Abnormal neural activity and functional connectivity in amnestic Mild cognitive impairmet: A resting state fMRI study

Mild cognitive impairment (MCI) is a brain-function syndrome involving the onset and evolution of cognitive impairments which are not significant enough to interfere with daily activities. In this study, we used resting state functional magnetic resonance imaging (fMRI) to detect the whole brain fractional amplitude of low-frequency fluctuations (fALFF) and functional connectivity in 32 amnestic MCI subjects (aMCIs) and 28 healthy elderly normal controls (NCs). Compared to NCs, aMCIs showed significant decreases of fALFF value in right inferior temporal gyrus, left inferior occipital gyrus and left postcentral gyrus, while increases were found mainly in the right lingual and precunues. The functional connectivity decreased in the regions of left dorsolateral superior frontal gyrus, the right orbital frontal gyrus and left inferior temporal gyrus. These findings may be helpful to understand the pathophysiological mechanism of mild cognitive impairment.