Impaired small-world network efficiency and dynamic functional distribution in patients with cirrhosis.
Impaired small-world network efficiency and dynamic functional distribution in patients with cirrhosis.
复制标题
DOI：
10.1371/journal.pone.0035266
复制
发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Lin CP
中科院分区：
文献类型：
--
作者：
Hsu TW;Wu CW;Cheng YF;Chen HL;Lu CH;Cho KH;Lin WC;Lin CP
肝性脑病(HE)是一种复杂的神经精神综合征，是肝硬变的主要并发症。与氨水平升高有关的大脑代谢障碍会干扰皮质间的连接和认知功能。对于网络效率的评估，小世界网络模型可以量化大脑网络中信息传输的有效性。本研究旨在利用小世界拓扑学方法，利用静息状态功能磁共振成像(rs-fMRI)研究肝硬变患者广泛分布脑区神经元连接的异常。17例无HE的肝硬变患者、9例轻度HE患者、9例显性HE患者和35名健康对照进行了比较。通过使用自动解剖标记模型对90个区域中每一个区域中的所有体素的RS-fMRI时间序列进行平均，获得区域间相关矩阵。然后，应用代价和相关性阈值来构建功能脑网络。计算了绝对和相对网络效率；量化了局部和全球拓扑网络组织的不同方面。使用线性回归和方差分析来确定网络拓扑参数、氨水平和HE严重程度之间的相关性。在HE患者中，功能连接网络的局部和全局拓扑效率明显受到破坏；表现出异常的小世界特性。区域特征的改变，包括结节效率和结节强度，主要发生在联合、初级和边缘/边缘旁区域。网络组织破坏的程度取决于HE的严重程度。氨水平也与局部网络属性的变化显著相关。结果表明，脑的rS-fMRI网络拓扑的改变与HE分级有关；局灶性或弥漫性病变干扰了功能网络，进一步改变了整个脑网络的整体拓扑结构和效率。这些发现提供了对HE中人脑功能变化的洞察。
Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome and a major complication of liver cirrhosis. Dysmetabolism of the brain, related to elevated ammonia levels, interferes with intercortical connectivity and cognitive function. For evaluation of network efficiency, a ‘small-world’ network model can quantify the effectiveness of information transfer within brain networks. This study aimed to use small-world topology to investigate abnormalities of neuronal connectivity among widely distributed brain regions in patients with liver cirrhosis using resting-state functional magnetic resonance imaging (rs-fMRI). Seventeen cirrhotic patients without HE, 9 with minimal HE, 9 with overt HE, and 35 healthy controls were compared. The interregional correlation matrix was obtained by averaging the rs-fMRI time series over all voxels in each of the 90 regions using the automated anatomical labeling model. Cost and correlation threshold values were then applied to construct the functional brain network. The absolute and relative network efficiencies were calculated; quantifying distinct aspects of the local and global topological network organization. Correlations between network topology parameters, ammonia levels, and the severity of HE were determined using linear regression and ANOVA. The local and global topological efficiencies of the functional connectivity network were significantly disrupted in HE patients; showing abnormal small-world properties. Alterations in regional characteristics, including nodal efficiency and nodal strength, occurred predominantly in the association, primary, and limbic/paralimbic regions. The degree of network organization disruption depended on the severity of HE. Ammonia levels were also significantly associated with the alterations in local network properties. Results indicated that alterations in the rs-fMRI network topology of the brain were associated with HE grade; and that focal or diffuse lesions disturbed the functional network to further alter the global topology and efficiency of the whole brain network. These findings provide insights into the functional changes in the human brain in HE.
登录
查看更多内容
影响因子：
5.3
作者：
Achard, S;Salvador, R;Bullmore, ET
通讯作者：
Bullmore, ET
影响因子：
4.3
作者：
Achard S;Bullmore E
通讯作者：
Bullmore E
影响因子：
4.8
作者：
Birn, Rasmus M.;Murphy, Kevin;Bandettini, Peter A.
通讯作者：
Bandettini, Peter A.
影响因子：
4.7
作者：
LAI, JCK;COOPER, AJL
通讯作者：
COOPER, AJL
影响因子：
9.8
作者：
Blei, AT;Córdoba, J
通讯作者：
Córdoba, J