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Myofascial Pain Syndrome

Understanding Mechanisms of Chronic Neck Pain


Representative Publications

  1. J. Ballyns, D. Turo, P. Otto, J. P. Shah, J. Hammond, T. Gebreab, L. Gerber, and S. Sikdar, “Office-based Elastography Technique for Quantifying Mechanical Properties of Skeletal Muscle ,” J. Ultrasound Med., in press, 2012.

  2. J. Ballyns, J. P. Shah, J. Hammond, T. Gebreab, L. Gerber, and S. Sikdar, “Objective ultrasonic measures for characterizing myofascial trigger points associated with cervical pain,” J. Ultrasound Med., vol. 30, pp. 1331-1340, 2011.
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  3. L. Gerber, S. Sikdar, J. Hammond and J. Shah, “A Brief Overview and Update of Myfascial Pain Syndrome and Myofascial Trigger Points,” J. Spine Research Foundation., vol. 6, pp. 55-64, 2011. 
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  4. S. Sikdar, J. P. Shah, T. Gebreab, R-H Yen, E. Gilliams, J. Danoff, and L. H. Gerber, “Novel application of ultrasound technology to visualize and characterize myofascial trigger points and surrounding soft tissue,” Arch Phys Med Rehabil. vol. 90, pp. 1829-1838, 2009. 
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Brief Description

Myofascial pain syndrome is a common non-articular disorder of the musculoskeletal system that affects roughly 9 million people in the US. Myofascial pain is associated with trigger points that are stiff, localized tender spots in a palpable taut band of skeletal muscle. Our working hypothesis is that trigger points represent sites of muscle injury where a vicious cycle of biochemical changes leads to sustained muscle contracture, compression of blood vessels and a local energy crisis that causes tissue hypoxia and the expression of nocioceptive (pain-producing) substances. In collaboration with researchers at the Rehabilitation Medicine Department at NIH and the Center for the Study of Chronic Illness and Disability at GMU, we are developing new methods for studying the pathophysiology of myofascial pain.

We are trying to understand the soft tissue milieu of the affected muscle in patients with symptomatic myofascial trigger points from multiple perspectives. All patients undergo a thorough physical exam, including several objective physical exam measures, such as cervical range of motion, pressure pain threshold, as well as questionnaires, such as the brief pain inventory, profile of mood states, Oswestry scale, and health status (SF32). We use ultrasound imaging and elastography to objectively describe the mechanical properties and microstructure of the muscle. We are using a microdialysis technique using a CMA 66 linear microdialysis catherer to sample the biochemical milieu of the trigger points. The subjects then undergo a course of dry needling treatment for three weeks, and all the measures are repeated after three and eight weeks to study how the muscle responds to the dry needle perturbation. Our research team consists of bioengineers, physiatrists and rehabilitation medicine physicians, proteomics experts, bioinformatics experts and statisticians.

Using vibration sonoelastography to visualize myofascial trigger points
sikdar image

An unique aspect of the study is the use of ultrasound to objectively image trigger points in the upper trapezius muscle. The trigger points appear as hypoechoic nodules on grayscale ultrasound, as shown in the bottom left panel. If the muscle is vibrated at low frequencies (~100 Hz) using an external vibrator (panels A and B), the palpably stiffer trigger points vibrate with lower amplitude compared to the surrounding tissue and can be imaged on vibration sonoelastography, as shown in the bottom right panel.


Funding

NIH R01: Pathogenesis and Pathophysiological Mechanisms of Myofascial Pain Syndromes

Abstract: Chronic soft-tissue (or myofascial) pain is a significant public health problem. Despite its high prevalence, the underlying mechanisms are poorly understood. In particular, very little is known about the pathophysiology and soft tissue environment of a myofascial trigger point (MTrP). MTrPs are palpable, localized painful nodules in a taut band of skeletal muscle that are a characteristic finding in myofascial pain syndrome (MPS). MTrPs are associated with spontaneous referred pain in symptomatic patients, and are the target for current management strategies for MPS, such as dry needle therapy. Recently, our research group has developed new ultrasound imaging methods to visualize and characterize the physiology and physical properties of the MTrPs and their surrounding soft tissue; and microanalytic techniques to assay the local biochemical milieu. These innovative methodological advances provide a unique opportunity to integrate the physical, physiological and biochemical findings to achieve a more comprehensive understanding of the abnormalities associated with MTrPs (e.g., muscle, fascia, blood vessels); and to correlate these findings with clinical assessments to better understand the role of MTrPs in chronic pain. Our ultimate goal is to develop a working model of the underlying mechanisms of MTrPs and translate the findings to objective clinical outcome measures using office-based technology. The specific aims of the project are: 1) To determine the mechanical tissue properties, vascular physiology and biochemical milieu of the affected soft tissue neighborhood of active MTrPs in patients with chronic neck pain compared to asymptomatic control subjects with/without palpable MTrPs; and 2) To determine the effect of a physical perturbation caused by dry needle therapy, a widely accepted method of treatment, on the soft tissue environment and biochemical milieu of active MTrPs in symptomatic subjects. Our working hypothesis is that MTrPs are sites of muscle injury where local biochemical changes lead to sustained muscle contracture, compression of blood vessels and a local energy crisis that causes tissue hypoxia. This condition perpetuates the release of inflammatory cytokines and nociceptive (pain-inducing) substances. To test this hypothesis, we will correlate ultrasound imaging scores, analyte levels and functional clinical measures in our specific aims. To translate these findings into clinical outcome measures that can be used in an office-based setting, we will adapt a reliable and inexpensive 3D Tactile Imaging instrument for quantifying mechanical soft tissue changes associated with MTrPs.

PUBLIC HEALTH RELEVANCE: Chronic pain is a significant public health concern. This proposal aims to identify anatomical and physiological abnormalities of muscle, fascia and blood flow in painful areas of the trapezius and neck associated with myofascial trigger points (MTrPs), which are a characteristic finding in myofascial pain syndrome (MPS). Demonstrating which tissues are involved (e.g., muscle, fascia, vessels), and which biochemicals are abnormal in MTrPs, will help develop appropriate preventive and therapeutic strategies, establish diagnostic criteria and potential outcome measures that can be used in treatment trials. Our approach would also be broadly applicable to elucidating the underlying mechanisms in other chronic musculoskeletal pain disorders, such low back pain.