Scher A I, Xu Y, Korf E S C, White L R, Scheltens P, Toga A W, Thompson P M, Hartley S W, Witter M P, Valentino D J, Launer L J
Department of Preventive Medicine and Biometrics, Uniformed Services University, Bethesda, MD 20814, USA.
Neuroimage. 2007 May 15;36(1):8-18. doi: 10.1016/j.neuroimage.2006.12.036. Epub 2007 Mar 12.
Hippocampal atrophy--particularly of the CA1 region--may be useful as a biomarker for Alzheimer's disease (AD) or the risk for AD. The extent to which the AD hippocampus can be distinguished in vivo from changes due to normal aging or other processes that affect the hippocampus is of clinical importance and is an area of active research. In this study, we use structural imaging techniques to model hippocampal size and regional shape differences between elderly men with incident AD and a non-demented comparison group of elderly men.
Participants are Japanese-American men from the Honolulu Asia Aging Study (HAAS). The HAAS cohort has been followed since 1965. The following analysis is based on a sub-group of men who underwent MRI examination in 1994-1996. Participants were diagnosed with incident AD (n=24: age=82.5+/-4.6) or were not demented (n=102: age=83.0+/-5.9). One reader, blinded to dementia diagnosis, manually outlined the left and right hippocampal formation using published criteria. We used 3D structural shape analysis methods developed at the Laboratory of Neuro Imaging (LONI) to compare regional variation in hippocampal diameter between the AD cases and the non-demented comparison group.
Mean total hippocampal volume was 11.5% smaller in the AD cases than the non-demented controls (4903+/-857 mm(3) vs. 5540+/-805 mm(3)), with a similar size difference for the median left (12.0%) and median right (11.6%) hippocampus. Shape analysis showed a regional pattern of shape difference between the AD and non-demented hippocampus, more evident for the hippocampal body than the head, and the appearance of more consistent differences in the left hippocampus than the right. While assignment to a specific sub-region is not possible with this method, the surface changes primarily intersect the area of the hippocampus body containing the CA1 region (and adjacent CA2 and distal CA3), subiculum, and the dentate gyrus-hilar region.
海马萎缩——尤其是CA1区的萎缩——可能作为阿尔茨海默病（AD）或AD风险的生物标志物。AD海马在体内与正常衰老或其他影响海马的过程所导致的变化相区分的程度具有临床重要性，并且是一个活跃的研究领域。在本研究中，我们使用结构成像技术来模拟患有新发AD的老年男性与非痴呆老年男性对照组之间海马大小和区域形状差异。
参与者是来自檀香山亚洲老年研究（HAAS）的日裔美国男性。HAAS队列自1965年起就受到随访。以下分析基于1994 - 1996年接受MRI检查的男性亚组。参与者被诊断为新发AD（n = 24：年龄 = 82.5 ± 4.6）或未患痴呆（n = 102：年龄 = 83.0 ± 5.9）。一名对痴呆诊断不知情的阅片者使用已发表的标准手动勾勒出左右海马结构。我们使用神经影像实验室（LONI）开发的3D结构形状分析方法来比较AD病例组和非痴呆对照组之间海马直径的区域差异。
AD病例组的平均海马总体积比非痴呆对照组小11.5%（4903 ± 857 mm³对5540 ± 805 mm³），左侧海马中位数（12.0%）和右侧海马中位数（11.6%）也有类似的大小差异。形状分析显示AD和非痴呆海马之间存在区域形状差异模式，海马体比头部更明显，并且左侧海马的差异比右侧更一致。虽然用这种方法无法指定到特定子区域，但表面变化主要与包含CA1区（以及相邻的CA2和远端CA3）、下托以及齿状回 - 海马 hilar区的海马体区域相交。
