Fan Dongqiong, Liu Tao, Jiang Jiyang, Kochan Nicole A, Wang Yilong, Brodaty Henry, Sachdev Perminder S, Wen Wei
Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, UNSW, Sydney, New South Wales, Australia.
Brain Imaging Behav. 2022 Oct;16(5):2120-2132. doi: 10.1007/s11682-022-00682-1. Epub 2022 Jul 21.
Resting state low-frequency brain activity may aid in our understanding of the mechanisms of aging-related cognitive decline. Our purpose was to explore the characteristics of the amplitude of low-frequency fluctuations (ALFF) in different frequency bands of fMRI to better understand cognitive aging. Thirty-seven cognitively normal older individuals underwent a battery of neuropsychological tests and MRI scans at baseline and four years later. ALFF from five different frequency bands (typical band, slow-5, slow-4, slow-3, and slow-2) were calculated and analyzed. A two-way ANOVA was used to explore the interaction effects in voxel-wise whole brain ALFF of the time and frequency bands. Paired-sample t-test was used to explore within-group changes over four years. Partial correlation analysis was performed to assess associations between the altered ALFF and cognitive function. Significant interaction effects of time × frequency were distributed over inferior frontal gyrus, superior frontal gyrus, right rolandic operculum, left thalamus, and right putamen. Significant ALFF reductions in all five frequency bands were mainly found in the right hemisphere and the posterior cerebellum; whereas localization of the significantly increased ALFF were mainly found in the cerebellum at typical band, slow-5 and slow-4 bands, and left hemisphere and the cerebellum at slow-3, slow-2 bands. In addition, ALFF changes showed frequency-specific correlations with changes in cognition. These results suggest that changes of local brain activity in cognitively normal aging should be investigated in multiple frequency bands. The association between ALFF changes and cognitive function can potentially aid better understanding of the mechanisms underlying normal cognitive aging.
静息态低频脑活动可能有助于我们理解与衰老相关的认知衰退机制。我们的目的是探索功能磁共振成像（fMRI）不同频段的低频波动幅度（ALFF）特征，以更好地理解认知衰老。37名认知正常的老年人在基线时和4年后接受了一系列神经心理学测试和磁共振成像扫描。计算并分析了来自五个不同频段（典型频段、慢波5、慢波4、慢波3和慢波2）的ALFF。采用双向方差分析来探索体素水平全脑ALFF在时间和频段上的交互作用。配对样本t检验用于探索四年内组内变化。进行偏相关分析以评估ALFF改变与认知功能之间的关联。时间×频率的显著交互作用分布在额下回、额上回、右侧中央 operculum、左侧丘脑和右侧壳核。所有五个频段的显著ALFF降低主要出现在右半球和小脑后部；而显著增加的ALFF主要位于典型频段、慢波5和慢波4频段的小脑，以及慢波3、慢波2频段的左半球和小脑。此外，ALFF变化与认知变化呈现出频率特异性相关性。这些结果表明，应在多个频段研究认知正常衰老过程中局部脑活动的变化。ALFF变化与认知功能之间的关联可能有助于更好地理解正常认知衰老的潜在机制。
