Objectives: This study was conducted to investigate the brain function of patients with temporomandibular disorders (TMD) by combining the static and dynamic amplitudes of low-frequency fluctuation (ALFF).
Methods: Thirty patients with TMD and 20 healthy controls were enrolled. All the participants completed their questionnaires, received clinical examinations, and underwent resting-state functional magnetic resonance imaging scanning. We compared the static and dynamic ALFF between the patients and healthy controls by conducting a two-sample t-test with AlphaSim correction for multiple comparisons. The correlation between the static and dynamic ALFF of the brain regions with significant group differences and clinical measurements was analyzed.
Results: The patients with TMD showed increased static and dynamic ALFF in the posterior cingulate cortex compared with that of the controls (whole-brain level, uncorrected P=0.005; region of interest level with AlphaSim correction, voxel level P<0.005, cluster level P<0.05). The dynamic ALFF of the posterior cingulate cortex was negatively correlated with bilateral condylar vertical discrepancies. The dynamic ALFF in the medial orbitofrontal cortex of the patients with TMD was greater than that of the controls (whole-brain level AlphaSim correction, voxel level P<0.005, cluster level P<0.05).
Conclusions: Our findings revealed that the resting-state brain function of the posterior cingulate cortex and the medial orbitofrontal cortex of patient with TMD increased. These changes probably indicated the potential central mechanisms underlying the increased self-relevant thoughts, negative emotion, and abnormal emotion regulation in TMD.
目的: 利用静息态功能磁共振成像技术，结合静态与动态低频振幅（ALFF）分析方法探讨颞下颌关节紊乱病（TMD）患者静息态脑功能活动的改变。方法: 招募30名TMD患者（患者组）和20名健康志愿者（对照组），对所有被试者进行问卷调查和临床检查并行3.0T静息态功能磁共振扫描。基于全脑灰质体素分析静态和动态ALFF的组间差异并进行AlphaSim校正，将存在组间差异的静态和动态ALFF值与临床指标做相关性分析。结果: 与对照组相比，患者组后扣带回的静态和动态ALFF均增加（全脑水平未校正P=0.005；感兴趣区水平AlphaSim校正，体素水平P<0.005，簇水平P<0.05），且后扣带回的动态ALFF与正中关系-最大牙尖交错位不调指数中双侧髁突垂直向不调指数呈负相关。患者组内侧眶额回皮质的动态ALFF也升高（全脑水平AlphaSim校正，体素水平P<0.005，簇水平P<0.05）。结论: TMD患者后扣带回和内侧眶额回皮质的静息态脑功能活动存在异常改变，可能反映了与患者自我相关思维增加、负面情绪及情绪调节异常相关的潜在中枢改变。.
Keywords: brain function; dynamic amplitude of low frequency fluctuation; resting-state functional magnetic resonance imaging; static amplitude of low frequency fluctuation; temporomandibular disorders.