The vagus nerve

Was for a while thought of as ‘just one of the cranial nerves’. Its very name implies it is a wandering vagabond of a nerve, meandering around the body to nearly everywhere (not the adrenals though) and doing this in a vague manner.

 It is one of the cranial nerves but it is also a huge part of the balance between the sympathetic and parasympathetic pathways of our autonomic nervous system. The nerve starts in the brainstem, just behind the ears and travels in multiple branches that diverge from two thick stems rooted in the cerebellum and brainstem, down each side of the neck across the chest and down into the lowest reaches of the abdomen. It connects from the brain to the lungs, the heart, the spleen the guts, the kidneys and the reproductive organs amongst other places. It also networks with the nerves involved in speech, facial expression, eye contact and much more. It receives stimulation from a lot of these organs and the information it receives can be very influential on whether we feel relaxed, confident, capable and energetic (toned) or stressed and alarmed. It conveys information from the different centres back to the brain to get a consensual decision.

Stress, inflammation, trauma, or tension in any region can cause an overall lack of balance or tone or lead to some quite unusual symptoms that are often dismissed as being hypochondria or psychosomatic, or all in the head. The vagus nerve can produce quite pronounced symptoms without the presence of organic disease process but these can be extremely debilitating to people. This happens when the parasympathetic activation of the vagus nerve does not kick in to balance out sympathetic response to adrenaline and cortisol by releasing neurotransmitters like acetylcholine and GABA to slow us down.

The symptoms of loss of vagal tone can be many and varied and may range from:

• Earache with no physical cause. Or other symptoms in the ears such as tinnitus or itching
• A sensation of tightness or a lump in the throat and difficulty swallowing
• Neck tension
• A sensation of pressure in the chest
• Tachycardia, palpitations, or skipped beats
• Stuttering
• Sensations of breathlessness
• Tingling and numbness or Raynauds type symptoms in the hands and/or feet
• Epigastric pain, stomach cramps or butterflies in the stomach
• Strange flitting pains in the intestines
• Faintness, dizziness, lightheadedness
• Nausea
• Sensations of being extremely hot or cold accompanied by sweating
• Fuzzy thoughts, a slight inability to form words
• Weakness
• Visual disturbances such as lights seem too bright, fuzzy or tunnel vision or black spots in the vision
• Nervousness
• Shaking
• Frequent urination
• A desire for copious amounts of cold water
• And others too many to mention

The Obvious

Obviously, some of these symptoms can be indicative of potentially serious organic disease and it is important to make sure these are not present.

The symptoms of vagal imbalance can be acute or chronic, depending on how healthy the vagus nerve is and how well it has retained its ability to return to tone. Chronic conditions can severely affect vagus tone.

Good vagal tone is when the parasympathetic part of the vagus nerve is able to kick in under pressure so that one can relax into dealing with a situation. However, many people today have gone beyond the point of healthy stress into a less coping place; this particularly true amongst many young people. Symptoms can also arise after a period of illness or extreme physical stress or trauma such as a car crash or fall. Extreme or prolonged emotional stress can also cause an imbalance.

For example, a young woman who came to me (the doctors had told her there was nothing wrong). She would get severe stomach cramps, craved large quantities of cold water and suffered painful spasms during and after sexual intercourse. She was extremely stressed about he college studies and the environment in which she was studying.

Some groups of herbs that can help with vagal tone:

Ones containing cyanogenic glycosides such as Sambucus nigra fructus, Achillea millefolium, Prunus serotina . All these herbs can help to rebalance all aspects of vagal tone. For example, one of my colleagues found that Wild cherry bark given for a bout of bronchitis also improved the patient’s digestion and helped bring down their blood pressure.

Volatile oil rich herbs of several classes can help:

Ones with a volatile oil rich in esters have a calming effect on the central nervous system and induce better parasympathetic tone, releasing stress, shock and tension in the system. These include Lavandula species, Cananga odorata, Pelargonium asperum, Anthemis nobilis, Citrus reticulata, Citrus aurantium flos. Citrus aurantium flos is traditionally used in the Lebanon as a ‘rescue remedy’ for clearing shock and trauma. It contains a volatile oil rich in esters which reset the CNS releasing trauma but it is also a gently warming bitter and seems to help balance the pancreas.

Plants

Plants with volatile oil rich in phenyl methyl ethers include Foeniculum vulgare, Angelica archangelica, Pimpinella anisum, Ocimum basilicum and Ocimum sanctum. These are rather more warming and stimulating but with improve both sympathetic and parasympathetic tone in small to moderate doses. Large doses can induce too much sympathetic stimulation.

Plants rich in monoterpenes include (Pinus sylvestris, Boswellia serrulata, Citrus limomum, Piper nigrum, Picea species. These are particularly good at improving vagal tone in the respiratory area although they will also work on other areas.

