原发性痛经患者自身不同状态下大脑低频振幅和功能连接的改变:一项基于静息态功能磁共振的研究

Alterations in amplitude of low frequency fluctuation and functional connectivity of brain in primary dysmenorrhea patients under different self-states:A resting-state functional magnetic resonance imaging study

目的采用低频振幅(amplitude of low frequency fluctuation,ALFF)、比率低频振幅(fractional amplitude of low frequency fluctuations,fALFF)和功能连接(functional connectivity,FC)方法探究原发性痛经(primary dysmenorrhea,PDM)患者疼痛的中枢机制。材料与方法纳入31例PDM患者,所有受试者均接受经期与围排卵期双期静息态功能磁共振成像检查。计算ALFF、fALFF值,提取ALFF和fALFF值都有差异的脑区作为感兴趣区(region of interest,ROI),计算ROI与全脑体素的FC值。采用配对样本t检验比较PDM患者疼痛与无痛状态下ALFF、fALFF、FC值,并采用皮尔逊相关分析探索PDM患者ALFF、fALFF值与临床指标的关系。结果与非疼痛期比较,PDM患者在疼痛期显示左侧内侧额上回、右侧小脑Ⅱ区ALFF值显著升高,左侧岛叶ALFF值显著降低(双尾检验P<0.05,Alphasim校正,团块大小>176);PDM患者疼痛期的左侧背外侧额上回、左侧额下回三角部、右侧豆状核的fALFF值显著高于非疼痛期,左侧楔前叶的fALFF值显著低于非疼痛期(双尾检验P<0.05,Alphasim校正,团块大小>154)。随后,基于种子点的FC分析显示,左侧额上回为ALFF和fALFF值都有差异的脑区,相较于非疼痛期,疼痛期其与左侧小脑Ⅷ区的连接性降低(双尾检验P<0.05,Alphasim校正,团块水平>181);Pearson相关分析显示PDM患者疼痛期的左侧岛叶ALFF值与CMSS-t呈负相关(r=−0.400,P=0.026)。结论本研究揭示了PDM存在ALFF与fALFF的异常改变,并涉及多个脑网络,为帮助理解PDM的中枢机制提供新见解。

Objective:The central mechanisms of pain in patients with primary dysmenorrhea(PDM)were investigated using the amplitude of low frequency fluctuations(ALFF),fractional amplitude of low frequency fluctuations(fALFF),and functional connectivity(FC)methods.Materials and Methods:Thirty-one patients with PDM were included,and all subjects underwent dual-phase resting-state functional magnetic resonance imaging during menstruation and periovulatory.ALFF and fALFF values were calculated,and brain regions with differences in both ALFF and fALFF values were extracted as regions of interest(ROI),and FC values of ROI versus whole-brain voxels were calculated.The paired-sample t-test was used to compare the ALFF,fALFF,and FC values of PDM patients in pain and pain-free states,and Pearson's correlation analysis was used to explore the relationship between the ALFF and fALFF values and the clinical indicators of PDM patients.Results:Compared with the non-painful phase,PDM patients showed significantly higher ALFF values in the left medial superior frontal gyrus and right cerebellar areaⅡand significantly lower ALFF values in the left insula during the painful phase(two-tailed test P<0.05,Alphasim-corrected,cluster level>176);fALFF values in the left dorsolateral superior frontal gyrus,left inferior frontal gyrus delta,and right pedunculopontine nucleus during the painful phase of PDM patients were significantly higher than in the non-painful phase,and the fALFF values in the left precuneus were significantly lower than in the non-painful phase(two-tailed test P<0.05,Alphasim corrected,cluster level>154).Subsequently,seed-point-based FC analysis showed that the left superior frontal gyrus was the brain region that differed in both ALFF and fALFF values,and its connectivity with the left cerebellar areaⅧwas reduced in the painful phase compared to the non-painful phase(two-tailed test P<0.05,Alphasim corrected,cluster level>181);Pearson correlation analysis showed that the left insula in the painful phase of PDM patients ALFF values were negatively correlated with CMSS-t(r=−0.400,P=0.026).Conclusions:The present study reveals abnormal alterations of ALFF and fALFF in PDM and involves multiple brain networks,providing new insights to help understand the central mechanisms of PDM.