By Alan Pocinki, MD, FACP
George Washington University Hospital
Autonomic nervous system (ANS) dysfunction is a common feature of CFS, and can cause symptoms in virtually every organ system. Circulatory symptoms include lightheadedness, cold hands and feet and palpitations or “anxiety.” In the digestive system, autonomic dysfunction can cause nausea, cramps, constipation, diarrhea and bloating. Autonomic dysfunction can also cause abnormal breathing and urinary patterns, and problems with balance and even vision.
With the availability of new in-office technologies for measuring ANS function, it is easy to demonstrate not only the nature of the autonomic dysfunction in CFS patients, but the benefits of treatment as well.
The ANS regulates all body processes that occur automatically, such as circulation (including heart rate and blood pressure), breathing, and digestion. The ANS is divided into two systems: the sympathetic, or “fight or flight,” which generally speeds up body processes; and the parasympathetic, or “rest and digest,” which generally slows body processes, except digestion.
The basic autonomic problem in CFS is the inability to maintain bodily functions at a stable normal level. For example, if the blood pressure drops a little, e.g., on standing up, instead of increasing sympathetic activity a little to raise the blood pressure closer to normal, in many CFS patients, the body increases sympathetic activity too much so that the blood pressure becomes too high. Sensing that it is too high, the body tries to increase parasympathetic activity to bring the blood pressure down, but often overshoots, dropping blood pressure too much – a major contributor to “orthostatic intolerance” – and triggering an increase in sympathetic activity, with this vicious cycle sometimes continuing literally ad nauseum.
Such “over-responses” to physical or emotional stresses, often followed by “over-corrections,” are responsible for many of the ANS problems associated with CFS:
- Chronic stresses such as sickness, pain, emotional stress and even fatigue itself can raise sympathetic activity, producing the “tired but wired” sensation and making it hard to sleep.
- Acute stresses can trigger sympathetic surges, making you jittery and “anxious” (a physical, not psychological, phenomenon).
- Worse, sudden increases in sympathetic activity can trigger excessive parasympathetic “corrections,” causing nausea, sweating, lightheadedness, diarrhea and of course, even more fatigue.
- Even sensory stimuli, such as bright lights or loud noises, can trigger an exaggerated response, resulting in sensitivity to light and sound.
Above is a slide comparing a healthy person's results during a six-step test, comparing them to a person with CFS and dysautonomia on the right. The slide shows both individuals' autonomic responses, sympathetic and parasympathetic, to:
A) before the test (baseline);
B) deep breathing, which should stimulate the parasympathetic system;
C) rest period;
D) valsalva (straining), which should stimulate the sympathetic;
E) rest period; and,
F) standing, which should cause a small increase in sympathetic activity to compensate for the normal small drop in blood pressure on standing.
The sympathetic “modulation” data are based on heart rate variability and parasympathetic data are based on respiratory variability.
The right side of the slide (above) shows the autonomic responses of a CFS patient. Note:
- Even sitting quietly at rest for the first five minutes (period A), there are excessive autonomic fluctuations, as if the ANS is struggling to regulate heart rate and blood pressure even at rest, with no stress.
- With deep breathing (B), there is a small increase in parasympathetic activity, but the body “overresponds” so much that when the deep breathing phase ends, the body feels the need to “correct” for this with a big sympathetic surge at the beginning of the rest period (C). This sympathetic excess then triggers an even bigger parasympathetic surge, slowing the system so much that there is no sympathetic response at all in stage D, when sympathetic activity should be stimulated.
- On standing (F), blood pressure drops initially, leading to an excessive sympathetic response, which in turn triggers an even greater parasympathetic response, which causes a precipitous drop, another rebound sympathetic surge, followed by another parasympathetic surge. Even after three minutes of standing, the ANS is still struggling to get things stabilized.
- The initial sympathetic-parasympathetic swing on standing was the ONLY time during this test when the patient had any symptoms – she was very transiently lightheaded.
- All of the other autonomic fluctuations did not produce any symptoms, suggesting that many CFS patients may have significant autonomic dysfunction and be unaware of it.
- If you think of the energy expended with each increase in sympathetic activity, you can see how a CFS patient could sit most of the day, stand up a few times and still be exhausted at the end of the day.
Below are the test results from another patient with CFS. At the time the test in the left panel was done, she couldn’t concentrate enough to work, was too tired to do almost anything and yet, was unable to sleep. Sound familiar?
In the panel below right, you see the improvement in her autonomic function after 18 months of treatment for pain, sleep, depression and autonomic dysfunction. These results are of course still not normal, but are vastly better than the previous ones, so much so that at this point, she had returned to work full-time. When I saw her a few weeks ago, she had just gone on a five-mile hike.
I think this patient and these pictures, which are typical of virtually every CFS patient I have tested in this way, say more about the importance of autonomic dysfunction in CFS than any words can.
(Editor's Note: There is no single medication that can be prescribed to treat ANS dysfunction and addressing all the problems it causes generally requires an individualized approach using medications, attention to diet, supportive care and lifestyle adjustments. Dr. Pocinki wrote an article titled, ”Developing An Individualized Treatment Plan for CFS,” for physicians that was published in 2005 in our publication, the CFS Research Review. For those who want to learn more about this combination approach to therapy, please check out these two resources:
- A Research1st post “The Ins and Outs of OI,” at http://www.research1st.com/2011/06/19/the-outs-and-ins-of-oi/ which links to lots of info about ANS dysfunction; and
- Dr. Peter Rowe’s general clinical info about OI at http://www.cfids.org/webinar/cfsinfo2010.pdf.
Dr. Rowe and Dr. Pocinki share many common approaches to treating ANS dysfunction and OI.)