A numerical study of the Figure-8 μMS coil configuration for Vagus Nerve Stimulation

Electrical stimulation of the cervical vagus nerve is an emerging field of treatment for various central nervous system (CNS) disorders. Invasive electrical VNS is an FDA-approved intervention for refractory partial-onset epilepsy, treatment-resistant depression, chronic pain (under clinical trials), schizophrenia, PTSD, anxiety, Alzheimer's disease, stroke, and traumatic brain injury. The therapeutic effect of VNS in CNS disorders depends on the stimulation of the afferent vagal fibers. However, the vagus is a mixed nerve containing both afferent and efferent fibers, and the current technology does not allow selective afferent stimulation. Considering the most severe side effect of VNS, bradyarrhythmia, is attributed to the activation of cardiac efferent fibers.