Brain Structural Network Compensation Is Associated With Cognitive Impairment and Alzheimer’s Disease Pathology

Abstract

BackgroundStructural network alterations in Alzheimer’s disease (AD) are related to worse cognitive impairment. The aim of this study was to quantify the alterations in gray matter associated with impaired cognition and their pathological biomarkers in AD-spectrum patients.MethodsWe extracted gray matter networks from 3D-T1 magnetic resonance imaging scans, and a graph theory analysis was used to explore alterations in the network metrics in 34 healthy controls, 70 mild cognitive impairment (MCI) patients, and 40 AD patients. Spearman correlation analysis was computed to investigate the relationships among network properties, neuropsychological performance, and cerebrospinal fluid pathological biomarkers (i.e., Aβ, t-tau, and p-tau) in these subjects.ResultsAD-spectrum individuals demonstrated higher nodal properties and edge properties associated with impaired memory function, and lower amyloid-β or higher tau levels than the controls. Furthermore, these compensations at the brain regional level in AD-spectrum patients were mainly in the medial temporal lobe; however, the compensation at the whole-brain network level gradually extended from the frontal lobe to become widely distributed throughout the cortex with the progression of AD.ConclusionThe findings provide insight into the alterations in the gray matter network related to impaired cognition and pathological biomarkers in the progression of AD. The possibility of compensation was detected in the structural networks in AD-spectrum patients; the compensatory patterns at regional and whole-brain levels were different and the clinical significance was highlighted.

Persistence of information flow: A multiscale characterization of human brain

“…Reuter-Lorenz & Cappell, 2008;Sheng et al, 2021;Yao et al, 2010). Our results are in agreement with the aforementioned studies, since they show a significant increase in persistence of information flows at -12-Downloaded from http://direct.mit.edu/netn/article-pdf/doi/10.1162/netn_a_00203/1926667/netn_a_00203.pdf by guest on 14 July 2021…”

Cognitive resilience depends on white matter connectivity: The Maastricht Study

“…43 In addition to these findings associating cognition and white matter connectivity, Lopez-Soley et al demonstrated in 181 participants that structural brain connectivity is associated with traditional proxy variables for reserve, as measured by a cognitive reserve questionnaire. 44 Together, these findings suggest that interventions aimed at increasing neural connections through brain-stimulating activities, education, and lifelong learning might provide an opportunity for improved resilience 1 .…”

Aberrant Topological Patterns of Structural Covariance Networks in Cognitively Normal Elderly Adults With Mild Behavioral Impairment

“…A recent study using graph theory methods demonstrated that distinct changes in functional connectivity at the global and local network levels were associated with different NPS clusters in patients with AD ( Chang et al, 2020 ). Moreover, another recent study reported that alterations in structural network measures in AD-spectrum patients were associated with impaired memory function and pathological biomarkers of AD ( Sheng et al, 2021 ). Structural covariance network analysis using graph theory methods may offer novel insights into the neural mechanisms underlying MBI at the network level.…”