What Is Fibromyalgia?
The term fibromyalgia comes from the Latin word “fibro” meaning fibrous tissue, and the Greek words “myo” meaning muscle and “algos” meaning pain. The term literally means “muscle and connective tissue pain.” The core fibromyalgia symptoms include chronic pain, fatigue, mood disorders, sleep disturbances, and cognitive dysfunction. This condition also shares many symptoms with chronic fatigue syndrome and lupus. The origins of fibromyalgia pain are unknown.
Fibromyalgia is a syndrome, as opposed to a disease. No primary causation can be determined in those suffering with the condition. The majority of people diagnosed with fibromyalgia pain will consult a rheumatologist, a specialist in the diagnosis and treatment of rheumatic disorders. Some of the cardinal symptoms of rheumatic disorders are swelling, pain, and inflammation in the muscles and joints. More than 100 rheumatic disorders have been described and the most common are rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), osteoarthritis (OA), Sjogren’s syndrome, and ankylosing spondylitis. Fibromyalgia visits run number two to osteoporosis visits among rheumatologists.
Fibromyalgia pain has been called by many other names such as:
- Muscular rheumatism
- Nonarticular rheumatism
- Periarticular fibrositis
- Rheumatoid myositis
- Tension myalgia
- Musculoskeletal pain syndrome
Some scientists believe fibromyalgia represents hypersensitivity of pain transmissions toward and away from the central nervous system. The disorder has multifaceted treatment including drug and non-drug modalities. The treatment team can grow large and may consist of medical specialists, medical subspecialists, and ancillary medical professionals.
Epidemiology and Impact Of Fibromyalgia
Fibromyalgia is diagnosed in 2-4% of the U.S. population. According to the National Fibromyalgia Association, the prevalence represents upwards of ten million people in the U.S. afflicted with the disorder. Prevalence numbers were calculated using the 1990 American College of Rheumatology (ACR) guidelines for the diagnosis of this condition. Some scientists argue the estimation of fibromyalgia prevalence using the ACR’s 1990 classification is too low and fails to capture almost 50% of people with clinical symptoms of the disorder.
Fibromyalgia has a predilection for women, and at its most prevalent has a nine to one ratio in favor of women. The majority of women diagnosed generally range in age from 20 to 50 years. In the past, researchers have found the prevalence of fibromyalgia increases with age. Scientists report that the gender inequality of the diagnosis may be linked to increased anxiety and depression in women. No evidence currently supports a predilection for this chronic pain condition when race and ethnicity are considered. The disorder has been diagnosed in all genders, races, and ethnicities.
The economic impact of fibromyalgia is burdensome. Some estimate healthcare expenditures of a little over $10,000 per patient per annum, or year, for the disorder. The expenditures for fibromyalgia patients are more than three times the average when compared to those with chronic conditions such as high blood pressure, diabetes, and elevated cholesterol. The U. S. government reports people diagnosed with fibromyalgia miss almost 17 days of work per annum. Overall, the estimates of healthcare expenditures related to fibromyalgia treatment represents upwards of $14 billion per year in the U.S.
Causes of Fibromyalgia
The cause of fibromyalgia has never been clearly delineated, although many researchers have examined factors for a link to the disorder. Currently scientists feel this condition is a complex interplay between sociological, biological, and psychological agents. Infections, trauma, and repetitive injury have been studied for their causality with respect to fibromyalgia. The disorder coexists in extraordinarily high prevalence with hepatitis C infections and other rheumatic disorders, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and osteoarthritis (OA). The common characteristic of all the disorders listed is systemic, chronic inflammation.
Fibromyalgia also shares clinical overlap with many diseases such as:
- Multiple chemical sensitivity
- Tension-type headaches
- Interstitial cystitis
- Chronic fatigue syndrome
- Irritable bowel syndrome
- Restless legs syndrome
- Post-traumatic stress disorder (PTSD)
- Temporomandibular joint dysfunction
- Pelvic pain syndrome
Fibromyalgia also shares associations with mental health conditions such as substance abuse, mood, anxiety, and eating disorders. The following diagnoses may coexist with fibromyalgia including:
- Bipolar disorder
- Generalized anxiety disorder (GAD)
- Panic disorder
- Social phobia
- Obsessive-compulsive disorder (OCD)
- Addictions (alcohol, medications, illicit drugs)
Lifestyle and environmental factors may have roles in the development of fibromyalgia pain. Stress related conditions such as IBS, PTSD, and chronic fatigue syndrome share similarities with this condition. Smoking, obesity, and a sedentary lifestyle are other elements that may influence the development of fibromyalgia.
