Fibromyalgia: Symptoms, Causes, Diagnosis, and Treatment

Introduction to Fibromyalgia

Fibromyalgia is one of the most confounding conditions in medicine today. It is debilitating and results in several quality-of-life issues. What makes it especially difficult is that it is hard both to diagnose and to treat. Most treatment modalities address one or more specific symptoms, but no treatment can comprehensively manage all of them (NIAMS, 2004). More holistic treatment approaches, however, are being researched, explored, and considered. Fibromyalgia often presents with symptoms that mimic other diseases. Essentially, it is characterized by widespread pain that cannot be localized to any single part of the body. It is also associated with fatigue and other specific — though not necessarily widespread — symptoms that are discussed throughout this paper.

Fibromyalgia syndrome, often abbreviated FMS, shares significant symptom overlap with other conditions such as chronic fatigue syndrome (CFS), myofascial pain syndrome (MPS), and multiple chemical sensitivity syndrome (MCS). Some researchers have argued that FMS, CFS, MPS, and MCS are part of a larger meta-syndrome called dysregulation spectrum syndrome (DSS). While there is no large concerted effort to formally identify DSS, one school of thought holds that this myriad syndrome — with its varied epidemiologies and varying acuity of symptom presentation — has its associations in the human neuro-hormonal system. Others have pointed to psychological and sociological factors. Van Houdenhove and Egle offer a biopsychosocial component to fibromyalgia, arguing that physiological manifestations arise from stress (Van Houdenhove & Egle, 2004).

Fibromyalgia's etymology combines three words from Greek: fibro (fibrous), myo (muscle), and algia (pain). It is classified as a rheumatic disease because pain originates from the joints and soft tissues. The word rheum in Greek means "to be in a state of flux," which aptly captures the shifting nature of the condition. Fibromyalgia is often confused with arthritis because of the chronic pain arising from the joints, but it can also afflict other soft tissue. Muscles, bones, joints, and ligaments are all susceptible to pain. Even very slight pressure on certain parts of the body — such as the neck, back, and extremities — can trigger waves of pain.

Notably, fibromyalgia is referred to throughout this paper as a condition rather than a disease. A disease is typically associated with a specific causative agent, defined symptoms, and a well-defined treatment modality. Fibromyalgia is more accurately classified as a syndrome — a collection of symptoms without a well-defined cause and without a single comprehensive treatment modality.

Symptoms

In addition to the debilitating, constant, chronic pain — or pain that varies in intensity — a range of other symptoms are commonly observed in fibromyalgia patients. The pain that most people experience is often described as shooting, throbbing, and stabbing. Patients frequently report that the pain seems to come from deep within the muscles. Pain and stiffness tend to be worst in the morning, and recurring headaches are common.

Recurrent migraines occur in approximately 50% of sufferers. About one quarter of all patients also experience temporomandibular joint dysfunction (TMJD), characterized by pain in the facial and jaw region arising from the ligaments and muscles surrounding the jaw. One of the most functionally disabling symptoms is irritable bowel syndrome (IBS), which can render a person unable to perform daily activities or remain employed. IBS symptoms include upset stomach, diarrhea, nausea, acidity, and constipation, and they affect between 40 and 70 percent of fibromyalgia patients. Another characteristic symptom is extreme sensitivity to atmospheric temperature fluctuations; approximately 40 percent of sufferers experience cold sensitivity due to abnormal responses of blood vessels in the hands, which produce spasms that mimic the body's response to cold stimuli.

Women, who suffer from fibromyalgia more frequently than men, experience more painful menstruation. Studies have shown that middle-aged, post-menopausal women are disproportionately affected. Cognitive problems are also common, including difficulty with motivation, concentration, and memory — a phenomenon patients describe as "fibromyalgic fog." This cognitive impairment is partly attributed to "brain fatigue," as the constant experience of pain leaves little cognitive capacity for other activities. Additional symptoms include dry eyes, muscle stiffness, sensitivity to bright lights, loud noises and certain odors, dizziness, muscle twitching, and painful, swollen extremities.

Those afflicted also experience numbness and tingling in the extremities. Sleep is significantly disrupted; restless leg syndrome (RLS) — the constant involuntary movement of the legs during sleep — is common and prevents sufferers from reaching the deeper stages of restorative sleep. As a result, patients frequently wake feeling unrefreshed, which exacerbates other symptoms. The underlying sleep disturbance is associated with a condition known as alpha EEG (electroencephalogram) anomaly (Gibson, Littlejohn, Gorman, Helme, & Granges, 1994). EEG studies of fibromyalgia patients showed that while the onset of sleep was not significantly different from normal, sudden bursts of brain activity during sleep prevented subjects from reaching the fourth stage — deep sleep — in which the body repairs itself through slowed metabolism. Other sleep-related disorders include sleep apnea, sleep myoclonus (involuntary jerking of the arms and legs during sleep), and a recently identified breathing-related condition called airway resistance syndrome, all of which further disrupt sleep patterns.

