Department of Neuroscience, Tor Vergata University, Rome.
Neurology. 2010 Jan 19;74(3):194-200. doi: 10.1212/WNL.0b013e3181cb3e39. Epub 2010 Jan 6.
The relationship between age-related memory decline and hippocampal anatomic changes is a matter of debate.
To investigate the relationship between age-related memory decline and MRI hippocampal anatomic changes in a cohort of healthy individuals.
In this cross-sectional study, 76 healthy individuals (44 male and 32 female), ranging in age from 20 to 80 years, were recruited from universities, community recreational centers, hospital personnel, and patients' relatives from 2005 to 2008. These individuals were submitted to a 3-T MRI protocol with a whole-brain T1-weighted and diffusion-weighted scanning and a neuropsychological assessment. For each subject, we calculated the volumes of the total brain (gray + white matter) and hippocampi. The segmented hippocampi defined the binary masks where mean values of mean diffusivity (MD) and fractional anisotropy (FA) were calculated. Neuropsychological evaluation included tests of verbal memory (15 minutes delayed recall of a 15-word list) and visuospatial memory (20 minutes delayed reproduction of Rey complex figure).
Hippocampal MD, but not hippocampal FA, hippocampal volume, or total brain volume, predicted performance of individuals beyond their 50s on tests of verbal and visuospatial memory.
High mean diffusivity values in the hippocampal formation of healthy elderly individuals predict memory decline, as reflected by performance on tests of declarative verbal and visual-spatial memory.
与年龄相关的记忆衰退与海马体解剖结构变化之间的关系一直存在争议。
在一组健康个体中研究与年龄相关的记忆衰退与 MRI 海马体解剖结构变化之间的关系。
在这项横断面研究中，2005 年至 2008 年间，我们从大学、社区娱乐中心、医院工作人员和患者亲属中招募了 76 名年龄在 20 至 80 岁之间的健康个体（44 名男性和 32 名女性）。这些个体接受了 3-T MRI 方案检查，包括全脑 T1 加权和弥散加权扫描以及神经心理学评估。对于每个个体，我们计算了大脑总容积（灰质+白质）和海马体容积。分割后的海马体定义了平均弥散度（MD）和各向异性分数（FA）的均值计算的二进制掩模。神经心理学评估包括言语记忆测试（15 分钟延迟回忆 15 个单词列表）和视空间记忆测试（20 分钟延迟再现 Rey 复杂图形）。
海马体 MD，而不是海马体 FA、海马体容积或大脑总容积，可预测个体在 50 多岁以上时言语和视空间记忆测试的表现。
健康老年人海马体结构中较高的平均弥散度值可预测记忆衰退，表现为在陈述性言语和视觉空间记忆测试中的表现下降。
