Increased hippocampal activation in mild cognitive impairment compared to normal aging and AD
Increased hippocampal activation in mild cognitive impairment compared to normal aging and AD
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DOI：
10.1212/01.wnl.0000171450.97464.49
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发表时间：
2005-08-09
期刊：
影响因子：
9.9
通讯作者：
Sperling, RA
中科院分区：
文献类型：
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作者：
Dickerson, BC;Salat, DH;Sperling, RA
目的：目的：利用功能磁共振成像（fMRI）研究轻度认知功能障碍（MCI）早期海马和内嗅区的激活是否发生改变。研究方法：研究了三组老年人：10名认知功能完好的对照组，9名轻度轻度认知障碍患者和10名可能患有阿尔茨海默病（AD）的患者。受试者在功能磁共振成像扫描过程中进行了一个面孔名称联想编码任务，并在随后进行了刺激识别测试。使用功能解剖学方法分析数据，其中内侧颞叶（MTL）感兴趣的区域从每个人的结构MRI中识别，并在每个区域内量化fMRI激活。结果如下：与对照组相比，MCI组中存在显著更大的海马激活;这两组之间的海马或内嗅体积没有差异。与此相反，AD组显示海马和内嗅功能减退和萎缩相比，对照组。MCI患者在功能磁共振成像识别记忆任务中的表现与对照组相似; AD患者表现较差。在所有29名受试者中，13名APOE β 4等位基因携带者亚组的平均内嗅激活高于16名非携带者。结论：作者假设，在前驱阿尔茨海默病的早期，内侧颞叶激活有一个增加的阶段，随后随着疾病的进展而减少。
Objective: To use fMRI to investigate whether hippocampal and entorhinal activation during learning is altered in the earliest phase of mild cognitive impairment (MCI). Methods: Three groups of older individuals were studied: 10 cognitively intact controls, 9 individuals at the mild end of the spectrum of MCI, and 10 patients with probable Alzheimer disease ( AD). Subjects performed a face-name associative encoding task during fMRI scanning, and were tested for recognition of stimuli afterward. Data were analyzed using a functional-anatomic method in which medial temporal lobe (MTL) regions of interest were identified from each individual's structural MRI, and fMRI activation was quantified within each region. Results: Significantly greater hippocampal activation was present in the MCI group compared to controls; there were no differences between these two groups in hippocampal or entorhinal volumes. In contrast, the AD group showed hippocampal and entorhinal hypoactivation and atrophy in comparison to controls. The subjects with MCI performed similarly to controls on the fMRI recognition memory task; patients with AD exhibited poorer performance. Across all 29 subjects, greater mean entorhinal activation was found in the subgroup of 13 carriers of the APOE epsilon 4 allele than in the 16 noncarriers. Conclusions: The authors hypothesize that there is a phase of increased medial temporal lobe activation early in the course of prodromal Alzheimer disease followed by a subsequent decrease as the disease progresses.