New Study Shines Light On Vagus Nerve Stimulation – This Time For Chronic Pain Care

June 10, 2020 / Thomas Cohn, MD

ear icon on light background

If you’ve been following this blog for a while now, you know that we’re very interested in how vagus nerve stimulation can be used to help treat certain health conditions. Our focus has mainly been on how vagus nerve stimulation can help with migraine headaches, and we’ve always paid attention to see what new studies are saying about the potential treatment. A new study suggests vagus nerve stimulation may be helpful in treating some forms of chronic pain.

For the study, researchers at the Medical University of Veinna, the Vienna University of Technology and other institutions used what’s known as high-resolution episcopic imaging (HREM) to generate histologic volume data from donated homan cadaver ears. They then used the data to reconstruct anatomical vascular and nerve structures, and a 3D model was used to calculate an optimal stimulation pattern of the vagal nerve branches.

Vagus Nerve Stimulation

It’s a little complicated, but essentially, researchers were able to find three points along the nerve that were within a close radial distance to a good portion of other nerves and vessels. By delivering a series of oscillating electrical pulses to these three areas, researchers believed they could help drown out pain signals.

“The blood vessels can be made clearly visible in patients by shining light through the ear. The nerves, however, cannot be seen,” said study co-author Professor Wolfgang Weninger, MD, of the MedUni Vienna division of anatomy. “Our microanatomical measurements on donated human bodies now tell us exactly where the nerves run in relation to blood vessels, as well as the average distance between blood vessels and nerves at certain important positions of the ear. This helps us to find the correct spot for placing the stimulation electrodes.”

Researchers then took the next step and tested their hypothesis on volunteers with chronic pain. The team said their understanding of pain was proven correct when the triphasic stimulation pattern was tested on real patients.

“In our computer simulation, it was shown for the first time that from a biophysical point of view, a triphasic signal pattern should be helpful, similar to what is known from power engineering, only with much lower magnitude,” said senior author Professor Eugenijus Kaniusas, PhD, of the Institute of Electrodynamics. “Vagus nerve stimulation is often a lifesaving option, especially for people with chronic pain who have already been treated with other methods and do not respond to medication anymore.”

Hopefully we can build on this understanding and really hammer out which types of chronic pain conditions could benefit from this triphasic stimulation of the vagus nerve. It certainly won’t be easy, especially considering that pain is unique to the individual, but it’s another step in the right direction for providing chronic pain patients with the right treatment options.

Daith Piercings, The Vagus Nerve, and Migraines

September 9, 2019 / Thomas Cohn, MD

Daith piercings have been showing success in helping to control migraine headaches. Now there is new research that seems to shine more light on what has been thought to be the mechanism that contributes to the success of this treatment. Research into dementia has recently been done with stimulating the ear with a slight bit of external and intermittent vibration. The research suggests that this may help prevent dementia. The mechanism of action is thought to be by stimulating the ear, a branch of the vagus nerve is also being affected and this is what is producing the results. Similar to what we assumed was happening with the daith piercing, vagus nerve stimulation is the key factor at play.

The latest information on stimulating the ear and the vagus nerve comes from a study out of England and the University of Leeds (Bretherton et al, 2019, in Aging). Stimulating the outer ear for 15 minutes a day for two weeks with gentle electrical vibratory signals improved the relaxation signals and parasympathetic activity. The researchers determined that they were electrically stimulating a branch of the vagus nerve that is in the region of the tragus. In older people (55 years and older) they may have a high sympathetic outflow and this leads to stress, tension, depression and low energy. The transcutaneous electrical stimulation of the ear rebalanced the system and seemed to slow the effects of aging. The major caution was this was a small study so one does not know if these findings would be present in a large controlled study.

The initial research at the University of Leeds in England was done in 2015 and was done in healthy young people. Stimulating the ear with transcutaneous electrical stimulation at the vagus nerve improved autonomic function. Normalizing autonomic function means decreasing sympathetic tone, stress, tension and most likely vascular tone. This would also mean blood vessels would not constrict and could impact the occurrence of migraine headaches.

