Comparison of memory fMRI response among normal, MCI, and Alzheimer's patients
Comparison of memory fMRI response among normal, MCI, and Alzheimer's patients
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DOI：
10.1212/01.wnl.0000079052.01016.78
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发表时间：
2003-08-26
期刊：
影响因子：
9.9
通讯作者：
Jack, CR
中科院分区：
文献类型：
--
作者：
Machulda, MM;Ward, HA;Jack, CR
目的：确定功能性磁共振成像（fMRI）记忆编码任务是否能区分认知正常的老年人、轻度认知障碍（MCI）患者以及早期阿尔茨海默病（AD）患者。
方法：对29名受试者（11名正常，9名MCI，9名AD）进行fMRI记忆编码任务研究。还进行了一项被动感觉任务，以评估fMRI反应性方面潜在的组间差异。研究了记忆任务中内侧颞叶的激活以及感觉任务中解剖学上的中央前回区域的激活。使用受试者工作特征（ROC）分析进行组间比较。ROC方法对人为的假阳性“激活”提供了严格控制。在fMRI研究之后，对受试者进行记忆编码任务刺激的回忆和再认测试。
结果：正常受试者内侧颞叶的激活程度大于MCI患者和AD患者（p = 0.03和p = 0.04）。AD患者和MCI患者在正常的fMRI记忆表现方面没有差异。fMRI记忆激活（ROC曲线下面积）与fMRI之后的再认和自由回忆表现之间存在关联。三组在感觉任务上没有差异。
结论：MCI患者和AD患者在记忆任务中内侧颞叶的激活比正常受试者少，但在感觉任务中激活与正常受试者相似。这些发现表明，内侧颞叶激活减少可能是由于AD的神经退行性变化导致的边缘系统功能障碍的一个特定标志物。此外，fMRI对检测疾病前驱期（MCI阶段）的变化足够敏感。
Objective: To determine whether an fMRI memory encoding task distinguishes among cognitively normal elderly individuals, patients with mild cognitive impairment (MCI), and patients with early Alzheimer's disease ( AD). Methods: Twenty-nine subjects (11 normal, 9 MCI, 9 AD) were studied with an fMRI memory encoding task. A passive sensory task was also performed to assess potential intergroup differences in fMRI responsiveness. Activation in the medial temporal lobe for the memory task and in the anatomic rolandic area for the sensory task was studied. Intergroup comparisons were performed using receiver operating characteristic (ROC) analyses. The ROC method provides rigorous control of artifactual false-positive "activation." Subjects were tested for recall and recognition of the encoding task stimuli following the fMRI study. Results: Medial temporal lobe activation was greater in subjects than MCI and AD patients (p = 0.03 and p = 0.04). There was no difference between AD and MCI patients in normal fMRI memory performance. There was an association between fMRI memory activation ( area under the ROC curve) and post-fMRI performance on recognition and free recall. There was no difference among the three groups on the sensory task. Conclusions: MCI and AD patients had less medial temporal lobe activation on the memory task than the normal subjects but similar activation as normal subjects on the sensory task. These findings suggest decreased medial temporal activation may be a specific marker of limbic dysfunction due to the neurodegenerative changes of AD. In addition, fMRI is sufficiently sensitive to detect changes in the prodromal, MCI, phase of the disease.