Suh Sooyeon, Kim Hosung, Dang-Vu Thien Thanh, Joo Eunyeon, Shin Chol
Sungshin Women's University, Department of Psychology, Seoul, Korea.
Stanford University, Department of Psychiatry, Palo Alto, CA.
Sleep. 2016 Jan 1;39(1):161-71. doi: 10.5665/sleep.5340.
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).
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.
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.
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.
近期研究表明，失眠症中的结构异常可能与默认模式网络（DMN）的改变有关。本研究比较了持续性失眠患者（PI）和睡眠良好者（GS）中与DMN相关的皮质厚度和结构连接性。
本研究使用了基于社区的韩国基因组与流行病学研究（KoGES）的临床子样本。将持续性失眠症状患者（PIS；n = 57）与睡眠良好者（GS；n = 40）中与DMN相关的皮质厚度和结构连接性进行了比较。所有参与者均接受了MRI扫描。基于文献综述，我们选择了与DMN相对应的皮质区域。基于种子的结构协方差分析测量了DMN的每个种子区域与其他皮质区域之间的皮质厚度相关性。进一步评估了皮质厚度和协方差与睡眠质量及神经心理学评估之间的关联。
与GS相比，PIS患者在前扣带回皮质、中央前皮质和外侧前额叶皮质出现皮质变薄。在PIS组中观察到DMN前后区域之间的结构连接性降低。DMN内结构协方差的降低与较高的PSQI评分相关。外侧额叶皮质变薄与PIS患者执行功能较差有关。
PIS中结构协方差网络的破坏可能反映了在从清醒到睡眠过渡期间DMN前后连接功能失调，这在正常睡眠中也很常见。观察到的结构网络改变可能进一步暗示了失眠中常见的持续睡眠困难和认知障碍。
