Wu Yu-Te, Huang Shang-Ran, Jao Chi-Wen, Soong Bing-Wen, Lirng Jiing-Feng, Wu Hsiu-Mei, Wang Po-Shan
Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
Institute of Biophotonics and Brain Research Center, National Yang-Ming University, Taipei, Taiwan.
Front Neurosci. 2018 Dec 17;12:935. doi: 10.3389/fnins.2018.00935. eCollection 2018.
Recent studies have shown that the patients with spinocerebellar ataxia type 3 (SCA3) may not only have disease involvement in the cerebellum and brainstem but also in the cerebral regions. However, the relations between the widespread degenerated brain regions remains incompletely explored. In the present study, we investigate the topological properties of the brain networks of SCA3 patients ( = 40) constructed based on the correlation of three-dimensional fractal dimension values. Random and targeted attacks were applied to measure the network resilience of normal and SCA3 groups. The SCA3 networks had significantly smaller clustering coefficients ( < 0.05) and global efficiency ( < 0.05) but larger characteristic path length ( < 0.05) than the normal controls networks, implying loss of small-world features. Furthermore, the SCA3 patients were associated with reduced nodal betweenness ( < 0.001) in the left supplementary motor area, bilateral paracentral lobules, and right thalamus, indicating that the motor control circuit might be compromised. The SCA3 networks were more vulnerable to targeted attacks than the normal controls networks because of the effects of pathological topological organization. The SCA3 revealed a more sparsity and disrupted structural network with decreased values in the largest component size, mean degree, mean density, clustering coefficient, and global efficiency and increased value in characteristic path length. The cortico-cerebral circuits in SCA3 were disrupted and segregated into occipital-parietal (visual-spatial cognition) and frontal-pre-frontal (motor control) clusters. The cerebellum of SCA3 were segregated from cerebellum-temporal-frontal circuits and clustered into a frontal-temporal cluster (cognitive control). Therefore, the disrupted structural network presented in this study might reflect the clinical characteristics of SCA3.
最近的研究表明，3型脊髓小脑共济失调（SCA3）患者不仅小脑和脑干会出现病变，大脑区域也会受累。然而，广泛退化的脑区之间的关系仍未得到充分探索。在本研究中，我们基于三维分形维数值的相关性，研究了40例SCA3患者脑网络的拓扑特性。应用随机和靶向攻击来测量正常组和SCA3组的网络弹性。与正常对照网络相比，SCA3网络的聚类系数（P<0.05）和全局效率（P<0.05）显著更小，但特征路径长度更大（P<0.05），这意味着小世界特征丧失。此外，SCA3患者左侧辅助运动区、双侧中央旁小叶和右侧丘脑的节点介数降低（P<0.001），表明运动控制回路可能受损。由于病理拓扑组织的影响，SCA3网络比正常对照网络更容易受到靶向攻击。SCA3显示出更稀疏和结构紊乱的网络，最大组件大小、平均度、平均密度、聚类系数和全局效率值降低，特征路径长度值增加。SCA3的皮质-脑回路被破坏并分为枕叶-顶叶（视觉空间认知）和额叶-前额叶（运动控制）簇。SCA3的小脑与小脑-颞叶-额叶回路分离，并聚集成额叶-颞叶簇（认知控制）。因此，本研究中呈现的结构紊乱网络可能反映了SCA3的临床特征。
