阻塞性睡眠呼吸暂停患者默认网络功能连接及拓扑属性异常

目的 观察阻塞性睡眠呼吸暂停（OSA）患者脑默认网络（DMN）内部各亚区的功能连接（FC）及拓扑属性的异常改变。方法 采集40例男性重度OSA患者（OSA组）和43名睡眠正常的男性志愿者（对照组）的静息态fMRI数据，以20个DMN亚区为种子点构建DMN的FC网络，获得OSA患者DMN各亚区间FC异常的脑区。计算拓扑属性参数小世界指数（σ）、网络全局效率（E_glob）和网络局部效率（E_loc），并评估与临床资料的相关性。结果 OSA组和对照组DMN均存在小世界属性。与对照组比较，OSA组前—后DMN、后DMN内部FC减低（P均<0.05），E_loc减低（P=0.02）。OSA组DMN异常的FC与E_glob值（r=-0.736，P<0.001）、蒙特利尔认知（MoCA）量表评分（r=-0.453，P=0.006）呈负相关。结论 OSA患者DMN内部各亚区功能连接受损，且DMN拓扑属性异常改变，可能是其认知、记忆等功能障碍的神经影像学机制。

Abnormality of functional connectivity and topological properties of default mode network in patients with obstructive sleep apnea

Objective To explore the disrupted functional connectivity (FC) of the sub-regions and topological reorganization of the default mode network (DMN) in patients with obstructive sleep apnea (OSA). Methods Resting-state fMRI data were obtained from 40 male patients with severe OSA (OSA group) and 43 male healthy controls (control group). Twenty sub-regions of DMN were specifically selected as ROIs, and functional connectivity (FC) of DMN architecture was constructed. Then the abnormal FC of sub-regions in patients with OSA was observed. The topological properties of DMN were characterized. The topological attribute parameters, such as small-world index (σ), network global efficiency (E_glob) and network local efficiency (E_loc) were calculated, and their relationship with clinical data were evaluated. Results DMN exhibited small-world topology in both OSA and control groups. Compared with control group, OSA group showed significantly decreased FC in the anterior-posterior DMN and posterior DMN (all P<0.05), and decreased E_loc (P=0.02). Abnormal DMN FC was negatively correlated to E_glob (r=-0.736, P<0.001) and MoCA scores (r=-0.453, P=0.006) in OSA group. Conclusion OSA patients showed disrupted FC within DMN sub-regions and topological properties of DMN, which might be the neuroimaging mechanism of cognitive function and memory deficits in patients with OSA.