Chemical brain imbalances may play a role in those with fibromyalgia. Neurotransmitters are chemical agents responsible for transmitting electrical signals in the central nervous system. Examples of neurotransmitters are cortisol, glutamate, acetylcholine, glycine, dopamine, serotonin, norepinephrine, and gamma-aminobutyric acid (GABA). Researchers have linked decreased levels of serotonin, dopamine, cortisol, and norepinephrine to the development of this chronic pain condition. In contrast, elevated levels of the neuropeptide substance P have also been linked to fibromyalgia. Substance P is thought to be responsible for the perception of pain and is found in the spinal cord.
Transmission of amplified pain signals are also thought to have a role in fibromyalgia. Functional and structural imaging techniques have been utilized to gain insight into exactly how pain signals move through the brain and spinal cord. Functional MRI has illuminated an increase in blood flow to the area of the brain responsible for processing pain stimuli in people contending with fibromyalgia. Research has also revealed dysfunction in descending pain fibers in those with the disorder. A combination of these two defects may result in an elevated perception of pain, which amplifies pain signals going to and from the central nervous system.
Researchers have also linked genetics, or heredity, to the development of fibromyalgia. In studies, a positive correlation was found regarding the incidence of fibromyalgia being diagnosed in first-degree relatives of those previously diagnosed with the disorder. Researchers have also found defects in the genes responsible for producing the neurotransmitters dopamine and serotonin in the central nervous system of those diagnosed with fibromyalgia. More emerging research is needed to uncover the full influence of genetics on the development of fibromyalgia.
Fibromyalgia is a syndrome with many symptoms. According to the 2010 revision of the American College of Rheumatology’s diagnostic criteria, fibromyalgia consists of chronic, widespread pain and tenderness. The designation of chronic is reserved for symptoms present longer than 12 weeks, or three months. Also the pain should be on both sides of the body, below and above the waistline, and include the vertebral column. In addition to the symptoms above, diagnostic criteria also require chronic fatigue, sleep cycle disturbances, and problems with thinking.
Reported symptoms may include:
- Cold or heat intolerance
- Decreased attention
- Tingling sensations in the hands and feet
- Muscle spasms
- Bladder or bowel incontinence
- Poor balance
- Restless leg syndrome
Patient evaluation for fibromyalgia begins with a detailed medical history and physical examination. Imaging and laboratory testing are also needed for the diagnosis in some cases. Disorders that routinely require diagnostic consideration include hypothyroidism (underactive thyroid), rheumatoid arthritis (RA), systemic lupus erythematosus, and polymyalgia rheumatica. Other ailments to consider include atypical chest pain, multiple chemical sensitivity, chronic fatigue syndrome, sick building syndrome, and vulvodynia. Inciting factors for fibromyalgia may include viral infection or trauma. The majority of those diagnosed with fibromyalgia may not recall an inciting event.
Pathophysiology Of Fibromyalgia
Today, fibromyalgia is thought of as a syndrome of incorrect processing of pain signals. Factors exist that culminate in the amplification of pain messages leading to the generalized, widespread pain of fibromyalgia. Brain imaging has been used by scientists to discover regions of decreased blood flow in the brain of fibromyalgia patients. The specific regions of the brain noted to have decreased blood flow were the basal ganglia and thalamus. Researchers feel the aberrant findings may explain the increased perception of pain experienced by those diagnosed with fibromyalgia.
Serotonin and dopamine are neurotransmitters that play an important role in the perception of pain. Positron emission tomography (PET) surveys have uncovered decreased levels of these two neurotransmitters in the brains of those diagnosed. In addition to pain perception, serotonin is involved in digestion, mood, appetite, and sleep. Likewise, dopamine is involved in memory, attention span, behavior, mood, and sleep. Low serotonin levels have been shown to be a hallmark of this condition.
Researchers have illuminated an increase in levels of a neuropeptide called substance P in the brains of fibromyalgia patients. Substance P is thought to enhance the transmission of pain stimuli to the brain and spinal cord. The substance not only amplifies pain stimuli, but it also amplifies inflammation signals that ultimately lead to more pain. In the end, increased levels of this neuropeptide are felt to heighten pain awareness in those with fibromyalgia.
