10.3389/fnagi.2018.00161.s001 Xiao Luo Xiao Luo Kaicheng Li Kaicheng Li Qingze Zeng Qingze Zeng Peiyu Huang Peiyu Huang Yeerfan Jiaerken Yeerfan Jiaerken Tiantian Qiu Tiantian Qiu Xiaojun Xu Xiaojun Xu Jiong Zhou Jiong Zhou Jingjing Xu Jingjing Xu Minming Zhang Minming Zhang Presentation_1_Decreased Bilateral FDG-PET Uptake and Inter-Hemispheric Connectivity in Multi-Domain Amnestic Mild Cognitive Impairment Patients: A Preliminary Study.PDF Frontiers 2018 mild cognitive impairment cerebral metabolism corpus callosum resting-state functional MRI voxel-mirrored homotopic connectivity 2018-06-05 14:21:51 Presentation https://frontiersin.figshare.com/articles/presentation/Presentation_1_Decreased_Bilateral_FDG-PET_Uptake_and_Inter-Hemispheric_Connectivity_in_Multi-Domain_Amnestic_Mild_Cognitive_Impairment_Patients_A_Preliminary_Study_PDF/6446210 <p>Background: Amnestic mild cognitive impairment (aMCI) is a heterogeneous condition. Based on clinical symptoms, aMCI could be categorized into single-domain aMCI (SD-aMCI, only memory deficit) and multi-domain aMCI (MD-aMCI, one or more cognitive domain deficit). As core intrinsic functional architecture, inter-hemispheric connectivity maintains many cognitive abilities. However, few studies investigated whether SD-aMCI and MD-aMCI have different inter-hemispheric connectivity pattern.</p><p>Methods: We evaluated inter-hemispheric connection pattern using fluorine-18 positron emission tomography – fluorodeoxyglucose (<sup>18</sup>F PET-FDG), resting-state functional MRI and structural T1 in 49 controls, 32 SD-aMCI, and 32 MD-aMCI patients. Specifically, we analyzed the 18<sup>F</sup> PET-FDG (intensity normalized by cerebellar vermis) in a voxel-wise manner. Then, we estimated inter-hemispheric functional and structural connectivity by calculating the voxel-mirrored homotopic connectivity (VMHC) and corpus callosum (CC) subregions volume. Further, we correlated inter-hemispheric indices with the behavioral score and pathological biomarkers.</p><p>Results: We found that MD-aMCI exhibited more several inter-hemispheric connectivity damages than SD-aMCI. Specifically, MD-aMCI displayed hypometabolism in the bilateral middle temporal gyrus (MTG), inferior parietal lobe, and left precuneus (PCu) (p < 0.001, corrected). Correspondingly, MD-aMCI showed decreased VMHC in MTG, PCu, calcarine gyrus, and postcentral gyrus, as well as smaller mid-posterior CC than the SD-aMCI and controls (p < 0.05, corrected). Contrary to MD-aMCI, there were no neuroimaging indices with significant differences between SD-aMCI and controls, except reduced hypometabolism in bilateral MTG. Within aMCI patients, hypometabolism and reduced inter-hemispheric connectivity correlated with worse executive ability. Moreover, hypometabolism indices correlated to increased amyloid deposition.</p><p>Conclusion: In conclusion, patients with MD-aMCI exhibited the more severe deficit in inter-hemispheric communication than SD-aMCI. This long-range connectivity deficit may contribute to cognitive profiles and potentially serve as a biomarker to estimate disease progression of aMCI patients.</p>