The Research Of Resting-state Brain Functional Activities Changes Of Amnestic Mild Cognitive Impairment

Objective: To investigate the difference of amplitude of low-frequency fluctuation(ALFF) and fraction of amplitude of low frequency fluctuation(fALFF) between amnestic mild cognitive impairment(aMCI) patientsand normal aging(NA) controls and the correlation with the Mini-Mental State Examination(MMSE) scores by resting-state functional magnetic resonance imaging.Methods:The subjects of this study who are amnestic mild cognitive impairment(aMCI) visited the Neurology and Geriatrics clinic of First Affiliated Hospital of Soochow University from March 2014 toDecember 2015 for the presence of cognitive impairment and the healthy controls(NC) who are recruited by advertising through the network. And 13 aMCI patients and 13 healthy volunteers were included in the final study. Blood oxygen level dependent functional(BOLD) EPI data were obtained during resting-state by using 8 channel head coil. Data were realigned, normalized and then smoothed with 8 mm FWHM kernel. Data processing assistant for resting-state fMRI(DPARSF) was used to generate ALFF and fALFF images.Independent two sample t-test was performed with SPM8 to compare ALFF and fALFF of aMCI and NA controls. Pearson correlation analysis was performed to examine the relationship between MMSE scores and ALFF and fALFF parameters respectively. The significance level was set to be AlphaSim corrected 0.001 on the voxel level and 0.05 on the cluster level.Results: ALFF values in aMCI patients are higher than normal controls in bilateral cingulate cortex, medial prefrontal cortex, limbic and right insula, and the difference was statistically significant(P <0.05). ALFF values in aMCI patients are lower than normal controls in left cerebral hemisphere, such as the left front wedge lobe, parietal lobe, cuneus, occipital lobe, cingulate gyrus and limbic and right medial temporal gyrus and the right frontal lobe, and the difference was statistically significant(P <0.05). fALFF values in aMCI patients are higher than normal controls in cerebellum and Left thalamus, and the difference was statistically significant(P <0.05). fALFF values in aMCI patients are lower than normal controls in frontal wedge front lobe, parietal lobe and right cingulate gyrus, and the difference was statistically significant(P <0.05). Right cerebellum, right occipital lobe, the left front and left frontal lobe wedge of ALFF and the MMSE score was fALFF were positively correlated(P <0.05).Conclusions: The normal elderly and aMCI patients have a default mode network(DMN) with spontaneous activity in the resting state. Reduction of the levels of resting state brain functional activity in aMCI patients’ right cerebellar right occipital lobe, left precuneus, left frontal part of the brain and has a positive correlation with MMSE scores, this, to a certain extent, suggests that the decline of recognition ability of aMCI patients may have association with these brain regions with abnormalities. Compared to normal controls, aMCI patients’ abnormalities in spontaneous neuronal activity not only exist in the default network-related area, but also in other brain regions, which provides the basis for the early radiologic diagnosis of aMCI.