Institute of Medical Science, Kangwon National University, School of Medicine, Chuncheon, Republic of Korea.
Neuroscience Research Institute, Kangwon National University Hospital, Chuncheon, Republic of Korea.
PLoS One. 2018 Nov 28;13(11):e0207281. doi: 10.1371/journal.pone.0207281. eCollection 2018.
Vagus nerve stimulation (VNS) is a neuromodulation method used for treatment of epilepsy and depression. Transcutaneous VNS (tVNS) has been gaining popularity as a noninvasive alternative to VNS. Previous tVNS neuroimaging studies revealed brain (de)activation patterns that involved multiple areas implicated in tinnitus generation and perception. In this study, functional magnetic resonance imaging (fMRI) was used to explore the effects of tVNS on brain activity in patients with tinnitus.
Thirty-six patients with chronic tinnitus received tVNS to the inner tragus, cymba conchae, and earlobe (sham stimulation).
The locus coeruleus and nucleus of the solitary tract in the brainstem were activated in response to stimulation of both locations compared with the sham stimulation. The cochlear nuclei were also activated, which was not observed in healthy subjects with normal hearing. Multiple auditory and limbic structures, as well as other brain areas associated with generation and perception of tinnitus, were deactivated by tVNS, particularly the parahippocampal gyrus, which was recently speculated to cause tinnitus in hearing-impaired patients.
tVNS via the inner tragus or cymba conchae suppressed neural activity in the auditory, limbic, and other tinnitus-related non-auditory areas through auditory and vagal ascending pathways in tinnitus patients. The results from this study are discussed in the context of several existing models of tinnitus. They indicate that the mechanism of action of tVNS might be involved in multiple brain areas responsible for the generation of tinnitus, tinnitus-related emotional annoyance, and their mutual reinforcement.
迷走神经刺激（VNS）是一种用于治疗癫痫和抑郁症的神经调节方法。经皮迷走神经刺激（tVNS）作为 VNS 的一种非侵入性替代方法越来越受欢迎。先前的 tVNS 神经影像学研究揭示了涉及多个与耳鸣产生和感知相关区域的脑（去）激活模式。在这项研究中，功能性磁共振成像（fMRI）被用于探索 tVNS 对耳鸣患者大脑活动的影响。
36 例慢性耳鸣患者接受了内耳屏、鼓室腔和耳垂（假刺激）的 tVNS 刺激。
与假刺激相比，刺激这两个部位会激活脑桥中的蓝斑和孤束核。耳蜗核也被激活，而正常听力的健康受试者中没有观察到这种现象。tVNS 可使多个听觉和边缘结构以及与耳鸣产生和感知相关的其他大脑区域失活，特别是最近被推测为听力受损患者耳鸣原因的海马旁回。
通过内耳屏或鼓室腔的 tVNS 通过耳鸣患者的听觉和迷走神经上行通路抑制了听觉、边缘和其他与耳鸣相关的非听觉区域的神经活动。本研究的结果在几个现有的耳鸣模型背景下进行了讨论。它们表明，tVNS 的作用机制可能涉及多个负责产生耳鸣、与耳鸣相关的情绪困扰及其相互增强的大脑区域。
