Bao Yi-Wen, Shea Yat-Fung, Chiu Patrick Ka-Chun, Kwan Joseph S K, Chan Felix Hon-Wai, Chow Wing-Sun, Chan Koon-Ho, Mak Henry Ka-Fung
Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China.
Department of Medicine, Queen Mary Hospital, Hong Kong, Hong Kong SAR, China.
Front Aging Neurosci. 2022 Jul 29;14:956222. doi: 10.3389/fnagi.2022.956222. eCollection 2022.
Patients with type 2 diabetes mellitus (T2DM) and subjective cognitive decline (SCD) have a higher risk to develop Alzheimer's Disease (AD). Resting-state-functional magnetic resonance imaging (rs-fMRI) was used to document neurological involvement in the two groups from the aspect of brain dysfunction. Accumulation of amyloid-β (Aβ) starts decades ago before the onset of clinical symptoms and may already have been associated with brain function in high-risk populations. However, this study aims to compare the patterns of fractional amplitude of low-frequency fluctuations (fALFF) maps between cognitively normal high-risk groups (SCD and T2DM) and healthy elderly and evaluate the association between regional amyloid deposition and local fALFF signals in certain cortical regions.
A total of 18 T2DM, 11 SCD, and 18 healthy elderlies were included in this study. The differences in the fALFF maps were compared between HC and high-risk groups. Regional amyloid deposition and local fALFF signals were obtained and further correlated in two high-risk groups.
Compared to HC, the altered fALFF signals of regions were shown in SCD such as the left posterior cerebellum, left putamen, and cingulate gyrus. The T2DM group illustrated altered neural activity in the superior temporal gyrus, supplementary motor area, and precentral gyrus. The correlation between fALFF signals and amyloid deposition was negative in the left anterior cingulate cortex for both groups. In the T2DM group, a positive correlation was shown in the right occipital lobe and left mesial temporal lobe.
The altered fALFF signals were demonstrated in high-risk groups compared to HC. Very early amyloid deposition in SCD and T2DM groups was observed to affect the neural activity mainly involved in the default mode network (DMN).
2型糖尿病（T2DM）患者和主观认知衰退（SCD）患者患阿尔茨海默病（AD）的风险更高。静息态功能磁共振成像（rs-fMRI）用于从脑功能障碍方面记录两组患者的神经受累情况。淀粉样β蛋白（Aβ）的积累在临床症状出现前几十年就已开始，并且可能已经与高危人群的脑功能相关。然而，本研究旨在比较认知正常的高危组（SCD和T2DM）与健康老年人之间低频振幅分数（fALFF）图谱的模式，并评估某些皮质区域的局部淀粉样蛋白沉积与局部fALFF信号之间的关联。
本研究共纳入18例T2DM患者、11例SCD患者和18例健康老年人。比较了健康对照组（HC）与高危组之间fALFF图谱的差异。在两个高危组中获取了区域淀粉样蛋白沉积和局部fALFF信号，并进一步进行相关性分析。
与HC相比，SCD组部分区域的fALFF信号发生改变，如左侧小脑后叶、左侧壳核和扣带回。T2DM组在颞上回、辅助运动区和中央前回显示神经活动改变。两组在左侧前扣带回皮质中，fALFF信号与淀粉样蛋白沉积之间均呈负相关。在T2DM组中，右侧枕叶和左侧颞叶内侧呈正相关。
与HC相比，高危组的fALFF信号发生改变。观察到SCD组和T2DM组中非常早期的淀粉样蛋白沉积会影响主要参与默认模式网络（DMN）的神经活动。
