Understanding Vagus Nerve Stimulation: A Decade of Progress
Despite being relatively unknown, Vagus Nerve Stimulation (VNS) has been the subject of medical research and treatment for over a decade. In the United States alone, hundreds of thousands of operations have been performed, implanting a pacemaker-like nerve stimulator into patients' chests. These devices are connected by wires to the vagus nerve in the neck. Although effective, this method was invasive, labour-intensive, expensive, and prone to complications like infections, wire displacement, faulty batteries, or device failure. Thankfully, this technique has been largely phased out in favour of more affordable, simple, and effective alternatives.
The Evolution: Transcutaneous Auricular Vagal Nerve Stimulation (taVNS)
Many devices can stimulate the Vagus Nerve in the neck, but a unique technique has emerged that offers several advantages. By "hijacking" the sensory branch of the Vagus Nerve in a specific region of the ear, we can send electrical messages to the brainstem. This, in turn, activates the main vagus nerve, resulting in a cascade of benefits. This non-invasive approach is known as Transcutaneous Auricular Vagal Nerve Stimulation, or taVNS.
Side Effects and Contraindications
Side effects are relatively mild and can include rare instances of headaches and fatigue—although this should not be confused with a relaxed state. More commonly, users might experience tingling, pricking, or a sensation akin to pins and needles. Any discomfort or pain in the ear is generally due to the newness and tightness of ear clips, or individual ear anatomy making it challenging to position the clips correctly.
When it comes to contraindications, the primary concern is cardiac-related. Stimulating the Vagus Nerve in the ear can affect the heart, unlike neck-based VNS. While it can slow down the heart rate—beneficial for those with anxiety—it can be problematic for people with arrhythmia, heart disease, or low blood pressure.
Warnings and Precautions
Before using any electrical device, exercise caution around water, open wounds, or infections. Remove hearing aids prior to treatment. Consult your doctor if you have a pacemaker, an active implantable medical device, or are pregnant. Exercise common sense and refrain from using the device while operating machinery or in proximity to microwaves or medical machines like MRIs.
Achieving Effective taVNS Treatment
Many people fail to benefit from taVNS simply because they place the clips incorrectly. The two regions of the ear innervated by the sensory Vagus Nerve are the tragus and the concha. Due to the size and shape of the tragus, it can be difficult to secure the clips. Thus, it is recommend placing both clips in the concha for a secure and comfortable 30- to 60-minute treatment.