Altered dynamic amplitude of low‐frequency fluctuation in individuals at high risk for Alzheimer's disease

• Published in: The European journal of neuroscience Vol. 59; no. 9; pp. 2391 - 2402
• Main Authors: Zhu, Qin‐qin, Tian, Shui, Zhang, Ling, Ding, Hong‐yuan, Gao, Ya‐xin, Tang, Yin, Yang, Xi, Zhu, Yi, Qi, Ming
• Format: Journal Article
• Language: English
• Published: France Wiley Subscription Services, Inc 01-05-2024
• Subjects: Aged; Alzheimer Disease - diagnostic imaging; Alzheimer Disease - physiopathology; Alzheimer's disease; Brain - diagnostic imaging; Brain - physiopathology; Brain mapping; canonical correlation analysis (CCA); Cognitive ability; Cognitive Dysfunction - diagnostic imaging; Cognitive Dysfunction - physiopathology; Correlation analysis; dynamic amplitude of low‐frequency fluctuation (dALFF); Female; Frontal gyrus; Functional magnetic resonance imaging; Humans; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Middle Aged; mild cognitive impairment (MCI); Neurodegenerative diseases; Neuroimaging; Neuropsychological Tests; Neuropsychology; resting‐state functional MRI (rs‐fMRI); subjective cognitive decline (SCD); mild cognitive impairment (MCI); canonical correlation analysis (CCA); dynamic amplitude of low‐frequency fluctuation (dALFF); resting‐state functional MRI (rs‐fMRI); subjective cognitive decline (SCD)
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.16267

The brain's dynamic spontaneous neural activity is significant in supporting cognition; however, how brain dynamics go awry in subjective cognitive decline (SCD) and mild cognitive impairment (MCI) remains unclear. Thus, the current study aimed to investigate the dynamic amplitude of low‐frequency fluctuation (dALFF) alterations in patients at high risk for Alzheimer's disease and to explore its correlation with clinical cognitive assessment scales, to identify an early imaging sign for these special populations. A total of 152 participants, including 72 SCD patients, 44 MCI patients and 36 healthy controls (HCs), underwent a resting‐state functional magnetic resonance imaging and were assessed with various neuropsychological tests. The dALFF was measured using sliding‐window analysis. We employed canonical correlation analysis (CCA) to examine the bi‐multivariate correlations between neuropsychological scales and altered dALFF among multiple regions in SCD and MCI patients. Compared to those in the HC group, both the MCI and SCD groups showed higher dALFF values in the right opercular inferior frontal gyrus (voxel P < .001, cluster P < .05, correction). Moreover, the CCA models revealed that behavioural tests relevant to inattention correlated with the dALFF of the right middle frontal gyrus and right opercular inferior frontal gyrus, which are involved in frontoparietal networks (R = .43, P = .024). In conclusion, the brain dynamics of neural activity in frontal areas provide insights into the shared neural basis underlying SCD and MCI.
SCD and MCI patients performed significantly poorer than normal people on the neuropsychological scales. The neural activity of specific brain functional areas changed in the early stage of cognitive impairment. We observed a significant positive correlation between the aberrant dALFF values and clinical measurements of the three groups (R = .43, P = .024).