Resting-State F Mri Study Of Chronic Primary Insomnia

Objective:To explore the abnormal connection properties of brain function network in patients with primary insomnia(PI) using resting-state functional magnetic resonance imaging(rs-fMRI) and a voxel-based degrees center(DC) method;to analyze the changes of inter-hemispheric functional connectivity in patients with PI by a voxel-mirrored homotopic connectivity(VMHC) method,and to explore the possible pathogenesis of PI. Methods:1.Recruited 38 PI patients conforming to the diagnostic criteria of diagnostic and statistical manual of mental disorders, fourth edition(DSM-IV) and 38 normal controls(NC) with gender, age, level of education matched.All the subjects underwent three-dimensional brain structure and rs-fMRI scan.2.On the day of the rs-fMRI scan, all participants were evaluated by Pittsburgh sleep quality index scale(PSQI), self-assessment lists of sleep(SRSS), severe insomnia index scale(ISI), self-evaluation of anxiety scale(SAS), depression self rating scale(SDS), Hamilton depression scale(HAMD), Hamilton anxiety scale(HAMA)and Profile of Mood States(POMS).3.The preprocessing and the calculation of voxel-based DC(threshold value 0.25) and VMHC for functional images in PI group and NC group were on Matlab 2010 a station; the DC and VMHC value between groups were compared respectively by two sample t test with REST software, then the brain areas which are statistically significant were obtained;then Pearson correlation analysis for regions with abnormal DC and VMHC value in PI group with Clinical scale Score were performed respectively using IBM SPSS19.0 statistical software. Results:1.There was no statistical difference between two groups in the age and education level(P>0.05); the PSQI, SRSS, SAS, SDS, HAMD, HDMD, POMS scores of PI group were significantly higher than that of the NC group, with difference statistically significant(P < 0.05).2.Compared with NC group, PI group showed significantly reduced DC value in bilateral superior frontal gyrus, left middle frontal gyrus, left Calcarine cortex and right cerebellum posterior lobe,as well as significantly increased DC value in the left middle temporal gyrus(P < 0.05, AlphaSim correction).3.Compared with NC group, PI group showed significantly reduced VMHC value in bilateral cerebellum posterior lobe, bilateral inferior temporal gyrus,and significantly higher VMHC value in bilateral cuneus, bilateral inferior parietal lobule(P < 0.05, AlphaSim correction).4.DC value in left middle frontal gyrus positively correlated with ISI(r=0.330,P=0.0435);DC value in left superior frontal gyrus positively correlated with PSQI(r=0.327,P=0.045) and ISI(r=0.322,P=0.049);VMHC value in bilateral cerebellum posterior lobe negatively correlated with HAMA(r=-0.330,P=0.043);VMHC value in bilateral inferior temporal gyrus negatively correlated with insomnia duration(r=-0.322,P=0.048) and SAS(r=-0.351,P=0.031);DC value in bilateral cuneus negatively correlated with ISI(r=-0.331,P=0.042);DC value in bilateral inferior parietal lobule negatively correlated with PSQI(r=-0.452,P=0.040) in PI group. Conclusion:1. PI patients exist changes of functional network centricity in the frontal lobes, occipital lobe, cerebellum, and temporal lobe.2. PI patients exist changes of functional connectivity between hemispheres in bilateral temporal lobe, cerebellum, occipital lobe and parietal lobe.3. The regions with altered DC and VMHC in PI patients are mainly related with cognition and emotion; DC values in left middle frontal gyrus, superior frontal gyrus and VMHC value in bilateral cerebellum posterior lobe, inferior temporal gyrus, cuneus and inferior parietal lobule were related with the Clinical scale Score,thus speculating that the DC and VMHC change in these brain areas is likely to be one of the main mechanisms of clinical symptoms generating in PI patients.