Fibromyalgia Syndrome

Alternative names :- Fibromyositis; Fibrositis; Myofascial pain syndrome

The name fibromyalgia is made up from "fibro" for fibrous tissues such as tendons and ligaments: "my" indicating muscles; and "algia", meaning pain. Fibromyalgia syndrome (FMS), previously called fibrositis, is a diffuse pain syndrome and one of the most common causes of chronic musculoskeletal pain. It's characterized by diffuse daily fatigue; widespread pain in the muscles, tendons, and ligaments; and nonrestorative sleep, along with multiple tender points on examination (in specific areas). It affects an estimated 3 to 8 million people in the United States. Approximately 80% to 90% of those affected are women. Although FMS may occur at almost any age, it occurs most commonly in women of childbearing age (between ages 20 and 60) and sometimes may occur in elderly persons and men. FMS has also been reported in children, who have more diffuse pain and sleep disturbances than adult patients. They may have fewer tender points and commonly improve over 2 to 3 years of treatment.

What causes Fibromyalgia syndrome?

The cause of FMS isn't certain. It may be a primary disorder or associated with an underlying disease, such as systemic lupus erythematosus,rheumatoid arthritis, osteoarthritis, and sleep apnea syndromes.

Many theories regarding the pathophysiology ofFMS have been explored. The pain is located mainly in muscle areas; however, no distinct abnormalities have been documented on microscopic evaluation of tender point biopsies when compared with normal muscle. One theory suggests that blood flow to the muscle is decreased (due to poor muscle aerobic conditioning, rather than otherphysiologic abnormalities); another suggests that blood flow in the thalamus and caudate nucleus is decreased,leading to a lowered pain threshold. Still other theories suggest that the cause lies in endocrine dysfunction, such as abnormal pituitary-adrenal axis responses, or in abnormal levels of the neurotransmitter serotonin in brain centers, which affect pain and sleep.Abnormal functioning of other painprocessing pathways may also be involved. Considerable overlap of symptoms with other pain syndromes, such as chronic fatigue syndrome, raises the question of an association with infection, such as parvovirus B 19 and others.

The development of FMS may be multifactorial and influenced by stress (physical and mental), physical conditioning, nonrestorative sleep, neuroendocrine factors, psychiatric factors and, possibly, hormonal factors (due to the predominance in women). Other associated features that can occur with FMS include irritable bowel syndrome, migraine or tension headaches, primary dysmenorrhea, temporomandibular joint pain, myofascial pain syndrome, puffy hands (hand swelling, especially in the morning), and paresthesia. All of these conditions, which commonly overlap, have been grouped under the umbrella term central sensitivity syndrome, which is now under research.

The disorder has an increased frequency among women 20 to 50 years old. The prevalence of the disease has been estimated between 0.7% and 13% for women, and between 0.2% and 3.9% for men.

Signs and symptoms of Fibromyalgia syndrome

The primary symptom of FMS is diffuse, dull, aching pain that's typically concentrated across the neck and shoulders and in the lower back and proximal limbs. It can involve all body quadrants (bilateral upper trunk and arms and bilateral lower trunk and legs) and is typically worse in the morning, when it's sometimes associated with stiffness. The pain can vary from day to day and be exacerbated by stress, lack of sleep, weather changes, and inactivity.

Sleep disturbance in FMS is another suggested factor in the development of symptoms. Many patients with this syndrome describe a habit of being a light sleeper, with frequent arousal and fragmented sleep (possibly secondary to pain in patients with underlying illnesses, such as osteoarthritis and rheumatoid arthritis). Other patients awaken frequently throughout the night but are unaware of the arousals. The patient awakens feeling fatigued and remains so throughout the day, hence the term nonrestorative sleep. Fatigue is commonly present from a half-hour to several hours after rising in the morning and can last for the rest of the day.

Women with fibromyalgia typically have pelvic pain, painful menorrhea, and pain during sexual intercourse. Some people have urinary symptoms, including a strong urge to urinate and bladder pain.

Diagnosis information

Diagnosis of fibromyalgia is difficult because many of the symptoms mimic those of other disorders. Also, diagnostic testing in FMS that isn't associated with an underlying disease is generally negative for any significant abnormalities. Examination of joints doesn't reveal synovitis or significant swelling; the neurologic examination is normal; and no laboratory or radiologic abnormalities are common in patients with FMS.

