Diffusion Tensor Imaging Tractography Reveals Disrupted White Matter Structural Connectivity Network in Healthy Adults with Insomnia Symptoms.

Tania A. Couto,Yu-Tao Xiang,Shun-Li Lu,Chun-Hong Liu,Chang-Le Tie,Li-Rong Tang,Heng Chen,Man-Xi He,Zhen Yuan,Feng-Mei Lu,Jing Dai,Hua-Fu Chen

doi:10.3389/fnhum.2017.00583

Abstract

Neuroimaging studies have revealed that insomnia is characterized by aberrant neuronal connectivity in specific brain regions, but the topological disruptions in the white matter (WM) structural connectivity networks remain largely unknown in insomnia. The current study uses diffusion tensor imaging (DTI) tractography to construct the WM structural networks and graph theory analysis to detect alterations of the brain structural networks. The study participants comprised 30 healthy subjects with insomnia symptoms (IS) and 62 healthy subjects without IS. Both the two groups showed small-world properties regarding their WM structural connectivity networks. By contrast, increased local efficiency and decreased global efficiency were identified in the IS group, indicating an insomnia-related shift in topology away from regular networks. In addition, the IS group exhibited disrupted nodal topological characteristics in regions involving the fronto-limbic and the default-mode systems. To our knowledge, this is the first study to explore the topological organization of WM structural network connectivity in insomnia. More importantly, the dysfunctions of large-scale brain systems including the fronto-limbic pathways, salience network and default-mode network in insomnia were identified, which provides new insights into the insomnia connectome. Topology-based brain network analysis thus could be a potential biomarker for IS.

Highlights

Insomnia is one of the most prevalent sleep disorders that is distinguished by difficulties in falling or maintaining sleep, and/or early morning awakening (Morin and Benca, 2012; Cheung et al, 2013; Morin et al, 2015; Riedner et al, 2016)
white matter (WM) Network Disruption in Insomnia Symptoms risk for developing other psychiatric disorders
Our findings indicated that the alterations of WM structural connectivity in frontal and temporal regions could influence information communication and functional integration for insomnia

Summary

Introduction

Insomnia is one of the most prevalent sleep disorders that is distinguished by difficulties in falling or maintaining sleep, and/or early morning awakening (Morin and Benca, 2012; Cheung et al, 2013; Morin et al, 2015; Riedner et al, 2016). Insomnia is associated with impaired daytime functioning and affects approximately one-third of the general population (Ohayon, 2002; Moore, 2012; Morin and Benca, 2012; Kronholm et al, 2015). WM Network Disruption in Insomnia Symptoms risk for developing other psychiatric disorders. Nearly 40% of the insomnia patients have a comorbid psychiatric disorder, and almost all of depression patients present high risk for insomnia (Taylor et al, 2005; Kaneita et al, 2006; Ohayon and Hong, 2006; Benca and Peterson, 2008; Wulff et al, 2010; Mayer et al, 2011). Well-documented neuroimaging studies have investigated insomnia, the neurobiological mechanisms underlying this psychiatric disorder remain poorly understood

Methods

Results

Conclusion