Objective: To explore the brain effect mechanism and the correlation between brain functional imaging and cognitive function in treatment of depressive disorder (DD) with transcutaneous auricular vagus nerve stimulation (taVNS) based on the resting-state functional magenetic reasonance imaging (rs-fMRI).
Methods: Thirty-two DD patients were included in a depression group and 32 subjects of healthy condition were enrolled in a normal group. In the depression group, the taVNS was applied to bilateral Xin (CO15) and Shen (CO10), at disperse-dense wave, 4 Hz/20 Hz in frequency and current intensity ≤20 mA depending on patient's tolerance, 30 min each time, twice daily. The duration of treatment consisted of 8 weeks. The patients of two groups were undertaken rs-fMRI scanning. The scores of Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA) and Wisconsin card sorting test (WCST) were observed in the normal group at baseline and the depression group before and after treatment separately. The differential brain regions were observed before and after treatment in the two groups and the value of degree centrality (DC) of fMRI was obtained. Their correlation was analyzed in terms of HAMD, HAMA and WCST scores.
Results: The scores of HAMD and HAMA in the depression group were all higher than those in the normal group (P<0.05). After treatment, the scores of HAMD and HAMA were lower than those before treatment in the depression group; the scores of total responses, response errors and perseverative errors of WCST were all lower than those before treatment (P<0.05). The brain regions with significant differences included the left inferior temporal gyrus, the left cerebellar peduncles region 1, the left insula, the right putamen, the bilateral supplementary motor area and the right middle frontal gyrus. After treatment, the value of DC in left supplementary motor area was negatively correlated to HAMD and HAMA scores respectively (r=-0.324, P=0.012; r=-0.310, P=0.015); the value of DC in left cerebellar peduncles region 1 was negatively correlated to the total responses of WCST (r=-0.322, P=0.013), and the left insula was positively correlated to the total responses of WCST (r=0.271, P=0.036).
Conclusion: The taVNS can modulate the intensity of the functional activities of some brain regions so as to relieve depressive symptoms and improve cognitive function.
目的：基于静息态功能磁共振成像（rs-fMRI）技术探讨经皮耳迷走神经刺激（taVNS）治疗抑郁症（DD）的脑效应机制及其与认知功能的相关性。方法：纳入32例DD患者为抑郁组，32例健康受试者作为健康组。抑郁组予双侧耳穴心、肾taVNS治疗，选用疏密波，频率4 Hz/20 Hz，电流强度≤20 mA，以患者耐受为度，每次30 min，每天2次，共治疗8周。于基线期及治疗8周后，两组均行rs-fMRI扫描。观察健康组基线期和抑郁组治疗前后汉密尔顿抑郁量表（HAMD）、汉密尔顿焦虑量表（HAMA）及威斯康星卡片分类测验（WCST）评分。观察两组间及抑郁组治疗前后差异的脑区，并获得fMRI度中心度（DC）值，将DC值与HAMD、HAMA及WCST评分做相关性分析。结果：抑郁组治疗前HAMD、HAMA评分高于健康组（P<0.05），抑郁组治疗后HAMD、HAMA评分低于治疗前（P<0.05），WCST总应答数、错误应答数、持续错误数评分低于治疗前（P<0.05）。左侧颞下回、左侧小脑脚1区、左侧岛叶、右侧壳核、双侧辅助运动区、右侧额中回为差异显著的脑区。治疗后，抑郁组患者左侧辅助运动区DC值与HAMD、HAMA评分呈负相关（r=-0.324，P=0.012；r=-0.310，P=0.015）；左侧小脑脚1区DC值与WCST总应答数评分呈负相关（r=-0.322，P=0.013）；左侧岛叶DC值与WCST总应答数评分呈正相关（r=0.271，P=0.036）。结论：taVNS具有调节部分脑区功能活动强度的作用，从而有效缓解抑郁症状、改善认知功能。.
Keywords: cognitive function; degree centrality; depressive disorder; functional connection strength; resting-state functional magenetic reasonance imaging; transcutaneous auricular vagus nerve stimulation.