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BioMed Research International
Volume 2015, Article ID 817595, 23 pages
http://dx.doi.org/10.1155/2015/817595
Research Article

Cortical Structural Connectivity Alterations in Primary Insomnia: Insights from MRI-Based Morphometric Correlation Analysis

1McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
2Department of Radiology, Henan Provincial People’s Hospital, People’s Hospital of Zhengzhou University, Henan 450003, China
3Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada H4H 1R3
4Department of Neurology, Henan Provincial People’s Hospital, People’s Hospital of Zhengzhou University, Henan 450003, China
5MRI Division, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, China

Received 23 March 2015; Revised 25 May 2015; Accepted 28 May 2015

Academic Editor: Enzo Terreno

Copyright © 2015 Lu Zhao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The etiology and maintenance of insomnia are proposed to be associated with increased cognitive and physiological arousal caused by acute stressors and associated cognitive rumination. A core feature of such hyperarousal theory of insomnia involves increased sensory processing that interferes with the onset and maintenance of sleep. In this work, we collected structural magnetic resonance imaging data from 35 patients with primary insomnia and 35 normal sleepers and applied structural covariance analysis to investigate whether insomnia is associated with disruptions in structural brain networks centered at the sensory regions (primary visual, primary auditory, and olfactory cortex). As expected, insomnia patients showed increased structural covariance in cortical thickness between sensory and motor regions. We also observed trends of increased covariance between sensory regions and the default-mode network, and the salience network regions, and trends of decreased covariance between sensory regions and the frontoparietal working memory network regions, in insomnia patients. The observed changes in structural covariance tended to correlated with poor sleep quality. Our findings support previous functional neuroimaging studies and provide novel insights into variations in brain network configuration that may be involved in the pathophysiology of insomnia.