Functional connectivity of paired default mode network subregions in primary insomnia

Neuropsychiatric Disease and Treatment Dovepress open access to scientific and medical research Original Research Neuropsychiatric Disease and Treatment downloaded from https://www.dovepress.com/ by 37.59.46.207 on 12-Jul-2018 For personal use only. Open Access Full Text Article Functional connectivity of paired default mode network subregions in primary insomnia This article was published in the following Dove Press journal: Neuropsychiatric Disease and Treatment 16 December 2015 Number of times this article has been viewed Xiao Nie 1,* Yi Shao 2,* Si-yu Liu 3 Hai-jun Li 1 Ai-lan Wan 4 Si Nie 1 De-chang Peng 1 Xi-jian Dai 1,5 Department of Radiology, The First Affiliated Hospital of Nanchang University, Nangchang, Jiangxi, People’s Republic of China; 2Department of Ophthalmology,The First Affiliated Hospital of Nanchang University, Nangchang, Jiangxi, People’s Republic of China; 3Medical College of Nanchang University, Nangchang, Jiangxi, People’s Republic of China; 4 Department of Psychosomatic Medicine, The First Affiliated Hospital of Nanchang University, Nangchang, Jiangxi, People’s Republic of China; 5 Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People’s Republic of China 1 *These authors contributed equally to this work Correspondence: Xi-jian Dai; De-chang Peng Department of Radiology, The First Affiliated Hospital of Nanchang University, No 17, Yongwai Zheng Street, Donghu District, Nanchang 330006, Jiangxi, People’s Republic of China Tel +86 791 8869 4457 Email ; Introduction Primary insomnia (PI), one of the most prevalent health complaints worldwide, characterized by difficulties in initiating or maintaining sleep, or non-restorative sleep in the absence of any related medical or psychiatric condition, has been associated with cognitive deficits, including the attention, memory, decision making, and executive function.1,2 In spite of a recent increase in the neuroimaging research into the PI, it has yet to establish a consistent conclusion about its neuropathology,3 especially the structural studies of the brain volume alterations.4–10 On the functional imaging aspects, the studies are too few and diverse in methodology to yield any general conclusions. Altena et al concluded that patients with PI (PIs) are cognitively compromised, as shown by hypoactivation in the left prefrontal cortex and left inferior frontal gyrus during task performance.11 Drummond et al12 further investigated the cognitive impairments in the PIs, they found less activation in the thalamus, fronto-parietal cortex, and cerebellum, and these brain regions normally associated with the working memory and the motor and visual processing during the cognitive tasks compared with the good sleepers (GSs).12 Previous study found that the aberrant activation of the insula, which 3085 submit your manuscript | www.dovepress.com Neuropsychiatric Disease and Treatment 2015:11 3085–3093 Dovepress © 2015 Nie et al. This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution – Non Commercial (unported, v3.0) License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php http://dx.doi.org/10.2147/NDT.S95224 Powered by TCPDF (www.tcpdf.org) Objective: The aim of this study is to explore the resting-state functional connectivity (FC) differences between the paired default mode network (DMN) subregions in patients with primary insomnia (PIs). Methods: Forty-two PIs and forty-two age- and sex-matched good sleepers (GSs) were recruited. All subjects underwent the resting-state functional magnetic resonance imaging scans. The seed-based region-to-region FC method was used to evaluate the abnormal connectivity within the DMN subregions between the PIs and the GSs. Pearson correlation analysis was used to investigate the relationships between the abnormal FC strength within the paired DMN subregions and the clinical features in PIs. Results: Compared with the GSs, the PIs showed higher Pittsburgh Sleep Quality Index score, Hamilton Anxiety Rating Scale score, Hamilton Depression Rating Scale score, Self-Rating Depression Scale score, Self Rating Anxiety Scale score, Self-Rating Scale of Sleep score, and Profile of Mood States score (P,0.001). Compared with the GSs, the PIs showed significant decreased region-to-region FC between the medial prefrontal cortex and the right medial temporal lobe (t=-2.275, P=0.026), and between the left medial temporal lobe and the left inferior parietal cortices (t=-3.32, P=0.001). The abnormal FC strengths between the DMN subregions did not correlate with the clinical features. Conclusion: PIs showed disrupted FC within the DMN subregions. Keywords: insomnia, functional connectivity, default mode network, functional magnetic resonance imaging, resting-state, blood oxygenation level dependent Dovepress Neuropsychiatric Disease and Treatment downloaded from https://www.dovepress.com/ by 37.59.46.207 on 12-Jul-2018 For personal use only. Nie et al integrates temporal and bodily states, in arousal networks may underlie the misperception of sleep quality and subjective distress in insomnia.13 Our previous study found that both female and male PIs showed different regional homogeneity in the temporal cortex, cingulate cortex, cerebellum, and frontal gyrus.2 Although these studies provided insights into the neural events occurring in the PIs, there was far less evidence for the neuromechanism changes. It is proposed that the resting-state functional magnetic resonance imaging (rs-fMRI), one of the hot areas in neuroimaging and one that is suitable for the mechanism research of central nervous system, can detect the spontaneous neuronal activity of the human brain and provide new insights into the pathophysiology of disease, because of its advantages in not requiring exposure to radioactive tracers, accurate positioning, and ease of combining functional imaging with structural imaging. Functional connectivity (FC) that is an important part of the rs-fMRI has been widely used as a technique for unbiased analysis of the brain’s functional connectome.14,15 Previous studies demonstrated that the PIs relative to the GSs showed reduced FC between the left orbitofrontal cortex and the left caudate head,16 and between the parietal lobe and the frontal lobe.17 Huang et al found decreased FC mainly between the amygdala and the insula, striatum, and thalamus, and increased FC mainly between the amygdala and the premotor cortex and sensorimotor cortex in the PIs compared with (...truncated)