A Functional Connectivity Analysis Of The Defaut Mode In Patients With Vascular Cognitive Impairment, No Dementia During The Resting State

Objective：To prospectively explore whether the default mode network(DMN)inpatients with vascular cognitive impairment,no dementia (VCIND)is abnormalor not, using functional magnetic resonance imaging(fMRI) and posteriorcingulate cortex (PCC) functional connectivity characteristics.Materials and Methods:14patients and17normal old people (NC) were recruitedand underwent the MoCA scale, Hachinski ischemia index scale (Hachinskiischemic scale, HIS) test and functional MRI scanning． The raw data of thefMRI were processed with the software SPM5.Selecting double side PCC for seedpoint, using single T test and double T test analyzed the PCC with all brainfunctional connective strength.Results: The single T test with the normal old people showed that the graphof the PCC functional connection almost completely match with the deaultmode network which we have assumpted.The brain regions which connectionincreased include: posterior cingulate cortex(pcc), precuneus(PC), doubleside inferior parietal cortex(IPC), medial prefrontal cortex(MPFC), ventralanterior cingulate cortex(VACC),double side inferolateral temporalcortex(ITC),left parahippocampal gyrus (PHG)and double side posteriorcerebellar lobe.For the VCIND patient,the active brain regions include:posterior cingulate cortex(PCC),precuneus(Pc),double side inferior parietal cortex(IPC), medial prefrontal cortex(MPFC),double side double sideinferolateral temporal cortex(ITC)and double side posterior cerebellar lobe,Compared with normal control group,the connection of default mode networkand the PCC was weaker, range reduced. Intergroup analysis showedthat:compared with normal control group,the patients of VCIND showedsignificantly decreased functional connectivity with the PCC in the righthippocampal gyrus,the anterior cingulate cortex,the right patietal inferiorlobe,upper right posterior cingulate cortex;The group of patients with VCINDshowed significantly increased functional connectivity in left superiortemporal gyrus,the left angular gyrus,the joint of right visual cortex,rightposterolateral prefrontal cortex,the left anterior motor cortex,the leftpatietal inferior lobules.Conclusion: The default mode network may be existed in VCIND patients duringresting state，but the range of functional connectivity of the DMN was decreased,the space distribution area and regional connectional intensity are alsochanged. Meanwhile a Certain compensatory exist. The functional connectionbased on the default network system (DMN)can be found these changes,and providehelp for the VCIND early clinical diagnosis.