Müller Matthias J, Greverus Dirk, Dellani Paulo Roberto, Weibrich Carsten, Wille Paulo R, Scheurich Armin, Stoeter Peter, Fellgiebel Andreas
Department of Psychiatry, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany.
Neuroimage. 2005 Dec;28(4):1033-42. doi: 10.1016/j.neuroimage.2005.06.029. Epub 2005 Aug 3.
Hippocampal atrophy has been related to mild cognitive impairment (MCI) and early Alzheimer disease (AD), but the diagnostic significance of cross-sectionally determined hippocampal volumes is still ambiguous. Diffusion-Tensor-Imaging (DTI) in MCI patients revealed an association of microstructural changes in hippocampal areas with verbal memory decline. MRI volumetry and DTI were combined to investigate 18 MCI patients attending a memory clinic, and 18 carefully age- and gender-matched healthy controls. Neuropsychological testing, high resolution T1-weighted volume MRI scans, and DTI scans with regions-of-interest in hippocampal areas were applied. Left hippocampal volume was significantly lower (-11%, P = 0.02) in MCI patients than in control subjects. No significant differences were found for the right hippocampus (-4%). Mean diffusivity (MD) was significantly elevated in MCI patients vs. controls in left (+10%, P = 0.002) and right hippocampal areas (+13%, P = 0.02). Hippocampal volume and MD values were not significantly correlated. Combining left hippocampal volume and MD measures showed that lower left hippocampal volumes were associated with poor verbal memory performance particularly when co-occurring with high MD values. No comparable associations could be found regarding the right hippocampal formation and with respect to non-verbal memory function. The results demonstrate that microstructural abnormalities as revealed by DTI are very sensitive early indicators of hippocampal dysfunction. The combination of macro- and microstructural parameters in hippocampal areas could be promising in early detection of neurodegenerative processes.
海马萎缩与轻度认知障碍（MCI）及早期阿尔茨海默病（AD）有关，但横断面测定的海马体积的诊断意义仍不明确。对MCI患者进行的扩散张量成像（DTI）显示，海马区域的微观结构变化与言语记忆衰退有关。将MRI体积测量法和DTI结合起来，对18名在记忆门诊就诊的MCI患者以及18名年龄和性别匹配的健康对照者进行研究。应用了神经心理学测试、高分辨率T1加权体积MRI扫描以及对海马区域感兴趣区的DTI扫描。MCI患者的左侧海马体积显著低于对照组（-11%，P = 0.02）。右侧海马体积差异无统计学意义（-4%）。MCI患者左侧（+10%，P = 0.002）和右侧海马区域（+13%，P = 0.02）的平均扩散率（MD）显著高于对照组。海马体积与MD值无显著相关性。综合左侧海马体积和MD测量结果显示，较低的左侧海马体积与较差言语记忆表现相关，尤其是当与高MD值同时出现时。关于右侧海马结构及非言语记忆功能，未发现类似关联。结果表明，DTI显示的微观结构异常是海马功能障碍非常敏感的早期指标。海马区域宏观和微观结构参数的结合在神经退行性过程的早期检测中可能很有前景。