The pines and spruce are particularly valuable for relaxing and expanding the lungs but also help balance the neuro-endocrine complex (acting on the HPA axis) and thereby improve vagal tone.

Plants containing aldehyde rich volatile oils include Melissa officinalis, Alyosia triphyllata, Cymbogon citratus. These exhibit different actions depending on the dose. Smaller doses are relaxing and improve vagal tone, lowering high blood pressure and relieving digestive spasm. However, higher doses can become over stimulating and irritating.

Plants rich in ketones can be wonderful. We have to be a little cautious with some of them since used for too long or in too high a dose some ketones become neurotoxic and can have the reverse effect to the desired one so they are often used in low dose or for a minimum of about 3 weeks then a break is taken.

Herbs rich in these constituents include Hyssop (used to treat epilepsy), rosemary, sage, mugwort, wormwood and thuja (all rich in thujone), fennel, peppermint and immortelle (Helichrysum italicum whose ketones are non-toxic). Jasmine flowers also contain non-toxic ketones. These plants all have a marked effect on parasympathetic tone.

There are many other examples of other herbs containing volatile oils and oils that are rich in other constituents but this gives some idea of how valuable herbs of this type (and the essential oils extracted from them) are for improving vagal tone.

Bitters

Bitters have a wonderful range of actions on vagal tone since they open the heart and circulation, work on the gut brain and clear the liver and gall bladder amongst other things. There are several classes of bitters and the ones chosen depend on several factors, not least whether the person needs warming (the type who goes cold when vagal tone is not good), cooling (the type who gets hot and sweaty when vagal tone is challenged), or needs balancing (they get temperature fluctuations when vagal tone is compromised).

Bitters are invaluable for balancing vagal tone since they work on the heart, the gut brain, the liver and on the nervous system. There are several classes of bitters and the bitter chosen for a particular individual depends on their particular condition.

Warming bitters are valuable for those who find that they become cold, with low blood pressure and pallor. These include Inula helenium, Angelica archangelica, Citrus aurantium flos, rosmarinus officinalis

Cooling bitters are more suitable for those who experience flushing, heat and elevated blood pressure and include Arctium lappa, Verbena officinalis, Gentaina lutea, Erythrea centaurea, Cyanara scolymus

Balancing bitters normalize the temperature and are good for those who experience alternating heat and cold; examples are Matricaria recutita and possible Stachys betonica. Stachys does a lovely visual description of the vagus nerve with its pink flowers held on rather wiggly stems reaching down to firmly anchored roots and leaves reminiscent of the pancreas.

The Heart

The heart is the largest and most powerful electro-magnetic resonator and centre of neural tissue in the body. As such the heart is the organ that is most able to balance vagal tone. If the heart is happy then this has a wonderful effect on vagal tone so heart herbs such as Leonorus cardiaca, Passiflora incarnata, Crateagus, Tilia, Theobroma, Rosa, Foeniculum vulgare, Melissa officinalis and Rosmarinus officinalis are excellent ones to consider.

Several of our endogenous chemicals are involved in improving vagal tone and allowing us to move through trauma and stress, releasing the trauma of the events so that although we remember the event we do not continually revisit the pain of this. A classic example is the way our hormones assist in childbirth (one of the hardest labour of love) where we release a balance of adrenaline and oxytocin to allow the work to be done (the stressful event to be dealt with) but we also release large amounts of endorphins. Afterward we produce a substance called anandamide which is our endogenous cannabinoid – Cocoa contains anandamide, proanthocyanidins fit into the cannabiniods receptors and blueberry has been suggested as a treatment for PTSD (Vaccinium myrtillus does similar work as does Elderberry, hawthorn, rosehip and sour cherries). Echinacea alkamides also fit into these receptors and this herb has been shown to help treat fatigue and burnout.

Capsicum constituents also fit into these receptors, possibly part of this herb’s slap in the face to re-centre effect. The appropriate stimulation of these receptors can help with vagal tone and re-balancing for sure.

I also wonder whether glucosilinates have an action since they have such a strong effect on the digestive system and the womb?

Any herb that stimulates or improves gut tone will help with vagal tone since if the gut brain is not happy we find it hard to relax and concentrate, to learn and perform well- contrary to present techniques in schooling in many places we actually learn better in community and co-operation rather than being encouraged to compete against others or ourselves or being forced into stressful tests and short fire questions which elicits answers from the adrenalized fear flight sympathetic system or causes a freeze. Having said that with good vagal tone the parasympathetic balances this to move towards fun solutions and engagement of creativity. This is not often welcomed in classrooms but is a great bonus in the real world especially with the challenges we fact at present. Plants such as mustard, horseradish and wasabi, wild rocket all help with gastrointestinal tone and clear the sinuses. Capsella bursa-pastoris is helpful for improving womb tone and reducing bleeding (along with Geranium robertianum, Mentha species and Vaccinium myrtillus).