Wednesday, June 19, 2013

Myopain: The Most Common Cause of Chronic Pain

By guest author, James Fricton, MD

More than 100 million adults in the United States are affected by chronic pain conditions, costing over $500 billion annually in medical care and lost productivity. When acute pain becomes chronic, it often results in missed work, disability, and significantly high cost of care.[1,2] In hopes of improving the condition, medical care often involves expensive and high-risk passive interventions, such as polypharmacy, opioid analgesics, high-tech imaging, implantable stimulators, and surgery.

Yet, half of the persons seeking care for pain conditions still have pain 5 years later, and up to 25% of them receive long-term disability.[3-5] Despite nearly one-third of the population suffering from chronic pain to some extent, most people assume these conditions are incurable.

Not so, says the International Myopain Society [myopain.org]. At their upcoming 2013 Myopain Congress — August 15-18, 2013 in Seattle, Washington, USA — members from the group will present results of research that show myopain conditions, such as myofascial pain (MP) and fibromyalgia (FM), are the most common cause of chronic pain and that these conditions can often be improved with a variety of treatments that focus on education and training to reduce muscle pain instead of high cost passive treatments.[6]

Two prior studies of clinic populations found that myopain conditions were cited as the most common cause of pain, responsible for 54.6% of chronic head and neck pain[7] and 85% of back pain.[8] Another study, in a general internal medicine practice, found that among those patients that presented with pain, MP was found in 29.6% of the population and was the most common cause of pain.[9]

The lack of awareness of these muscle pain conditions is surprising. Everyone, at some point in their lives, has experienced acute muscle pain associated with muscle spasm or repetitive strain. However, when acute pain becomes chronic, patients and their healthcare providers can become confused and overlook the muscle in favor of treating other conditions, particularly joint pathology.

This lack of understanding leads to misdiagnosis and mistreatment, along with progression of an acute problem to chronic pain. Then, the behavioral and psychological components of chronic pain become misunderstood, and some providers assume the patient’s experience of pain is imagined or exaggerated. Thus, the principals of etiology, diagnosis, and management of myopain conditions are relevant for all healthcare providers.

Etiology of Myopain
Acute injury to the muscles through trauma or repetitive strain from sustained muscle contraction are the most common onset factors. This can result in localized progressive increases in oxidative metabolism and metabolic distress at motor endplates, particularly in type I muscle fibers that are associated with static muscle tone and posture. Tenderness and pain in the muscle, as mediated by type III and IV muscle nociceptors, are activated by locally released noxious substances — eg, potassium, histamine, kinins, or prostaglandins.

If multiple peripheral and central factors facilitate the nociceptive input through modulation at the brain stem, peripheral and central sensitization and chronic pain will result.[10,11] This explains how diverse factors can either exacerbate or alleviate the pain, such as stress, repetitive strain, poor posture, relaxation, medications, temperature change, massage, local anesthetic injections, and electrical stimulation.

Clinical Presentation
The pain found with MP and FM is frequently described as a “chronic dull aching pain” and is associated muscle and soft tissue tenderness. The tenderness sensations in myofascial pain are termed trigger points (TrP), which are localized tender points in palpable bands of skeletal muscle, tendons, and ligaments that reflect peripheral sensitization. In contrast, the diagnostic criteria for FM includes the presence of tender points at specific locations of the body that reflect central sensitization. Studies have also shown that the pain in FM is considerably more severe and spread over a larger body area than the pain found in patients with MP.

Treatment of Myopain
There are 3 essential elements in treating myopain: 1) stretching, postural, and relaxation exercises; 2) reduction of all contributing factors that strain the muscle and heighten peripheral and central sensitization; and 3) if needed, direct therapy to muscles through counterstimulation to desensitize the soft tissues, using physical medicine modalities or muscle injections. The short-term goal is to restore the muscles and joints to normal function, posture, and full joint range of motion with gentle stretching exercises.

