By Celeste Cooper, RN
October is dysautonomia awareness month. But what is dysautonomia?
Dysautonomia is a term used to express dysfunction in the autonomic nervous system. The autonomic nervous system (ANS) consists of two branches, the sympathetic, and the parasympathetic.
The sympathetic nervous system prepares the body for fight or flight in stressful situations. It gives us superhuman powers in a fearful or dangerous situation, like being able to lift a car off someone who is trapped. Certain things take place, like the release of adrenaline, heart rate increasing, etc. These things happen so our muscles can have more oxygen.
The parasympathetic nervous system counterbalances the sympathetic nervous system. It calms the body, so we aren’t stuck in fight or flight mode after the threat has dissipated. It is the parasympathetic nervous system that normalizes things after the threat is gone. It provides a check and balance system, so we can do everyday things, like digest food and sleep. Both branches of the autonomic nervous system work “automatically” to provide the body balance and well-being, homeostasis.
Scientists have identified multiple abnormalities in fibromyalgia, including problems in the central nervous system and the autonomic nervous system, but for this article, we are discussing the role of the autonomic nervous system in fibromyalgia.
According to Dr. Roland Staud, “ANS abnormalities include but are not limited to: tachycardia, postural intolerance, Raynaud’s phenomenon, and diarrhea or constipation. Heart rate variability analysis of FM patients can be used to assess ANS dysfunction, specifically related to sympathovagal balance. “(1)
That last one was a mouth full. Sympathovagal is a term that describes the relationship between the sympathetic branch of the autonomic nervous system (fight or flight) and the vagus nerve (which controls parasympathetic responses, such as heart rate and digestion). An example of sympathovagal imbalance would be emotional stress causing an irritable bowel (IBS) attack or Raynaud’s phenomenon. Both IBS and Raynaud’s phenomenon also occur due to factors that are independent of emotional stress, but in this example, both are indicators of sympathovagal dysautonomia. As suggested by Dr. Staud, both have been implicated in fibromyalgia.
Heart Rate Variability
Heart rate variability (HRV) is a fluctuation in time intervals between heartbeats. These variances occur in milliseconds measured on an EKG graph. You can’t feel them with your pulse. There are several factors involved, but generally, low HRV is associated with illness and high HRV is associated with physical fitness.
According to a research review, the majority of researchers observed lower HRV in FM patients.(2) Particularly interesting, scientists found nocturnal heart rate variability could be a potential biomarker for fibromyalgia.(3) Since poor sleep has been associated with both fibromyalgia and low HRV, this could be significant. The good news is that treatments, such as resistance training, biofeedback, and even massage may increase HRV.
Dysautonomia and Neurally Mediated Hypotension (NMH)
Depending on our activity, our vital signs fluctuate. As we walk or run, our heart rate, blood pressure and respirations (breathing rate) work together to meet the increased oxygen demand necessary for making our muscles work. When this doesn’t happen, there are consequences to pay.
In neurally mediated hypotension, there is a lack of normal equalization, called orthostatic intolerance, indicated by a sudden drop in blood pressure with position changes as simple as standing from a seated position.
Symptoms of NMH include:
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- Exercise intolerance
If you suspect you have NMH, please discuss your symptoms with your physician or cardiologist.
Postural Orthostatic Tachycardia (POTS)
Postural orthostatic tachycardia refers to an autonomic dysfunction related to heart rate. There is an abnormal raise in heart rate with position changes, orthostatic intolerance. Interestingly, small fiber neuropathy has been implicated in POTS(4) and in fibromyalgia(5).
- Abnormal increase in heart rate
- Exercise intolerance
- Extreme fatigue
Other Autonomic Effects
Though the cause of Raynaud’s phenomenon is unknown, it is thought to be due to a disturbance in the sympathetic branch of the autonomic nervous system. The color changes (white and blue), numbness, and extreme cold are due to abnormal constriction of small blood vessels in the hands feet, nose, and sometimes nipples. Re-warming is painful and the affected areas turn bright red as blood rushes back into the tissue.
Several dynamics are at play in irritable bowel syndrome. Smooth muscles that line our digestive tract normally work in a coordinated effort to pass food through the stomach and intestines by gently contracting and relaxing. However, in IBS associated with diarrhea, contractions are excessive in strength and duration leading to functional symptoms of bloating, gas, and diarrhea. In constipative IBS, the opposite occurs, contractions are not strong enough or long enough to move stool through the intestines. In alternating constipative/diarrhea IBS, both occur. Factors that trigger IBS include foods, hormones, bacterial overgrowth, and emotional stress. The cause is unknown.
Whether fibromyalgia is the result of dysautonomia or dysautonomia is a result of fibromyalgia, we don’t really know. But there seems to be sufficient evidence to correlate the two. If you have symptoms of dysautonomia, discuss it with your physician. Diagnosis needs to be made in order to explore possible treatments that will ease your symptoms and improve your health.
1. Staud R. Heart rate variability as a biomarker of fibromyalgia syndrome
Future Rheumatology, Fut Rheumatol. 2008 Oct 1; 3(5): 475–483. (doi: 10.2217/17460818.104.22.1685)
2. Meeus M, et al. Heart rate variability in patients with fibromyalgia and patients with chronic fatigue syndrome: a systematic review. Semin Arthritis Rheum. 2013 Oct;43(2):279-87. doi: 10.1016/j.semarthrit.2013.03.004. Epub 2013 Jul 6.
3. Lerma C, et al. Nocturnal heart rate variability parameters as potential fibromyalgia biomarker: correlation with symptoms severity. Arthritis Res Ther. 2011; 13(6): R185. Published online 2011 Nov 16. doi: 10.1186/ar3513
4. Haensch CA, et al. Small-fiber neuropathy with cardiac denervation in postural tachycardia syndrome. Muscle Nerve. 2014 Dec;50(6):956-61. doi: 10.1002/mus.24245. Epub 2014 Aug 29.
5. Doppler K, et al. Reduced dermal nerve fiber diameter in skin biopsies of patients with fibromyalgia. Pain. 2015 Jul 7. [Epub ahead of print]
Celeste Cooper, RN is an advocate, writer and published author, and she is a person living with chronic pain. She is lead author of Integrative Therapies for Fibromyalgia, Chronic Fatigue Syndrome, and Myofascial Pain and Broken Body, Wounded Spirit, Balancing the See Saw of Chronic Pain (a four book series). She spends her past time enjoying her family and the rewards she receives from interacting with nature through her writing and photography. You can learn more about Celeste’s writing, advocacy work, helpful tips, and social network connections at http://CelesteCooper.com