Update: Clinical Challenges in the Diagnosis And Management of Fibromyalgia
Fibromyalgia (FM) is a complex disorder that is difficult to diagnose and treat. It is characterized by chronic pain that occurs throughout the body and is often accompanied by fatigue, non-restorative sleep, mood disorders, and variable somatic symptoms. The challenges of FM are multiple: The exact pathogenesis has been enigmatic, symptoms are variable, and treatment responses are unpredictable. The lack of diagnostic tests and the absence of a gold standard of treatment further complicate FM management.
The prevalence of FM ranges from 2% to 3% of the general population, with women affected between 6 to 9 times more commonly than men.1 Although seen most commonly in middle-aged women, FM is also seen in children, teenagers, and the elderly.
The objective of this paper is to highlight the current knowledge of the pathogenesis and treatment of FM, identify attitudes and practice patterns of physicians treating these patients, and to suggest areas where improvement will enhance clinical care. The authors of the article were part of a Canadian taskforce to study FM. Taskforce participants included family physicians, anaesthesiologists, neurologists, psychiatrists, physiatrists, rheumatologists, nurses, chiropractors, physiotherapists, and a single naturopathic doctor.
Scientific Basis for Fibromyalgia
Recent neurophysiologic studies support the presence of pain in the body in the absence of identifiable physical abnormalites.2-8 Abnormalities in pain processing have been identified at various levels in the peripheral, central, and sympathetic nervous systems, as well as the hypothalamic-pituitary-adrenal (HPA) axis stress-response system.2-8 Documented abnormalities include evidence of peripheral sensitization and wind-up phenomenon; central sensitization with changes in functional magnetic resonance imaging (fMRI) and single photon emission computed tomography (SPECT) scans of the brain; increased levels of substance P in the cerebrospinal fluid; and impairment of diffuse noxious inhibitory control (DNIC). Recent research also points to interactions between peripheral, central bulbo-spinal, and central cortical mechanisms.9,10
Genetic factors may predispose some individuals to a dysfunctional stress response via the HPA axis.11 In addition, there is increasing evidence that early-life adversity—such as the death of a mother, being in institutional care, or family financial hardships—are linked to chronic widespread pain in adult life.12 These interacting factors combined with a stressful event—such as a viral illness, as reported by up to 30% of patients, trauma, or psychologic event—can lead to a vulnerable health status and may trigger FM in some patients.
For many physicians, the diagnosis of FM is a challenge. Fibromyalgia, however, can be positively diagnosed and should no longer be seen as a diagnosis of exclusion. The 1990 American College of Rheumatology (ACR) diagnostic criteria13 were developed as a research tool, but are often mistakenly used as a diagnostic instrument. The ACR criteria require the presence of widespread pain for at least 3 months’ duration with the presence of at least 11 of 18 tender points in designated areas. These tender points, the only physical examination finding that has been used to help validate a diagnosis of FM, are a reflection of an overall reduction in pain threshold. The tender point examination, however, does not represent localized soft tissue pathology, is open to subjective interpretation, and its validity has been questioned in recent reports.
There is currently a move to eliminate the tender point examination from current criteria in favor of incorporating other clinically meaningful symptoms, including sleep disturbance, fatigue, mood disorder, cognitive changes, and various somatic symptoms frequently present in patients with FM. Other commonly described somatic complaints include an irritable bowel or bladder, migraines, restless leg syndrome, intolerance to external stimuli, and excessive sensitivity to medications.
As there is no single routine laboratory test that confirms a diagnosis of FM, it is recommended that only minimal testing, including ordering a complete blood count (CBC), erythrocyte sedimentation rate (ESR), thyroid function test, and creatinine kinase levels, be done in the first instance and that any other investigations or referrals to a specialist be driven by findings on clinical history and examination.14 Appropriate additional testing may be required in selected patients to rule out conditions that can mimic FM, such as an endocrine disorder (hypothyroidism), rheumatic conditions (early inflammatory arthritis or polymyalgia rheumatica), or neurological disease (myopathy or multiple sclerosis). Excessive and unnecessary testing may be detrimental to a patient’s well-being by promoting an illness-centered focus and fostering a sense of uncertainty.
While a positive diagnosis of FM may alleviate patient concerns and is associated with reduced healthcare utilization and decreased investigations, many clinicians continue to question the validity of reported functional disability.15,16 A positive diagnosis also has medico-legal and work ability implications.
Improving the diagnostic abilities of primary care physicians could lead to more rapid and appropriate care.17 Consultation with a specialist may be helpful for selected patients, but primary care physicians should coordinate patient management.18
The ideal FM treatment should take into account the various symptoms that may be present, including sleep disturbances, fatigue, mood disorder, cognitive impairment, and somatic symptoms, which all play a role in modulating the pain experience (see Algorithm). The goals of treatment should be to attain improvement in symptoms as well as function, encouraging the patient to be an active participant in self-management. Documentation of functional outcomes can be achieved by using the Brief Pain Inventory or the Fibromyalgia Impact Questionnaire (FIQ), although use of questionnaires in clinical practice is limited.19
Optimal treatment requires a multidisciplinary approach with a combination of non-pharmacological and pharmacological treatment modalities tailored to pain intensity, function, and associated comorbidities.20,21 Patient education regarding pathogenesis and current treatment options should be initiated early. Patients should be strongly encouraged to work and do other normal activities. Once the patient stops working, getting back into the workforce is more difficult.
Maintenance of healthy lifestyle habits should be the foundation of managing FM. These should include regular physical activity, attention to sleep hygiene, healthy eating habits with weight control, smoking cessation, and avoidance of excessive alcohol and caffeine consumption. Exercise programs (eg, aerobic, strength training, flexibility) should be recommended according to a patient’s fitness level. For those unable to do weight-bearing exercise, aqua therapy may be useful.22