Myofascial Trigger Points Key to Treating Fibromyalgia

April 5, 2011

Therapies that target myofascial trigger points may be effective at reducing fibromyalgia-related pain.

Therapies that target myofascial trigger points may be effective at reducing fibromyalgia-related pain

The authors of a study published in Arthritis Research and Therapy report that they were able to reproduce patients’ fibromyalgia pain patterns by stimulating trigger points. This finding, in conjunction with earlier studies, suggests that therapies targeted at myofascial trigger points (MTPs) may significantly improve fibromyalgia-related pain.

Noting that evidence in the literature indicates that “nociceptive inputs from muscle tissues and myofascial trigger points (MTPs) in particular are important in the initiation and/or maintenance” of fibromyalgia pain, the authors sought to assess whether the overall spontaneous fibromyalgia pain pattern “can be reproduced by the local and referred patterns from multiple active MTPs in different muscles.”

Researchers looked at 30 women (average age of 53 years) who had a diagnosis of fibromyalgia confirmed by a physician according to The American College of Rheumatology 1990 criteria for the classification of fibromyalgia, and an age-matched control group of 30 women. Members of the fibromyalgia group had been diagnosed an average of 10 years prior, “had an average pain rating of 6.2 ± 2.2 cm for the past 24 hours and of 5. 3 ± 2.2 cm for the current spontaneous pain on the day of experiment on a 0 to 10 cm visual analogue scale (VAS).” More than three-quarters of the patients in the fibromyalgia group were taking one or more of the following: NSAIDs, opioids, sedatives, antidepressants, and/or gabapentinoids.

The control group reported “no current spontaneous pain, no major pain experience during the past month prior to the experiment, and no pain-related diagnoses.”

In the study, patients in the fibromyalgia group were asked “to rate the current overall spontaneous pain intensity and to draw on an anatomical map the pain areas felt on the day of the experiment.” The researchers used this information, along with manual palpation, to identify active MTPs in different muscles (defined as “the most tender spot together with the largest nodule compared to other spots” as identified manually via palpation), with the aim “to reproduce each patient's pain pattern.” Researchers used manual and flat palpation to induce local pain and referred pain, identifying active and latent MTPs according to proposed diagnostic criteria. They recorded “evoked local and referred pain patterns from each key active MTP,” marking the locations of key active MTPs on fibromyalgia group patients and also on age-matched healthy subjects. They then examined the MTPs using intramuscular electromyography (EMG) to measure spontaneous electrical activity in the subjects.

The researchers reported “a significant difference in spontaneous FM pain and evoked pain areas” between fibromyalgia and control groups, but found no significant differences between spontaneous pain and MTP-evoked pain in either group. In fibromyalgia patients, the local and referred pain patterns evoked from key active MTPs “were similar to the overall spontaneous pain pattern.” In the control group (where no spontaneous pain was reported) local and referred pain were evoked from latent MTPs. The authors reported “significant positive correlation between the evoked pain area from all key active MTPs and the overall spontaneous pain intensity” in fibromyalgia.

In their discussion of these results, the authors said the key finding in this study was “the reproduction of patient-specific overall spontaneous pain pattern in [fibromyalgia] by manual stimulation of key active MTPs,” making this the first study “to show that the overall spontaneous pain pattern in each [fibromyalgia] patient can be decomposed into muscle-specific local and referred pain patterns from active MTPs.” These findings show that “active MTPs are the major peripheral pain generator” in fibromyalgia.

Evidence that “widespread spontaneous pain pattern in [fibromyalgia] is a summation of multiple regional pains due to active MTPs” supports the idea that targeting active MTPs may significantly improve FM pain and dysfunction.

The authors caution that “identification of key active MTPs should not be confined to the predetermined tender point sites” in fibromyalgia, and suggest that clinicians attempting to identify active MTPs “should follow the overall spontaneous pain pattern of each patient” and adopt “a patient-specific MTP identification strategy due to large between-subject differences in real-time FM pain reports.”