Fibromyalgia: How? Why? For what reason?

20. July 2015

It may be so that doctors still held fibromyalgia in the 1990s to largely be due to psychological factors; today more and more studies have noted physical correlates. What causes the controversial illness still remains unclear though.

Physiological correlates

Fibromyalgia syndrome consists of pain in muscles, ligaments, bones and tendons, in all four quadrants of the body, and along the spine. Although blood tests are normal, changes are able to be observed [Paywall], for example an increased concentration of substance P in the free nerve endings of muscles, decreased carnitine concentrations in the muscles as well as an altered serotonin metabolism. As part of a study on the topic, scientists led by Nurcan Üçeyler, University of Würzburg (Germany), in 2013 verified that small nerve fibres are damaged in instances of fibromyalgia.

ACR criteria

Fibromyalgia is among other things diagnosed using the American College of Rheumatology (ACR)’s criteria. The ACR criteria from 1990 state that 11 of the 18 “tender points” of the body need to be diagnosed as painful when subjected to pressure in order to establish the diagnosis “fibromyalgia”. According to the ACR criteria 2010 this rule has been eliminated. Today the following applies: If the Widespread Pain Index (WPI) is reported to be ≥ 7 and the symptom severity score (SS) is ≥ 5, or WPI occurs in the range 3-6 and the SS at ≥ 9, full diagnostic criteria for fibromyalgia have been satisfied. The pains must also have existed for at least three months and otherwise be medically inexplicable. Fibromyalgia is distinguished not only by pain, but also by various vegetative symptoms; the connection between these symptoms and pains involved in fibromyalgia have up until now had been difficult to note.

Central sensitisation syndrome and fibromyalgia

Chronic fatigue, irritable bowel syndrome, chronic headaches, itching, bladder and pelvic pain are just a few of the many complaints that are intertwined with those of fibromyalgia. In the Department of Fibromyalgia and Chronic Fatigue at the Mayo Clinic in Rochester, Minnesota (USA), scientists research “central sensitisation syndrome”, which many fibromyalgia sufferers are also apparently affected by.

This refers to a series of vague but unpleasant symptoms that occur at the same time, such as dry mouth, jaw pain, sleep problems, Crohn Meniere or sick building syndrome. Scientists assume that with central sensitisation syndrome the visceral and central nervous system react hypersensitively, so that the smallest stimuli already lead to strong sensations.

Kevin C. Fleming and Mary M. Volchek describe in a post on April 2015 what it is that physicians should pay attention to in order to become more attentive to central sensitisation syndrome and to avoid unnecessary testing and diagnostic odysseys. After all, it is primarily the multiple examinations that make fibromyalgia so expensive: costs arise each year per patient, depending on the severity of the disease, to the tune of 5000-9000 dollars, write Fleming and Volchek.

Chronic Widespread Pain (CWP) and Fibromyalgia

Whether CWP syndrome and fibromyalgia are two different things is something also being discussed. Arzu Yagiz On and colleagues at Ege-University, Izmir (Turkey), insist that maintaining a distinction between fibromyalgia syndrome (FMS) and CWP is not something useful. In their current study [Paywall] involving 284 patients, they turned to the ACR diagnostic criteria from 1990 and 2010. 65% of patients met the criteria from 1990s and 94% the criteria from 2010. According to the results, FMS occurs along the CWP spectrum. The authors believe that FMS is not a separate diagnostic entity. The delimitation for CWP is said not to be useful therefore, because the multimodal treatments of FMS and CWP are largely identical.

Both patients with CWP and with FMS suffer from insomnia and daytime sleepiness, thereby often allowing a connection between chronic fatigue syndrome and FMS to be deduced. John McBeth and colleagues (January 2015) [Paywall] at the Keele University, Staffordshire (UK), ask the question whether lack of sleep leads to the development of CWP or whether the patient is kept awake by the pain present. They came to a clear “either-or” result: poor sleep can promote the emergence of CWP and CWP can interrupt sleep.

Higher BMI and more anxiety among FMS sufferers

Edgar Adams and colleagues (Covance Market Access Services Inc., Gaithersburg, Maryland, USA) found out in their study [Paywall] that FMS could occur as an extreme point in the CWP range. They were able to evaluate data from 125 patients without CWP, 176 patients with CWP and 171 patients with FMS. It was found that body mass index (BMI) increasingly rose, with CWP-negative participants to a BMI of 28.8, with CWP-positive participants (BMI 30.7) all the way to FMS patients who had a BMI of 32.1.

On the continuity scale from negative CWP all the way to FMS itself increases were found in the intensity of migraines and other headaches, joint aches and bowel irritability (P < 0.003 for all comparisons). Psychological disorders such as anxiety disorders and depression occurred to an increasing extent (p < 0.0001) as well. Similarly, patients with FMS suffer significantly more pain and functional limitations than patients with CWP. Whereas only 32.8% of CWP-negative patients were taking medications, 52.8% of the CWP-positive patients used medications. With fibromyalgia-patients It was 62.6% (p < 0.0001, respectively). Opioids were most commonly mentioned.

One thing is clear: there is still much to be explored in fibromyalgia’s filing cabinet of symptoms. In particular it’s the complex combination of pains, autonomic and psychological symptoms which is a challenge. The elements involved include hormones, the immune system, nerve and muscle tissue, sleep and the psyche. Simpler answers, enlightening links and the study that could reveal everything is something those affected are waiting for eagerly – and perhaps will do so forever.

7 rating(s) (4.57 ø)



It is clear that there is still much to explore. A promising approach would be to focus on the mechanisms of the remission of symptoms of fibromyalgia, and other painful inflammatory syndromes, with the hypotoxic diet (gluten-free, no dairy animals etc.)

#2 |
mag.pharm. Tone Strnad
mag.pharm. Tone Strnad

Is there a clear distinction among ACR, CWP, and polymyalgia rheumatica?

#1 |

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