## INTRODUCTION

ESSENTIALS OF DIAGNOSIS

• Multisite chronic pain: Individuals with fibromyalgia describe widespread pain that waxes and wanes and is experienced for more than 3 months.

• Fatigue: Patients report persistent, moderate to severe mental or physical fatigue that is exacerbated by mild exertion.

• Nonrestful sleep: Research has shown that patients with fibromyalgia have reduced short-wave sleep (SWS) of non–rapid-eye movement (NREM) sleep during which alpha-rhythm intrudes the normal delta rhythm.

• Cognitive symptoms: Patients describe difficulties with executive function, such as working memory and attention. These disease features may be explained by depression and pain.

• Exercise and other therapies that address both body and mind issues are essential to successful treatment strategies.

Fibromyalgia is a common condition estimated to affect between 2% and 8% of the population. It is the leading cause of musculoskeletal pain among women aged 20–55 years. Fibromyalgia is more prevalent in patients with autoimmune disease: approximately 16% of patients with rheumatoid arthritis (RA), as well as 22% of those with systemic lupus erythematosus (SLE) and 15% of those with axial spondyloarthritis, meet criteria for fibromyalgia. Patients with fibromyalgia and RA or spondyloarthritis have also been shown to frequently have higher disease activity scores than in patients without fibromyalgia. The co-occurrence of fibromyalgia and inflammatory rheumatologic disorders can therefore confuse management and prevent achievement of “treat-to-target” goals. Thus, effective treatment of symptoms makes it paramount that rheumatologists consider fibromyalgia when evaluating patients with widespread pain.

Not only is fibromyalgia common, it is also costly to patients and society. The Centers for Disease Control and Prevention has estimated that the total cost of civilian care for fibromyalgia increases at an average of $30 million per year and in 2010 amounted to$232.1 million. Health care costs might be further increased by underdiagnosis of this condition, leading patients to accumulate costs from medical testing and imaging as well as pharmacotherapy and referrals in order to understand and manage their pain levels.

## PATHOPHYSIOLOGY OF FIBROMYALGIA: ABNORMAL OBJECTIVE FINDINGS

Patients with fibromyalgia have altered pain processing compared to normal individuals. Not only do patients with fibromyalgia have increased subjective sensitivity to pain, but a body of literature has also provided objective evidence that there is amplified or enhanced pain processing at the level of the central nervous system (CNS) as demonstrated by electromyography (EMG), cerebrospinal fluid (CSF), functional magnetic resonance imaging (fMRI), and positron emission tomography (PET) studies. This is described as central sensitization syndrome. Evidence shows elevations in neurotransmitters associated with potentiation of pain in the CSF, such as substance P, glutamate, excitatory amino acids, and nerve growth factor, as well as reductions in levels of neurotransmitters associated with inhibition of pain, such as norepinephrine. Concentration of natural opioids have also been found to be elevated in patients with fibromyalgia. EMG studies have also demonstrated that patients with fibromyalgia have measurable differences in pain sensitivity compared to patients without fibromyalgia. ...

### Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.