Fibromyalgia and Myofascial Pain
Pain Management Secrets, Chapter 24, 148-153
1
What are the chronic pain syndromes that involve muscle and fascia?
Myofascial pain syndrome and fibromyalgia are chronic pain syndromes that involve the muscle and soft tissues. Myofascial pain syndrome is regional in distribution whereas fibromyalgia involves the entire body. These diagnoses may represent two points in a spectrum of disease, as subgroups of fibromyalgia have been identified on the basis of differing clinical findings and prognoses.
2
Describe the myofascial pain syndrome
The myofascial pain syndrome is a chronic, regional pain syndrome that involves muscle and soft tissues. It is characterized by trigger points and taut bands (see Questions 7 and 8). Originally described by Travell and later elaborated on by Travell and Simons, myofascial pain syndrome occurs in most body areas, most commonly in the cervical and lumbar regions.
3
What is fibromyalgia?
Fibromyalgia is a clinical syndrome characterized by chronic, diffuse pain and multiple tender points at defined points in muscle and other soft tissues. Periosteal tender points are frequently present. Widespread pain can be felt both above and below the waist and bilaterally. Other characteristic features of the syndrome include fatigue, sleep disturbance, irritable bowel syndrome, interstitial cystitis, stiffness, paresthesias, headaches, depression, anxiety, and decreased memory and vocabulary.
4
What are the American College of Rheumatology 1990 criteria for the classification of fibromyalgia?
- ▪ History of widespread pain
- ▪ Pain in 11 of 18 tender point sites
Pain is widespread when it is present both in the left and right sides of the body, and both above and below the waist. In addition, axial skeletal pain (cervical spine, anterior chest, thoracic spine, or low back) must be present. Low back pain is considered lower segment pain.
Pain must be present in at least 11 of the following 18 trigger point sites (9 pairs) on digital palpation:
- Occiput—bilateral, at suboccipital muscle insertions
- Low cervical—bilateral, at anterior intertransverse spaces C5–C7
- Trapezius—bilateral, at midpoint of upper border of muscle
- Supraspinatus—bilateral, above scapular spine near medial border
- Second rib—bilateral, at second osteochondral junctions
- Lateral epicondyle—bilateral, 2 cm distal to epicondyles
- Gluteal—bilateral, in upper outer quadrants of buttocks
- Greater trochanter—bilateral, posterior to trochanteric prominence
- Knee—bilateral, at medial fat pad proximal to joint line
Digital palpation should be performed with an approximate force of 4 kg/1 cm 2 . For a trigger point to be considered “positive,” the subject must state that the palpation is painful. “Tender” is not to be equated with “painful.”
5
Do all fibromyalgia patients have the same symptoms?
No. There is a high degree of variability in the presentation of fibromyalgia. Subgroups of the syndrome have been identified based on the number of active tender points, sleep quality, and cold pain threshold. These subgroups have different prognoses. Patients may also be grouped according to related disease. Of patients with irritable bowel syndrome (IBS), 20% demonstrate findings consistent with fibromyalgia. Fibromyalgia is more common in diabetics than in the general population, and the severity of pain correlates with the duration of diabetes. These may constitute additional subgroups of fibromyalgia.
6
Name syndromes that are associated with fibromyalgia
- ▪ Chronic fatigue syndrome
- ▪ Irritable bowel syndrome
- ▪ Restless leg syndrome
- ▪ Interstitial cystitis
- ▪ Temporomandibular joint dysfunction
- ▪ Sicca syndrome
- ▪ Raynaud's phenomenon
- ▪ Autonomic dysregulation with orthostatic hypotension
- ▪ Mood disorder
7
What are trigger points?
Trigger points are sites in muscle or tendon that, when palpated, produce pain at a distant site. These occur in consistent locations with predictable patterns of pain referral. Trigger points are often associated with prior trauma, “near falls,” or degenerative osteoarthritis.
8
What are “taut bands”? How are they associated with trigger points?
In patients with myofascial pain, deep palpation of muscle may reveal areas that feel tight and bandlike. Stretching this band of muscle produces pain. This is a taut band. Trigger points are characteristically found within taut bands of muscle. Despite the muscle tension, taut bands are electrophysiologically silent (i.e., the electromyogram [EMG] is normal). Rolling the taut band under the fingertip at the trigger point (snapping palpation), may produce a local “twitch” response. This shortening of the band of muscle is one of the cardinal signs of fibromyalgia.
11
What laboratory investigations are useful in fibromyalgia?
