Subsystem mechanisms of default mode network underlying white matter hyperintensity‐related cognitive impairment
Dan Yang, Jiangnan Li, Zhi-Hong Ke, Ruo-Meng Qin, Cheng-Lu Mao, Li-Li Huang, Yuting Mo, Zhe-Qi Hu, Wei-Ping Lv, Ya-Nan Huang, Bing-Feng Zhang, Yun Xu
Human Brain Mapping February 1, 2023 DOI: 10.1002/hbm.26215 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cross-sectional study Peer reviewed |
|---|---|
| Sample size | 308 |
| Population | Patients with white matter hyperintensity (n = 206), divided into mild cognitive impairment and normal cognition groups, plus healthy controls (n = 102) |
| Topics | Default mode network |
| Key findings | Among people with white matter hyperintensity, mild cognitive impairment was associated with lower static functional connectivity within and between default mode network subsystems, and these reductions correlated with information processing speed. Higher dynamic connectivity within the medial temporal lobe subsystem mediated the relationship between WMH and memory span (indirect effect −0.2251, 95% CI [−0.6295, −0.0267]). Impaired participants also showed longer dwell time and higher reoccurrence in a sparsely connected dynamic state, which was negatively associated with processing speed. |
Abstract
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.
Comparable studies
Other cross-sectional and survey studies on default mode network, most cited first.