A Resting State Functional Magnetic Resonance Imaging Study Of Chronic Non-specific Low Back Pain With Depression

Background Chronic non-specific low back pain(CNLBP)is a common musculoskeletal health problem.Epidemiological investigations and clinical intervention have shown that low back pain has a high comorbidity rate with mental/psychological disorders,such as depression and anxiety,and the most significant of these is depression.CNLBP with depression have more severe pain and worse prognosis.Previous related resting-state fMRI studies have shown that CNLBP patients have extensive changes in brain function,but it is not yet clear that the changes of brain function when depression coexist in CNLBP.AimResting state fMRI technology was applied to explore the corresponding changes in brain function of CNLBP with depression and its correlation with clinical behavior,so as to explore the possible central nervous mechanism of CNLBP with depression,and provide theoretical basis for future clinical diagnosis and treatment.MethodA total of 63 subjects were enrolled in this study,including 14 CNLBP with depression,25 CNLBP,and 24 healthy controls.All subjects underwent resting state fMRI scanning after clinical evaluation.Data analysis was based on MATLAB2013b(Math Works,Inc.,Natick,MA,USA)platform,the resting state fMRI data preprocessing assistant(DPARSF＿V2.3 Basic Edition,DPARSFA)software package was used for resting state data preprocessing,and using Resting-State fMRI Data Analysis Toolkit(REST)software package performed statistical analysis of the image,and performed one-way analysis of variance(P<0.05,Alpha Sim correction)on the three groups of data.The post-hoc two-sample t test was performed between the two groups(P<0.05,Alpha Sim correction).Finally,the average Re Ho value of all CNLBP patients with different brain regions was extracted and correlated with the clinical behavior evaluation results Visual Analogue Scale(VAS),disease course,Beck Depression Inventory-II(BDI-Ⅱ),Pain Catastrophizing Scale-total(PCSt)and Oswestry Disability Index(ODI)scores.ResultsThe levels of Mc Gill pain questionnaire-pain rating index(MPQ-PRI),Mc Gill pain questionnaire-present pain intensity(MPQ-PPI),functional disorder and pain catastrophe of CNLBP with depression were significantly higher than those of CNLBP subjects without depression.Under the condition of controlling age and gender,the brain function of all subjects was analyzed using the Re Ho and FC of resting-state fMRI.One-way analysis of variance showed that the three groups were significant differences in the left hippocampus/parahippocampal gyrus,right hippocampus,left rectus/right olfactory cortex,left superior frontal gyrus(medial orbital part),right inferior frontal gyrus(opercular part),right caudate,and right superior frontal gyrus(dorsolateral part)(P<0.05,Alpha Sim correction).Based on Re Ho statistical analysis of the different brain regions,the right dorsolateral superior frontal gyrus was used as the region of interest(ROI),and the time-domain correlations between ROI and whole brain voxels were calculated.The three groups were significant differences in the functional connections between the right superior frontal gyrus(dorsolateral part)and bilateral posterior cerebellar lobes,the left putamen/inferior frontal gyrus(medial orbital part),and right calcarine(P<0.05,Alpha Sim correction).The brain regions with differences in Re Ho statistical analysis were taken as regions of interest,and the average Re Ho values of relevant brain regions in all CNLBP subjects were extracted for correlation analysis with the clinical evaluation results.The results showed that the reduction of the average Re Ho value in patients with low back pain was negatively correlated with BDI-Ⅱ and PCSt scores,including the right inferior frontal gyrus(opercular part)(BDI-Ⅱ: r=-0.352,P=0.028;PCSt: r=-0.363,P=0.023),left superior frontal gyrus(medial orbital)(BDI-Ⅱ: r=-0.538,P=0.001;PCSt: r=-0.418,P=0.008),right superior frontal gyrus(dorsolateral part)(BDI-Ⅱ: r=-0.681,P<0.001;PCSt: r=-0.549,P<0.001);The increase in average Re Ho value is positively correlated with BDI-Ⅱ and PCSt scores on the left hippocampus/parahippocampal gyrus(BDI-Ⅱ: r=0.340,P=0.034;PCSt: r=0.411,P=0.009)and the right hippocampus(BDI-Ⅱ: r=0.461,P=0.003;PCSt: r=0.539,P<0.001),the decrease in the average Re Ho value of the right superior frontal gyrus(dorsolateral part)is negatively correlated with the ODI score(r=-0.482,P=0.002)There is no significant correlation between the average Re Ho value of different brain regions and VAS and disease course.ConclusionsCNLBP patients with depression have two-way changes in multiple brain areas that increase or decrease Re Ho and FC,involving key node brain areas,such as sensory,emotion,cognition,and movement.The abnormal activity of frontal lobe related brain region may be the important reason of chronic nonspecific low back pain with depression.The change in the average Re Ho value of the right dorsolateral superior frontal gyrus may be a potential target for the treatment of CNLBP comorbid depression.Behavioral evaluation results BDI-Ⅱ,PCSt and ODI have specific related brain regions,but it is still necessary to further explore the possibility of changes in the corresponding brain regions as an indicator of the severity of depression comorbidity and dysfunction in the future.