3. Cranial Nerves

The Role of the Cranial Nerves

Head, Face and Neck

The Vagus Nerve, which we explored in the previous section, is one of the Para-Sympathetic Cranial Nerves, that control the muscles and sensory organs of the head, face, and neck.

The Vagus Nerve works in tandem with other Cranial Nerves. In this section, we consider the rest of the Cranial Nerves, which are sometimes numbered 1 to 12, but also have their own names. We will also provide examples of symptoms of chronic illnesses that may be explained by one or more of these Nerve pathways becoming weak or having low “tone”.

EYES

2, 3, 4, 6 OPTIC NERVEOCULOMOTOR NERVETROCHLEAR NERVE , ABDUCENS NERVE 

Cranial Nerve 2 –  “a paired nerve that transmits visual information from the retina to the brain.” 


Cranial Nerve 3 – “supplies muscles that enable most movements of the eye and that raise the eyelid and enables the ability to focus on near objects as in reading.”


Cranial Nerve 4 – ” a motor nerve that supplies the superior oblique muscle” which controls turning of the eye in the socket, in particular the actions of looking down or towards the nose.


Cranial Nerve 6 – “a motor nerve that supplies the lateral rectus muscle of the eye” which controls turning of the eyes outwards, away from the nose.

Eye and vision problems abound in chronic illness, from dry eyes, involuntary closing of the eye lids, to fixed and unfocused eyes.

Visual problems that have been strongly correlated with chronic illnesses include issues with: visual acuity; contrast sensitivity; color vision; motion perception; visual disturbances and hallucinations.

Physical and structural changes to the eye and retina have also been found in people with chronic illness, as determined by a number of modern eye examination methods. 

FACE

5, 7 TRIGEMINAL NERVEFACIAL NERVE

Cranial Nerve 5 – “a nerve responsible for sensation in the face and motor functions such as biting and chewing.”

Cranial Nerve 7 –

“emerges from the brainstem, controls the muscles of facial expression, and conveys taste sensations from the anterior two-thirds of the tongue and oral cavity.” 

A blank or expressionless face is one of the classic signs of chronic illness, used as a principle diagnostic point by neurologists. If this is allowed to progress, the face can take on a “plastic mask” appearance: featureless (puffy), with a “waxy” or shiny appearance. Problems chewing, over-clenching and misalignment of the jaw are common symptoms too. Indeed, temporomandibular joint (TMJ) disorders are strongly correlated. 

EARS

VESTIBULOCOCHLEAR NERVE

Cranial Nerve 8 – “the auditory vestibular nerve, transmits sound and balance information from the inner ear to the brain.”

People with chronic illness may have very poor balance and may experience dizziness. These symptoms become more pronounced if the disease is allow to progress. People with chronic illness are often hyper-sensitive to noise and can become averse to listening to music.

TONGUE

GLOSSOPHARYNGEAL NERVE 

Cranial Nerve 9 – “connected to tasting, swallowing, salivary secretions and visceral pain, supplying the tonsils, pharynx, middle ear and the posterior third of the tongue.”

Loss of sense of taste is strongly associated with chronic illnesses, as is dry mouth, thickened saliva and/or dribbling. Visceral pain (dystonia) is also frequently involved.

GUT, ORGANS

10 VAGUS NERVE 

Due to the far reaching effects of this nerves influence, the Vagus Nerve:

“…it’s a unique cranial nerve in that it innervates the trunk, the torso, the organs, it actually supplies all of the major trunk organs and it’s a bi-directional nerve -we call it a mixed nerve. It’s got fibers going from the brain to the organs, controlling them, and then it’s got fibers going from the organs to the brain, which is a way of letting the brain know what’s happening in the torso, in the body,

NECK, SHOULDERS

11 ACCESSORY NERVE 

Cranial Nerve 11 – “supplies specific muscles which tilt and rotate the head, and the trapezius muscle, which works the scapula, including for shoulder elevation and movement of the arm away from the body.”

Neck and shoulder problems are extremely common  in chronic illnesses. For example, “frozen shoulder” is a very common initial mis-diagnosis. The head and shoulder movements may be particularly difficult.

TONGUE, MOUTH

12 HYPOGLOSSAL NERVE

Cranial Nerve 12 – “controls tongue movements required for speech and swallowing, including sticking out the tongue and moving it from side to side.”

Speech problems are another classic, major feature of chronic illnesses, as are issues with swallowing.

Video: Muscles of Facial Expression

This video gives a good understanding of some Cranial Nerve functions and helps to visualize the specific muscles.

Exercises to Improve Cranial Nerve Function

The health of the Cranial Nerve functions can be improved or maintained by exercising the relevant muscles.

  1. Take a few minutes to perform the exercise routine just once or twice a day, do not overdo, especially initially – less is more, consistent practice every day is more important.
  2. Hold each expression made for a few seconds, and concentrate (embody) the feelings and sensations created, then relax face before moving on to next.
  3. If particular exercises are difficult to perform, use fingers to assist, or close eyes and simply visualize/imagine making the expression and the muscle movement – even micro-twitches will be beneficial.

