Abstract: Objective To study the default mode network (DMN) of mild cognitive impairment (MCI) related to leukoaraiosis (LA) with resting-state functional magnetic resonance imaging (rs-fMRI). Methods 31 LA patients (Clinical Dementia Rating of 0.5) and 27 normal controls (Clinical Dementia Rating of 0, and matched in age, gender and lever of education) were scanned with the rs-fMRI. The data was analyzed with SPM5 software, using independent component analysis. The differences between the both groups were compared with two-sample t-test. Results The DMN during resting-state of normal controls was posterior cingulate cortex/precuneus, bilateral medial frontal cortex, bilateral middle temporal gyrus, bilateral inferior parietal gyrus, angular gyrus, bilateral hippocampus. The DMN of MCI group was consistent with the normal controls, but the activation decreased in anterior cingulate cortex/left medial frontal lobe, right parahippcampus/ uncus, right inferior temporal gyrus, left deep frontal white matter/head of caudate nucleus; and increased in the left caudate nucleus/anterior cingulate cortex, left frontal lobe, and left superior temporal gyrus/inferior parietal gyrus. Conclusion Activation of resting-state functional network is disorder in LA, which may relate to cognitive impairment.

Key words: leukoaraiosis, mild cognitive impairment, resting-state functional magnetic resonance imaging, default mode network