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Fibromialgia Syndrome

A. Definition

1. Fibromialgia syndrome (FMS) is characterized by musculoskeletal aching and tenderness on palpation of tendinomusculoskeletal sites called tender points.

2.Frequently associated with a sleep disorder and daytime fatigue.

3.May be associated with several other organ specific syndromes.

B. Classification

1. Primary - Fibromyalgia syndrome occurring in absence of any underlying or concomitant condition.

2. Concomitant - Fibromyalgia syndrome occurring in association with another rheumatic condition.

a. Concomitant FMS is clinically identical to primary fibromyalgia syndrome.

3. Secondary - FMS caused by rheumatic or other disease.

4. Localized - pain and tenderness in a few (1-4) contiguous anatomic sites. 

a. Usually above the waist, especially around the neck and shoulder. 

b. Frequently precipitated by injury or trauma. 

c. Similar to myofascial pain syndromes.

d. May develop into generalized FMS over time.

A. FMS

1.Primary FMS - no specific etiology has been identified.

a. Neurohormonal abnormality.

(1) Insulin-like growth factor-1 (IGF-1) deficiency?

(2) Serotonin deficiency.

(3) Increased substance P in CSF.

(4) Altered thalamic blood flow.

(5) Abnormal hypothalamic-pituitary-adrenal axis homeostasis.

b. Result of initial insult is stage 4 sleep anomaly.

2. Etiological factors causing stage 4 sleep anomaly leading to FMS.

a. Musculoskeletal pain.

b. Physical trauma and/or Emotional trauma.

(1) No cause and effect relationship established.

(2) Possible relationship to physical and sexual abuse.

c. Sleep apnea. d. Nocturnal myoclonus/periodic limb movement disorder (PLMD). 

e. Drugs. 

f. Exogenous causes of sleep disturbance - noise. 

g. No evidence of infectious cause, ie, Lyme disease, EBV.

B. Pathogenesis

1. Stage 4 sleep anomaly.

a. Normal non-REM/stage 4 (restorative) sleep shows I cps delta pattern on EEG. 

b. FMS patients showed baseline delta pattern with 8-10 cps alpha intrusion in original investigations.

c. This is similar to normal healthy sleep with stage 4 deprivation, ie, noise.

d. More recent studies have not found any consistent abnormalities in sleep EEG.

2.Stage 4 sleep anomaly in predisposed patient results in a positive feedback cycle: 

a. Abnormal neurohormonal homeostasis. 

b. Poor restorative sleep. 

c. Daytime fatigue.

d. Muscle microtrauma, inactivity, deconditioning. 

e. Musculoskeletal pain.

3. Final result- FMS.

4. Patients frequently exhibit depressive symptoms, poor pain coping mechanisms.

C. Spectrum of FMS and related disorders.

1. Several disorders with similar etiopathogenesis and overlapping clinical manifestations.

2. Stage 4 sleep anomaly unifying underlying pathogenic mechanism.

3. Often associated with musculoskeletal pare and fatigue.

4. Fibromyalgia Syndrome (FMS)/Chronic Fatigue Syndrome (CFS).

5. Tension headaches, TMJ syndrome, noncardiac chest pain.

6. Irritable bowel syndrome, chronic cystitis, primary dysmenorrhea.

7. Others:

a. Periodic limb movement disorder/nocturnal myoclonus (PLMD).

b. Restless leg syndrome (RLS).

c. Repetitive strain injury (RSI).

d. Multiple drug sensitivities (MDS).

III. Clinical manifestations

A. Epidemiology

1. Probably the most common rheumatic disease.

2. Prevalence of FMS in typical rheumatology practice is 20%.

3. Prevalence of FMS in typical primary care practice is 2-5%.

4. Prevalence of FMS in general population is probably about 2%.

a. Females - 3.5%, Males - 0.5%.

5. Mean age of patients - 44 years.

a. Increasing prevalence with increasing age.