All laboratory values in fibromyalgia are used for exclusionary purposes. There are no characteristic chemical, electrical, or radiographic laboratory abnormalities. However, several consistent investigational serum markers of the disease have been reported in the literature. An increase in cytokines, with a direct relationship between pain intensity and interleukin-8, has been reported. Other investigational findings include a decrease in circulating cortisol (this may play a role in decreased exercise tolerance), a decrease in branched-chain amino acids (perhaps correlating with muscle fatigue), and decreased lymphocyte Gi protein and cAMP concentrations. At present, these findings are not clinically useful for the diagnosis, prognosis, or monitoring of the treatment response of fibromyalgia patients. Sleep studies are often abnormal (“alpha-delta,” nonrestorative sleep), but the abnormalities are also seen in other chronic painful conditions.
12
What treatments are commonly used for fibromyalgia and for myofascial pain?
A combination of physical, anesthesiologic, and pharmacologic techniques are employed. Some of the most common treatments involve lidocaine injection or dry-needling of trigger points. These approaches are based on the concept that trigger points represent areas of local muscle spasm. However, the efficacy of trigger point injections has never been fully substantiated, although they do offer transient relief to some patients. Physical techniques, such as stretching, spray and stretch (see Question 19), massage, and heat and cold application have all been advocated, but none are fully validated by well-controlled studies.
13
Describe the role of physical therapy modalities in the treatment of myofascial pain
Most studies documenting the efficacy of physical therapy modalities are anecdotal and include relatively small subject numbers. They suggest the efficacy of transcutaneous electrical nerve stimulation (TENS), balneotherapy, ice, massage, ischemic compression (acupressure), and biofeedback in the treatment of myofascial pain. Low-power laser has been studied for its effect on myofascial pain associated with fibromyalgia. This modality seems to significantly reduce pain, muscle spasm, stiffness, and number of tender points.
14
Which medications are commonly used in the treatment of fibromyalgia and myofascial pain syndrome?
Tricyclic antidepressants are widely used drugs for these disorders. They are used because they have the potential to regularize sleep patterns, decrease pain and muscle spasm, and because of their mood-enhancing properties. Selective serotonin-reuptake inhibitors (SSRIs) are used to elevate mood, but have little analgesic effect. Serotonin-norepinephrine reuptake inhibitors (SNRIs), such as duloxetine, have recently been shown to have pain-reducing properties in patients with fibromyalgia and can also improve mood. The use of antidepressants as analgesics in these conditions is not a recognized indication for these drugs, although their use is widespread in practice. Pregabalin and duloxetine have recently received an indication for the treatment of fibromyalgia in the United States. Nonsteroidal antiinflammatory drugs (NSAIDs), opioids, and nonnarcotic analgesics are also frequently used, but their role is also unclear and not evidence based. Many medications, such as cyclobenzaprine, baclofen, tizanidine, and chlorzoxazone, have been used to achieve symptom relief. However, a treatment effect has not been consistently supported. Medications that target associated symptoms are often employed. Among the most common of these are sleep medications such as zolpidem, and fludrocortisone to treat postural hypotension and adynamia.
15
What are some other interventions that have been studied for the treatment of fibromyalgia?
There is a large series investigating the role of diet in treating fibromyalgia. Some studies promote a raw vegetarian diet; others tout Chlorella pyrenoides (algae) as a dietary supplement. Monosodium glutamate and aspartame have both been implicated in producing symptoms common to fibromyalgia and may play a role in pathogenesis for certain fibromyalgia subgroups.
Botulinum toxin injection and acupuncture have also been studied. They appear to be helpful in certain instances, but consistent efficacy has not been proven.
16
Is exercise useful in the treatment of fibromyalgia and myofascial pain syndrome?
Yes! The most consistent improvement in fibromyalgia and myofascial pain syndrome occurs with exercise. The exercise hormonal response is abnormal in patients with fibromyalgia (increase in growth hormone concentration, the opposite of normal response), so the frequency and intensity of exercise needs to be carefully adjusted to the patient's tolerance. Although strengthening (progressive resistive or isokinetic) exercise can be helpful, the best outcome appears to result from conditioning, or aerobic, exercise.
17
What are the proposed pathophysiologic mechanisms for fibromyalgia?
Fibromyalgia is associated with an augmentation of sensation. Pathophysiologic explanations for fibromyalgia have ranged from primarily central, to a combination of central and peripheral, to primarily peripheral. Examples:
- ▪ Fibromyalgia is a variation of an affective disorder. This idea was based on its common association with depression, IBS, and chronic fatigue syndrome.
- ▪ A sleep abnormality is the main disturbance, leading to altered pain perception.
