Impaired functional connectivity of anterior cingulated cortex in vascular cognitive impairment with no dementia explored by resting state functional magnetic resonance imaging

Objective To study the functional connectivity (FC) pattern of anterior cingulated cortex in patients with vascular cognitive impairment with no dementia (VCIND) after subcortical ischemic vascular disease, and to analyze the relationship between FC and cognitive function. Methods Resting state functional magnetic resonance imaging (MRI) data were acquired from 14 patients with VCIND and 16 healthy volunteers with normal cognition. The altered functional connectivity pattern in VCIND was valuated by comparing to normal control. Then a correlation analysis was performed between the strength of FC and the Montreal Cognitive Assessment (MoCA) scores in patients with VCICD. Results (1) The visual space or executive function (3.14±0.29), attention or computing power (3.79±0.37), language (1.14±0.21), directional power (4.14±0.53) items, and the total points of MoCA（17.29±1.53）in VCIND were significantly lower than that in the normal control group (4.93±0.07，5.93±0.07，2.93±0.26， 5.93±0.07，27.57±0.33；t=31.62，32.50，28.51，12.00，39.71，all P 0.05). (2) Compared with the control group, the patients showed FC decrease between the anterior cingulated cortex and several brain regions, including the left middle temporal gyrus/left superior temporal gyrus, the left superior frontal gyrus/left middle frontal gyrus/left inferior frontal gyrus, the left posterior cingulated cortex/left precuneus, the left inferior parietal lobule/left angular gyrus, the right middle temporal gyrus/right superior temporal gyrus, the right orbit frontal cortex/right inferior frontal gyrus, the right inferior parietal lobule/right angular gyrus, and the right superior frontal gyrus/right middle frontal gyrus. There were also some regions that showed increased FC, which included the right posterior lobe of the cerebellum, the calcarine fissure, the left middle frontal gyrus, and the left precentral gyrus. (3) In the VCIND patients, the brain regions which positively correlated with the MoCA scores were the left inferior parietal lobule, the right middle temporal gyrus, the right superior frontal gyrus, and the left superior temporal gyrus. The negative-related brain regions were the right posterior limb of internal capsule, the left middle temporal gyrus, the left precuneus, and the right anterior limb of internal capsule. Conclusions VCIND patients show abnormal FC pattern of anterior cingulated cortex, which could be the pathological basis of VCIND, and have certain predictive value for VCIND. Key words: Cognition disorders; Gyrus cinguli; Magnetic resonance imaging;  Cerebrovascular disorders