- The vagus nerve (VN) comprises an intricate neuro-endocrine-immune network that maintains homeostasis.
- The vagus nerve is the main nerve of the parasympathetic autonomic nervous system. Beyond its vegetative functions, the vagus nerve possesses anti-inflammatory and analgesic properties.
- While most VN fibers are unmyelinated C-fibers from the visceral organs, myelinated A- and B-fiber play an important role in somatic sensory, motor, and parasympathetic innervation.
- Latest studies revealed that VN is also involved in inflammation, mood, and pain regulation, all of which can be potentially modulated by vagus nerve stimulation (VNS).
- The Vagus nerve stimulation was developed to treat seizures but has been investigated for several disorders, including tinnitus, migraine, and pain, by targeting the vagus nerve at sites in both the ear and the neck. Both invasive (surgically implanted) and non-invasive (transcutaneous) techniques of VNS exist.
- Transcutaneous VNS (tVNS) delivery systems rely on the cutaneous distribution of vagal afferents, either at the external ear (auricular branch of the vagus nerve) or at the neck (cervical branch of the vagus nerve).
- VNS has shown promising results in treating chronic inflammatory disorders such as sepsis, lung injury, rheumatoid arthritis (RA), and diabetes. It is also being used to control pain in fibromyalgia and migraines.
- Some questions remain, such as the settings of stimulation, the duration of treatment, or the optimal stimulation route.
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