Interhemispheric Functional Connectivity In Insomnia Disorder:A Resting-state Funtional Magnetic Resonance Imaging Study

Objective: To investigate the resting-state functional connectivity between the two hemispheres in insomnia disorder by using voxel-mirrored homotopic connectivity(VMHC) based on resting state functional magnetic resonance imaging(rs-f MRI). And to examine its relationships with polysomnography(PSG) results. Exploring the neurophysiological mechanisms of insomnia disorder.Methods: Rs-fMRI scan were performed in thirty insomnia patients and twenty three age- and sex- matched healthy volunteers in resting state. Patients were selected with the diagnostic criteria of insomnia disorder according the diagnostic and statistical manual of mental diseases(DSM-V) developed by American psychiatric association.Results: The insomnia disorder patients showed lower VMHC than normal controls in the bilateral inferior temporal gyrus, bilateral lingual gyrus, bilateral cuneus, bilateral precuneus, bilateral precentral gyrus, bilateral superior frontal gyrus. Negative correlation was observed between VMHC coefficient of bilateral inferior temporal gyrus,bilateral lingual gyrus, bilateral cuneus, bilateral precuneus and N1 time in patients. Positive correlation was observed between VMHC coefficient of bilateral cuneus, bilateral precuneus and sleep latency period of time in patients. The other regions showing significant VMHC changes had no correlation with the PSG results.Conclusion: 1. Decreased homotopic connectivity brain areas of insomnia disorder patients may have associated with function impairment. This shoud be the pathology base with cognitive function impairment.2. Information exchange between bilateral inferior temporal gyrus, bilateral lingual gyrus, bilateral cuneus, bilateral precuneus has a close relationship with Non-Rapid Eye Movement Sleep(NREM) N1 time. Information exchange between bilateral cuneus, bilateral precuneus has a close relationship with sleep latency period of time.3. There may be some kind of compensatory function by reducing the incubation period of sleep time to reverse mental and physical injury caused by lack of sleep in human.