Brain and Ageing Research Program, School of Psychiatry, University of New South Wales, Sydney, Australia.
Int Psychogeriatr. 2012 Sep;24(9):1483-93. doi: 10.1017/S1041610212000270. Epub 2012 Mar 27.
Previous studies using diffusion tensor imaging (DTI) have observed microstructural abnormalities in white matter regions in both Alzheimer's disease and mild cognitive impairment (MCI). The aim of this work was to examine the abnormalities in white matter and subcortical regions of MCI and its subtypes in a large, community-dwelling older aged cohort.
A community-based sample of 396 individuals without dementia underwent medical assessment, neuropsychiatric testing, and neuroimaging. Of these, 158 subjects were classified as MCI and 238 as cognitively normal (controls) based on international MCI consensus criteria. Regional fractional anisotropy (FA) and mean diffusivity (MD) measures were calculated from the DTI and compared between groups. The false discovery rate correction was applied for multiple testing.
Subjects with MCI did not have significant differences in FA compared with controls after correction for multiple testing, but had increased MD in the right putamen, right anterior limb of the internal capsule, genu and splenium of the corpus callosum, right posterior cingulate gyrus, left superior frontal gyrus, and right and left corona radiata. When compared with controls, changes in left anterior cingulate, left superior frontal gyrus, and right corona radiata were associated with amnestic MCI (aMCI), whereas changes in the right putamen, right anterior limb of the internal capsule, and the right corona radiata were associated with non-amnestic MCI (naMCI). On logistic regression, the FA values in the left superior gyrus and MD values in the anterior cingulate distinguished aMCI from naMCI.
MCI is associated with changes in white matter and subcortical regions as seen on DTI. Changes in some anterior brain regions distinguish aMCI from naMCI.
先前使用弥散张量成像（DTI）的研究观察到阿尔茨海默病和轻度认知障碍（MCI）患者的白质区域存在微观结构异常。本研究旨在检查大量社区居住的老年人群中 MCI 及其亚型的白质和皮质下区域的异常。
一项基于社区的 396 名无痴呆症的个体接受了医学评估、神经心理测试和神经影像学检查。其中，158 名受试者根据国际 MCI 共识标准被分类为 MCI，238 名被分类为认知正常（对照组）。从 DTI 中计算出各区域的分数各向异性（FA）和平均弥散度（MD）测量值，并在组间进行比较。应用错误发现率校正进行多重检验。
在进行多重检验校正后，MCI 患者的 FA 与对照组相比没有显著差异，但右侧壳核、内囊前肢、胼胝体膝部和压部、右侧后扣带回、左侧额上回以及右侧和左侧辐射冠的 MD 增加。与对照组相比，左前扣带回、左额上回和右侧辐射冠的变化与遗忘型 MCI（aMCI）有关，而右侧壳核、右侧内囊前肢和右侧辐射冠的变化与非遗忘型 MCI（naMCI）有关。在逻辑回归中，左侧额上回的 FA 值和前扣带的 MD 值可区分 aMCI 和 naMCI。
MCI 与 DTI 上观察到的白质和皮质下区域的变化有关。一些前脑区域的变化可区分 aMCI 和 naMCI。
