Department of Neurology, Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China.
Department of Neurology, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, China.
J Alzheimers Dis. 2024;101(2):577-587. doi: 10.3233/JAD-231040.
The fractional amplitude of low-frequency fluctuations (fALFFs) can detect spontaneous brain activity. However, the association between abnormal brain activity and cognitive function, amyloid protein (Aβ), and emotion in Alzheimer's disease (AD) patients remains unclear.
This study aimed to survey alterations in fALFF in different frequency bands and the relationship between abnormal brain activity, depressive mood, and cognitive function to determine the potential mechanism of AD.
We enrolled 34 AD patients and 32 healthy controls (HC). All the participants underwent resting-state magnetic resonance imaging, and slow-4 and slow-5 fALFF values were measured. Subsequently, the study determined the correlation of abnormal brain activity with mood and cognitive function scores.
AD patients revealed altered mfALFF values in the slow-5 and slow-4 bands. In the slow-4 band, the altered mfALFF regions were the right cerebellar crus I, right inferior frontal orbital gyrus (IFOG), right supramarginal gyrus, right precuneus, angular gyrus, and left middle cingulate gyrus. Elevated mfALFF values in the right IFOG were negatively associated with Montreal Cognitive Assessment scores, Boston Naming Test, and Aβ1-42 levels. The mfALFF value of the AD group was lower than the HC group in the slow-5 band, primarily within the right inferior parietal lobule and right precuneus.
Altered mfALFF values in AD patients are linked with cognitive dysfunction. Compared with HCs, Aβ1-42 levels in AD patients are related to abnormal IFOG activity. Therefore, mfALFF could be a potential biomarker of AD.
低频振幅分数（fALFF）可检测自发性脑活动。然而，阿尔茨海默病（AD）患者的异常脑活动与认知功能、淀粉样蛋白（Aβ）和情绪之间的关系尚不清楚。
本研究旨在调查不同频带的 fALFF 变化，以及异常脑活动与抑郁情绪和认知功能之间的关系，以确定 AD 的潜在机制。
我们纳入了 34 例 AD 患者和 32 例健康对照者（HC）。所有参与者均接受静息态磁共振成像检查，并测量慢 4 期和慢 5 期 fALFF 值。随后，研究确定了异常脑活动与情绪和认知功能评分的相关性。
AD 患者在慢 5 期和慢 4 期显示出 mfALFF 值的改变。在慢 4 期，改变的 mfALFF 区域为右侧小脑 crus I、右侧额下回眶部（IFOG）、右侧缘上回、右侧楔前叶、角回和左侧中央扣带回。右侧 IFOG 的 mfALFF 值升高与蒙特利尔认知评估量表、波士顿命名测验和 Aβ1-42 水平呈负相关。AD 组的 mfALFF 值在慢 5 期低于 HC 组，主要位于右侧顶下小叶和右侧楔前叶。
AD 患者的 mfALFF 值改变与认知功能障碍有关。与 HC 相比，AD 患者的 Aβ1-42 水平与异常 IFOG 活动有关。因此，mfALFF 可能是 AD 的潜在生物标志物。
