基于静息态功能磁共振的脑肿瘤患者手术麻醉前后健侧脑功能网络构建及分析

Construction and analysis of functional network of hemi-brain in patients with brain tumors before and after anesthesia based on resting-state functional magnetic resonance imaging

目的应用静息态功能磁共振(rs-fMRI)成像技术,对脑肿瘤患者手术麻醉前后健侧脑功能网络进行构建及分析。方法前瞻性纳入2018年12月至2021年12月北京大学国际医院行胶质瘤切除术患者18例,均为右利手。年龄20~65(45.1±13.6)岁,其中男6例,女12例。美国麻醉医师协会(ASA)分级Ⅰ~Ⅱ级。分别在患者清醒和外科麻醉深度下进行磁共振扫描,并以图理论的方式进行健侧脑功能网络构建及分析,计算其全局和节点拓扑属性。全局拓扑属性包括:全局效率(Eg)、局部效率(Eloc)、集聚系数(Cp)、最短路径长度(Lp)和小世界属性(SW)。节点拓扑属性包括:节点度(ND)、节点效率(NE)及介数中心度(BC)。比较所有不同脑半球占位患者在清醒和麻醉状态下健侧脑网络全局和节点拓扑属性的改变。结果清醒状态下,所有患者健侧脑网络全局拓扑属性中的Eloc和Cp分别为0.259±0.007和0.197±0.010,麻醉后降低到0.242±0.013和0.177±0.021,差异均有统计学意义(均P<0.01)。所有患者健侧脑网络节点拓扑属性表现为默认模式网络相关脑区的ND、NE及BC升高,边缘系统和皮层下结构NE和BC降低。左侧脑半球占位患者清醒状态下Eloc和Cp分别为0.258±0.008和0.198±0.008,麻醉后降低到0.241±0.011和0.177±0.015,差异均有统计学意义(均P<0.01);而右侧脑半球占位患者麻醉后仅发生Eloc降低,清醒和麻醉后Eloc分别为0.260±0.006和0.243±0.016,差异有统计学意义(P<0.05);麻醉后不同脑半球占位患者节点拓扑属性呈双向变化,且左侧脑半球占位患者麻醉后更易受广泛影响,麻醉药物的作用可能存在一定半球偏侧性,如果肿瘤在优势半球,则优势侧代偿功能更易受损。结论麻醉诱发的脑肿瘤患者意识丧失期间,大脑整合信息能力变弱,局部区域之间的功能连接减弱,部分脑区发生了功能连接重组,脑网络变化呈双相调控。

Objective To construct and analyze the functional network changes of hemi-brain in patients with brain tumor before and after anesthesia by using resting state functional magnetic resonance imaging(rs-fMRI).Methods A total of 18 right-handed patients were prospectively included(6 males and 12 females).The patients underwent glioma resection in Peking University International Hospital from December 2018 to December 2021,and age ranged from 20 to 65(45.1±13.6)years,with American Society of Anesthesiologists(ASA)grade ofⅠ-Ⅱ.MRI scans were performed while the patient was awake and at the depth of surgical anesthesia.The functional network of healthy lateral brain was constructed and analyzed by means of graph theory,and its global and local topological properties were calculated.Global topology attributes included global efficiency(Eg),local efficiency(Eloc),clustering parameters(Cp),length parameter of shortest path(Lp),and small world(SW).Topology attributes of nodes included node degree(ND),node efficiency(NE)and between centrality(BC).The global and nodal topological properties of the hemi-brain network were compared between patients with different hemispherical space occupying under wakefulness and anesthesia.Results At the awake state,Eloc and Cp in the global topological attributes of hemi-brain network were 0.259±0.007 and 0.197±0.010,respectively,and decreased to 0.242±0.013 and 0.177±0.021,respectively after anesthesia,with statistically significant differences(all P<0.01).The topological attributes of the nodes in hemi-side brain showed that ND,NE and BC were increased in the default mode network-related brain regions,while NE and BC were decreased in the limbic system and subcortical structures.Eloc and Cp were 0.258±0.008 and 0.198±0.008 respectively in the patients with left hemisphere space occupying,and decreased to 0.241±0.011 and 0.177±0.015 respectively after anesthesia,with statistically significant differences(all P<0.01).However,only Eloc decreased in patients with right hemisphere space occupying after anesthesia,and Eloc was 0.260±0.006 and 0.243±0.016 respectively when awake and after anesthesia,with statistically significant differences(P<0.05).The topological attributes of nodes in patients with space occupying in different cerebral hemispheres showed bidirectional changes after anesthesia,and patients with space occupying in the left cerebral hemisphere were more likely to be widely affected after anesthesia.The effects of anesthetic drugs may show hemispheric laterality.If the tumor was in the dominant hemisphere,the compensatory function of the dominant side was more likely to be damaged.Conclusions During anesthesia-induced loss of consciousness in patients with brain tumors,both the ability to integrate information and the functional connections between local regions are weakened,and some brain regions have functional connection reorganization.The changes of brain network after anesthesia are bidirectional regulation.