What It Means For Migraines

Vagus nerve stimulation has a history that is long standing. Vagus nerve stimulation devices were implanted after 2005 for treatment of major depression. They also have been used for gastro-intestinal disorders, epilepsy, and some inflammatory disorders. Now there is an FDA-approved device (GammaCore) to stimulate the vagus nerve through the skin to relieve migraine headaches.

Daith piercings we now know are not placebo treatments for migraine headaches. It is pretty clear they work through stimulating the auricular branch of the vagus nerve in the region of the tragus in the ear. Stimulating the vagus nerve will increase parasympathetic activity and decrease excessive sympathetic tone. This would likely decrease the vascular events that surround migraine headaches. Furthermore it may reduce overall personal stress and anxiety that may be migraine triggers. The piercing would cause physical stimulation of the vagus system and thus rebalance the autonomic nervous system in the body. If piercing is not an option, then using a transcutaneous nerve stimulator (TENs) unit with a very light current to the tragus unit would likely do the same. The good news is that science is validating the practice of this piercing.

As a side note, research is underway specifically on the daith piercing. Studies are being done in England and elsewhere in Europe with regards to the effectiveness of this technique. Whether the daith piercing will work for any one individual is unknown. Since migraines may have a number of triggering causes, the effectiveness of the daith piercing is likely dependent on whether a component of the migraine is related to autonomic balance in the body and if it can be corrected with vagus nerve stimulation. Hopefully we continue to learn more about vagus nerve stimulation and how to best treat these types of migraines in the near future.

Headaches, Daith Piercings, and the Vagus Nerve

December 16, 2015December 16, 2015 / Thomas Cohn, MD

On November 28th, Science News published an interesting article on the science of the vagus nerve in the human body. It is the tenth cranial nerve in the body traveling from the brain to multiple organs in the body. It has thousand of fibers, and it influences functions throughout the body from the stomach and intestines to the heart and brain. The nerve has fibers that travel relatively superficially through the neck and in the skin of the ear. Stimulation of the vagus nerve in the neck has been used for a variety of disorders including many stomach and gastrointestinal problems as well as depression and seizures. Now the ear is the focus of treatment of number of problems by stimulating the vagus nerve as it travels in the region of the tragus of the ear.

The Vagus Nerve and Headaches

Headaches are extremely common. Many people struggle with the management of chronic daily headaches. Drugs are often not the answer, and can oftentimes make headaches worse. A lot of people also do not want to be putting more chemicals into their body. Finding suitable alternatives is difficult. Treatments for headaches run the gamut from diets to all kinds of supplements to stress management. Alternative medicine also has a number of treatments from chiropractic adjustment to acupuncture. Now there may be link to why these therapies work in terms of traditional medical knowledge, it is not just a coincidence they are effective.

Daith piercings and regionalized acupuncture for headache relief may now have a scientific root in the vagus nerve. This nerve has sensory branches that travel in the ear in the region of where the targets for acupuncture are and where a Daith piercing is placed. Electrical stimulation of the ear and vagus nerve has been done to treat headaches, depression, memory loss, and seizures. The vagus nerve has control over a variety of the body’s hormones, including acetylcholine and norepinephrine. The balance of these hormones can be affected by stimulating branches of the vagus nerve. Electrical or mechanical stimulation in the ear can accomplish changes to the branch of the vagus nerve and thus affect any process influenced by this nerve. Headaches have been known to be affected by vagal stimulation, and some have found pain relief through nerve stimulation.

As noted above, some headaches respond to vagal stimulation and improve, while others don’t. There are multiple ways to stimulate the nerve – electrical stimulation, mechanical stimulation as well as medication stimulation. Acupuncture, massage and Daith piercings provide mechanical stimulation of the region and possibly the nerve. Some varieties may respond to different types of stimulation. If your headaches have a vagal component, probably ear massage, electrical stimulation or acupuncture trials will determine if this may be helpful. If those work, consideration of Daith piercing for headaches may be aligned with your treatment strategies. If the above is not helpful, working with a neurologist, a headache specialist or pain specialist may also be helpful to find other solutions.