Mosquera Mario A, Leon-Ariza Juan S, Fonseca Angelo, Leon-Ariza Daniel S, Iglesias Samuel, Mora Jorge C, Leon-Sarmiento Fidias E
Surgical Neurophysiology, Baptist Health, Miami, USA.
Family Medicine, Saint Francis Hospital, Wilmington, USA.
Cureus. 2025 May 9;17(5):e83802. doi: 10.7759/cureus.83802. eCollection 2025 May.
Historical studies reported that electrical stimulation applied over vagus nerve (VN) afferents from the tragus of the human ear-induced skull responses labeled as the vagus nerve somatosensory evoked potential (VSEP). Miscellaneous results acquired from healthy and diseased populations suggested that the origin of the VSEP might not correspond to brain neural activity, but rather to unwanted electromyographic oscillations. Our objective is to definitively demonstrate that scalp recordings labeled as the formerly VSEP (fVSEP) are the expression of muscle activity surrounding recording electrodes.
Using surface electrodes, we electrically stimulated the right ear tragus of five healthy male individuals (mean age: 44 ± 12 years) at 2, 4, 6, 8, and 10 mA, respectively. We recorded the VSEP from the skull of participants while they were relaxed and during controlled voluntary craniofacial muscle movements.
Increasing the stimulus intensity significantly paralleled the increase of the motoneuronal recruitment of the fVSEP during relaxed conditions (eyes open: p = 0.04; eyes closed: p = 0.03). Likewise, voluntary craniofacial muscle contractions significantly modified the duration (p < 0.01) and amplitude (p = 0.013) of the fVSEP.
Our results indicate that the fVSEP is the graphical expression of depolarization and repolarization overflow of signals happening at a distance from the source, as well as the electromyographic expression of unwanted muscle oscillations exerted by craniofacial muscle events registered beyond the point of recording. Therefore, the fVSEP should no longer be considered a brain somatosensory evoked potential nor a measure of autonomic function.
历史研究报告称，对人耳耳屏处的迷走神经（VN）传入神经施加电刺激会诱发颅骨反应，标记为迷走神经体感诱发电位（VSEP）。从健康人群和患病群体获得的各种结果表明，VSEP的起源可能与脑神经元活动不对应，而更可能是不需要的肌电图振荡。我们的目的是明确证明标记为先前VSEP（fVSEP）的头皮记录是记录电极周围肌肉活动的表现。
我们使用表面电极，分别以2、4、6、8和10 mA的电流对5名健康男性个体（平均年龄：44±12岁）的右耳耳屏进行电刺激。在参与者放松以及进行受控的自主颅面部肌肉运动时，我们记录其颅骨的VSEP。
在放松状态下（睁眼：p = 0.04；闭眼：p = 0.03），刺激强度增加与fVSEP运动神经元募集的增加显著平行。同样，自主颅面部肌肉收缩显著改变了fVSEP的持续时间（p <0.01）和幅度（p = 0.013）。
我们的结果表明，fVSEP是源距离处发生的信号去极化和复极化溢出的图形表现，也是记录点之外记录到的颅面部肌肉事件所产生的不需要的肌肉振荡的肌电图表现。因此，fVSEP不应再被视为脑体感诱发电位或自主神经功能的测量指标。
