depiction of vagal nerve stimulation, light impulses flowing from the ear into the brain.

Hacking the Nervous System

A remarkable treatment for brain dysfunction has emerged in the last decade called transcutaneous auricular vagal nerve stimulation (taVNS).  It’s the ulitmate hack of your nervous system. taVNS is a form of bioelectric neuromodulation, meaning that it brings about changes in the functioning of the brain.  We use it with patients who are depressed, bipolar, anxious, or suffering from post-traumatic stress disorder. We have had amazing success using taVNS to boost recovery after stroke, traumatic brain injury, and heart attack. It also helps with chronic pain and inflammatory conditions. We also use it with older people who are encountering memory difficulties. Let me tell you more about vagal nerve stimulation…

What is the Vagal Nerve?

The vagal nerve (aka the vagus nerve) is the 10th cranial nerve.  It is the longest nerve in the parasympathetic nervous system. It connects the brain to the pharynx, heart, lungs, kidneys, liver, gallbladder, stomach, pancreas, duodenum, intestines, colon, bladder, and genitals.  The vagal nerve plays a significant role in the control of heart rate, digestion, sexual arousal, inflammation and the immune response, amongst other functions. Of critical importance, the vagal nerve also induces neuroplasticity in the brain.

The vagal nerve is a major component of the parasympathetic nervous system.  Activation of the parasympathetic nervous system causes you to chill out and relax or “rest and digest.”  In contrast, activation of the sympathetic nervous system triggers the “fight or flight” response and hypes you up.  Typically, there is a seesaw relationship between the sympathetic and parasympathetic nervous systems, with only one being dominant at any time. Thus, stimulating the vagal nerve tends to bring down the activity of the sympathetic nervous system. 

Chronic activation of the sympathetic nervous system causes fear, anxiety, elevated blood pressure, rapid heartbeat, inflammation, headaches, and chronic pain.  So taVNS increases parasympathetic tone, lowering BP, slowing heart rate, diminishing pain and reducing inflammation, and quashing depression and anxiety.  I am not saying that chronic sympathetic over-activation causes hypertension, depression, or any of the other conditions we’re discussing. It is not that simple!  What I am pointing out is that taVNS provides a lever by which we are able to damp down symptoms caused by elevated sympathetic tone.

Doing taVNS

When we do transcutaneous auricular VNS, we send mild electrical impulses across the skin (“transcutaneous”) of your ear (“auricular”) and straight into your brain.  We know that we are stimulating the vagal nerve with precision thanks to the discoveries of German neuroanatomists (see below).  The stimulation is so gentle that you can barely feel it.  Three little AAA batteries power the device, so you cannot get a serious shock. So, you really don’t have to worry about any discomfort. 

We attach electrodes to the ear using standard ECG electrodes. That is the cheapest way of doing it. If you’d like, we can use clip-on electrodes at your expense.

Image showing transcutaneous vagal nerve stimulation. You can see the electrode in an ear.
Vagal nerve stimulation. The bioelectric signal travels from the ear into the vagal nerve and then into the brain.

Why Does Vagal Nerve Stimulation Work?

When we do taVNS, we send a signal directly into the brain.  The auricular branch of the vagal nerve forms the solitary tract and then synapses with the nucleus tractus solitarius, a major relay station of vagal information.  From there, the solitary tract travels up the brainstem to synapse with the locus coeruleus, a critical region of the brain that plays a major role in neuroplasticity.

In other words, from the electrode on your ear, a crucial centre for neuroplasticity is only two synapses away!  That is remarkable! taVNS makes neuroplasticity accessible, allowing us to literally change the physical connections within the brain.  It primes the brain, making it malleable and open to change and reconnection, providing, of course, that we use appropriately shaped electrical impulses.

It is interesting too that not only do we have to get the electrode in exactly the right place, we also have to ensure that the intensity of the electrical impulses is correct.  They cannot be too weak or too strong.  Fortunately, science advances and we are quickly figuring out exactly how to fine tune taVNS.

What are the Benefits of Vagal Nerve Stimulation?

VNS has proved to be beneficial for a number of conditions, some of which we have already touched upon.  Let’s list them here:

  • Alzheimer’s disease (not a cure but slows rate of deterioration)
  • Anxiety
  • Autonomic dysreflexia due to spinal cord injury
  • Cardiac failure, especially atrial fibrillation
  • Chronic pain
  • Cognitive impairment
  • Depression
  • Epilepsy
  • Functional neurological disorders
  • Gastric dysbiosis
  • Haemostasis
  • Immunocompromise
  • Kidney dysfunction due to hepatic ischaemia or reperfusion injury
  • Long covid-19
  • Parkinson’s disease
  • Phobias
  • Postural tachycardia syndrome
  • Rheumatoid arthritis
  • Stroke, especially for improving hemiparesis and aphasia
  • Traumatic brain injury

The benefits of taVNS for each of these conditions requires specific comment.  As time goes by, I will write about how VNS positively affects each of these conditions.  It is just too much information for this webpage!

FDA Approval

You might like to know that vagal nerve stimulation (VNS) has been approved as a treatment by the Food and Drug Administration (FDA).  This should reassure you that the treatment is not mumbo-jumbo voodoo nonsense.  VNS was approved by the FDA in 1997 for the treatment of drug resistant epilepsy.  In 2005, it was approved for the treatment of intractable depression.  A series of approvals were granted from 2017 to 2020 for the treatment and prevention of cluster headaches and migraine headaches.  Importantly, in 2021 the FDA approved (invasive) VNS for rehabilitation after stroke.

Some History: The Transcutaneous Revolution

You will want to know that vagal nerve stimulation no longer requires surgery.  In the early days, VNS required invasive surgery during which a stimulator was implanted in the chest wall and a tiny electrode was clamped to the vagal nerve in the neck.  As you would expect, this was a costly exercise and came with attendant risks of infection. 

electroCore, Inc. were the first to come up with a non-invasive solution for VNS, a handheld device called gammaCore.  This is a great idea and has been used effectively for the treatment of headache.  They report that:

During treatments, gammaCore can be placed on either side of the neck where the vagus nerve is located and sends proprietary gentle electrical energy non-invasively through the skin.  The electrical energy stimulates the vagus nerve and begins sending messages to the brain.

Then, in 2002, two German neuroanatomists carefully traced out the auricular branch of the vagal nerve in more detail than anyone had ever done before.  Their research provided game-changing information and meant that we now knew exactly where the vagal nerve terminated in the ear.  That meant that instead of doing surgery or holding a device against the neck, we could now stimulate the vagal nerve by applying an electrode to the ear in precisely the areas identified by the neuroanatomists.  This enables stimulation that is as focused as invasive VNS but without any of the risks.  That’s a brilliant advance!

Vagal Nerve Stimulation: What Next?

Don’t just take my word, read more about vagal nerve stimulation. That should convince you I am not just on a sales pitch. Here is a nice article in Scientific American on VNS in which they focus on the benefits for inflammation, especially in conditions like rheumatoid arthritis and the inflammatory bowel disease Crohn’s.

Here is a link to Wikipaedia’s article on vagal nerve stimulation. Keep in mind that they discuss both noninvasive taVNS and invasive VNS that requires surgery. The side effects that occur with the invasive method do not arise with the taVNS that we use.

NewYork Times published a nice review of vagal nerve stimulation with a focus on benefits for mental health. It’s an easy read. Lastly, if you’re into the technical stuff, here is a review of VNS published in Frontiers of Neuroscience.

Once you’re happy that vagal nerve stimulation is not quackery but a genuine medical treatment backed up by hard science, contact Ormond Neuroscience and we’ll get you going with treatment.