Chen Li-Ting, Fan Xiao-Le, Li Hai-Jun, Nie Si, Gong Hong-Han, Zhang Wei, Zeng Xian-Jun, Long Ping, Peng De-Chang
Department of Radiology.
Department of General Surgery.
Neuropsychiatr Dis Treat. 2017 Jun 8;13:1471-1482. doi: 10.2147/NDT.S135426. eCollection 2017.
Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder that can damage cognitive function. However, the functional network organization remains poorly understood. The aim of this study was to investigate the topological properties of OSA patients using a graph theoretical analysis.
A total of 30 male patients with untreated severe OSA and 25 male education- and age-matched good sleepers (GSs) underwent functional magnetic resonance imaging (MRI) examinations. Clinical and cognitive evaluations were conducted by an experienced psychologist. GRETNA (a toolbox for topological analysis of imaging connectomics) was used to construct the brain functional network and calculate the small-world properties (γ, λ, σ, E, and E). Relationships between these small-world properties and clinical and neuropsychological assessments were investigated in OSA patients.
The networks of both OSA patients and GSs exhibited efficient small-world topology over the sparsity range of 0.05-0.40. Compared with GSs, the OSA group had significantly decreased γ, but significantly increased λ and σ. The OSA group's brain network showed significantly decreased E (<0.05) over the sparsity range of 0.09-0.15, but significantly increased E over the sparsity range of 0.23-0.40. In OSA patients, γ was significantly negatively correlated with apnea-hypopnea index (AHI; =-0.326, =0.015) and Epworth Sleepiness Scale (ESS; =-0.274, =0.043), λ was significantly positively correlated with AHI (=0.373, =0.005) and ESS (=0.269, =0.047), and σ was significantly negatively correlated with AHI (=-0.363, =0.007) and ESS (=-0.295, =0.029).
Our results suggest that the high degree of local integration and integrity of the brain connections in OSA patients may be disrupted. The topological alterations of small-world properties may be the mechanism of cognitive impairment in OSA patients. In addition, σ, γ, and λ could be used as a quantitative physiological index for auxiliary clinical diagnoses.
阻塞性睡眠呼吸暂停（OSA）是一种常见的与睡眠相关的呼吸障碍，可损害认知功能。然而，其功能网络组织仍知之甚少。本研究旨在通过图论分析研究OSA患者的拓扑特性。
共有30名未经治疗的重度OSA男性患者和25名年龄及受教育程度匹配的睡眠良好者（GSs）接受了功能磁共振成像（MRI）检查。由经验丰富的心理学家进行临床和认知评估。使用GRETNA（一种用于成像连接组学拓扑分析的工具箱）构建脑功能网络并计算小世界特性（γ、λ、σ、E和E）。研究了OSA患者这些小世界特性与临床和神经心理学评估之间的关系。
OSA患者和GSs的网络在0.05 - 0.40的稀疏度范围内均表现出有效的小世界拓扑结构。与GSs相比，OSA组的γ显著降低，但λ和σ显著增加。OSA组的脑网络在0.09 - 0.15稀疏度范围内E显著降低（<0.05），但在0.23 - 0.40稀疏度范围内E显著增加。在OSA患者中，γ与呼吸暂停低通气指数（AHI；=-0.326，=0.015）和爱泼沃斯嗜睡量表（ESS；=-0.274，=0.043）显著负相关，λ与AHI（=0.373，=0.005）和ESS（=0.269，=0.047）显著正相关，σ与AHI（=-0.363，=0.007）和ESS（=-0.295，=0.029）显著负相关。
我们的结果表明，OSA患者脑连接的高度局部整合和完整性可能受到破坏。小世界特性的拓扑改变可能是OSA患者认知障碍的机制。此外，σ、γ和λ可作为辅助临床诊断的定量生理指标。