This is followed long-term with a regular muscle stretching, postural, conditioning, and strengthening exercise program, as well as long term control of contributing factors. The difficulty in long-term management often lies not only in treatment of the muscle and joints, but also in the complex task of changing the identified contributing factors, since these can be integrally related to factors in the 7 realms of patients’ lives. These realms include body, cognitive, emotional, behavioral, spiritual, social, and physical environments. Many approaches such as cognitive-behavioral techniques, biofeedback, mindfulness meditation, and stress management have been used as part of a comprehensive integrative care model.

About the 2013 Myopain Congress
The 2013 Myopain Congress hopes to raise awareness that muscle pain is a physical disorder that is real, measurable, and treatable. This landmark conference will present the latest basic and clinical research, scientific abstracts, and workshops on muscle pain and other soft tissue pains to train practitioners in therapeutic approaches [see more information here].

The International Myopain Society was founded in 1983 as a nonprofit, international, interdisciplinary healthcare organization for research scientists, physicians, dentists, other healthcare professionals dedicated to exchanging ideas, conducting research, or learning more about myopain conditions. Since its inception 20 years ago, the Society has held international congresses every few years, and has spawned the Journal of Musculoskeletal Pain and several organizations that provide hands-on workshops. After Seattle, the next Congress will be in Australia in 2015. Persons interested in joining the organization and/or attending the Congress should visit myopain.org.

REFERENCES:

  1. Institute of Medicine. Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research. National Academies Press, Washington, DC; June 29, 2011.
  2. DHHS. National Institutes of Health PA-13-118 [available here].
  3. Stewart WF, Ricci JA, Chee E, Morganstein D, Lipton R. Lost Productive Time and Cost Due to Common Pain Conditions in the US Workforce. JAMA. 2003;290:2443-2454.
  4. Kato KSP, Evengard B, Pedersen NL. Chronic widespread pain and its co-morbidities: a population-based study. Arch Intern Med. 2006;166(15):1649-1654.
  5. National Center for Health Statistics. Health, United States, 2006, Special Feature on Pain With Chartbook on Trends in Americans. Hyattsville, MD [PDF available here].
  6. Bennett R. Myofascial Pain Syndromes and the Fibromyalgia Syndrome: A Comparative Analysis. In: Fricton J, Awad EA, editors. Myofascial Pain and Fibromyalgia. New York: Raven Press; 1990: 43-66.
  7. Fricton J, Kroening R, Haley D, Siegert, R. Myofascial pain syndrome of the head and neck: a review of clinical characteristics of 164 patients. Oral Surgery, Oral Medicine, Oral Pathology 1985;60(6):615-623.
  8. Rosomoff HL, Fishbain DA, Goldberg M, Santana R, Rosomoff RS. Physical findings in patients with chronic intractable benign pain of the neck and/or back. Pain. 1989;37:279-87.
  9. Skootsky S, Jaeger B, Oye RK. Prevalence of myofascial pain in general internal medicine practice. Western Journal of Medicine. 1989;151(2):157-60.
  10. Fricton J. Masticatory Myofascial Pain: An explanatory model integrating clinical, epidemiological, and basic science research. Bull. Group Int. Rech. Sci. Stomatol Odontol. 1999;41:14-25.
  11. Shah J, Heimur J. New Frontiers in Pathophysiology of Myofascial Pain. Pain Practitioner. 2(2):26-33.

 

JameFrictonAbout the Author: James Fricton, MD is a Professor at the University of Minnesota, a Senior Researcher at HealthPartners Institute for Education and Research, and a Pain Specialist at the Minnesota Head and Neck Pain Clinic. He is author of several books on chronic muscle pain and one book for the general public about health issues. His recent book, The Last Scroll [here], written as a romantic thriller, is a creative approach to helping people understand the 7 realms of their lives that are involved in preventing chronic pain and achieving health and wellness. He serves on the board of the International Myopain Society.

Editor’s Proviso: All observations, opinions, advice, or facts expressed above are those of the guest author, and do not necessarily reflect the positions of Pain Treatment Topics, our staff and advisors, or our educational supporters/sponsors. Opposing views, opinions, or clarifications regarding this UPDATE article are welcomed in comments below or by separate submission for consideration of publication.

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