- ▪ Peripheral factors, especially musculoskeletal derangements, are most important, along with the depression resulting from chronic pain.
- ▪ Travell and Simons believed that the muscle problem was primary.
It remains unclear whether there is one pathological mechanism for fibromyalgia or a variety of etiologic factors. Nevertheless, current hypotheses under investigation hold some promise that the pathogenesis and pathophysiology of fibromyalgia may soon be clarified:
- ▪ The cause is neuroendocrine in origin. This concept is largely based on the observation of decreased circulating cortisol levels and abnormal 5-HT metabolism.
- ▪ Peripheral C-fiber and central nociceptive sensitization occurs following a painful stimulus.
- ▪ High levels of circulating immunoglobulin M (IgM) in response to an enteroviral infection have been demonstrated in some fibromyalgia patients.
- ▪ A Chiari I malformation, with brainstem compression, leads to an altered autonomic response, orthostasis, and fibromyalgia syndrome.
18
How is sleep disturbance related to fibromyalgia?
Sleep disturbance is one of the most common complaints of patients with fibromyalgia. It was initially described as “nonrestorative sleep.” Some patients were shown to have an intrusion of alpha rhythms into their stage-IV sleep (“alpha-delta” sleep). However, the same electroencephalographic pattern is often seen in other chronically painful conditions. Moreover, other disorders frequently found in association with fibromyalgia, such as the restless leg syndrome, can contribute to a sleep disorder. The incidence of sleep disturbance seems more related to the duration of chronic pain than to the specific diagnosis of fibromyalgia.
19
What is the “spray and stretch” technique?
The spray and stretch technique is based on the theory that trigger points located in taut muscle bands are the principle cause of pain in fibromyalgia and in myofascial pain syndrome. A taut band in the muscle is identified, and then a vapo-coolant spray (ethylchloride or fluoromethane) is applied directly along the muscle band. Once cooled, the muscle is stretched along its long axis. This helps to relax muscle tension (via muscle spindle and Golgi tendon organ stimulation), improve local circulation, decrease the number of active trigger points, and reduce the amount of pain.
20
True or false: There are a number of controlled studies that demonstrate the efficacy of the various treatments used for fibromyalgia
False. There is a paucity of controlled studies with adequate outcome measures. Most studies have small cohorts and are largely anecdotal. Studies have been performed using tricyclic antidepressants, EMG biofeedback, education, physical training, hypnotherapy, a variety of drug combinations, and many other treatment strategies. In 145 reports of outcome measures, only 55 were able to differentiate the active treatment from placebo.
The treatment of fibromyalgia and myofascial pain syndrome remains a significant challenge to the practice of evidence-based medicine.
21
Are there any factors that can precipitate the onset of fibromyalgia?
Fibromyalgia can occur without any identifiable precipitating factors. However, it seems that it can also be initiated by trauma (e.g., surgery, childbirth, accident, severe infection, severe emotional strain) and can then be classified as “posttraumatic fibromyalgia.”
22
What drugs have recently been added to the list of medications used in the symptomatic treatment of fibromyalgia?
Although only Pregabalin and duloxetine have received a specific indication for use in the treatment of fibromyalgia, a number of others have recently been used in increasing volumes. These include SRNIs such as the muscle relaxant/analgesic tizanidine and the 5-HT3 antagonists such as ondansetron, granisetron, and tropisetron.
23
Are there any alternative therapeutic options for the treatment of myofascial syndrome?
Pregabalin and duloxetine are examples of oral drugs, indicated for other disease states, which can be used with benefit in the treatment of myofascial syndrome. A number of topical options also exist. These include topical capsaicin, glyceryl trinitrate (which has a localized antiinflammatory effect), lidocaine (Lidoderm patch), and doxepin (a tricyclic antidepressant with localized analgesic effects). Injection of local anesthetic into tender points can be used, as well as injection with corticosteroid. Corticosteroids stabilize nerve membranes, reduce ectopic neural discharge, and have a specific effect on dorsal horn cells as well as their well known antiinflammatory effects.
24
Are there any acute treatments that can be used to lessen the pain of fibromyalgia during a flare-up of this condition?
It has recently been shown that parenteral injection of the 5-HT3 antagonist tropisetron can reduce the pain of fibromyalgia.
- 1 Myofascial pain syndrome is regional in distribution whereas fibromyalgia is bodywide.
- 2 Fibromyalgia is more common in females.
- 3 Laboratory investigations cannot be used to diagnose fibromyalgia but can be used to exclude other conditions.
- 4 The cause of fibromyalgia is not known.
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