Other researchers tout dysfunction in the hypothalamic-pituitary-adrenal (HPA) axis as being the impetus for fibromyalgia. Dysfunction in the HPA axis is thought to lead to inappropriate levels of cortisol, high levels of adrenocorticotropic hormone, and decreased levels of growth hormone. Sleep disturbances in those with fibromyalgia can be directly linked to a precipitous decline in levels of growth hormone. The decline in growth hormone can also negatively affect the repair and maintenance of muscle. Overall, a blend of metabolic, biochemical, and immune dysfunction contribute to fibromyalgia.
Fibromyalgia Risk Factors
Risk factors can be defined as conditions, behaviors, or other factors that increase the chances of developing a disease or disorder. Possible identifiable risk factors for fibromyalgia include heredity, gender, age, trauma, and poor physical conditioning. Despite these established risk factors, many patients have no distinguishing risk factors.
Heredity, or genetics, is a possible risk factor for fibromyalgia pain. Researchers have identified gene mutations leading to the enhancement of painful stimuli. The enhancement of painful stimuli has the potential to induce fibromyalgia in susceptible groups. DNA analysis by scientists has revealed familial links to this condition.
Female gender may also play a role in fibromyalgia. Researchers believe the pain pathways in women are augmented by cyclic alterations in the levels of their hormones. The augmentation of pain pathways is thought to contribute to the overall amplification of painful stimuli, which is felt to increase the risk of fibromyalgia in women. The cyclic alterations in the levels of female hormones control the reproductive cycle. The contributing hormones are progesterone and estrogen.
Age is another possible risk factor in the development of fibromyalgia. Most people diagnosed with this condition report pain commencing in the second, third, fourth, or fifth decades of life. Research has revealed the diagnosis of the disorder increases with age. The prevalence of fibromyalgia has been shown to peak from 60 to 79 years of age.
Trauma, whether physical or psychological, is a probable risk factor for fibromyalgia. Research from the American Journal of Medicine has spoken on this subject. Trauma due to physical stressors was examined in categories such as heavy lifting, repetitive movements, and squatting or sitting for extended periods. Trauma as a result of physical stressors was found to lead to fibromyalgia. Trauma due to psychological stressors was examined by looking at disagreements among coworkers and levels of disillusionment with work. Trauma due to psychological stressors was found to directly contribute not only to fibromyalgia, but also correlated with increased pain scores among those included in the study.
Lastly, poor physical conditioning is another probable risk factor for fibromyalgia. Researchers correlate this risk factor to the sleep disturbances commonly seen with this disorder. Fibromyalgia wreaks havoc on the fourth phase of sleep, which is the most restorative and restful phase of sleep. Disruption of the fourth phase of sleep leads to waking unrefreshed. The observation speaks to the importance of regular physical exercise in the management of fibromyalgia, although pain can lead to a significant reduction in physical activity.
Conditions Related To Fibromyalgia
There are many common conditions associated with fibromyalgia. These common disorders can occur together or they can occur alone. The conditions may have significant overlap with the symptoms of fibromyalgia. The following conditions may be related to this condition:
- Irritable bowel syndrome (IBS), or spastic colon, which is a chronic disorder of the colon (large intestine) characterized by abdominal pain and cramping, bloating, gas, and changes in bowel patterns (diarrhea or constipation)
- Osteoarthritis, which is inflammation of bones and joints that leads to deterioration and loss of joint cartilage
- Rheumatoid arthritis, which is the most severe form of arthritis and characterized by swelling, pain, and rigidity in the joints of the feet and hands
- Chronic fatigue syndrome, which is a complicated disorder characterized by extreme fatigue with no identifiable cause
- Tension-type headaches
- Migraine headaches
- Myofascial pain syndrome, which is a disorder characterized by muscle trigger point pain
- Polymyalgia rheumatica, which is an inflammatory disorder causing muscle pain and stiffness
- Hypothyroidism, which is a condition characterized by the thyroid gland producing low levels of thyroid hormone
Diagnosing fibromyalgia can be complicated. An exhaustive medical history, thorough physical exam, and lab testing can lead to a proper diagnosis. Imaging studies are not routinely done, but may be needed, in an evaluation for this condition.
