Abnormalities of interhemispheric functional connectivity in individuals with acute eye pain: a resting-state fMRI study

AIM: To study the changes of the resting state functional connectivity(rsFC) between acute eye pain(EP) subjects and healthy controls(HCs) in the two hemispheres by using voxel-mirrored homotopic connectivity(VMHC) method.METHODS: Totally 20 patients with EP and 20 HCs were enrolled, sex, age, and education were matched, and all subjects were examined by functional magnetic resonance imaging(fMRI) scans at resting-state. The changes of rs FC between the hemispheres were evaluated by the VMHC method according to Gaussian random field(GRF) theory. In order to identify the VMHC, as biomarkers for distinguishing EP and from HC, the receiver operating characteristic curves(ROC) had been analyzed. The relationships were evaluated with Pearson correlation analysis between the mean VMHC signal values and clinical features in these patients.RESULTS: By comparing with health subjects, the significant decreased VMHC values was observed in lingual/calcarine(Brodmann area, BA 30), precentral/postcentral gyrus(PreCG/PosCG; BA 4) and medial frontal gyrus(MFG; BA 8)(false discovery rate corrected <0.01) in the acute EP individuals. The accuracy of area under curve was excellent indicated by the ROC curve analysis of each brain regions.CONCLUSION: Our study demonstrates preliminary evidence of disrupted interhemispheric rsFC in acute EP in sensorimotor and limbic system and somatosensory cortex, which might give some useful information for understanding the neurological mechanisms in acute EP individuals.

Altered regional homogeneity in patients with diabetic vitreous hemorrhage

BACKGROUND Diabetic vitreous hemorrhage(DVH)is a common complication of diabetes.While the diagnostic methods nowadays only concentrate on the eye injury in DVH patients,whether DVH leads to abnormalities of other visual systems,including the eye,the visual cortex,and other brain regions,remains unknown.AIM To explore the potential changes of brain activity in DVH using regional homogeneity(ReHo)and their relationships with clinical features.METHODS Thirty-one DVH patients and 31 matched healthy controls(HCs)were recruited.All subjects were examined by resting-state functional magnetic resonance imaging.The neural homogeneity in the brain region was estimated by ReHo method.Pearson correlation analysis was used to evaluate the relationships between average ReHo values and clinical manifestations in DVH patients.RESULTS Compared with HCs,the ReHo values in the bilateral cerebellar posterior lobes,right superior(RS)/middle occipital gyrus(MOG),and bilateral superior frontal gyrus were significantly increased.In contrast,in the right insula,bilateral medial frontal gyri,and right middle frontal gyrus,the ReHo values were significantly decreased.Furthermore,we found that best-corrected visual acuity of the contralateral eye in patients with DVH presented a positive correlation with the mean ReHo value of the RS/MOG.We also found that depression score of the DVH group presented a negative correlation with the mean ReHo values of the right insula,bilateral medial frontal gyrus,and right middle frontal gyrus.CONCLUSION We found that DVH may cause dysfunction in multiple brain areas,which may benefit the exploration of pathologic mechanisms in DVH patients.