RENEW OR SUBSCRIBE TO PPM
Subscription is FREE for qualified healthcare professionals in the US.
11 Articles in Volume 17, Issue #4
Algopathy—Acknowledging the Pathological Process of Pain Chronification
Are Abuse-Deterrent Opioid Products A Double-Edged Sword?
CMS Tackles Opioid Prescribing
How do you handle end-of-life care in a patient who does not know they are dying?
Letters to the Editor: Functional Medicine, Naloxone, Hormone Testing, CRPS
Look at the Patient’s Life Story, Then Implement a Management Plan
Myofascial Pain: Overview of Treatment Options
Pain in Parkinson’s Disease: A Spotlight on Women
Parkinson's Initiative—Women and PD Talk
Patient in Pain? When to Refer for Physical Therapy
Somatic Symptom Disorder: DSM-5's Removal of Mind-Body Separation

Myofascial Pain: Overview of Treatment Options

The best course for patients with myofascial pain syndrome, a common yet underdiagnosed pain disorder, will be an integrated, multifaceted approach to treatment.

Myofascial pain syndrome (MPS) is the chief complaint for patients presenting to orofacial pain centers.1 It is associated with pain and muscle stiffness and is characterized by the development of myofascial trigger points (MTrPs)—hyperirritable, palpable nodules in the skeletal muscle fibers.2 The abnormal release of acetylcholine, which shortens sarcomeres and produces a “contraction knot,” is thought to be the mechanism of MTrPs development.3

Myofascial pain is generally described as a taut or hard band within a muscle, with tenderness and referred pain that can be present either locally, regionally or secondary to some other condition. Myofascial pain is estimated to affect approximately 44 million Americans.4 The muscle pain can be acute or chronic and oftentimes presents as dull and achy.

Stimulation of MTrPs will cause referred pain that does not follow a dermatome or myotome distribution.5 In one study by Audette and colleagues, investigators found that unilateral needle stimulation produced bilateral motor unit activation.6 This helps explain the referred pain of MTrPs and how individuals with chronic myofascial pain have a lower threshold for pain via increased neuronal excitability and release of substance P, glutamate, bradykinin, and other substances.3

Diagnosis of MPS

The commonly accepted key diagnostic criterion for MPS is the presence of MTrPs.7 Active trigger points are defined by the presence of spontaneous pain at rest, as well as the association of a local twitch response and/or pain referral with manual or intramuscular needle provocation.8 MTrPs can be either active or latent, and stress, tension, and factors such as poor posture can cause a latent MTrP to become active, causing pain.9

While manual palpation is the most commonly employed clinical method to confirm the presence of MTrPs, the sensitivity and specificity of palpation to detect MTrPs has not been validated, and there is no known “gold standard” for identifying the presence of MTrPs.10,11

Other diagnostic methods may have promise for the diagnosis of MPS. These include both diagnostic ultrasound and the use of biomarker analysis. Diagnostic ultrasound is a safe, portable method of achieving high-resolution imaging of soft tissue. Unfortunately, while ultrasound may offer important diagnostic images of the structural properties of MTrPs, it has not yet been validated.12 Ultrasound was able to distinguish between active, latent, and normal sites in one study. 12

While biomarkers (such as bradykinin, substance P, calcitonin gene-related peptide, tumor necrosis factor- alpha, interleukin 1beta (IL-1beta), IL-6, IL-8, serotonin, and norepinephrine) may offer an objective test for the diagnosis of MPS, sample testing is not practical or necessary when nodules can be diagnosed by manual palpation.13,14

MPS, while very common in the specialty of pain management, can mimic many other musculoskeletal and visceral diagnoses.15,16 As noted, MPS presents as both acute and chronic muscle pain that may also be accompanied by a sensory component of paresthesia or dysesthesia; the underlying cause of MPS is not always obvious. Low back pain (LBP) is one of the common manifestations of patients with MPS. While LBP is a commonly reported symptom, in many cases, a specific diagnosis is not well established.17,18 MPS may be a common cause of LBP, and should be considered as part of any LBP differential diagnosis since it can be treated.19

Treatment of MTrPs

Given the interrelationship of chronic pain with biopsychosocial factors, directing awareness toward decreasing stress and anxiety can help alleviate myofascial pain. In a study conducted with 26 participants experiencing facial myofascial pain, pain intensity decreased by 73% (P < 0.05) with a group cognitive behavioral therapy (CBT) course.1 There were 2 to 5 people per session, with 3 sessions each lasting 2 hours. The course focused on habit reversal, relaxation techniques, and changing rumination and exaggeration of thoughts.1

While addressing mental health conditions is an important factor in a comprehensive care plan, many efficacious medical treatments are available to manage MPS (Table 1). All treatments are designed to “release” the MTrPs—whether by mechanical or chemical means. Since many of these treatments are conservative and cost effective, each will be discussed briefly. We have broken the treatments down into categories, starting with dry needling, which is the traditional treatment recommended by Janet G. Travell, MD, creator of the term MPS.2

