This month I would like to discuss the vagus nerves and their importance in neural therapy.
The vagus nerves are currently not attracting the attention that they once did. A few decades ago every medical student was taught the indications for vagotomy (usually in combination with partial gastrectomy) in cases of peptic ulcers. The idea was that severing the vagus nerves would decrease acid production and alter peristalsis in the stomach, thereby facilitating healing. This was before the invention of acid suppressing medication and the discovery of antibiotic-sensitive h. pylori in ulcers. These new treatments have made vagotomy (almost) "history". See: http://www.ncbi.nlm.nih.gov/pubmed/15906900?ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum.
Other attempts to treat visceral illness by vagotomy were made in the first half of the twentieth century. In experimental work vagotomy was demonstrated to reduce inflammation in the lungs, stomach and peritoneum (in rabbits). However the price was weight loss, disordered gastrointestinal function and increased morbidity. The procedure therefore did not become established in clinical medicine except in cases of peptic ulcer disease.
The vagus nerve is a major conduit of information between the regulatory centers in the brain stem and the thoracic and abdominal viscera. Its interface with the abdominal viscera is not direct, but rather through the enteric nervous system. Most clinicians know that the vagus nerves carry parasympathetic nerve fibers, but many do not know that 80% of vagus nerve fibers are afferent, i.e carry information to the brain.
The vagus nerves also supply the thoracic viscera and small branches innervate the meninges, part of the external ear and ear canal, the pharynx and the larynx. Its role in a case of recurrent inflammation of the external ear can be seen in plate 1 in my book http://www.neuraltherapybook.com.
In my experience, interference fields in the vagus nerves most commonly occur in
- entrapment by the suboccipital musculature at the exits from the skull.
- irritation of the small intestine, usually from food sensitivity.
Paediatric cranial osteopaths are very familiar with the first category. Infant colic is commonly associated with cranial somatic dysfunction, probably a result of birth trauma. One cranial manipulation is usually all that is required to give the baby (and its parents) complete relief. Presumably normalizing the tissue tension at the cranial base removes the irritation of one or both vagus nerves.
This phenomenon (vagus nerve entrapment) can also occur in adults. A case I saw recently in my office went like this:
A 65 year old woman had been in excellent health until sustaining an injury at work 3½ years ago. While pulling a heavy box off a shelf, the box slipped and she was struck on the right parietal region. The blow stunned her but no other sign of cerebral concussion ensued. From the time of the accident she developed difficulty with balance, vomiting 2 or 3 times a week and right occipital headaches 3 or 4 times a week. She had indigestion, could not eat full meals, but obtained some relief from vomiting. A slight woman, she lost 15 pounds and became underweight. Numerous investigations resulted in a diagnosis of "depression" and she was prescribed antidepressants, with no relief.
On the first visit the only positive physical findings were stiffness in the upper neck, greatly restricted cranio-sacral motion in the cranium and compression of the cranial base. No interference fields could be found in the head, neck or abdominal viscera. Treatment on the first two visits was osteopathic manipulation, resulting in reduced headaches, but little change in the gastrointestinal symptoms.
On the third visit an interference field was detected (by autonomic response testing) in the left vagus nerve. This was treated with the Tenscam device (an electrophysical modality producing an effect similar to that from procaine injections). The response was almost immediate - complete relief of all gastrointestinal symptoms. One further neural therapy treatment was needed a few weeks later. The patient now (three months later) appears to be cured.
Vagus nerve entrapment can occur with head or neck trauma and is not always relieved by manipulation. Neural therapy of the vagus nerve can give lasting relief.
The injection technique is described on page 418 of the old edition of the Dosch textbook and page 318 of the new one. My method is to insert a 1½ in. 27 gauge needle medially through a point just posterior to the ascending ramus of the mandible and anterior to the mastoid. Draw back the plunger to make sure the needle is not in a blood vessel and then slowly inject 5 ml of procaine ½% solution.
Vagus nerve interference fields emanating from the GI tract usually require more than simple treatment of the interference field. This category may be the cause of the infant colic that is not associated with cranial somatic dysfunction. It is also found in adults, presenting with chronic gastrointestinal disturbances of various kinds. Treatment is avoidance of the foods that are causing the irritation. Food sensitivity testing is often needed to sort this out. I will perhaps write more about this in another newsletter.
The Neural Therapy in Practice newsletter was intended as a complement to Dr. Kidd's book, Neural Therapy: Applied Neurophysiology and Other Topics, which is still available for sale through Amazon.