Background: Longitudinal changes of brain metabolites during a functional stimulation are unknown in amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD) subjects.

Objective: This study was to evaluate the longitudinal changes of brain metabolites using proton magnetic resonance spectroscopy (1H MRS) in response to treatment during a memory task in the subjects of cognitive normal (CN), aMCI, and AD.

Methods: We acquired functional magnetic resonance spectroscopy (fMRS) data from 28 CN elderly, 16 aMCI and 12 AD subjects during a face-name association task. We measured fMRS metabolite ratios over 24 months in the 8-month apart, determined the temporal changes of the metabolites, and evaluated the differences among the three groups under the three different conditions (base, novel, repeat).

Results: The results of comparisons for the three subject groups and the three-time points showed that tNAA/tCho and tCr/tCho were statistically significant among the three subject groups in any of the three conditions. The dynamic temporal change measurements for the metabolites for each condition showed that Glx/tCho and Glu/tCho levels at the third visit increased significantly compared with in the first visit in the novel condition in the AD group.

Conclusion: We found declines in tNAA/tCho and tCr/tCho in the aMCI and AD subjects with increasing disease severity, being highest in CN and lowest in AD. The Glx/tCho level increased temporally in the AD subjects after they took an acetylcholine esterase inhibitor. Therefore, Glx may be suitable to demonstrate functional recovery after treatment.

背景：在健忘性轻度认知障碍 (aMCI) 和阿尔茨海默病 (AD) 受试者中，功能刺激期间脑代谢物的纵向变化是未知的。

目的：本研究旨在使用质子磁共振波谱 (1H MRS) 评估认知正常 (CN)、aMCI 和 AD 受试者在记忆任务期间响应治疗的脑代谢物的纵向变化。

方法：我们在面部姓名关联任务中从 28 名 CN 老年人、16 名 aMCI 和 12 名 AD 受试者获得了功能磁共振波谱 (fMRS) 数据。我们在相隔 8 个月的时间内测量了 24 个月的 fMRS 代谢物比率，确定了代谢物的时间变化，并评估了在三种不同条件下（基础、新颖、重复）下三组之间的差异。

结果：三个受试者组和三个时间点的比较结果表明，tNAA/tCho 和 tCr/tCho 在三个受试者组中在三个条件中的任何一个中均具有统计学意义。每种条件下代谢物的动态时间变化测量表明，在 AD 组的新条件下，第三次访问时的 Glx/tCho 和 Glu/tCho 水平与第一次访问时相比显着增加。

结论：我们发现 aMCI 和 AD 受试者的 tNAA/tCho 和 tCr/tCho 随着疾病严重程度的增加而下降，在 CN 中最高，在 AD 中最低。服用乙酰胆碱酯酶抑制剂后，AD 受试者的 Glx/tCho 水平暂时增加。因此，Glx 可能适合证明治疗后的功能恢复。