Fibromyalgia (FM) is a debilitating condition characterized by widespread musculoskeletal pain. It occurs in about 2% of the population, affecting about 5 million people in the United States. Most people diagnosed are middle-aged females, outnumbering males 7 to 1. Symptoms include pain (often in the neck and shoulder area), sleep disturbance, fatigue, headaches, and, often, psychological distress. Adults with FM are 3.4 times more likely to have major depression than those without FM. Unfortunately, the exact cause of FM has not been identified, and risk factors still remain unknown; however, there is sometimes an association with post-traumatic stress or repetitive injuries.
The American College of Rheumatology (ACR) developed clinical diagnosis guidelines for FM in 1990. Diagnosis is based on the presence of widespread pain at least three months in duration and tenderness in at least 11 of 18 pressure points (so-called “tender points” or “trigger points”). Despite recognition as a medical diagnosis by the ACR, some physicians remain skeptical about the syndrome. “Syndromes” by definition, are identified by clusters of signs and symptoms with nonspecific etiologies. As a diagnosis, FM is often missed or misdiagnosed. Sometimes, a diagnosis of FM is a revelation to a chronic pain patient, and sometimes it is a stigma. It’s often seen in women who have contacted countless medical professionals who can’t seem to diagnose them or help them, which inevitably leads to psychological distress. Those patients successfully managing FM (there is no cure) sometimes perceive their diagnosis as a revelation rather than a stigma.
Treatment often begins with medication such as anti-inflammatories, pain medicines, and anti-depressants. Although there is some evidence for their effectiveness, medications are often used to treat symptoms rather than the cause of FM. As stated earlier, however, the cause of FM remains unknown. In order to better treat FM with nonpharmacological methods, we need to better understand the mechanisms of pain processing in FM patients.
Pain Processing in FM Patients
Some researchers have pointed out that, although FM patients feel pain in their muscles, there is little evidence that muscles themselves are the cause of FM, and they find no relationship between pain and muscle activity (Bansevicius et al. 2001, Nilsen et al. 2006, Simms 1996). Patients with FM experience pain differently than those without FM, most notably by a general increase in pain sensitivity, lowered pain thresholds, and altered temperature sensitivity (Gibson et al. 1994, Hurtig et al. 2001, Mountz et al. 1995). It is now thought that the brain and central nervous system play a significant role in FM rather than the musculoskeletal system by itself (Hakkinen et al. 2001, Staud 2002, Staud et al. 2005). Because FM is affected by both the sensory system and motor system, it can be considered dysfunction of the “sensorimotor” system.
Landmark studies by Gracely and colleagues (2002) used functional MRI to investigate pain processing in the brains of patients with FM. Researchers found that FM patients experience pain in totally different parts of the brain than those without FM; furthermore, FM patients’ brains became active with less painful stimuli. These findings, similar to findings in patients with chronic low back pain, point to the brain as the mediator of FM pain.
Exercise as Effective Intervention
One of the hallmark symptoms of FM is the presence of tender, or trigger, points. It’s important to consider these as symptoms of the underlying disease rather than the cause of FM. In other words, clinicians should not directly treat the trigger points; instead, they should treat the central nervous system with appropriate exercise and monitor trigger points as a response to treatment.
Understanding more about the underlying mechanisms behind FM will help improve treatment. In addition to medications and behavioral interventions, research has supported exercise as an effective intervention for FM (Busch et al. 2002, Mannerkorpi & Iversen 2003), particularly when combined with the aforementioned interventions. In particular, supervised, low-intensity aerobic and strengthening exercises are helpful, as are pool exercises. Traditional exercise programs are sometimes ineffective because they are applied without understanding that FM patients respond differently to exercise than those without FM. Patients with FM often take longer to recover between exercise bouts than those without FM.