Transcutaneous vagal nerve stimulation (tVNS) is a non-invasive technique that involves stimulating the vagus nerve through the skin, typically using a handheld device that delivers electrical impulses. It has gained attention as a potential therapy for various conditions, including headaches, without the need for surgical implantation. Here’s how tVNS can potentially help with Migraines:
Mechanism of Action
Buckle up (or skip this section) as it is about to get nerdy! Some super cool functional MRI (fMRI) studies have shown how tVNS affects the brain in helping to reduce migraine attacks. An area of the brain called the thalamus is thought to play a crucial role in the pain experience during a migraine attack. The neural pathways between the thalamus and cortex are thought to be altered in those with migraines. Recent studies have indicated that through a variety of pathways, tVNS can alter the abnormal connections between the thalamus and cortex. tVNS was also found to activate anti-nociceptive pathways (think of these as anti-pain pathways). The cool part is that with fMRI studies, researchers can see changes in these areas of the brain!
Neck or Ear?
There are two main ways to stimulate the vagus nerve through the skin. One approach is by placing electrodes on specific points on the ear and the other common approach is by stimulating the vagus nerve on the neck. Research has showed efficacy for both approaches. Typically stimulating through the ear is the most cost effective approach because you can use a basic TENS unit with an ear clip electrode – the whole setup will cost around $40. Units that stimulate the vagus nerve at the site of the neck are specialized and cost significantly more. There are two products that I know of that stimulate the vagus nerve at the site of the neck: Truvaga and gammaCore. Truvaga is a wellness device that does not have FDA clearance for treatment of any condition. gammaCore is FDA cleared for treatment of migraine and cluster headaches. You will need to work with a healthcare provider to get a prescription for gammaCore. The major upside of performing stimulation with Truvaga or gammaCore is that treatment time only take a few minutes. When stimulating the vagus nerve through the ear, treatment times are typically around 30 minutes.
How To Setup and Perform At Home
For the purpose of being cost effective and DIY friendly, I am going to share guidelines of completing tVNS through the ear with a simple TENS unit. First step is to get ear clip electrodes and an analog tens unit. I get my ear clip electrodes from TensPros. The TENS 3000 is an example of an inexpensive analog TENS unit (also available on TensPros and amazon). You are going to take one lead (aka the wire with 2 plugs at one end and 1 plug at the other end) and plug the single plug end into one channel on the TENS unit and then attach an ear clip electrode to each of the ends of the lead (one will be black and one will be red). Then place one ear clip electrode on each of the areas depicted by a red dot as seen below:
Now you are going to slide the panel back on the device and turn the frequency dial to 1 hz and the pulse width dial to 200us. Now gently turn on the intensity dial (typically on top of the machine where the lead plugs into). These devices are very sensitive so slowly turn up the intensity until the stimulation is strong but not painful. Leave this on for 30 minutes and complete 3 times a week. You need to be consistent with this intervention for at least 4 weeks. Studies have shown improvement in headache intensity, duration, and frequency with consistent use.
If you have tried this let me know about your experience in the comments below!
References
Zhang, Yue, et al. “Transcutaneous auricular vagus nerve stimulation (taVNS) for migraine: an fMRI study.” Regional Anesthesia & Pain Medicine 46.2 (2021): 145-150.
Luo, Wenting, et al. “The instant effects of continuous transcutaneous auricular vagus nerve stimulation at acupoints on the functional connectivity of amygdala in migraine without aura: a preliminary study.” Neural plasticity 2020 (2020).
Zhang, Yue, et al. “Transcutaneous auricular vagus nerve stimulation at 1 Hz modulates locus coeruleus activity and resting state functional connectivity in patients with migraine: an fMRI study.” NeuroImage: Clinical 24 (2019): 101971.
The Headache Therapist 