6. Female predominance- 90%.

7. Caucasian predominance - 94% (may be selection bias).

8. Duration of symptoms before diagnosis - 6 years.

B. Clinical manifestations.

1. Musculoskeletal symptoms.

2. Non-musculoskeletal symptoms.

IV. Diagnosis

A. Diagnostic criteria for FMS.

1. History of widespread pain for at least 3 months.

2. Pain in 11 of 18 tender sites.

a. Classic tender points.

3. Diagnosis also supported by a history of a sleep disorder and daytime fatigue.

4. Differential diagnosis: Must rule out other possible causes of symptoms.

a. Connective tissue disease - prodrome of SLE, Söjgren's syndrome, RA.

b. Hypothyroidism.

c. Other rheumatic problems - PMR, OA, tendinitis/bursitis, overuse syndromes.

d. Hyperparathyroidism.

e. Myofascial pain syndrome.

(1) Regional pain syndromes with local symptoms similar to FMS.

(2) Commonly involve shoulder, neck or low back.

(3) Some patients evolve into generalized FMS over time.

(4) Symptoms often begin after injury or trauma.

(5) Trigger points - muscle areas-tender to palpation with referred pain distally.

(a) Poor scientific evidence for trigger points.

(6) Unlike FMS, males are equally affected, symptoms of pain and stiffness are localized with regional tenderness, fatigue is unusual, sleep disorder occurs occasionally secondary to pain, response to treatment is generally good.

f. Psychogenic pain.

(1) Unlike FMS, pain and tender points are widespread and variable. 

(2) Patient response to question are inappropriate. 

(3) Response to therapy inconsistent. 

(4) General demeanor is affected.

(5) Response to treatment is poor- emotional problems and secondary gain.

5. Helpful to obtain several laboratory tests such as CBC, ESR, TSH and occasionally ANA and RF in order to rule out other diagnostic possibilities.

V. Prognosis

A. Poor prognostic indicators.

1. Symptoms for 

VI. Management

A. Firm diagnosis ruling out other possible causes of symptoms.

1.Patients are often relieved to learn that their symptoms are not caused by a progressive, crippling or fatal disease.

2.Obtain a panel of laboratory tests to-rule out other diagnostic possibilities.

3.Avoid ordering more tests on subsequent visits; -this will increase patient anxiety. 

B. Patient education and support.

1. Patient cooperation is important for a good therapeutic outcome.

2. FMS is not progressive, is not crippling and is not fatal.

3. Encourage patient to continue working and keep physically active.

4. Outcome is in patient's hands - try to minimize dependence on physician.

5. Educate patient about the pathophysiology of FMS and its treatment.

a. Importance of restorative sleep.

b. Understand factors that affect symptoms. 

c. Importance of physical conditioning. 

d. Role of medical therapy - benefits and side effects.

C. Behavior modification

1. Avoidance of factors which aggravate symptoms.

2. Learn to live with chronic pain.

a. Occasional patient may benefit from input of psychologist or psychiatrist.

D. Physical therapy

1.Improve physical fitness with mild to moderate regular exercises.

a. Walking, swimming, cardiovascular fitness training program.

2. Use of heat with stretching exercises.

3. Periodic rest periods during physical activity.

E. Medical therapy

1. Pain

a. Analgesics - acetaminophen, propoxyphene HCI, NSAIDs.

b. Local injection of tender points with lidocaine +/- corticosteroids.

2. Sleep disorder.

a. Tricyclic antidepressants

(1) Cyclobenzaprine (Flexeril) 10-40 mg po qhs.

(2) Amitriptyline (Elavil) 10-50 mg po qhs.

(3) Nortriptyline (Pamelor) 10-50 mg po qhs.

b. Specific serotonin reuptake inhibitors (SSRIs)

(1) Sertraline (Zoloft) 50-100 mg po qhs.

(2) Paroxetine (Paxil) 20-40 mg po qhs.

(3) Fluoxetine (Prozac) 20-40 mg po q day (not effective alone, ? in combination).

c. Hypnotics

(1) Alprazolam (Xanax) 0. 5-1 mg po. qhs.

(2) Zolpidem (Ambien) 10 mg po qhs.