Frisoni G B, Sabattoli F, Lee A D, Dutton R A, Toga A W, Thompson P M
LENITEM Laboratory of Epidemiology Neuroimaging and Telemedicine, IRCCS Centro S. Giovanni di Dio-FBF, via Pilastroni 4, 25125 Brescia, Italy.
Neuroimage. 2006 Aug 1;32(1):104-10. doi: 10.1016/j.neuroimage.2006.03.015. Epub 2006 May 2.
Early involvement of the hippocampal formation is the biological basis of the typical learning deficit in Alzheimer's disease (AD). However, the hippocampal formation is unevenly affected by AD pathology, deposits of plaques and tangles being particularly dense in the CA1 field and subiculum. The aim of the study was to locate in vivo the structural changes within the hippocampal formation in AD patients of mild to moderate severity. A group of 28 AD patients and 40 cognitively intact persons (age 74 +/- 9 and 71 +/- 7 years) underwent T1-weighted high-resolution MR scans. The hippocampal formation was isolated by manually tracing on 35 coronal slices the outlines of the hippocampus proper and subiculum after registration to a common stereotactic space. Group differences were assessed with algorithms developed ad hoc that make use of three-dimensional parametric surface mesh models. In AD patients, significant atrophic changes amounting to tissue loss of 20% or more were found in regions of the hippocampal formation corresponding to the CA1 field and part of the subiculum. Regions corresponding to the CA2-3 fields were remarkably spared. We conclude that the regions of the hippocampal formation that we found atrophic in AD patients are those known to be affected from pathological studies. This study supports the possibility of carrying out in vivo macroscopic neuropathology of the hippocampus with MR imaging in the neurodegenerative dementias.
海马结构的早期受累是阿尔茨海默病（AD）典型学习缺陷的生物学基础。然而，海马结构受AD病理的影响并不均匀，斑块和缠结在CA1区和下托的沉积尤为密集。本研究的目的是在体内定位轻度至中度AD患者海马结构内的结构变化。28例AD患者和40名认知功能正常者（年龄分别为74±9岁和71±7岁）接受了T1加权高分辨率磁共振扫描。在将海马结构配准到一个共同的立体定向空间后，通过在35个冠状切片上手动描绘海马体和下托的轮廓来分离海马结构。使用专门开发的算法，利用三维参数化表面网格模型评估组间差异。在AD患者中，在与CA1区和部分下托相对应的海马结构区域发现了显著的萎缩性变化，组织损失达20%或更多。与CA2-3区相对应的区域明显未受影响。我们得出结论，我们在AD患者中发现萎缩的海马结构区域是那些在病理研究中已知受影响的区域。本研究支持在神经退行性痴呆中利用磁共振成像对海马进行体内宏观神经病理学研究的可能性。
