Original articleBiochemicals Associated With Pain and Inflammation are Elevated in Sites Near to and Remote From Active Myofascial Trigger Points
Section snippets
Participants
Subjects were recruited from members of the staff of the clinical center at the National Institutes of Health (NIH). All subjects underwent a thorough musculoskeletal evaluation so as to rule out potential causes of their symptoms other than MTPs in the upper trapezius muscle. Exclusion criteria included a history of the following conditions: fibromyalgia, cervical or lumbar radiculopathy, other pain syndromes, or cancer. Subjects with knee pain, pathology or infection, previous injection
Results
Subjects in the active group reported greater pain levels (P<.001) on the VAS than did subjects in the latent and normal groups. The active group also had a lower PPT in both the trapezius and gastrocnemius muscles, which would indicate a greater sensitivity to direct pressure. The PPT differences were not significant, however.
In comparing data from subjects previously sampled6 with the subjects in this study, we found close agreement of biochemical concentrations. Figure 2 shows, as examples,
Discussion
We have confirmed that biochemicals associated with pain and inflammation are elevated in soft tissue in the vicinity of active MTPs. The concentrations of these biochemicals, including protons (equivalent to inverse pH), bradykinin, SP, CGRP, TNF-α, IL-1β, 5-HT, and norepinephrine differentiate the active group from the latent and normal groups. Two additional analytes not previously sampled, IL-6 and IL-8, were also significantly higher in the active group.
We have also shown that the
Conclusions
Our microdialysis system, utilizing samples of less than 1μL, is capable of continuous, near real-time, in vivo recovery of molecules 75kDa and smaller directly from the soft tissue environment without harmful effects on subjects.
There is a unique biochemical milieu of substances associated with pain and inflammation in the vicinity of an active MTP in the upper trapezius that includes elevated concentrations of protons, SP, CGRP, bradykinin, TNF-α, IL-1β, IL-6, IL-8, 5-HT, and norepinephrine.
References (21)
Myofascial pain syndromes and their evaluation
Best Pract Res Clin Rheumatol
(2007)Determination of in situ tissue neuropeptides by capillary immunoelectrophoresis
Anal Chim Acta
(1998)Review of enigmatic MTrPs as a common cause of enigmatic musculoskeletal pain and dysfunction
J Electromyogr Kinesiol
(2004)- et al.
Pain due to tissue acidosis: a mechanism for inflammatory and ischemic myalgia?
Neurosci Lett
(1996) Retrograde signaling in the nervous system: dorsal root reflexes
- et al.
Intramuscular injection of tumor necrosis factor-alpha induces muscle hyperalgesia in rats
Pain
(2003) - et al.
Excitatory and modulatory effects of inflammatory cytokines and neurotrophins on mechanosensitive group IV muscle afferents in the rat
Pain
(2005) - et al.
Hypernociceptive role of cytokines and chemokines: targets for analgesic drug development?
Pharmacol Ther
(2006) - et al.
Travell and Simons’ myofascial pain and dysfunction: the trigger point manual. Vol 1. Upper half of body
(1999) A study of 96 subjects examined for both fibromyalgia and myofascial pain
J Musculoskeletal Pain
(1995)
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Supported by the Intramural Research Program, National Institutes of Health (NIH), the Clinical Center and Office of the Director, NIH.
A commercial party having a direct financial interest in the results of the research supporting this article has conferred or will confer a financial benefit upon the author or 1 or more of the authors. Shah, Danoff, Phillips, and Gerber have filed a patent application for the device used in this study.