1 Sungshin Women's University, Department of Psychology, Seoul, Korea.
2 Stanford University, Department of Psychiatry, Palo Alto, CA.
3 University of California San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA.
4 Center for Studies in Behavioral Neurobiology, PERFORM Center & Department of Exercise Science, Concordia University, Montreal, Canada.
5 Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal & Department of Neurosciences, University of Montreal, Montreal, Canada.
6 Samsung Medical Center, Department of Neurology, Sungkyunkwan University School of Medicine, Seoul, Korea.
7 Korea University Ansan Hospital, Institute of Human Genomic Study, Seoul, Korea.
8 Korea University Ansan Hospital, Department of Internal Medicine, Seoul, Korea.

Cortical Thinning and Altered Cortico-Cortical Structural Covariance of the Default Mode Network in Patients with Persistent Insomnia Symptoms.

Sleep. 2016 Jan 01;39(1):161-71

Authors: Suh S, Kim H, Dang-Vu TT, Joo E, Shin C

Abstract

STUDY OBJECTIVES: Recent studies have suggested that structural abnormalities in insomnia may be linked with alterations in the default-mode network (DMN). This study compared cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia (PI) and good sleepers (GS).

METHODS: The current study used a clinical subsample from the longitudinal community-based Korean Genome and Epidemiology Study (KoGES). Cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia symptoms (PIS; n = 57) were compared to good sleepers (GS; n = 40). All participants underwent MRI acquisition. Based on literature review, we selected cortical regions corresponding to the DMN. A seed-based structural covariance analysis measured cortical thickness correlation between each seed region of the DMN and other cortical areas. Association of cortical thickness and covariance with sleep quality and neuropsychological assessments were further assessed.

RESULTS: Compared to GS, cortical thinning was found in PIS in the anterior cingulate cortex, precentral cortex, and lateral prefrontal cortex. Decreased structural connectivity between anterior and posterior regions of the DMN was observed in the PIS group. Decreased structural covariance within the DMN was associated with higher PSQI scores. Cortical thinning in the lateral frontal lobe was related to poor performance in executive function in PIS.

CONCLUSION: Disrupted structural covariance network in PIS might reflect malfunctioning of antero-posterior disconnection of the DMN during the wake to sleep transition that is commonly found during normal sleep. The observed structural network alteration may further implicate commonly observed sustained sleep difficulties and cognitive impairment in insomnia.

PMID: 26414892 [PubMed - indexed for MEDLINE]