经颅直流电刺激对最小意识状态患者脑功能网络静息态调节效应的对照研究

A comparative study of the effect of a single transcranial direct current stimulation on resting state of brain functional network in patients in a minimally conscious state

目的 比较经颅直流电刺激（tDCS）单次治疗对最小意识障碍（MCS）患者静息态低频振幅（ALFF）的调节效应，以探讨该疗法的作用机制。 方法 收集11例MCS患者作为研究对象，其中男9例，女2例；脑外伤10例，脑出血1例；平均年龄（37.3±8.4）岁，平均病程（3.4±0.1）个月。所有患者入组前均给予1次静息态功能性磁共振（rs-fMRI）扫描；随后给予单次tDCS治疗，将阳极固定于患者左侧前额叶背外侧区，阴极固定在眶上区，并按照下列顺序进行实验。先给予单次安慰tDCS（sham-tDCS）治疗20min，结束后进行第2次rs-fMRI扫描；然后给予单次真tDCS（real-tDCS）治疗20min，结束后进行第3次rs-fMRI扫描。在每次进行rs-fMRI检查时还采用修订版昏迷恢复量表（CRS-R）对患者意识障碍程度进行评分。 结果 与治疗前比较，入选患者经单次sham-tDCS治疗后其CRS-R评分、静息态脑功能网络ALFF均明显变化（P〉0.05）；经单次real-tDCS治疗后，发现患者默认网路（左侧楔前叶）、额顶网络（左侧额叶、右侧顶上回）、感觉运动网络（左侧辅助运动区）、皮质下（右侧丘脑、双侧尾状核）ALFF显著增强（P〈0.05）；而额顶网络（右侧额叶）、听觉网络（双边颞叶）ALFF显著减弱（P〈0.05）；与单次sham-tDCS治疗后比较，入选患者经单次real-tDCS治疗后其默认网络（右侧前额叶）ALFF显著增强（P〈0.05）；凸显网络（左侧岛叶）、感觉运动网络（右侧中央前回）ALFF显著减弱（P〈0.05）。 结论 MCS患者经单次tDCS治疗后，发现其静息态脑功能网络ALFF活动增强，表明tDCS对神经网络神经元兴奋性具有调节作用，这可能是促进MCS患者意识恢复的神经机制之一。

Objective To investigate the effect of transcranial direct current stimulation （tDCS） on the amplitude of low-frequency fluctuation （ALFF） of the resting brain function network in patients in a minimal conscious state （MCS） so as to explore the mechanism. Methods Eleven MCS patients were selected. Among them, there were 9 males and 2 females, 10 with cerebral trauma and 1 with cerebral hemorrhage, with an average age of （37.3±8.4） and an average course of disease of （3.4±0.1） months. All subjects were given a resting-state functional magnetic resonance imaging （rs-fMRI） assessment prior to the single tDCS treatment, followed by a 20-minute single sham tDCS treatment at a time. After single-sham stimulation, a second time rs-fMRI assessment test will be conducted, followed by a real tDCS treatment for 20 minutes. Eventually, a third time rs-fMRI assessment test will be implemented. Results No significant statistical difference was shown in terms of all the parameters after single sham-tDCS as compared to those before the treatment （P〉0.05）. After single real-tDCS, no significant change was observed with CRS-R score, ALFF of default network （left anterior wedge） ,the frontal-parietal network （left frontal lobe, right superior gyrus）, sensory motor network （left auxiliary motor area）, subcortical network （right thalamus, bilateral caudate nuclei） was significantly higher than that before treatment ,while the ALFF of the frontal network （frontal lobe） and auditory network （bilateral temporal lobes） was significantly decreased （P〈0.05）. After single real-tDCS, the ALFF of default network （right frontal lobe） was significantly enhanced compared to that after single sham-tDCS （P〈0.05）, while that of the salient network （left insula） and sensorimotor network （right central frontal） was significantly decreased （P〈0.05）. Conclusion The enhancement of ALFF activity in the resting state brain function network is a possible neural mechanism for tDCS to promote the recovery of consciousness level in patients with minimal conscious state.