudinal fascicle, as well as medio-temporal white matter. These results lend support to the coexistence of white matter disintegration of the late myelinating associating fibers and wallerian degeneration-related disintegration, in accordance with the retrogenesis and wallerian degeneration hypothesis.
几项最近的研究表明，阿尔茨海默病（AD）会影响白质。弥散张量成像（DTI）是一种可活体检测白质微观结构的工具，可能为识别 AD 中白质解体的模式提供了一种可能性。在当前的分析中，我们利用一种新的无模型链接独立成分分析方法，来识别代表 AD 的扩散参数改变模式。对 16 名 AD 患者和 17 名年龄匹配的健康受试者的扩散数据进行分析，揭示了六个独立成分，其中两个成分在患者和对照组之间存在差异。成分 #0 主要由轴突弥散度决定，但也检测到各向异性分数、平均弥散度和径向弥散度的显著改变。在主要白质通路（如内囊、放射冠和上纵束）以及中颞叶白质的交叉区域发现了改变。这些结果支持晚期髓鞘形成的联合纤维白质解体和 Wallerian 变性相关解体共存的假说，符合退行性变和 Wallerian 变性假说。
