Journal Article

Subsystem mechanisms of default mode network underlying white matter hyperintensity‐related cognitive impairment

Li, Jiangnan, Mao, ChengLu, Huang, Yanan, Yang, Dan, Mo, Yuting, Lv, Weiping, Hu, Zheqi, Zhang, Bing, Xu, Yun, Ke, Zhihong, Huang, Lili, Qin, Ruomeng

2023

Overview

Functional changes of default mode network (DMN) have been proven to be closely associated with white matter hyperintensity (WMH) related cognitive impairment (CI). However, subsystem mechanisms of DMN underlying WMH‐related CI remain unclear. The present study recruited WMH patients (n = 206) with mild CI and normal cognition, as well as healthy controls (HC, n = 102). Static/dynamic functional connectivity (FC) of the DMN's three subsystems were calculated using resting‐state functional MRI. K‐means clustering analyses were performed to extract distinct dynamic connectivity states. Compared with the WMH‐NC group, the WMH‐MCI group displayed lower static FC within medial temporal lobe (MTL) and core subsystem, between core‐MTL subsystem, as well as between core and dorsal medial prefrontal cortex subsystem. All these static alterations were positively associated with information processing speed (IPS). Regarding dynamic FC, the WMH‐MCI group exhibited higher dynamic FC within MTL subsystem than the HC and WMH‐NC groups. Altered dynamic FC within MTL subsystem mediated the relationship between WMH and memory span (indirect effect: −0.2251, 95% confidence interval [−0.6295, −0.0267]). Additionally, dynamic FCs of DMN subsystems could be clustered into two recurring states. For dynamic FCs within MTL subsystem, WMH‐MCI subjects exhibited longer mean dwell time (MDT) and higher reoccurrence fraction (RF) in a sparsely connected state (State 2). Altered MDT and RF in State 2 were negatively associated with IPS. Taken together, these findings indicated static/dynamic FC of DMN subsystems can provide relevant information on cognitive decline from different aspects, which provides a comprehensive view of subsystem mechanisms of DMN underlying WMH‐related CI. Static/dynamic FCs from DMN subsystems in WMH‐MCI subjects were significantly changed. These alterations helped facilitate the progression of WMH‐related CI. Altered dynamic FC within MTL subsystem was shown to be a mediation framework between WMH and memory span. Static and dynamic FC in DMN subsystems can provide relevant information on WMH‐related CI from different aspects.

• Publisher: John Wiley & Sons, Inc
• Subject: Alzheimer's disease / Brain - diagnostic imaging / Chen, Huang / Cluster analysis / Clustering / Cognition / Cognition & reasoning / Cognitive ability / Cognitive Dysfunction / Cognitive impairment / Data processing / default mode network / Default Mode Network - diagnostic imaging / Dementia / Dwell time / Executive function / Functional magnetic resonance imaging / Humans / Illiteracy / Impairment / Information processing / Investigations / Magnetic Resonance Imaging / Memory / Neuropsychology / Prefrontal cortex / resting‐state functional MRI / Substantia alba / subsystem / Subsystems / Temporal lobe / Vector quantization / White Matter - diagnostic imaging / white matter hyperintensity