Insomnia Disorder and Brain’s Default-Mode Network

Abstract

The default-mode network (DMN) is presumed to be correlated with self-referential information processing, and it appears to be altered or unbalanced in insomnia. A growing body of evidence suggests the lack of deactivation of brain regions comprising the DMN when insomnia patients are at rest. Moreover, core areas of the DMN demonstrate greater activation in insomnia patients when compared to healthy controls in self-referential related tasks. Despite the few studies on the topic, underpinning the correlation between abnormal DMN activity and ID deserves further attention in the future. Implications for therapeutics are briefly outlined.

Objective and subjective measures of prior sleep–wake behavior predict functional connectivity in the default mode network during NREM sleep

“…Of these, only the ISI was found to be predictive of differences in DMN FC, specifically FC of the RTL to all regions within the DMN was reduced in subjects reporting a greater level of insomnia symptomatology. Although none of our participants explicitly experienced insomnia itself, our observation is consistent with the theory that DMN FC could be linked with insomnia more than other brain networks (Marques, Gomes, Caetano, & Castelo-Branco, 2018).…”

Sleep/Wake Regularity Associated with Default Mode Network Structure among Healthy Adolescents and Young Adults

“…The current findings dovetail with a growing literature suggesting that sleep and DMN connectivity are closely linked. Specifically, this study suggests that in addition to sleep deprivation 4,6 , quality 36 , and disorders, such as insomnia and OSA 3,5,20 , greater sleep/wake irregularity may impact network structure within the DMN. Previously, reduced DMN functional connectivity has been proposed as a neural substrate of the behavioral correlates for sleep deprivation 4 and/or may reflect a "local sleep" in which a portion of the brain enters a sleep state when an individual is otherwise conscious 7,55 .…”

“…In the last decade, there has been growing interest in the impact of sleep on the spontaneous neuronal activity of the brain as assessed by resting-state functional connectivity magnetic resonance imaging 2 . In particular, of the six identified resting-state networks, particular attention has been paid to the role sleep may play in the functional connectivity of the default mode network (DMN) 3 -and to a lesser extent, its anticorrelated network (ACN) -given the strong associations of both sleep and these specific networks to cognitive function [4][5][6][7][8] .…”

“…Specifically, prior work has shown that sleep deprivation results in reduced functional connectivity of the DMN and the DMN-ACN anticorrelation during both rest and task performance and among both young and older adults 4,6 . In addition, reduced DMN connectivity has been observed among young and elderly adults who report high levels of daytime sleepiness 7 as well as individuals diagnosed with insomnia and obstructive sleep apnea (OSA) disorders 3,5,20 . Taken together, these studies suggest a close association between sleep and DMN connectivity and highlight a potential neural mechanism by which poor sleep results in cognitive deficits.…”

The Instant Spontaneous Neuronal Activity Modulation of Transcutaneous Auricular Vagus Nerve Stimulation on Patients With Primary Insomnia

“…When an individual is awake and yet not actively engaged in an attention-demanding task, a default state of brain activity exists that involves the medial prefrontal cortex and the posterior cingulate and precuneus (Raichle et al, 2001). The precuneus is mainly involved in episodic memory, emotional regulation, and introspection (Marques et al, 2018). In addition, the DMN is associated with the hyperarousal of brain regions (Marques et al, 2015).…”