If FMS is considered part of the broader DSS framework, it is instructive to compare its symptoms with those of chronic fatigue syndrome (CFS). CFS is characterized by chronic feelings of tiredness that are disproportionate to the level of physical, mental, or intellectual effort expended, and by a distinct onset of symptoms without a genetic predisposition to extreme fatigue. Most symptoms of CFS closely parallel those of FMS, including impaired cognitive function, widespread non-arthritic pain, muscle pain, headaches, disturbed sleep, and unrelenting fatigue. The same hormonal system — the renin-angiotensin-aldosterone system — shows abnormalities in both conditions (Denko & Malemud, 2004).

Depression is one of the primary symptoms of FMS, though it is not considered a cause. A study by Korszun and colleagues demonstrated that sleep impairment leads to eventual depression (Korszun, Young, Engleberg, Brucksch, Greden, & Crofford, 2002). That study divided respondents into four groups: a control group with no signs of FMS or depression; an FMS group without depression; a depressed group without FMS; and an FMS group with depression. The study used actigraphy — a wrist-worn device placed on the non-dominant arm that measures activity levels throughout the day and during sleep. Patients with both FMS and depression showed the most abnormal levels of nighttime activity, while even subjects with depression alone showed elevated unconscious nighttime activity.

Regarding the long-term trajectory of symptoms, most evidence suggests that symptoms neither increase nor decrease significantly over time. Without a cure, patients tend to feel more capable of managing their condition as time passes because they have learned to carry on despite the discomfort. A six-year clinical follow-up study found that most respondents reported better control over their symptoms (Baumgartner, Finckh, Cedraschi, & Vischer, 2002). The parameters assessed included sleep quality, morning stiffness, medication use, functional ability, anxiety, and perceived severity of overall symptoms. Patients did not report meaningful worsening except for certain specific pains.

Understanding Pain

Because pain is the central component of fibromyalgia, understanding its mechanisms and the body's natural responses to it is essential. Pain is the mechanism by which the body protects itself; the capacity to monitor bodily integrity and to be made aware of injury through pain is critical for survival. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage" (Merskey, 1979). Social scientist and registered nurse Margaret McCaffrey offered a complementary perspective: "Pain is whatever the experiencing person says it is, and exists whenever he says it does."

There are several distinct types of pain. Chronic pain persists for a month or more beyond the normal recovery time for an illness and can range from dull and nagging to intense and severe. Acute pain is short-lived and is experienced with injury or acute illness. Breakthrough pain is a third type — short in duration but moderate to severe in intensity, occurring on top of already existing or controlled pain.

Although pain is difficult to quantify, clinicians use several methods to support effective diagnosis. The McGill Pain Questionnaire asks patients to describe their pain in their own words. The Submaximal Effort Tourniquet Test is a physical assessment. The Visual Analogue Scale measures pain along a continuum between two extremes. The 101-Point Numerical Rating Scale (NRS-101) uses a progressive numerical scale from 0 to 100. When these methods are compared, the NRS-101 is generally considered optimal for clinical use (Jensen, Karoly, O'Riordan, Bland, & Burns, 1989). PET and MRI studies, as well as autoradiography in animal models, help identify the neurological mechanisms in the brain and nervous system that are activated following a pain stimulus.

The body contains millions of receptors that carry impulses related to temperature, organ status, and other stimuli. Nerves carry these impulses from the receptors to the brain through bundles of fibers. Large fiber bundles are associated with the sense of touch, while smaller bundles carry pain impulses at a slower conduction velocity. These bundles converge at the spinal cord, and the central nervous system processes the stimulus across multiple brain regions through parallel pathways, ensuring that the pain mechanism can function even if one pathway is damaged. Key structures involved in pain processing and pain relief include sensory receptors and their afferent nerve fibers, the dorsal horns, ascending and descending pathways, the reticular formation in the midbrain and medulla, the thalamus, the limbic system, and the cerebral cortex.

Melzack and Wall (1965) proposed their influential gate control theory of pain, which models a gate-like mechanism that can open or close to allow or impede pain signals from entering the spinal cord — the first processing step before pain reaches the brain. Acupuncture is thought to work by activating points in the system where these gates are located, causing them to close to pain impulses. Earlier frameworks included the Specificity Theory, which held that pain was a distinct system with its own dedicated neurons and pathways separate from other sensory mechanisms, and the Pattern Theory, which proposed that pain receptors are functionally similar to other sensory receptors (Baldry, 1993). In fibromyalgia, pain is most frequently reported as originating in the muscles, though some patients report joint origins.

Conclusion

The preceding report has touched on several aspects of fibromyalgia, including identifying the symptoms, recognizing the prognosis, understanding where current research lies, and suggesting ways in which patients can improve their quality of life. There is a large body of literature dealing with different aspects of the condition. This paper represents a small slice of that knowledge — one that informs while also acknowledging that much more work remains to be done. Approximately two percent of the population in the United States and around the world is affected by fibromyalgia and needs relief. A concerted effort is needed to resolve the surrounding confounding factors so that those who suffer for years can finally obtain the help they need.