Altered Coupling Of Resting-state Cerebral Blood Flow And Functional Connectivity Strength In MTrPs Induced Pain

Objective:MTrPs induced pain,caused by long-term and sustained nociceptive stimulation from MTrPs,is a common clinical symptoms.We intend to use the resting cerebral blood flow?CBF?and functional connectivity strength?CBF?method,starting from the neurovascular coupling theory,to explore the coupling changes and clinical significance of cerebral blood flow and nerve function activities in patients with MTrPs pain,and to provide new ideas for the study of neuropathological mechanism of MTrPs pain.Methods:In this study,a total of 23 patients with MTrPs-related pain?12 men,MTrPs group?and 23 healthy controls?10 men,HC group?were enrolled.Both groups were right handed,matched in age,gender and education.MRI data were acquired by the 3-Tesla MR scanner?Signa HDxt,General Electric?,including perfusion imaging?arterial spin labeling,ASL?and resting state functional magnetic resonance imaging?rs-fMRI?and high-resolution T₁ structure images.The score of visual analogue scale?VAS?and the course of pain were collected..The data of 3D ASL,rs-fMRI and 3D T₁ structure image were processed to obtain the CBF,FCS and GMV of each subject for subsequent analysis.The correlation of CBF-FCS in grey matter template of each subject was calculated and compared among groups.The differences between CBF/FCS,CBF and FCS groups were compared using independent sample t-test?P<0.05,FDR correction?.CBF/FCS with significant difference between groups was extracted to explore the correlation between CBF/FCS and VAS score and course of disease in patients with MTrPs pain.After the gray matter volume of subjects was removed as a covariate,CBF/FCS group comparison was repeated to explore the impact of GMV on the results and verify the reliability of the results.Result:1.Compared with HC group,the CBF-FCS coupling of whole brain in MTrPs group was significantly decreased?T=2.221,P=0.0296?.2.Compared with HC group,the CBF/FCS ratio of MTrPs group decreased in bilateral superior temporal gyrus,right hippocampus,right parahippocampal gyrus,caudate nucleus,right superior frontal gyrus and periaqueductal gray matter,while CBF/FCS ratio increased in bilateral lingual gyrus,posterior cingulate gyrus and bilateral inferior parietal lobules?P<0.05,FDR correction?,which are important components of the default network and the limbic system.The abnormal CBF/FCS ratio of periaqueductal gray in patients with MTrPs-related pain was negatively correlated with VAS score and course of disease??=-0.505,P=0.024;?=-0.493,P=0.031?.3.After GMV correction,the CBF-FCS coupling in MTrPs pain group was still significantly lower than that in HC group?T=2.181,P=0.0309?;the distribution of brain regions with different CBF/FCS ratio was basically the same as that of non regression GMV,indicating that the GMV changes in the two groups had little effect on neurovascular coupling.Conclusion:This study found that patients with MTrPs-related pain showed neurovascular coupling changes,including the decrease of CBF-FCS coupling in the whole brain and the change of CBF/FCS ratio in the local brain area.These changes are also related to the pain degree and course of patients with MTrPs pain,which is helpful to understand the neuropathological mechanism of MTrPs pain from the perspective of neurovascular coupling.