The Neuroimaging Study On Abnormalities Of White Matter Pathway And Striatum Function Connection In Primary Insomnia Patients

Insomnia is one of the most prevalent sleep disorders that causes patients to increase their risk of suffering from other mental illnesses.Researchers have widely investigated on the neurobiological mechanisms of insomnia using advanced neuroimaging methods.However,its neurobiology is poorly understood.In the present dissertation,we use magnetic resonance imaging(MRI)technology to study two phenomena:"abnormal changes in white matter(WM)microstructure caused by insomnia" and "striatum plays a key role in regulating sleep-wakeness."The WM microstructure in the brain plays an important role in regulating brain activity and mediating functional coupling between brain regions and behavior.To date,differences in WM microstructures between primary insomnia(PI)patients and healthy sleepers and the behavioral implications of such differences remain unclear.Therefore,studying the abnormal changes in the WM microstructure of the brain is of great significance for exploring the underlying neural mechanisms of PI.In the present study,we used Automated Fiber Quantification(AFQ)to assess WM diffusion properties differences between 23 PI patients and 32 matched healthy controls in 20 tracts.The relationships between neuroimaging differences and sleep behaviors were explored.The results of the study showed that compared with the healthy control group,right arcuate fasciculus(Arc)and superior longitudinal fasciculus(SLF)showed significant higher fractional anisotropy(FA),mean diffusivity(MD)and radial diffusivity(RD)along tract length in PI patients.Axial diffusivity(AD)for PI patients was higher in right Arc and lower in right SLF.Correlation analysis revealed that the diffusion coefficients of the right Arc and the right SLF in PI were correlated with the Pittsburgh Sleep Quality Index(PSQI)score and insomnia severity index scale(ISI)score.Our findings can improve the understanding of the effects of abnormal white matter microstructure on the neural mechanism of PI.Based on the extensive literature demonstrating the critical roles of the striatum in sleep regulation,we hypothesized that insomnia may be related to changes in the function of the striatum.In order to better understand the neural mechanism of primary insomnia,exploring abnormal changes in striatum function in the brain of PI patients is an extremely important research direction.In the present study,caudate,nucleus accumbens(NAc)and putamen were selected as seed points in the striatum subregion to analyze the resting-state functional connectivity(RSFC)and the relationship between neuroimaging differences and clinical featuresa was assessed.The results of the study showed that compared with the healthy control group,we found the decreased functional connectivity of the caudate,NAc,and putamen in PI group with multiple brain regions,including hippocampus,thalamus,bilateral anterior cingulate cortex(ACC)and insula.The RSFC mainly between the left NAc and right insula,left putamen and right insula,left putamen and right caudate,left putamen and right putamen in PI patients showed significant positive correlation with the self-rating depression scale(SDS)score.And the RSFC between the left putamen and right caudate,left putamen and right putamen,right putamen and right caudate was positively correlated with the self-rating anxiety scale(SAS)score.This work suggests that the striatum is abnormal in PI patients and that these abnormalities are related to the main clinical features of insomnia.This study of abnormal striatum functional connectivity and WM microstructures in PI has given us a deeper understanding of the neural mechanisms of PI,and provided a scientific basis for future treatment and relief of insomnia symptoms.