Lau Chi Ieong, Yeh Jiann-Horng, Tsai Yuh-Feng, Hsiao Chen-Yu, Wu Yu-Te, Jao Chi-Wen
Institute of Biophotonics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan.
School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei 242, Taiwan.
Brain Sci. 2023 Jan 3;13(1):93. doi: 10.3390/brainsci13010093.
Mild cognitive impairment (MCI) is widely regarded to be the intermediate stage to Alzheimer's disease. Cerebral morphological alteration in cortical subregions can provide an accurate predictor for early recognition of MCI. Thirty patients with MCI and thirty healthy control subjects participated in this study. The Desikan-Killiany cortical atlas was applied to segment participants' cerebral cortex into 68 subregions. A complexity measure termed fractal dimension (FD) was applied to assess morphological changes in cortical subregions of participants. The MCI group revealed significantly decreased FD values in the bilateral temporal lobes, right parietal lobe including the medial temporal, fusiform, para hippocampal, and also the orbitofrontal lobes. We further proposed a novel FD-based brain structural network to compare network parameters, including intra- and inter-lobular connectivity between groups. The control group had five modules, and the MCI group had six modules in their brain networks. The MCI group demonstrated shrinkage of modular sizes with fewer components integrated, and significantly decreased global modularity in the brain network. The MCI group had lower intra- and inter-lobular connectivity in all lobes. Between cerebral lobes, the MCI patients may maintain nodal connections between both hemispheres to reduce connectivity loss in the lateral hemispheres. The method and results presented in this study could be a suitable tool for early detection of MCI.
轻度认知障碍（MCI）被广泛认为是阿尔茨海默病的中间阶段。皮质亚区域的脑形态改变可为MCI的早期识别提供准确的预测指标。30例MCI患者和30例健康对照者参与了本研究。采用Desikan-Killiany皮质图谱将参与者的大脑皮质划分为68个亚区域。应用一种称为分形维数（FD）的复杂性度量来评估参与者皮质亚区域的形态变化。MCI组双侧颞叶、右侧顶叶（包括内侧颞叶、梭状回、海马旁回）以及眶额叶的FD值显著降低。我们进一步提出了一种基于FD的新型脑结构网络，以比较两组之间的网络参数，包括脑叶内和脑叶间的连通性。对照组的脑网络有5个模块，MCI组有6个模块。MCI组的模块化大小缩小，整合的组件减少，脑网络的全局模块化显著降低。MCI组所有脑叶的脑叶内和脑叶间连通性均较低。在脑叶之间，MCI患者可能维持双侧半球之间的节点连接，以减少外侧半球的连通性损失。本研究中提出的方法和结果可能是早期检测MCI的合适工具。
