Study Title: The predetermined sites of examination for tender points in Fibromyalgia Syndrome are frequently associated with myofascial trigger points
Author(s): Hong-You G. et al.
Publication Information: The Journal of Pain 2010; 11(7): 644-651.
Fibromyalgia Syndrome (FMS) refers to a clinical picture involving diffuse musculoskeletal pain in addition to other symptoms such as cognitive impairment, fatigue, sleep disturbance and morning stiffness. There is currently no diagnostic test for this condition, so clinicians must rely on clinical history and the American College of Rheumatology (ACR) criteria for diagnosis.
The palpation of tender points (TP) as identified by these criteria certainly has its limitations, which has led to controversy surrounding the identification of FMS. As our understanding of central sensitization and pain mechanisms, as well as fascia and muscle physiology evolves, our ability to accurately identify and diagnose FMS will hopefully improve. More specifically, it has been suggested that myofascial trigger points (MTrPs) play an important role in FMS. MTrPs have been identified in FMS patients in previous studies1; however, the clinical importance of this finding has never been evaluated.
In this study, the authors’ aim was to test the hypothesis that the 18 predetermined tender point sites in FMS are actually MTrPs, and that the pain induced from active MTrPs can mimic FMS pain patterns.
CONCLUSIONS AND PRACTICAL APPLICATION
This study was the first to evaluate whether the 18 predetermined TPs used to diagnose FMS are associated with active and/or latent MTrPs identified via manual palpation and intramuscular EMG, and whether pain elicited from these MTrPs can mimic the pain reported by FMS patients.
The results suggest that the presence of active (but not latent) MTrPs correlates with the spontaneous pain pattern and intensity in FMS patients. Thus, the authors suggest that active MTrPs may be a peripheral pain generator in FMS, a link between TP sites and pain intensity in the context of the ACR diagnostic criteria. They also replicate previous research findings that FMS patients exhibit a generalized reduction in pressure pain threshold (PPT), suggesting the presence of mechanical pain sensitization in FMS patients. It should be noted that reduced PPT values have also previously been correlated with the presence of MTrPs.2
FMS is certainly a multidimensional condition. From a practical perspective, this study reminds us that TP evaluation might be searching for the same pathological entity (a trigger point) that we search for in many of our patients that present with a variety of complaints. In FMS, the cause-and-effect relation between the trigger points and the syndrome itself may resemble a “chicken-and-egg” commentary. The bottom line is that patients with FMS seem to have a generalized sensitization that affects the myofascial system, which may lead to a high number of active MTrPs (the authors appropriately note that such MTrPs could also be present elsewhere aside from the 18 TPs used to diagnose FMS). As mentioned, integrating the findings of this study with our expanding knowledge about central sensitization and myofascial physiology begins to clarify the difficult clinical picture that often accompanies FMS. Further research is required to determine how these concepts can guide our treatment approaches.
To view this review in full, including study methods, pertinent results, an overview of ACR criteria for FMS diagnosis, and additional references, please visit www.cndoctor.ca.
Dr. Shawn Thistle is the founder and president of Research Review Service Inc., an online, subscription-based service designed to help busy practitioners to integrate current, relevant scientific evidence into their practice. Shawn graduated from CMCC and holds an Honours Degree in Kinesiology from McMaster University. He also holds a certificate in Contemporary Medical Acupuncture from McMaster University, and is a Certified Active Release Techniques (ART®) Provider. For more information about the Research Review Service, visit www.researchreviewservice.com.
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