Evidence that Muscle Pressure is Almost Three Times Higher than Expected in the Trapezius Muscle in Fibromyalgia Opens a Pathway to Identify Fibromyalgia Pain with a Definitive Test

Frank Leavitt Ph.D.

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Frank Leavitt Ph.D.

This article champions the theory that fibromyalgia is a muscle pressure disorder. Support for the linkage between muscle pressure and pain flows from findings in a groundbreaking article entitled “Intramuscular Pressure in the Trapezius is Almost Three Times Higher in Fibromyalgia: A Possible Mechanism for Understanding the Muscle Pain and Tenderness” published in the prestigious Journal of Rheumatology https://doi.org/10.3899/jrheum.191068. April 2021, 48(4); 598-602.

The muscle pressure connection in creating and sustaining pain arises from a straight forward process. Fibromyalgia affects intramuscular pressure in the trapezius, elevating it to a high degree. A common complication of high intramuscular pressure is oxygen deprivation. The compressing effects of high intramuscular pressure prevent blood from circulating normally. Low oxygen states in muscle tissue are well known generators of aching and pain. Low oxygen also induces muscle fatigue. This process may occur across other sites of the body.

The abnormality in muscle pressure is of sufficient magnitude to reframe understandings of fibromyalgia by expanding existing representations of the disorder. Within the confines of existing knowledge, the pain of fibromyalgia has many different faces, but a disorder of muscle pressure is not one of them. This terrain is new. Elevated pressure in the trapezius muscle is a central characteristic of fibromyalgia, a condition almost three times higher than expected, in both women and men with fibromyalgia.

Adding muscle pressure to the list of representations of fibromyalgia allows clinicians to view the reality of fibromyalgia from a non-contested perspective. Solid evidence of a measurable abnormality gives medical legitimacy to a condition which is often maligned as a psychological derivative or a creation of the imagination. The argument goes, if the pain of fibromyalgia sprouts without an identifiable cause, then the pain is not real.

Diagnosis lies at the heart of clinical practice; yet, the level of mistrust in the diagnosis of fibromyalgia should not be underestimated. Believe it or not, many general practitioners are not well versed about the condition and often will downplay its symptoms. It is not unusual for individuals with conspicuously obvious symptoms of fibromyalgia to undergo 4 to 6 consultations with different general practitioners before the proper diagnosis is made. It is a condition with a long history of controversy that is just as often misdiagnosed as over-diagnosed.

A measurable indicator of disease gives hope to the possibility that a revolution in the detection of fibromyalgia may be on the horizon. Currently, the diagnosis relies on symptom based criteria with their intrinsic uncertainties and their susceptibility to error. By testing alone, the medical exam is usually at a dead end when routine medical tests return normal. The symptoms are medically unexplained and often at risk of being marginalized. This medical scenario sets off a series of referrals to other disciplines which expose patients to the burden of multiple tests to rule out other conditions.

Diagnosis focused on elevated pressure in the trapezius muscle is a potential pathway for the development of a definitive test to identify those with fibromyalgia. As an observable indicator of abnormality, it eliminates the biases and flaws inherent in clinical judgment when the diagnosis is based solely on symptom criteria and the results of rule out testing.

Looking ahead, a measurement may be on the horizon that slashes the level of diagnostic uncertainty. The differences in trapezius muscle pressure in pain patients with and without fibromyalgia are remarkably large. Pressure in the trapezius muscle in fibromyalgia at rest was on average 22 mmhg higher. A pressures score of ≥ 23 mmHg accurately flagged 98% of the fibromyalgia sample. Pressure elevations ≥ 23 mmHg were found in 0% of the pain group without fibromyalgia. These values indicate that there may be clear boundaries that can be used to tailor a definitive test of fibromyalgia since in research to date pressure elevations ≥ 23 mmHg have been found only in patients with pain who have fibromyalgia. Testing of trapezius muscle pressure may be an entry point early in the examination of patients with widespread “unexplained” pain that eliminates the need for unnecessary and burdensome rule-out tests. It may also serve as a metric for measuring the progress of therapeutic change.

Learn more about pain expression in fibromyalgia in a link entitled: Fibromyalgia’s future is a biomarker.

See: www.sites.google.com/view/fmsbiomarker