1型发作性睡病非快速眼动睡眠期脑网络拓扑特征及其与认知行为评价的相关性

Abnormal brain network topology during non-rapid eye movement sleep and its correlation with cognitive behavioral abnormalities in narcolepsy type 1

目的应用同步脑电-功能磁共振成像技术(electroencephalography-functional magnetic resonance imaging,EEG-fMRI),探讨1型发作性睡病(narcolepsy type 1,NT1)患者非快速眼动(non-rapid eye movement,NREM)睡眠状态下脑功能网络的连通性和拓扑特性,探讨其与认知行为的关系。材料与方法对25例NT1患者和25例年龄匹配的健康对照组进行北京版蒙特利尔认知评估(The Beijing version of the Montreal Cognitive Assessment,MoCA-BJ)和EEG-fMRI扫描。所有受试者首先进行夜间多导睡眠图(nocturnal polysomnogram,nPSG)研究,计算总睡眠时间(total sleep time,TST)、各睡眠阶段占总睡眠时间百分比(TST%)和觉醒指数。采用Epworth嗜睡量表(Epworth Sleepiness Score,ESS)衡量白天的嗜睡程度。并在睡眠状态下对所有被试进行同步EEG-fMRI扫描。应用MoCA-BJ量表评估所有被试认知功能。利用EEG数据进行睡眠分期,基于fMRI数据建立被试睡眠状态下的全脑功能连接网络,使用图论方法分析网络的拓扑特征。比较各组之间拓扑参数的差异,并用相关分析方法分析脑网络拓扑特性与MoCA-BJ量表的关系。结果与对照组比较,NT1组的MOCA-BJ评分降低;而且NT1 NREM 2期睡眠期(N2)全脑全局效率以及小世界性均明显降低。NT1组的全脑功能网络的整体效率与MoCA-BJ评分显著相关(r=-0.589,P=0.002)。结论NT1患者在N2期睡眠状态下脑功能网络的网络拓扑属性异常与其认知障碍相关。

Objective:Simultaneous electroencephalography(EEG)and functional magnetic resonance imaging(fMRI)were applied to investigate the abnormalities in the topological characteristics of functional brain networks during non-rapid eye movement(NREM)sleep.And we investigated its relationship with cognitive abnormalities in patients with narcolepsy type 1(NT1)disorder in the current study.Materials and Methods:The Beijing version of the Montreal Cognitive Assessment(MoCA-BJ)and EEG-fMRI were applied in25 patients with NT1 and 25 age-matched healthy controls.All subjects participated in a nocturnal video polysomnography(PSG)study,and total sleep time(TST),percentage of TST(TST%)for each sleep stage and arousal index were calculated.The Epworth Sleepiness Score(ESS)was used to measure the degree of daytime sleepiness.The EEG-fMRI study was performed simultaneously using a 3.0 T MRI system and a 32-channel MRI-compatible EEG system during sleep.Visual scoring of EEG data was used for sleep staging.Cognitive function was assessed for all subjects using the MoCA-BJ.The fMRI data were applied to establish a whole-brain functional connectivity network for all subjects,and the topological characteristics of the whole-brain functional network were analyzed using a graph-theoretic approach.The topological parameters were compared between groups.Lastly,the correlation between topological parameters and the assessment scale using Montreal Cognition was analyzed.Results:The MoCA-BJ scores were lower in patients with NT1 than in normal controls.Whole-brain global efficiency during stage N2 sleep in patients with NT1 displayed significantly lower small-world properties than in normal controls.Whole-brain functional network global efficiency in patients with NT1 was significantly correlated with MoCA-BJ scores(r=-0.589,P=0.002).Conclusions:The global efficiency of the functional brain network during stage N2 sleep in patients with NT1 and the correspondingly reduced small-world attributes were associated with cognitive impairment.