The MRI Research Of Structural And Functional Abnormality Of Brain In Migraine Patients Without Aura

As a primary headache disorder, migraine causes a significant individual and socialburden. Frequent migraine attacks may produce pain, sensitivities and productivity loss,and even increase the risk of psychiatric disorders with a variety of psychologicalcharacteristics such as depressive symptoms. Advanced neuroimaging approaches havebeen employed to investigate structural and functional brain changes in migrainepatients. This dissertation is mainly concerned with the abnormalities during the restingstate or in the white matter of migraine patients without aura (MWoA) and the influenceaffected by depressive symptoms. The author’s major contributions are outlined asfollows:1. Previous studies provided evidence of structural and task-related functionalchanges in the brain of migraine patients without aura. However, few studies focused onthe resting state abnormalities in migraine patients without aura. We employed adata-driven method, regional homogeneity (ReHo), to analyze the local features ofspontaneous brain activity in migraine patients without aura during the resting state.Compared with healthy controls, migraine patients without aura showed a significantdecrease in ReHo values in the right rostral anterior cingulate cortex (rACC), theprefrontal cortex (PFC), the orbitofrontal cortex (OFC) and the supplementary motorarea (SMA). Additionally, we found that ReHo values were negatively correlated withduration of disease in the right rACC and PFC. Our results suggested that the restingstate abnormalities of these regions may be associated with functional impairments inpain processing in migraine patients without aura.2. Tract-based spatial statistics (TBSS) with multiple diffusion tensor imaging(DTI) derived indices, including fractional anisotropy (FA), mean diffusivity (MD),radial diffusivity (RD) and axial diffusivity (AD), may help to deduce thepathophysiological type of white matter (WM) changes and provide more specificbiomarkers of WM neuropathology in the whole brain of MWoA. Compared withhealthy controls, MWoA showed significantly lower FA, MD and AD in multiple brainregions, while no difference in RD was observed. Additionally, some of the WMfindings were significantly correlated with duration and headache frequency inMWoA.Given that decreased AD may suggest axonal loss, our findings may revealaxonal loss in MWoA.3. Previous studies proved that migraine and depression are bidirectionally linked.However, few studies investigated WM integrity affected by depressive symptoms in MWoA. Forty MWoA were divided into two groups according to their self-ratingdepression scale (SDS) score in the present study, including20in the SDS (+)(SDS>49) group and20in the SDS (-)(SDS≤49) group. TBSS analyses with multipleDTI-derived indices (FA, MD, RD, AD) were employed collectively to investigated theWM integrity among all MWoA, SDS (-) group, SDS (+) group and healthy controls.Compared with healthy controls, decreased AD was similarly shown in several WMtracts of the whole MWoA group, SDS (-) group and SDS (+) group. In addition,compared with the SDS (-) group, the SDS (+) group showed decreased FA andincreased MD and RD with conserved AD in multiple WM tracts, which were similarwith previous findings in depression disorder. Furthermore, mean FA and RD in theseWM tracts in the SDS (+) group were significantly correlated with SDS scores. Ourresults might suggest that white matter integrity might be affected by both depressionsymptoms (more sensitive as RD) and migraine (more sensitive as AD). The findingsmay serve as a sensitive biomarker to reflect depression severity in MWoA.4. Based on similar hypothesis as above mentioned, the resting state abnormalitiesaffected by depressive symptoms in MWoA were investigated. Through similar desion,compared with healthy controls, decreased ReHo in similar regions were shown in theMWoA group and subgroups. It is noteworthy that the caudate showed increased ReHoin the SDS (-) group compared with healthy controls, and decreased ReHo in the SDS(+) group compared with the SDS (-) group. Moreover, the average ReHo values of thecaudate were significantly negatively correlated with the SDS scores and positivelycorrelated with duration. Our results suggested that ReHo patterns in migraine patientsmay be affected by depressive symptoms and serve as a biomarker to reflect depressionseverity in MWoA.In summary, ReHo changes and WM changes in MwoA may provide morescientific evidence for the role in the pathology of migraine, which may serve as asensitive biomarker to reflect disease progression and depression severity of migrainewithout aura. We hope that our results could improve the understanding of migrainepathophysiology.