Tender points are elicited by applying a moderate amount of pressure to a specific location. This examination can be fairly subjective, but many patients with true tender points wince or withdraw when pressure is applied to an appropriate intensity. Nontender control points, such as mid forehead,distal forearm, and midanterior thigh, can also be tested to assess for conversion reactions (psychogenic rheumatism), in which patients hurt everywhere or exhibit other psychosomatic illnesses.

Overall, the diagnosis of FMS is made clinically in a patient with characteristic symptoms, such as widespread pain for more than 3 months, tenderness in at least 11 of the 18 specific tender point sites, and exclusion of other illnesses that can cause similar features. A workups for rheumatoid arthritis, primary sleep disorders, endocrinopathies (such as hypothyroidism), infections (such as Lyme disease and human immunodeficiency virus infection), neuropathies, and psychiatric illness (such as major depression) should be ruled out.

Treatment of Fibromyalgia syndrome

The most important aspect in FMS management is patient education. Patients must understand that although FMS pain can be severe and is commonly chronic, it's treatable and doesn't lead to deforming or life threatening complications.

Treatment of fibromyalgia usually requires a comprehensive approach, combining exercise, medication, physical therapy, and relaxation. A regular, low-impact aerobic exercise program,such as swimming, walking, or biking, has been shown to be effective in improving muscle conditioning, energy levels, and the patient's overall sense of well-being. The patient with FMS should be taught stretching be fore and after exercise to minimize injury and told to begin at a low intensity with slow and gradual increases.

Medications are typically used to improve sleep and control pain. A bedtime dose of amitriptyline, nortriptyline (Pamelor), trazodone (Desyrel), or doxepin (Sinequan) may be useful to improve sleep; however, they can be associated with ticholinergic adverse effects and daytime drowsiness. The combination of a tricyclic antide pressant at bedtime and a daytime dose of a serotonin uptake inhibitor, such as fluoxetine (Prozac), sertraline (Zoloft), or paroxetine (Paxil) have been found effective. Muscle relaxants such as cyclobenzaprine at bedtime may decrease muscle pain and spasms. Benzodiazepines are usually avoided because they haven't shown any long-term benefits and have the potential for drug dependence.

Nonsteroidal anti-inflammatory drugs (NSAlDs) and corticosteroids typically haven't been effective in relieving FMS pain, although NSAlDs may be used for coexisting tendinitis or arthritis. However, the combination of oral corticosteroids and an NSAlD can put a patient at increased risk for peptic ulcer disease. For patients who require steroids for treatment and don't tolerate the discontinuation of their regular NSAlD (for underlying arthritis, for example), the addition of a GI protective agent, such as misoprostol (Cytotec), should be considered. Some patients may get relief from a cyclooxygenase-2 inhibitor, which doesn't have the adverse GI effects associated with most NSAlDs. Tramadol (IDtram) has also been effective for patients who aren't sensitive to codeine preparations. Narcotics to control the chronic pain of FMS should be used only with extreme caution, preferably under the guidance of a pain clinic, because of their potential for dependence and addiction.

Complications

Conditions reported as associated with fibromyalgia or that mimic its symptoms include: rheumatoid arthritis, hypothyroidism, cervical and low-back degenerative disease, Lyme disease, chronic fatigue syndrome, sleep disorders, depression, cancer, and HIV infection.

Special considerations or prevention

Reassurance and social and emotional support are extremely important for the patient with FMS. She commonly goes through extensive diagnostic workups and multiple consultations with no significant abnormal findings. The patient may think that no one believes that the pain is present and that it's "all in her head."Reassure the patient that FMS is common and, although chronic, can be treated.

• The deconditioned FMS patient may experience increased muscle pain with the initiation of a new exercise program. Reassure her that this may occur and, if it does, she may reduce the duration or intensity of her exercise.
• Encourage the patient not to stop exercising altogether (unless specifically told to do so) because even a limited amount of exercise each day may be beneficial.
• A bedtime dose of a tricyclic antidepressant can cause morning drowsiness in some patients. Taking the dose 1 to 2 hours before bedtime can sometimes improve sleep benefits while reducing this morning after effect.