Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu Province, China.
PLoS One. 2013;8(1):e53677. doi: 10.1371/journal.pone.0053677. Epub 2013 Jan 11.
The basal ganglia often show abnormal metabolism and intracranial hemodynamics in cirrhotic patients with hepatic encephalopathy (HE). Little is known about how the basal ganglia affect other brain system and is affected by other brain regions in HE. The purpose of this study was to investigate whether the effective connectivity network associated with the basal ganglia is disturbed in HE patients by using resting-state functional magnetic resonance imaging (rs-fMRI).
METHODOLOGY/PRINCIPAL FINDINGS: Thirty five low-grade HE patients and thirty five age- and gender- matched healthy controls participated in the rs-fMRI scans. The effective connectivity networks associated with the globus pallidus, the primarily affected region within basal ganglia in HE, were characterized by using the Granger causality analysis and compared between HE patients and healthy controls. Pearson correlation analysis was performed between the abnormal effective connectivity and venous blood ammonia levels and neuropsychological performances of all HE patients. Compared with the healthy controls, patients with low-grade HE demonstrated mutually decreased influence between the globus pallidus and the anterior cingulate cortex (ACC), cuneus, bi-directionally increased influence between the globus pallidus and the precuneus, and either decreased or increased influence from and to the globus pallidus in many other frontal, temporal, parietal gyri, and cerebellum. Pearson correlation analyses revealed that the blood ammonia levels in HE patients negatively correlated with effective connectivity from the globus pallidus to ACC, and positively correlated with that from the globus pallidus to precuneus; and the number connectivity test scores in patients negatively correlated with the effective connectivity from the globus pallidus to ACC, and from superior frontal gyrus to globus pallidus.
CONCLUSIONS/SIGNIFICANCE: Low-grade HE patients had disrupted effective connectivity network of basal ganglia. Our findings may help to understand the neurophysiological mechanisms underlying the HE.
肝硬化伴肝性脑病（HE）患者的基底节常表现出代谢和颅内血流动力学异常。但对于基底节如何影响其他脑系统以及在 HE 中如何受到其他脑区的影响，目前知之甚少。本研究旨在通过静息态功能磁共振成像（rs-fMRI）探讨 HE 患者基底节相关有效连接网络是否受到干扰。
方法/主要发现：35 例低级别 HE 患者和 35 名年龄和性别匹配的健康对照者参与了 rs-fMRI 扫描。采用格兰杰因果分析（Granger causality analysis）描述与基底节主要受累区苍白球相关的有效连接网络，并将其与健康对照组进行比较。对所有 HE 患者的异常有效连接与静脉血氨水平和神经心理学表现进行 Pearson 相关分析。与健康对照组相比，低级别 HE 患者的苍白球与前扣带回（ACC）、楔前叶之间的相互影响降低，苍白球与楔前叶之间的双向影响增加，苍白球与额叶、颞叶、顶叶和小脑许多其他脑回之间的影响或降低或增加。Pearson 相关分析显示，HE 患者的血氨水平与苍白球至 ACC 的有效连接呈负相关，与苍白球至楔前叶的有效连接呈正相关；患者的连线测试评分与苍白球至 ACC 的有效连接以及额上回至苍白球的有效连接呈负相关。
结论/意义：低级别 HE 患者的基底节有效连接网络受到破坏。我们的研究结果可能有助于理解 HE 的神经生理机制。
