Relationship between Amyloid-β Deposition and the Coupling between Structural and Functional Brain Networks in Patients with Mild Cognitive Impairment and Alzheimer’s Disease

Abstract

Previous studies have demonstrated that the accumulation of amyloid-β (Aβ) pathologies has distinctive stage-specific effects on the structural and functional brain networks along the Alzheimer’s disease (AD) continuum. A more comprehensive account of both types of brain network may provide a better characterization of the stage-specific effects of Aβ pathologies. A potential candidate for this joint characterization is the coupling between the structural and functional brain networks (SC-FC coupling). We therefore investigated the effect of Aβ accumulation on global SC-FC coupling in patients with mild cognitive impairment (MCI), AD, and healthy controls. Patients with MCI were dichotomized according to their level of Aβ pathology seen in 18F-flutemetamol PET-CT scans—namely, Aβ-negative and Aβ-positive. Our results show that there was no difference in global SC-FC coupling between different cohorts. During the prodromal AD stage, there was a significant negative correlation between the level of Aβ pathology and the global SC-FC coupling of MCI patients with positive Aβ, but no significant correlation for MCI patients with negative Aβ. During the AD dementia stage, the correlation between Aβ pathology and global SC-FC coupling in patients with AD was positive. Our results suggest that Aβ pathology has distinctive stage-specific effects on global coupling between the structural and functional brain networks along the AD continuum.

Altered structural-functional coupling in Parkinson’s disease

“…The associations between SC-FC network coupling and pathological markers in neurodegenerative diseases remain unclear. In MCI and AD patients, SC-FC network coupling is correlated with Aβ deposition (27). We found GM-Fun network coupling was negatively correlated with the levels of α-synuclein, tau, and p-tau in CSF.…”

“…Importantly, SC-FC coupling was found to be associated with clinical manifestations of diseases (8, 13, 24). In addition, SC-FC coupling was correlated with pathological biomarkers in neurodegenerative disease (27). For example, in MCI patients with positive β-amyloid (Aβ) deposition, the level of Aβ pathology and SC-FC coupling was negatively correlated (27), while the correlation between Aβ deposition and SC-FC coupling was positive during AD dementia stage (27).…”

Traditional Chinese medicine promotes the control and treatment of dementia

“…Soluble amyloid-β plays a beneficial role in memory and synaptic transmissions among cells ( Lee et al, 2021 ). However, amyloid-β aggregations form insoluble protein fibers and promote amyloid plaque depositions, leading to cell death ( Zhang et al, 2021 ).…”

Advanced Diffusion MRI for prediction of Stroke Recovery

“…52,53 It is posited to represent the presence of structural constraints on functional connections, whereby higher coupling indicates convergence of the patterns of structural and functional connections. 53 It has been shown to be altered due to stroke, 54,55 age-related changes, 52,56 dementia, 57,58 Parkinson's disease, 59 multiple sclerosis, 60 Schizophrenia, 61 and epilepsy. 51 Apart from LNM and FBM, modeling of the microstructural properties of brain tissues may also potentially provide alternative biomarkers of stroke recovery, albeit often at the cost of collecting more data with high b-values and diffusion encoding directions.…”