Clinical pain challenges: fibromyalgia (part one)

Now that I have covered the basics of chronic pain including pain mechanisms, lets start discussing pain conditions. I have picked up one of the most prevalent but also most challenging diagnoses, fibromyalgia (FM).Let's briefly review the evolution of the term. It is VERY important to do this to understand why to this day, many physicians still have difficulties with acceptance of the condition, diagnosis and treatment: The first description of the condition was provided by Guillaume de Baillou (1642), who used the term “muscular rheumatism.”W.R. Gowers (1904) coined the term “fibrositis” to describe pain on touching by the fingertips of muscles hardened by inflammation noting the existence of spontaneous pain and hypersensitivity W. Graham (1953) used the term “fibrositis” to denote a pain syndrome in the absence of any specific organic disease P.K. Hench (1976) coined the term fibromyalgia as a form of non-articular rheumatism. The FM concept was then widely criticized being considered a circular concept, a medicalized disorder or a socially constructed concept H.A. Smythe and H. Moldofsky (1977), described the illness and proposed diagnostic criteria based on key features of non-refreshing sleep and tender points. Yunus et al. (1981) introduced a set of formal criteria to diagnose primary FM. In 1987, the American Medical Association accepted FMS as a disease. A task force by the American College of Rheumatology (ACR), accepted the term Fibromyalgia and produced the first official diagnostic criteria (1990), i.e., pain in response to algometric pressure up to 4 kg/cm2 evaluated in 18 body bilateral points (the diagnosis necessitated a painful response in 11 of these points) In 2010, the ACR proposed a new version of the diagnostic criteria based exclusively on the use of two scales: the Widespread Pain Index (WPI) and the Symptom Severity (SS) Scale. To diagnose FM Syndrome, one of these two conditions must be fulfilled: a WPI ≥ 7 and SS ≥ 5, or a WPI between 3 and 6 and SS ≥ 9. Symptoms must be present for at least 3 months (like the 1990 criteria). The 2010 criteria always require a physician’s assessment and should never be replaced by patient self-report. In 2011, Wolfe et al. revised and modified the 2010 ACR diagnostic criteria (also called the 2011 criteria in Wolfe et al., with further proposed modification in 2016).Currently, only the 1990 and the 2010 criteria have been officially recognized by ACR. The 1990 criteria are stricter than the 2010 criteria, identifying only more severely affected patients. Despite ACR statements, criteria, revisions, and general suggestions (see recent suggestions ad interviews with specialists in J. Montminy article in HealthCare, April 24, 2024), lack of objective diagnostic criteria is a source of frustration among patients and clinicians, and adds to the possible reasons for inaccurate diagnoses. Since I direct a community-based academic clinic serving not only Toronto, but central and southern Ontario, we collect data on our referrals including diagnosis, response to treatments etc.In the first place, 70% of all referrals for pain consultation to our centre are women. Several of these women are being referred with the diagnosis of FM (diagnosed by primary care providers or specialists, without any details how the diagnosis was made). In many occasions, there are several comorbidities reported in the referrals, so FM is not the only diagnosis.A brief look at our data indicates that about 8%-to-10% of patients referred to us every year and possibly more, would meet criteria for FM if one considers disabling whole body pain coupled with sleep issues, mood/anxiety, cognitive issues, etc. These numbers, however, do NOT include the many patients we see with the diagnosis of FM who, instead, have: inflammatory arthropathies and spondyloarthropathies; localized (regional) MSK problems; neurological issues (eg radiculopathies, small fiber neuropathies etc.); and diffuse widespread pain which is the “least of their concern and easily managed” while their primary issue is some specific MSK or neurological problems.In other words, the diagnosis of FM in many cases is made haphazardly. Furthermore, based on our experience (which appears to be the experience of several other clinics), “chronic widespread pain” is interchangeably used with fibromyalgia and includes a large heterogeneous group of disorders; a “cookie cutter” approach does not work.Determining the pain generators in each case is of paramount importance as it leads to rational management of the underlying pain conditions. Even in the case of FM as a co-diagnosis with other biomedical conditions, it is fundamental to understand whether FM pain is the primary complaint or the patient considers it insignificant and rather well managed, while another pain issue is in the driver’s seat. Additionally, if the patient does have widespread pain, is this really “multi-site” such as multi-joint osteoarthritis, or true FM i.e. with widespread tenderness to touch or low grade pressure (indicative of Central Sensitization we discussed earlier). If Central Sensitization is present (alone or with defined biomedical pain generators), it may affect substantially treatments, outcomes and prognosis for chronification.In the next Pain Point, I will be pulling data out of our own database and then discussed short and variable cases (always anonymized with alteration of any detail that could breach privacy).Most information in this article is derived from: Galvez-Sánchez CM, Reyes Del Paso GA. Diagnostic Criteria for Fibromyalgia: Critical Review and Future Perspectives. J Clin Med. 2020 Apr 23;9(4):1219. doi: 10.3390/jcm9041219. PMID: 32340369; PMCID: PMC7230253

Clinical pain challenges: fibromyalgia (part one)

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ANGELA MAILIS

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