What is Vagus Nerve Stimulation?
The Vagus Nerve (Cranial nerve X) is the longest of the 12 cranial nerves and plays a HUUGE role in the body’s functions. First of all, the Vagus nerve is a neuromodulator which has motor and sensory fibres that connect the brain stem to many organs in the body which include the heart, lungs, stomach, large intestine, small intestine, spleen, liver, gallbladder, ureter, female fertility organs, kidneys, ears, tongue, and is the main parasympathetic nerve in the body. The Vagus nerve also effects different parts of the brain such as the amygdala, hippocampus, prefrontal cortex, insula in a bidirectional manner from these organs. Recently it was found that stress directly inhibits the Vagus nerve…. Hmmm, it is interesting when comparing the symptoms of stress with Vagus nerve dysregulation? You would have to be splitting hairs to draw a difference, with striking similarities between the two.
This nerve is grossly underappreciated and utilised even with the growing body of evidence showing major improvements in gut health, mental health, cardiac health, inflammatory disorders, autoimmune conditions and epilepsy. Vagus Nerve stimulation may involve manual manipulation of the nerve in the neck, exercises which strengthen Vagal tone, neural tensioners and electrical stimulation with auricular clips (transcutaneous vagus nerve stimulation) or electro needling. Stimulation of the Vagus nerve improves signals going to and from the brain which improves negative feedback loops (If its too high brings it down and if its too low brings it up).
As well as tVNS there are a variety of things which can be done to increase vagal tone with some being more effective for particular conditions than others. Exercises such as gargling, gag-reflex, singing, uvula elevations, meditation and putting the face in a bowl of ice water (divers reflex) all upregulate vagal tone and improves its functions.
Things Transcutaneous Vagus Nerve Stimulation (tVNS) can treat:
Migraine Chronic Pain
Reflux Atrial Fribrillation
Allergy Autoimmune Disease
Epilepsy Behavioural Issues (e.g. autism)
GIT Complaints Digeston
Depression Crohn's Disease
Working Memory Blood Brain Barrier
Cerebral Palsy Inflammatory Disorders
Neuroplasticity via BDNF (stroke, rehabilitation)
So how can the Vagus nerve treat the gut?
The Vagus nerve is what modulates the release of hydrochloric acid (stomach acid) and digestive enzymes Gastrin and Leptin in the stomach. When there is too much hydrochloric acid in the stomach the Vagus nerves afferent fibres perceive this and inform the brain to make a change. An efferent message is then sent down the efferent fibres of the Vagus nerve and levels of hydrochloric acid are adjusted to suitable levels. The same can also be said when there is too little hydrochloric acid when we get slow digestion and bloating as a result. The Vagus nerve also has a motor role and that is it sets the tone of the pyloric sphincter which is the sphincter between the oesophagus and the stomach. When this is weak as a result of Vagus dysregulation, stomach acid can travel up the oesophagus causing heart burn and chronically Barret’s oesophagus. It has also been found that tVNS increases gut permeability, improves peristaltic activity and treats inflammatory gut disorders such as Celiac, SEBO and ileitis.
As a Musculoskeletal Therapist which is a branch of functional medicine it is clear to me the importance of this modern medicine technique in integrative medicine. I have been using tVNS at City Cave to treat patients suffering from thyroid conditions, depression, anxiety, reflux, memory, rehabilitation for the past 4 months with patients reporting weekly improvements. Currently there have been no reported side effects since the begun studies on the Vagus nerve in the 1990s. As the new year is upon us it is time to “wake up to the power of your Vagus nerve and what it can do for you”.
If you have any questions or are unsure whether Vagus Nerve Stimulation is right for you, feel free to contact the practise.
So how can Vagus nerve treat depression and anxiety?
Research shows the tVNS increases noradrenalin, adrenaline, 5-HT and dopamine in the brain. In depression, there are lower levels of these monoamines which has been found to be correlated with decreased mood, focus and attention, memory formation however tVNS has been shown to increase focus, mood, memory and anxiety. It has also been found that tVNS upregulates the prefrontal cortex which is the area for reasoning and responsible for inhibiting inappropriate thoughts or behaviour to normal situations. This is an important part of improving anxiety. Brain Derived Neurotrophic Factor is the fertiliser to neuroplasticity and also a mechanism of action for treating depression and anxiety.
The vagus nerve has a few ways it can treat depression. One of the key ways is it regulates inflammation systemically. Inflammation in the brain correlates to increased depression and anxiety scores. It can also increase norepinephrine in the frontal lobe from the vagus nerve. The frontal lobe plays a huge role in mood regulation, and the majority of dopaminergic sensitive receptors are also located in the frontal lobe. The vagus nerve also directly decreases the activity of areas of the brain that make up the default mode network. The default mode network is made up of different areas of the brain, which are overactive in depression. To go from being in a depressed state to non-depressed state means the brain has to rewire itself. This is called neuroplasticity and a major part of neuroplasticity is brain derived neurotrophic factor (BDNF), which is increased in the brain with vagus nerve stimulation.