Exploring the relevance between brain glucose metabolism and functional connectivity in Chinese cognitive...

Simultaneously resting brain glucose metabolism and intrinsic functional activity, by integrated PET/MRI scans, both reflect nerve actions. Studies showed that there existed relevance between two phenotypes of neuros in normal human brains. However, whether the relevance will change in cognitive dysfunction (CD) brains is still unknown. The aim of this study therefore is to explore the relevance between voxel-wise glucose metabolism and functional connectivity in Chinese CD people. The dataset in this study included two imaging modalities and clinical information of 21 healthy control (HC) individuals and 15 CD patients, from Xuanwu hospital, Beijing, China. Firstly, we calculated the standardized uptake value rate (SUVR) from positron emission tomography (PET), and three parameters for intrinsic functional activity from functional magnetic resonance imaging (fMRI), including amplitude of low frequency fluctuations (ALFF), fractional amplitude of low frequency fluctuations (fALFF) and regional homogeneity (ReHo). Second, the two sample t-test was used to compare each parameter between HC and CD groups respectively. Third, the relevance between SUVR and the three fMRI parameters were measured by Spearman's rank correlation. The results of t-test showed that glucose metabolism consumption decreased in Default Mode Network (DMN) (p < 0.01), and the damage of functional connection also happened DMN area in CD group. The correlation between glucose metabolism and functional activity in CD group was lower than that in HC group in DMN. Especially, the correlation between SUVR and ReHo was significantly reduced (p < 0.05). Above results promoted a deeper understanding on the pathogenesis of cognitive impairment, and providing new biomarkers to discriminate CD and HC subjects.