Functional implications of hippocampal volume and diffusivity in mild cognitive impairment
Functional implications of hippocampal volume and diffusivity in mild cognitive impairment
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DOI：
10.1016/j.neuroimage.2005.06.029
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发表时间：
2005-12-01
期刊：
影响因子：
5.7
通讯作者：
Fellgiebel, A
中科院分区：
文献类型：
--
作者：
Müller, MJ;Greverus, D;Fellgiebel, A
海马萎缩与轻度认知功能障碍（MCI）和早期阿尔茨海默病（AD）有关，但海马横截面体积的诊断意义仍不明确。扩散张量成像（DTI）显示MCI患者海马区的微结构变化与言语记忆下降有关。MRI容量测定和DTI相结合，调查18 MCI患者参加记忆诊所，18仔细年龄和性别匹配的健康对照。应用神经心理学测试、高分辨率T1加权容积MR 1扫描和海马区感兴趣区域的DTI扫描。MCI患者的左侧海马体积显著低于对照组（-11%，P = 0.02）。右侧海马体无显著差异（-4%）。与对照组相比，MCI患者左侧（+10%，P = 0.002）和右侧海马区（+13%，P = 0.02）的平均扩散率（MD）显著升高。海马体积与MD值无显著相关性。结合左侧海马体积和MD测量结果表明，左下海马体积与言语记忆表现差相关，特别是当与高MD值同时发生时。关于右侧海马结构和非文字记忆功能，没有发现类似的关联。结果表明，微结构异常所揭示的DTI是非常敏感的海马功能障碍的早期指标。海马区的宏观和微观结构参数的组合可能是有前途的神经退行性过程的早期检测。(c)2005年爱思唯尔公司All rights reserved.
Hippocampal atrophy has been related to mild cognitive impairment (MCI) and early Alzheimer disease (AD), but the diagnostic significance of cross-section ally 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 MR1 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. (c) 2005 Elsevier Inc. All rights reserved.