Rest but busy: Aberrant resting-state functional connectivity of triple network model in insomnia.

Xiaojuan Dong,Keren Liao,Hua Hu,Dong Gao,Haixia Qin,Taoyu Wu,Fei Cheng,Xu Lei

doi:10.1002/brb3.876

Abstract

IntroductionOne classical hypothesis among many models to explain the etiology and maintenance of insomnia disorder (ID) is hyperarousal. Aberrant functional connectivity among resting‐state large‐scale brain networks may be the underlying neurological mechanisms of this hypothesis. The aim of current study was to investigate the functional network connectivity (FNC) among large‐scale brain networks in patients with insomnia disorder (ID) during resting state.MethodsIn the present study, the resting‐state fMRI was used to evaluate whether patients with ID showed aberrant FNC among dorsal attention network (DAN), frontoparietal control network (FPC), anterior default mode network (aDMN), and posterior default mode network (pDMN) compared with healthy good sleepers (HGSs). The Pearson's correlation analysis was employed to explore whether the abnormal FNC observed in patients with ID was associated with sleep parameters, cognitive and emotional scores, and behavioral performance assessed by questionnaires and tasks.ResultsPatients with ID had worse subjective thought control ability measured by Thought Control Ability Questionnaire (TCAQ) and more negative affect than HGSs. Intriguingly, relative to HGSs, patients with ID showed a significant increase in FNC between DAN and FPC, but a significant decrease in FNC between aDMN and pDMN. Exploratory analysis in patients with ID revealed a significantly positive correlation between the DAN‐FPC FNC and reaction time (RT) of psychomotor vigilance task (PVT).ConclusionThe current study demonstrated that even during the resting state, the task‐activated and task‐deactivated large‐scale brain networks in insomniacs may still maintain a hyperarousal state, looking quite similar to the pattern in a task condition with external stimuli. Those results support the hyperarousal model of insomnia.

Highlights

One classical hypothesis among many models to explain the etiology and maintenance of insomnia disorder (ID) is hyperarousal
The current study investigated the aberrant temporal relationship among the resting-state brain functional networks in patients with ID
Patients with ID exhibited a significant increase in dorsal attention network (DAN)-frontoparietal control network (FPC) functional connectivity

Summary

| INTRODUCTION

Insomnia disorder (ID) is a prevalent clinical condition characterized by difficulty in falling asleep at bedtime, frequent awakenings in the middle of the night, waking up too early in the morning, and dissatisfaction with sleep duration and quality, often accompanying diminished memory, attention, academic performance, and deteriorated emotions including fatigue, decreased mood, irritability, or general malaise (Morin & Benca, 2012; Morin et al, 2015; Sateia, 2014). Insomniacs showed a significantly decreased functional connectivity between the medial prefrontal cortex (mPFC) and the right medial temporal lobe (rMTL), and between the left MTL and the left inferior parietal cortices (Dai et al, 2015), while another study suggested stronger functional connectivity between retrosplenial cortex/hippocampus and various nodes of DMN in patients with ID (Regen et al, 2016). It appeared to alter the functional connectivity between parietal and prefrontal cortices in insomniacs, inducing memory retrieval deficits (Li et al, 2014). We selected the anterior default mode network (aDMN) and posterior default mode network (pDMN) as the task-deactivated networks, and dorsal attention network (DAN) and frontoparietal control network (FPC) as the task-activated networks to evaluate the temporal relationship among them, that is, the functional network connectivity (FNC) (Jafri, Pearlson, Stevens, & Calhoun, 2008); (2) whether significant correlation was found in patients with ID between abnormal FNC with sleep parameters, cognitive and emotional scores, and reaction time (RT) of psychomotor vigilance task (PVT)

| Participants

Findings

| DISCUSSION