Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.
CNS Neurosci Ther. 2021 Mar;27(3):320-329. doi: 10.1111/cns.13449. Epub 2020 Sep 23.
The mechanisms of vagal nerve stimulation (VNS) for the treatment of drug-resistant epilepsy (DRE) remain unclear. This study aimed to measure spontaneous brain activity changes caused by VNS in DRE patients using resting-state functional MRI (rs-fMRI).
The rs-fMRI scans were performed in 16 DRE patients who underwent VNS surgery. Amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) was generated and examined using paired sample t-test to compare activity changes at different current intensity stage. The preoperative and postoperative ALFF/ReHo were also compared in eight responders (≥50% reduction of seizure frequency three months after surgery) and eight nonresponders using paired sample t-test.
The significant ALFF and ReHo changes were shown in various cortical/subcortical structures in patients under different current intensity. After three months of stimulation, responders exhibited increased ALFF in the right middle cingulate gyrus, left parahippocampal gyrus, and left cerebellum, and increased ReHo in the right postcentral gyrus, left precuneus, left postcentral gyrus, right superior parietal gyrus, right precentral gyrus, and right superior frontal gyrus. Nonresponders exhibited decreased ALFF in the left temporal lobe and right cerebellum, increased ALFF in bilateral brainstem, decreased ReHo in bilateral lingual gyri, and increased ReHo in the right middle frontal gyrus and right anterior cingulate gyrus.
The spontaneous neural activity changes in DRE patients caused by VNS were in an ongoing process. Increased ALFF/ReHo in frontal cortex, cingulate gyri, precentral/postcentral gyri, parahippocampal gyri, precuneus, parietal cortex, and cerebellum may implicate in VNS-induced improvement in seizure frequency.
迷走神经刺激（VNS）治疗耐药性癫痫（DRE）的机制尚不清楚。本研究旨在使用静息态功能磁共振成像（rs-fMRI）测量 VNS 引起的 DRE 患者的自发性脑活动变化。
对 16 例接受 VNS 手术的 DRE 患者进行 rs-fMRI 扫描。使用配对样本 t 检验生成并检查低频波动幅度（ALFF）和局部一致性（ReHo），以比较不同电流强度阶段的活动变化。还使用配对样本 t 检验比较了 8 名（术后 3 个月癫痫发作频率降低≥50%）和 8 名无反应者的术前和术后 ALFF/ReHo。
在不同电流强度下的患者中，不同皮质/皮质下结构显示出显著的 ALFF 和 ReHo 变化。刺激 3 个月后，反应者表现出右侧中央扣带回、左侧海马旁回和左侧小脑的 ALFF 增加，以及右侧中央后回、左侧楔前叶、左侧中央后回、右侧顶叶上回、右侧中央前回和右侧额上回的 ReHo 增加。无反应者表现为左侧颞叶和右侧小脑的 ALFF 减少，双侧脑干的 ALFF 增加，双侧舌回的 ReHo 减少，右侧额中回和右侧前扣带回的 ReHo 增加。
VNS 引起的 DRE 患者的自发性神经活动变化是一个持续的过程。额叶、扣带回、中央前/后回、海马旁回、楔前叶、顶叶、小脑的 ALFF/ReHo 增加可能与 VNS 诱导的癫痫发作频率改善有关。
