The Autonomic Nervous System (ANS) is a critical part of the nervous system that is responsible for a number of sub-systems including the endocrine, immune, digestive, urinogenital, cardio-vascular, endocrine and respiratory systems.   It is also controlling the involuntary muscles of all the above systems and vital body functions, including sweating, fluid balance and reflexes.  The Autonomic System regulates all the organs connected to these sub-systems, for instance, heart, lungs, kidneys, bladders, glands, etc.

The Autonomic Nervous System is very susceptible to stress, which can be psychological, physical or environmental in nature.

The ultimate goal of the Autonomic Nervous System is to regulate all sub-systems and maintain a healthy equilibrium in the body.

The Autonomic Nervous System has two subsidiary systems:  the sympathetic and the para-sympathetic.  The sympathetic can be looked as the gas pedal of a car which, when needed, will charge the system and make it ready to deal with demands from different parts of the brain. The para-sympathetic is equivalent to the brake pedal, which slows the system down.

The sympathetic is in action when the individual is under stress or requires a higher level of arousal, whereas the para-sympathetic is more active when the person is asleep, relaxing or recovering.  A healthy individual has a balance between the two branches of the autonomic nervous system.

There are many causes for chronic conditions such as chronic fatigue, chronic pain, emotional disorders, or chronic sleep disorder.  They include injuries, prolonged stress or post-traumatic stress disorder and neuro-chemical imbalances; genetic pre-dispositions may also be playing a role in the background.  It has been observed that when the ANS is out of balance, susceptibility to illness is far greater.  There is some “chicken and egg” in play, i.e. does the autonomic system get out of balance because of illness or does the imbalance of the autonomic facilitate illness?  The truth is most likely a combination of the two.

Clinicians looked at the phenomena of patients who do not respond well to traditional treatment modalities, realizing that their Autonomic Nervous System was out of balance. This may explain the resistance to the different treatments.

Assessment of the Autonomic Nervous System

Until recently, there were no accurate scientific tools to assess the ANS and its function.  However, since the introduction of HRV (Heart Rate Variability) analysis, we can now obtain a much clearer picture of how the Autonomic Nervous System is working.  What is HRV? It is a way to measure an individual’s ability to respond to changes as directed by the autonomic nervous system by measuring changes in the cardio-vascular system.  The demands put on the body are immediately relayed to the heart via the ANS to allow it to respond to such changes.  These changes in heart rate variability are analyzed to determine ANS activity.

The second part of the assessment includes an analysis of respiratory activity.  Both assessments serve to indicate how strong and how much in balance the autonomic nervous system is.  There could be four areas of imbalances, which include the following:

Excess sympathetic activity.
Excess para-sympathetic activity.
Over-activity of both sympathetic and para-sympathetic activity.
Under-activity of both.

Heart Rate Variability and  Fibromyalgia, Chronic Pain and Chronic Fatigue

There is now data that connects this regulation of the ANS and the above-mentioned conditions.  Dr. Manuel Martinez Lavin, an American rheumatologist, measured the patterns of dysfunction of the Autonomic Nervous System in patients with chronic pain and chronic fatigue. He discovered that Fibromyalgia patients exhibited relentless hyperactivity of the sympathetic nervous system, which was evident during awakening as well as during sleeping hours.  This can explain why Fibromyalgia and chronic fatigue sufferers have sleeping problems.  These individuals also reacted more drastically to stress, which according to Dr. Lavin, explained some of their symptoms such as profound fatigue and morning stiffness.  This may also explain associated symptoms including irritable bowel, urinary discomfort, and numbness.  Such hyper sympathetic activity may also serve to understand the chronic nature of their pain, a phenomena known as “sympathetically maintained pain.”

Treatment

Although a definite treatment for curing Fibromyalgia and chronic fatigue, has not been found yet, studies are showing that the modalities that help in balancing the Autonomic Nervous System serve to reduce the symptoms and in some cases, eliminate them.

Clinicians who use HRV spectrum analysis equipment can point out to different mental exercises and techniques that help in achieving such balance.  It has been observed that with such techniques, patients have experienced reduced pain, improved sleep, relaxation and improved sense of well-being.

Conclusion

The existence of modern modalities to assess and treat the ANS is of great hope for sufferers of chronic conditions. With better understanding of the role of the Autonomic Nervous System in various chronic conditions, more treatment modalities will be created to provide further relief or, in some cases, even cure of such conditions.  As researchers continue to understand the different mechanisms involved, our ability to treat these conditions more effectively is expected to further improve and hopefully even eliminate related symptoms.

References:

Dr. Martinez M. Lavin, M. Hermosillo AG, Autonomic Nervous System Dysfunction explain the multi-system of Fibromyalgia.  Semin-Arthritis, Rhume Arthritis, Rheum 2000,29:1907.