Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital Radiology, Harvard Medical School, Charlestown, Massachusetts, USA.
Department of Radiology, Logan University, Chesterfield, Missouri, USA.
Neurogastroenterol Motil. 2022 Oct;34(10):e14396. doi: 10.1111/nmo.14396. Epub 2022 May 13.
Functional dyspepsia (FD) is a disorder of gut-brain interaction, and its putative pathophysiology involves dysregulation of gastric motility and central processing of gastric afference. The vagus nerve modulates gastric peristalsis and carries afferent sensory information to brainstem nuclei, specifically the nucleus tractus solitarii (NTS). Here, we combine MRI assessment of gastric kinematics with measures of NTS functional connectivity to the brain in patients with FD and healthy controls (HC), in order to elucidate how gut-brain axis communication is associated with FD pathophysiology.
Functional dyspepsia and HC subjects experienced serial gastric MRI and brain fMRI following ingestion of a food-based contrast meal. Gastric function indices estimated from 4D cine MRI data were compared between FD and HC groups using repeated measure ANOVA models, controlling for ingested volume. Brain connectivity of the NTS was contrasted between groups and associated with gastric function indices.
Propagation velocity of antral peristalsis was significantly lower in FD compared to HC. The brain network defined by NTS connectivity loaded most strongly onto the Default Mode Network, and more strongly onto the Frontoparietal Network in FD. FD also demonstrated higher NTS connectivity to insula, anterior cingulate and prefrontal cortices, and pre-supplementary motor area. NTS connectivity was linked to propagation velocity in HC, but not FD, whereas peristalsis frequency was linked with NTS connectivity in patients with FD.
CONCLUSIONS & INFERENCES: Our multi-modal MRI approach revealed lower peristaltic propagation velocity linked to altered brainstem-cortical functional connectivity in patients suffering from FD suggesting specific plasticity in gut-brain communication.
功能性消化不良（FD）是一种胃肠脑相互作用紊乱，其假定的病理生理学涉及胃动力调节和胃传入的中枢处理异常。迷走神经调节胃蠕动，并将感觉传入信息传递到脑干核，特别是孤束核（NTS）。在这里，我们将胃动力学的 MRI 评估与 FD 患者和健康对照者（HC）的 NTS 与大脑的功能连接测量相结合，以阐明肠脑轴通讯如何与 FD 的病理生理学相关。
FD 和 HC 受试者在摄入基于食物的对比餐后接受了一系列胃 MRI 和脑 fMRI。使用重复测量 ANOVA 模型，控制摄入的体积，从 4D 电影 MRI 数据中估计的胃功能指数在 FD 和 HC 组之间进行比较。在组间对比 NTS 的大脑连接，并与胃功能指数相关联。
FD 患者的胃蠕动传播速度明显低于 HC。由 NTS 连接定义的脑网络主要加载到默认模式网络上，而在 FD 中更多地加载到额顶叶网络上。FD 还显示出与岛叶、前扣带和前额叶皮质以及补充运动前区更强的 NTS 连接。在 HC 中，NTS 连接与传播速度相关，而在 FD 中则不相关，而蠕动频率与 FD 患者的 NTS 连接相关。
我们的多模态 MRI 方法显示出较低的蠕动传播速度，与 FD 患者的脑干-皮质功能连接改变有关，这表明肠道-大脑通讯存在特定的可塑性。