Dry Needling/Acupuncture

Dry needling is not acupuncture. Dry needling is based on Western principles and should not be confused with traditional Chinese medicine techniques of acupuncture. Both, however, use filament needles. As noted, dry needling is a popular treatment method for addressing MTrPs as introduced by Dr. Travell.2

Most of the literature, however, discusses the role of acupuncture, which is performed by certified professionals trained in either Japanese or Chinese techniques. Acupuncture has been used for the treatment of myofascial pain because it inactivates the neural loop of the trigger point, reducing pain and muscular hypertonicity.20-22 Acupuncture stimulates points on the body typically along meridian lines to prevent or modify the perception of pain, or to alter physiologic functions.22 Acupuncture and electro-acupuncture, which is where an electric current passes through the needle, have been shown to effectively decrease the intensity of chronic myofascial pain.22,23

Electromedicine

Electromedical methods to “release” myofascial trigger points include biofeedback, therapeutic ultrasound, transcutaneous electrical nerve stimulation (TENS), and laser therapy. Surface electromyographic (SEMG) biofeedback, one of the oldest biofeedback methods, has been a major modality to reduce pain and optimize muscle function for decades. By measuring muscle activity, patients can be trained to reduce muscle tension or increase weak muscle activity. Three electrodes are required to measure a single muscle area: 1 positive, 1 negative, and 1 reference electrode.24 SEMG biofeedback records muscle activity, turns it into visual or auditory cues, and helps the patient modify muscle tension accordingly.25

Biofeedback exhibits usefulness as a modality to diminish pain in a noninvasive and productive way.26,27 Patients with low back pain, for example, often present with impaired flexion-relaxation response.28 SEMG biofeedback and ultrasound imaging biofeedback have been shown to be effective in the treatment of myofascial lower back pain, with solid empirical evidence of positive beneficial effect.29 In a small study, SEMG was combined with assisted stretching to reduce pain in patient with low back pain.28

Although there are a limited number of controlled studies regarding its efficacy, therapeutic ultrasound has been recommended for the treatment of MPS.30,31 Therapeutic ultrasound is thought to stimulate the tissue beneath the skin’s surface using high frequency waves, which would shorten the healing process as a result of increased blood flow, with a secondary reduction of inflammation and pain. As noted, the benefits of therapeutic ultrasound have been debated. In a recent Cochrane review, the authors found no “high-quality evidence to support the use of ultrasound for improving pain or quality of life in patients with non-specific chronic LBP.32 There is some evidence that therapeutic ultrasound has a small effect on improving low-back function in the short term, but this benefit is unlikely to be clinically important.” Therapeutic ultrasound, with and without muscle and myofascial stretching, has been reported to be more successful than muscle stretching alone.33 Continuous ultrasound therapy in MPS has been shown to be superior to pulsed ultrasound in reducing pain at rest.34

TENS has been shown to be an effective treatment option in relieving pain caused by a number of different disorders, including low back pain.35,36 TENS stimulates release of endogenous opioids and excites non-nociceptive afferent fibers “closing the gate of facilitated sensory input.” It is useful for both chronic and acute pain.3 However, TENS is not described as a specific treatment for trigger points (MTrPs) by Simons or others.37 TENS also has been widely used in the treatment of both fibromyalgia and myofascial pain, with considerable relief of pain (higher intensity TENS; 100 Hz, 250 msec) and pain reduction (lower intensity TENS; 2 Hz, 250 msec) in a study by Graff-Radford et al.37 The results suggest that “high-frequency, high-intensity TENS is effective in reducing myofascial pain.” Despite these findings, TENS “did not reflect changes in local trigger point sensitivity,” the authors concluded.37 In a 2016 study, Amjad et al concluded that both therapeutic ultrasound and TENS resulted in significant improvement in pain intensity and cervical range of motion (ROM) in patients with upper trapezius trigger points. Ultrasound, however, was clinically more effective compared to TENS.38

Low-level laser therapy (LLLT) applies a low-powered laser or light- emitting diode to the surface of the body to enhance cellular regeneration or function and relieve pain. The effect of the LLLT appears to be limited to a wavelength between 600 and 1000 nm, and a power from 5 to 500 MW, outside of which the treatment is ineffective.39 Gur et al compared LLLT with placebo, used daily for 2 weeks (except weekends).39 The active laser group showed significantly greater improvement.39 Although there is a lack of scientific validity, some studies show efficacy in relieving MPS, speeding wound healing, reducing inflammation, and in the treatment of inflammatory diseases such as rheumatoid arthritis.40,41

Intramuscular electrical stimulation therapy (IMS) utilizes electrodes placed over the skin to deliver electrical impulses mimicking the action potential from the central nervous system to the target muscles, causing them to contract. IMS has been applied by the layman for a variety of purposes, such as improved muscle tone, strength, and endurance as a part of fitness training or sports performance.42-45 A physical therapist would typically apply this modality to prevent disuse muscle atrophy following joint immobilization or other musculoskeletal injuries.

