Development and identification of magnetic resonance, electrophysiological, and fiber-optic imaging biomarkers of myofascial pain - PROJECT SUMMARY Myofascial pain is a type of pain that originates in the muscle and surrounding fascia and is accompanied by a loss of range of motion, weakness, and sometimes autonomic symptoms. Affecting more than 85% of the general population sometime in their lives, myofascial pain has been a leading cause of health-care visits, absenteeism, and invalidity pensions—representing a significant health concern and economic burden. However, despite the high incidence of myofascial pain and substantial financial cost, the underlying pathophysiology remains largely unknown. As a result, clinical diagnosis and management of myofascial pain are largely empirical. Objective and quantitative biomarkers acquired by imaging, electromyography, laboratory tests, or muscle biopsy do not exist in the clinic for the assessment of myofascial pain. To address this unmet challenge, we propose to develop and translate a multi-modal, multi-parametric, multi-scale imaging approach to comprehensively assess the different aspects of the pathophysiology underlying myofascial pain both locally at the trigger point and regionally across the entire myofascial tissue, based on which we will identify candidate biomarker(s) that are most sensitive and specific to distinguish different states of myofascial pain and then test the biomarker’s ability to monitor treatment responses and predict clinical outcomes in a randomized clinical trial. Specifically, in the R61 phase (technology development & observational study), we will develop noninvasive magnetic resonance and electrophysiological imaging biomarkers and minimally invasive fiber-optic imaging biomarkers in parallel (Aim 1), and then identify candidate biomarkers that are best capable of differentiating different states (healthy, latent, and active) related to myofascial pain in an observational clinical study (Aim 2). Our prior research and preliminary studies provide strong premises for the proposed biomarker development and clinical testing. In the R33 Phase (interventional study), our research team—consisting of expertise in imaging, myofascial pain, quantitative analysis, and clinical trial—will examine the ability of the imaging biomarker(s) identified in the R61 phase for monitoring the responses to local chemical injection treatment and predicting clinical outcomes in a randomized clinical trial. The proposed research will create vital knowledge about myofascial pain and contribute to the creation of quantitative imaging biomarkers that may guide our choices of appropriate pain management and reduce opioid addiction.