The Autonomic Nervous System and it's Relationship to Headache. by Dr. Dietrich Klinghardt, M.D., PhD Thomas Willis, the “father”of modern neurology, proposed the vascular theory of headache in 1672. He suggested that the source of pain was not the brain itself but nerve fibers being pulled by the distended vessels(1) Harold Wollf reported in 1930 on the autonomic nervous system (ANS) involvement in migraine headaches: he postulated, that the primary cause of migraine is vasoconstriction of the extracranial arteries in the early phases of the headache followed by vasoconstriction -with associated peripheral vasoconstriction in the limbs(2). Other signs suggesting ANS involvement in headache include nausea, diarrhea(3),constipation (4), coldness in hands and feet, paroxysmal tachycardia (5), chest pain (6), variant angina (7), paraesthesia and numbness of the skin and others. The vascular theory of migraine was the generally accepted working model until the cell receptor theory came along around 1970. In 1908 Nobel prize laureate Paul Ehrlich postulated the existence of cell receptors, whose interaction with specific agents was a mechanism responsible for many illnesses. Receptor biochemistry has become the basis for most pharmacological approaches. A recent example is the development of the drug sumatriptan which attaches to the 5-HT1 receptor. Other receptors involved in headache include the alpha-2 receptors, u-opioid receptors and somatostatin receptors. Until today there are numerous theories on the neurophysiology of headache, none of which are completely proven(8). Anatomy To understand the role of the ANS in headache, the anatomy has to be understood. The ANS serves 3 basic functions in the brain: 1. Innervation of the smooth muscle of the vascular tree within the brain. A stress signal within the sympathetic nervous system will generally lead to vasoconstriction in the affected area of the brain 2. Transport of neuropeptides and informational substances within the axons of the ANS into the terminals within the vascular endothelium. Several dozen substances travel via the ANS axons to the endothelium and are released into the bloodstream, causing both local and systemic effects. Serotonin, enkephalin, nitric oxide and the inflammatory peptides such as substance P, neurokinin A and calcitonin gene related peptide are thought to be involved in the genesis of migraine pain. 3. 80% of ANS fibers are thought to be sensory in nature and may be directly involved in pain perception. Sensory autonomic nerves are present in the cranial membranes (dura, arachnoid, tentorium), in the connective tissue and in the walls of the larger blood and lymphatic vessels. The ANS is known to have a wind-up effect (sensitizing effect) on the wide dynamic range(WDR) cells in the spinal chord, which modulate the pain pathway. If pain originates for example in the trigeminal system, this message has to pass through the WDR cells. Is the threshold lowered by arousal of the sympathetic nervous system in the same segment, the pain message passes through the WDR cell up into the brain. Arousal in the ANS can be caused by any excitatory stimulus acting on the axons, nerve endings or ganglia of the ANS. Common in the dental arena are abnormal electrical signals (“abnormal signaling”) arising from dysfunctional scars (from tooth extractions or surgical procedures) or from dysfunctional teeth (decay, incompatible restoration materials, mechanical stress, toxicity from filling materials and infections etc.). The dental pulp has it’s own autonomic nervous system mostly comprised of sympathetic fibers traveling piggyback on the arteries, veins and lymphatic vessels of the toothpulp. The fibers are post-ganglionic and arise in the anterior cervical ganglia (stellate, middle-and upper cervical sympathetic ganglia) and travel to the teeth piggyback on the vessels and trigeminal nerve fibers). Any dysfunction in a tooth or related structure (muscles of mastication, periosteum, dental ligaments, jaw joint capsule) may cause arousal in the adjacent sympathetic fibers, causing local or systemic electrical chaos in the ANS, which in turn can often result in the clinical picture of headache. This includes organic headaches, tension headache, cluster headache, TMJ/dental related headache, migraine headache, cervicogenic headaches, sinus headaches and others. Treatment Options Only 3 treatment systems have evolved, that utilize the current understanding of the ANS involvement in headache patients in a sophisticated manner: 1.Acupuncture 2.Biofeedback 3.Neural Therapy Neural Therapy is a treatment modality developed in Germany over the last 75 years, that adresses dysfunction of the ANS in a targeted and specific way. Other treatment modalities certainly work by modifying the ANS, such as chiropractic, cranio-sacral therapy etc., but the practitioner is rarely aware of this fact and is not utilizing the current physiological and anatomical knowledge base to further improve skills and results. Health issues, that affect the ANS Research has shown, that the ANS is commonly disturbed by a selected number of factors: 1.membrane instability caused by nutritional and hormonal deficits (i.e.: a number of nutrients, such as aminoacids, minerals and vitamins are required for the daily nutrition of a nerve; DHEA and pregnenolone have a membrane stabilizing effect) 2. food allergies 3. toxicity from metals and solvents : mercury toxicity destroys
the enzyme that makes tubulin, a major structural component of every nerve axon 4. emotional factors : unresolved psycho-emotional issues create chronic arousal of the sympathetic nervous system via the
limbic-hypothalamic-ANS axis. 5. occlusal problems: healthy proprioception has a suppressive
effect on pain messages traveling through the WDR cells, poor proprioception facilitates pain signals. Poor occlusion also stimulates
abnormal ANS signals in the ANS nerve endings in the involved structures 6. chronic infections (especially in face and jaw): toxins from teeth are often neurotoxic- interfering with the healthy function of a
nerve 7. electromagnetic and other manmade biophysical stress : nerve
conduction is the spreading of an electric field along the axon of a nerve. Man-made electric and magnetic fields can interfere with that
function, often leading to lasting dysfunction, even if the noxious input is removed 8. the“interference field (IF)” or “focus”
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