A randomized controlled study compared the use of LLLT in combination with stretching exercises and IMS in combination with stretching exercises, versus stretching exercises alone on treatment of patients diagnosed with MPS of the trapezius muscle.46 The results showed significant statistical improvements in pain using multiple pain metrics for the groups that combined stretching exercises with either LLLT or IMS when compared to stretching alone and the control group. While this study indicates efficacy of both modalities when combined with stretching, in their review of literature, the authors point to several studies that show conflicting efficacy for both modalities. This being said, considering the safety and cost effectiveness, these 2 modalities seem to be reasonable options in a conservative approach to MPS.

Physical Medicine

Osteopathic Manipulative Treatment (OMT) is a manual medical treatment approach that addresses many medical problems, including MPS. The myofascial trigger points, though not synonymous with somatic dysfunction, correlate to osteopathic somatic dysfunctions. The somatic dysfunctions in muscles and fascial tissues are easily palpated by an osteopathic physician and treated manually with a variety of different treatment approaches.

One type of somatic dysfunction, referred to as a “trigger point,” differs from a “tender point” in that the former refers to pain when palpated, has distinctive palpatory tissue features, and embryonic sclerotomal patterns that may be treated with either direct or indirect treatment modalities.47

Direct modalities involve direct tissue pressure and release. Applying a slow, steady pressure allows the muscle spindle to change slowly and reset itself such that the contributing pathology of the long fibrous muscle strands is resolved and recurrence of facilitated myofascial pain patterns is eliminated.48

Indirect modalities focus on the fascial restrictions primarily and the muscular dysfunctions secondarily by balancing the tissues in the direction of ease of motion of the tissues and waiting for a release to occur. This allows a loosening of the tissues and a slow resetting of proprioceptive changes, causing a reduction in soft tissue tension. This results in an increase in arterial circulation, lymphatic flow, and venous return. The increased efficiency in fluid flow allows a return to homeostasis of all involved structures and allows the body’s chemical mediators of injury to drain efficiently; thus, the stage is set for tissue recovery and normalization.49

Indirect and direct modalities all include rebalancing at the level of the spinal ganglion and the autonomic nervous system, allowing the entire system to reset back to a resilient baseline of function. In this way, somatic dysfunctions, or trigger points, are in fact resolved. The nervous system and the neuro-hormonal influences of tissue change are normalized and the recurrent pattern of injury, or facilitation, is addressed and resolved.49

Interventional Techniques

Botulinum Toxin A Injections
Botulinum Toxin A (BTX-A) can cause prolonged muscle relaxation through inhibition of acetylcholine release from the terminal ending of the motor nerve axon. Avendano-Coy et al concluded that BTX-A injections with physiotherapy is an alternative to conventional treatment and should be considered when treating refractory MPS.50 Khalifeh et al concluded that pain was reduced significantly with BTX-A, compared to a placebo group at 2 to 6 months.51 However, additional studies are needed to confirm the results.

Trigger Point Injections
Various agents may be used in trigger point injections, although a common formulation involves a mixture of the anesthetics lidocaine and bupivacaine. A single injection infiltrating the specific MTrPs may be sufficient in breaking the pain cycle, although repeated injections may be necessary. The mechanism of action may include local vasodilation, tissue relaxation and lengthening, and removal of nociceptive substrates.52

In a comparative study, dry needling was found to be as effective as injection of lidocaine, indicating that mechanical disruption by the needle may be the key therapeutic factor.53

Pharmacologic Management

The pharmacologic management of MPS has focused on anti-inflammation and muscle relaxants. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to provide pain relief and ameliorate perceived inflammation.54 Long-term use of NSAIDs is discouraged due to the frequent occurrence of renal and gastrointestinal adverse effects. Short-term use of muscle relaxants is traditionally used to treat MPS, with some studies showing effectiveness;55 however, these agents often have a sedative effect.4

The onset of action of local anesthetics depends on concentration and total dose. Lidocaine is widely used because of its rapid onset of action, potency, and tissue penetration. Application of the lidocaine patch (5%) is an effective treatment for MPS.56,57 The heated lidocaine/tetracaine patch has potential utility as a non-invasive pharmacologic approach for managing MTrPs pain.58

If myofascial pain is a spinal-mediated disorder and occurs in musculotendinous structures affected by neuropathic dysfunction, neuropathic analgesics including anticonvulsants may be utilized in the treatment. Gabapentin has been shown to be effective for the treatment of myofascial and neuropathic pain.4,59

Summary

MPS is common yet underdiagnosed in clinical practice, either as a primary or secondary pain disorder. Since no one treatment approach seems to be efficacious for all patients, it is important to take an integrated, multi-faceted approach to MPS treatment. Even with a variety of conservative and cost-effective treatment modalities available, MPS continues to be one of the most challenging pain conditions to effectively treat.

Last updated on: May 6, 2019
Continue Reading:
Algopathy—Acknowledging the Pathological Process of Pain Chronification

Join The Conversation

Register or Log-in to Join the Conversation
close X
SHOW MAIN MENU
SHOW SUB MENU