Jin Mei, Wang Liyan, Wang Hao, Han Xue, Diao Zongli, Guo Wang, Yang Zhenghan, Ding Heyu, Wang Zheng, Zhang Peng, Zhao Pengfei, Lv Han, Liu Wenhu, Wang Zhenchang
Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
PeerJ. 2020 Apr 15;8:e8989. doi: 10.7717/peerj.8989. eCollection 2020.
Altered cerebral blood flow (CBF) and amplitude of low-frequency fluctuation (ALFF) have been reported in hemodialysis patients. However, neurovascular coupling impairments, which provide a novel insight into the human brain, have not been reported in hemodialysis patients.
We combined arterial spin labeling (ASL) and blood oxygen level dependent (BOLD) techniques to investigate neurovascular coupling alterations and its relationships with demographic and clinical data in 46 hemodialysis patients and 47 healthy controls. To explore regional neuronal activity, ALFF was obtained from resting-state functional MRI. To measure cerebral vascular response, CBF was calculated from ASL. The across-voxel CBF-ALFF correlations for global neurovascular coupling and CBF/ALFF ratio for regional neurovascular coupling were compared between hemodialysis patients and healthy controls. Two-sample -tests were used to compare the intergroup differences in CBF and ALFF. Multiple comparisons were corrected using a voxel-wise false discovery rate (FDR) method ( < 0.05).
All hemodialysis patients and healthy controls showed significant across-voxel correlations between CBF and ALFF. Hemodialysis patients showed a significantly reduced global CBF-ALFF coupling ( = 0.0011) compared to healthy controls at the voxel-level. Of note, decreased CBF/ALFF ratio was exclusively located in the bilateral amygdala involved in emotional regulation and cognitive processing in hemodialysis patients. In hemodialysis patients, the decreased CBF (right olfactory cortex, anterior cingulate gyrus and bilateral insula) and ALFF (bilateral precuneus and superior frontal gyrus) were mainly located in the default mode network and salience network-related regions as well as increased CBF in the bilateral thalamus.
These novel findings reveal that disrupted neurovascular coupling may be a potential neural mechanism in hemodialysis patients.
已有报道称血液透析患者存在脑血流量（CBF）改变及低频波动幅度（ALFF）异常。然而，血液透析患者中尚未见对神经血管耦合障碍的报道，而神经血管耦合障碍为研究人类大脑提供了新的视角。
我们联合使用动脉自旋标记（ASL）和血氧水平依赖（BOLD）技术，对46例血液透析患者和47例健康对照者的神经血管耦合改变及其与人口统计学和临床数据的关系进行研究。为探究局部神经元活动，通过静息态功能磁共振成像获取ALFF。为测量脑血管反应，由ASL计算CBF。比较血液透析患者和健康对照者之间全脑体素水平上的CBF-ALFF相关性以及局部神经血管耦合的CBF/ALFF比值。采用两样本t检验比较两组间CBF和ALFF的差异。使用基于体素的错误发现率（FDR）方法校正多重比较（P<0.05）。
所有血液透析患者和健康对照者的CBF与ALFF之间均显示出显著的全脑体素相关性。在体素水平上，与健康对照者相比，血液透析患者的全脑CBF-ALFF耦合显著降低（P=0.0011）。值得注意的是，血液透析患者中CBF/ALFF比值降低仅见于参与情绪调节和认知加工的双侧杏仁核。在血液透析患者中，CBF降低区域（右侧嗅皮质、前扣带回和双侧脑岛）和ALFF降低区域（双侧楔前叶和额上回）主要位于默认模式网络和突显网络相关区域，同时双侧丘脑的CBF增加。
这些新发现表明，神经血管耦合受损可能是血液透析患者潜在的神经机制。