ADDITIONAL OPTIONS

  1. Look in the mirror while performing the workout, and consciously notice/observe changes to face.
  2. Gently place finger tips on each muscle which is being innervated.
  3. Rotate daily between exercising left side only, right side only, and both sides.
  4. Find a partner/guide with a healthy Social Engagement/Cranial Nervous System, and follow/mirror/mimic their facial expressions as they go through the routine, exploiting the Mirror Neurons which fire when watching other people move.

FACIAL NERVE EXERCISES

  1. Wrinkle forehead.
  2. Close eyelids gently and relax face.
  3. Close eyes tightly.
  4. Draw eyebrows down and inward.
  5. Frown and wrinkle top of nose.
  6. Flare nostrils out.
  7. Draw nose downwards with septum.
  8. Close lips tight together.
  9. Purse lips as if kissing,
  10. Purse lips as if whistling.
  11. Puff up cheeks, then slowly blow out breath.
  12. Draw corners of the mouth outwards with lips closed.
  13. Draw corners of mouth upwards with lips closed.
  14. Draw corners of mouth downwards with lips closed.
  15. Open lips and show upper teeth by curling/lifting upper lip, opening nostrils.
  16. Starting with lips closed, push lower lip out as if pouting.
  17. Open lips and show lower teeth, by pulling lower lip down.
  18. Smile broadly, showing teeth.
  19. Raise ears (for most people this will require manual assistance with fingers).
  20. Draw ears back (“).
  21. Draw ears up and forwards (“).

Videos: Cranial Nerve Stimulation

Here are some other techniques being used for general Cranial Nerve health. While none of these are quick fixes, anecdotal evidence from people with chronic illnesses suggests practising these over the medium to long term can help to cumulatively reduce symptoms.

Exercising the facial muscles daily is vital to cranial nerve health. Pulling faces or making exaggerated facial expressions is a simple but effective way to do this. Here is a video about facial masking in Parkinson’s Disease, together with a series of optimal exercises for improvement:

Vigorous rubbing of the head and face, using a small amount of coconut oil for lubrication, can be helpful.

A number of stress relieving techniques have been developed around the concepts of tapping key points on the face, head and shoulders with the fingers. These include Emotional Freedom Techniques (EFT) and FASTER EFT. The tapping action stimulates the various Cranial Nerves and hence, as well as quickly providing temporary stress relief, practising these should also help increase the strength or “tone” of the Para-Sympathetic Nervous System over time.

“Paida” is a Chinese practice of gentle head slapping as a therapy. There are many videos one can find on this on youtube, with many benefits claimed.#

Ventral Vagus Complex and the Face-Heart Connection

In the previous section, we mentioned that there is a part of the Para-Sympathetic Nervous System responsible for anti-inflammation, detoxification and restoration. We can now identify those parts with main responsibility for these health giving functions. Dr Stephen Porges calls this the “Ventral Vagus Complex”. It consists of a myelinated part of the Vagus Nerve, called the Ventral Vagus Nerve, and four other Cranial Nerves: Trigeminal, Facial, Accessory and Glossopharyngeal. These nerves control muscles and sensation in the face, biting, chewing, the tongue, tilting and rotation of the head, shoulder movements, ear membranes, sucking in air, and muscles in the throat for vocalization and swallowing.

The Ventral Vagus Complex in humans therefore integrates functions such as head rotation to orient the senses toward the source of stimulation, mastication to ingest food, salivation to initiate digestive processes, facial expression and creating noises for purposes of social communication.

Furthermore, in evolutionary terms, the voluntary muscles supplied by these five Cranial Nerves evolved from regions in the body which were gills in early stages of life, and hence were, and remain, strongly associated with oxygen supply and chemically sensing oxygen and carbon dioxide levels in the body. They influence the rate of rhythmic movements such as heart beat, impacting on states of stress or relaxation, via the voluntary control of breathing, and are also responsible for voluntary control of the volume and tone of vocalizations (speech and making noises).

Hence the overall Ventral Vagus Complex is also strongly associated with movement, emotion, and communication, contributing to the unique social and survival behaviors observed in mammals.

The Ventral Vagus Nerve, however, is not only involved with the regulation of facial muscles, but also the cardiac and pulmonary muscles – heart and lungs. The Ventral Vagus Complex therefore is a two-way communication channel connecting the face to the organs, and the body to the brain. It allows brain function to affect the visceral organs and vice versa. It links the regulation of the heart to that of the facial muscles. It enables our inner physiological state to be written our faces and to be heard in our voice, and enables changes in our facial expression or tone of voice to affect heart/breathing rate.

Many chronic illnesses are known to include both poor regulation of the heart and dampening of facial expressiveness, vocal range and auditory hypersensitivities, and stiff neck. These health problems are connected with loss of ability of the Ventral Vagus Complex to regulate the muscles which it supplies.

This heart-face integrated system comprises a evolutionary purposeful “social engagement” system, allowing humans (and other mammals) to work together in social groupings – we will consider in much greater depth the social aspects in later sections.

This social engagement is downregulated/inhibited in those conditions which include expressionless faces, auditory and language, and neck/shoulder problems as symptoms. A damped social engagement system is bilaterally associated with increased fight-flight or freezing behaviours. When this system is damped early in life, it can lead to significant developmental problems.