Lab testing may be in the form of the following:
- Complete metabolic panel
- Complete blood count
- Thyroid function tests
- Vitamin D, vitamin B 12, iron, and magnesium levels
- Sedimentation rate
- Anti-nuclear antibody (ANA)
Diagnosis And Classification Of Fibromyalgia
Before 1990, no standard diagnostic guidelines existed for fibromyalgia. The diagnosis of this condition was completely subjective. Some physicians even questioned the existence of such a syndrome. In 1990, the American College of Rheumatology (ACR) published criteria for the formal diagnosis of fibromyalgia. The criteria set forth by the ACR in 1990 are now widely accepted in the medical sphere.
The 1990 ACR criteria for fibromyalgia diagnosis include:
- Widespread pain involving the left and right portions of the body and below and above the waistline. Axial skeletal pain must also be present.
- Pain in 11 of 18 trigger, or tender, points during physical examination. Trigger points are found on both sides of the body near the shoulders, elbows, biceps, hips, chest, buttocks, and knees.
- Other clinical signs and symptoms, which may include fatigue, mood disorders, trouble sleeping, and memory impairment.
Furthermore, the discomfort of this condition must last three months or more after which it is considered chronic. For a trigger point to count as positive, the patient must feel pain not tenderness upon examination. At least four kilograms of force is needed when examining the trigger points. Healthcare professionals should be aware that some clinical disorders coexist with fibromyalgia. As a result, a patient may have a dual diagnosis.
The following trigger, or tender, point sites are examined on both sides of the body when pursuing a diagnosis:
- Low cervical
- Lateral epicondyle
- Second rib
- Greater trochanter
Treatments For Fibromyalgia
There is currently no cure for fibromyalgia. Physicians should express candor about this fact when addressing patients diagnosed with the disorder. Subsequently, the focal points of treatment of fibromyalgia become areas such as patient education, lifestyle adjustments, and medications to keep patients comfortable while coping with the malady. Successfully treating this condition requires a multipronged approach incorporating a mix of drug and non-drug modalities.
Drug classes used in the treatment of fibromyalgia include analgesics (pain relievers), antidepressants, muscle relaxants, antianxiety agents, antipsychotics, and anticonvulsants. Drug therapies are often combined with non-drug therapies that may include:
- Stress management
- Behavioral therapy
- Water therapy and float tanks
Furthermore, treatment requires a large multidisciplinary treatment team, which may include internists, rheumatologists, neurologists, pain management physicians, physiatrists, psychiatrists, nurses, psychologists, chiropractors, exercise physiologists, acupuncture specialists, and physical and occupational therapists.
Medication Treatments For Fibromyalgia
The pharmacological treatment for this condition focuses on improvement of pain, mood, and sleep. Most of the treatment options are evidence-based and primarily derived from randomized, controlled clinical trials. A variety of drug classes are utilized in the treatment of this disorder, which is no surprise since this syndrome has a myriad of symptoms.
Tricyclic Antidepressants (TCAs)
In clinical trials, tricyclic antidepressants (TCAs) in a low dose have been proven to provide short-term relief of pain, mood disorders, and sleep disorders associated with this condition. These drugs were some of the first antidepressants developed by pharmaceutical companies. Today, they are seldom used to treat depression, but they are used to treat other disorders.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Another class of antidepressants with utility in the treatment of fibromyalgia is the selective serotonin reuptake inhibitors (SSRIs). The mechanism of action of these antidepressants is the inhibition of the reabsorption of the neurotransmitter serotonin in the central nervous system. Blocking reabsorption of this neurotransmitter will lead to elevated levels in the brain, which is helpful for some of the symptoms of this condition.
Serotonin plays a major role in the following:
- Mood and social behavior
- Appetite and digestion
- Sexual desire and function
Low levels of serotonin are thought to play a key role in the role development of depression. In clinical trials, SSRIs in low doses were shown to improve pain and depression associated with this condition.
Serotonin/Norepinephrine Reuptake Inhibitors (SNRIs)
A third class of antidepressants called the serotonin/norepinephrine reuptake inhibitors (SNRIs) is also helpful in treating the symptoms of fibromyalgia. The mechanism of action of SNRIs is the inhibition of the reuptake of the neurotransmitters serotonin and norepinephrine.
