Chronic Pain Syndromes: Myofascial Pain Syndrome.

Myofascial pain syndrome (MPS) is a regional musculoskeletal pain disorder characterized by trigger points within the muscle or fascia. There are no universally accepted diagnostic criteria. Diagnosis currently is based on a physical examination finding of at least one localized trigger point that, when palpated, recreates the pain at the site or produces pain away from the site in a referral pattern. MPS is thought to be related to sustained muscle contraction from under- or overuse. This syndrome commonly coexists with other chronic pain conditions, including fibromyalgia. The difference between MPS and fibromyalgia is that MPS involves localized pain with discrete areas of tenderness, whereas fibromyalgia symptoms are more diffuse and widespread. Most management recommendations for MPS are based on low-quality clinical trials or expert opinion. A multimodal approach is recommended, involving patient education, exercise, behavior modification, pharmacotherapy, and procedural interventions. Commonly used drugs include topical analgesics, nonsteroidal anti-inflammatory drugs, and muscle relaxants. Procedural interventions include manual therapy (eg, deep tissue massage, spray and stretch technique, myofascial release), dry needling, trigger point injections, onabotulinumtoxinA injections, acupuncture, kinesiology tape, transcutaneous electrical nerve stimulation, extracorporeal shockwave therapy, and low-level laser therapy. Symptoms often resolve with these interventions if they are used early in the course of the condition. As MPS enters the chronic stage, it becomes increasingly refractory to treatment.