Re-Examining Myofascial Pain Syndrome: Toward Biomarker Development and Mechanism-Based Diagnostic Criteria

Purpose of ReviewWe discuss the need for a mechanism-based diagnostic framework with a focus on the development of objective measures (e.g., biomarkers) that can potentially be added to the diagnostic criteria of the syndrome. Potential biomarkers are discussed in relation to current knowledge on the pathophysiology of myofascial pain syndrome (MPS), including alterations in redox status, inflammation, and the myofascial trigger point (MTrP) biochemical milieu, as well as imaging and neurophysiological outcomes. Finally, we discuss the long-term goal of conducting a Delphi survey, to assess the influence of putative MPS biomarkers on clinician opinion, in order to ultimately develop new criteria for the diagnosis of MPS.Recent FindingsMyofascial pain syndrome (MPS) is a prevalent healthcare condition associated with muscle weakness, impaired mood, and reduced quality of life. MPS is characterized by the presence of myofascial trigger points (MTrPs): stiff and discrete nodules located within taut bands of skeletal muscle that are painful upon palpation. However, physical examination of MTrPs often yields inconsistent results, and there is no gold standard by which to diagnose MPS.SummaryThe current MPS diagnostic paradigm has an inherent subjectivity and the absence of correlation with the underlying pathophysiology. Recent advancements in ultrasound imaging, systemic biomarkers, MTrP-specific biomarkers, and the assessment of dysfunction in the somatosensorial system may all contribute to improved diagnostic effectiveness of MPS.