While antidepressants have proved beneficial in the treatment of this condition, they can also have adverse effects. Potential adverse side effects of antidepressants may include:
- Dry mouth
- Changes in vision
- Increased sweating
- Nausea and vomiting
- Weight gain
- Erectile dysfunction
- Decreased sexual desire
- Urinary retention
Abrupt discontinuation of SSRIs is not recommended due to an increased risk of developing serotonin syndrome. Signs and symptoms of this syndrome include confusion, headache, agitation, rapid heart rate, excessive sweating, nausea, vomiting, diarrhea, and impaired muscle coordination.
A key symptom of fibromyalgia is poor sleep. Benzodiazepines are a group of antianxiety medications helpful in treating sleep disturbances. These medications also ease muscle pain as they have a relaxing effect. Benzodiazepines can be habit forming and should be used judiciously.
Analgesics can also be implemented in the treatment of fibromyalgia. These are medications with the ability to reduce pain. Their mechanism of action is the inhibition of prostaglandins. One of the functions of prostaglandins is to mediate the inflammatory response in the human body. By inhibiting the production of prostaglandins, analgesics reduce inflammation and pain that may be associated with this condition.
Non-steroidal anti-inflammatory drugs (NSAIDs) are a group of analgesics that have the ability to reduce the pain accompanying fibromyalgia. Common adverse effects may include rash, dizziness, swelling, vomiting, nausea, and diarrhea. The most serious adverse effects of NSAIDs are ulcers, bleeding, kidney failure, and liver failure.
Another group of analgesics that may be helpful in treating the chronic pain of fibromyalgia are narcotic pain medications. Physicians should consider their implementation when trials of NSAIDs are inadequate in reducing pain. The mechanism of action of this group is the inhibition of pain signals bombarding the brain. Potential adverse effects of narcotic pain medications include itching, constipation, drowsiness, slowed breathing, confusion, nausea, and vomiting. Medical professionals should exercise caution when prescribing narcotic medications, as the likelihood of abuse and addiction is very high.
Muscle relaxants are another option utilized in treating fibromyalgia. These medications help relieve pain by reducing or eliminating muscle tension. They also may be helpful in the treatment of sleep disorders accompanying this condition. In controlled studies, the muscle relaxant cyclobenzaprine achieved clinically significant reductions in pain. Potential adverse effects of this class are dizziness, dry mouth, loss of coordination, confusion, visual disturbances, and drowsiness.
Furthermore, muscle relaxants lower a person’s seizure threshold and should not be prescribed to those suffering with epilepsy or alcoholism. The elderly are at great risk for confusion and loss of coordination when taking muscle relaxants. Some muscle relaxants, such as carisoprodol, have high potential for abuse and addiction.
Anticonvulsants (Antiepileptic Drugs)
Anticonvulsants are another drug class utilized in treating the symptoms of fibromyalgia. In controlled studies, these drugs achieved significant clinical reductions in fatigue and pain while improving sleep in patients. Historically, anticonvulsants are used in the treatment of epilepsy. Over the years, they have developed off-label uses including the treatment of fibromyalgia. The mechanisms of action of this class of drugs are varied and may be inhibition of sodium channels and upregulation or downregulation of particular neurotransmitters. These actions ultimately decrease pain transmission.
The first anticonvulsant approved by the U.S FDA to be used in the treatment of this condition was pregabalin. Potential adverse effects of anticonvulsants are drowsiness, vomiting, nausea, and liver damage.
Atypical antipsychotics are primarily used to treat psychosis related to bipolar disorder or schizophrenia. Recently olanzapine, an atypical antipsychotic, has been found to provide clinically meaningful reductions in pain for those suffering with this condition. The mechanism of action of this class involves antagonizing, or blocking, D2 receptors, which is felt to decrease the pain hypersensitivity of this condition. Potential adverse effects of atypical antipsychotics include hypotension, drowsiness, dry mouth, diminished muscle strength, fatigue, weight gain, and headache.
The syndrome of fibromyalgia consists of pain, fatigue, and mood and sleep disturbances. These hallmarks are usually accompanied by a plethora of generalized symptoms. Fibromyalgia is best approached with a large multidisciplinary team of healthcare professionals. The treatment of this condition is multifaceted and incorporates pharmacotherapy and non-pharmacotherapy options. Complementary and alternative treatment options are gaining acceptance in the management of the disorder. Today, patients suffering from fibromyalgia may achieve the best possible outcomes due to recent and ongoing research.