Tadesse Gebreab

Objective Sonographic Measures for Characterizing Myofascial Trigger Points Associated With Cervical Pain

The purpose of this study was to determine whether the physical properties and vascular environment of active myofascial trigger points associated with acute spontaneous cervical pain, asymptomatic latent trigger points, and palpably normal muscle differ in terms of the trigger point area, pulsatility index, and resistivity index, as measured by sonoelastography and Doppler imaging.

Ultrasonic Characterization of the Upper Trapezius Muscle in Patients with Chronic Neck Pain

Myofascial trigger points (MTrPs) are palpable, tender nodules in taut bands of skeletal muscle that are painful on compression. MTrPs are characteristic findings in myofascial pain syndrome (MPS). The role of MTrPs in the pathophysiology of MPS is unknown. Localization, diagnosis, and clinical outcome measures of painful MTrPs can be improved by objectively characterizing and quantitatively measuring their properties. The goal of this study was to evaluate whether ultrasound imaging and elastography can differentiate symptomatic (active) MTrPs from normal muscle. Patients with chronic (>3 months) neck pain with spontaneously painful, palpable (i.e., active) MTrPs and healthy volunteers without spontaneous pain (having palpably normal muscle tissue) were recruited for this study. The upper trapezius muscles in all subjects were imaged, and the echotexture was analyzed using entropy filtering of B-mode images. Vibration elastography was performed by vibrating the muscle externally at 100 Hz. Color Doppler variance imaging was used to quantify the regions of color deficit exhibiting low vibration amplitude. The imaging measures were compared against the clinical findings of a standardized physical exam. We found that sites with active MTrPs (n = 14) have significantly lower entropy (p < 0.05) and significantly larger nonvibrating regions (p < 0.05) during vibration elastography compared with normal, uninvolved muscle (n = 15). A combination of both entropy analysis and vibration elastography yielded 69% sensitivity and 81% specificity in discriminating active MTrPs from normal muscle. These results suggest that active MTrPs have more homogeneous texture and heterogeneous stiffness when compared with normal, unaffected muscle. Our methods enabled us to improve the imaging contrast between suspected MTrPs and surrounding muscle. Our results indicate that in subjects with chronic neck pain and active MTrPs, the abnormalities are not confined to discrete isolated nodules but instead affect the milieu of the muscle surrounding palpable MTrPs. With further refinement, ultrasound imaging can be a promising objective method for characterizing soft tissue abnormalities associated with active MTrPs and elucidating the role of MTrPs in the pathophysiology of MPS.

Assessment of myofascial trigger points (MTrPs): A new application of ultrasound imaging and vibration sonoelastography

Myofascial trigger points (MTrPs) are palpable hyperirritable nodules in skeletal muscle that are associated with chronic musculoskeletal pain. The goal of this study was to image MTrPs in the upper trapezius muscle using 2D gray scale ultrasound (US) and vibration sonoelastography (VSE) for differentiating the soft tissue characteristics of MTrPs compared to surrounding muscle. MTrPs appeared as hypoechoeic elliptically-shaped focal regions within the trapezius muscle on 2D US. Audio-frequency vibrations (100–250 Hz) were induced in the trapezius muscle of four volunteers with clinically identifiable MTrPs, and the induced vibration amplitudes were imaged using the color Doppler variance mode, and were further quantified using spectral Doppler analysis. Spectral Doppler analysis showed that vibration amplitudes were 27% lower on average within the MTrP compared to surrounding tissue (p<0.05). Color variance imaging consistently detected a focal region of reduced vibration amplitude, which correlated with the hypoechoeic region identified as an MTrP (r =0.76 for area). Real-time 2D US identifies MTrPs, and VSE is feasible for differentiating MTrPs from surrounding tissue. Preliminary findings show that MTrPs are hypoechoeic on 2D US and the relative stiffness of MTrPs can be quantified using VSE. Ultrasound offers a convenient, accessible and low-risk approach for identifying MTrPs and for evaluating clinical observations of palpable, painful nodules.

A Systematic Comparison Between Subjects With No Pain and Pain Associated With Active Myofascial Trigger Points

To determine whether standard evaluations of pain distinguish subjects with no pain from those with myofascial pain syndromes (MPS) and active myofascial trigger points (MTrPs) and to assess whether self‐reports of mood, function, and health‐related quality of life differ between these groups.

Understanding the vascular environment of myofascial trigger points using ultrasonic imaging and computational modeling

Myofascial pain syndrome (MPS) is a common, yet poorly understood, acute and chronic pain condition. MPS is characterized by local and referred pain associated with hyperirritable nodules known as myofascial trigger points (MTrPs) that are stiff, localized spots of exquisite tenderness in a palpable taut band of skeletal muscle. Recently, our research group has developed new ultrasound imaging methods to visualize and characterize MTrPs and their surrounding soft tissue. The goal of this paper was to quantitatively analyze Doppler velocity waveforms in blood vessels in the neighborhood of MTrPs to characterize their vascular environment. A lumped parameter compartment model was then used to understand the physiological origin of the flow velocity waveforms. 16 patients with acute neck pain were recruited for the study and the blood vessels in the upper trapezius muscle in the neighborhood of palpable MTrPs were imaged using Doppler ultrasound. Preliminary findings show that symptomatic MTrPs have significantly higher peak systolic velocities and negative diastolic velocities compared to latent MTrPs and normal muscle sites. Using compartment modeling, we show that a constricted vascular bed and an enlarged vascular volume could explain the observed flow waveforms with retrograde diastolic flow.

Office-Based Elastographic Technique for Quantifying Mechanical Properties of Skeletal Muscle

Our objectives were to develop a new, efficient, and easy‐to‐administer approach to ultrasound elastography and assess its ability to provide quantitative characterization of viscoelastic properties of skeletal muscle in an outpatient clinical environment. We sought to show its validity and clinical utility in assessing myofascial trigger points, which are associated with myofascial pain syndrome.

Novel Use of Ultrasound Elastography to Quantify Muscle Tissue Changes After Dry Needling of Myofascial Trigger Points in Patients With Chronic Myofascial Pain

To compare a mechanical heterogeneity index derived from ultrasound vibration elastography with physical findings before and after dry‐needling treatment of spontaneously painful active myofascial trigger points in the upper trapezius muscle.

Ultrasonic tissue characterization of the upper trapezius muscle in patients with myofascial pain syndrome

Myofascial trigger points (MTrPs) are palpable, tender nodules in skeletal muscle that produce symptomatic referred pain when palpated. MTrPs are characteristic findings in myofascial pain syndrome (MPS). The role of MTrPs in the pathophysiology of MPS is unknown. Objective characterization and quantitative measurement of the properties of MTrPs can improve their localization and diagnosis, as well as lead to clinical outcome measures. MTrPs associated with soft tissue neck pain are often found in the upper trapezius muscle. We have previously demonstrated that MTrPs can be visualized using ultrasound imaging. The goal of this study was to evaluate whether texture-based image analysis can differentiate structural heterogeneity of symptomatic MTrPs and normal muscle.

Poster 147: Novel Use of Ultrasound Imaging to Investigate Myofascial Trigger Points and the Effects of Dry Needling: A Case Series

Patients or Programs: A 33-year-old woman, 8 weeks postpartum, who suffered a left knee multi-ligamentous rupture (anterior cruciate ligament [ACL], posterior cruciate ligament, lateral collateral ligament, medial collateral ligament), lateral meniscal tear, and popliteal artery rupture secondary to a hyperextension injury while getting out of her car. Program Description: During acute care the patient developed compartment syndrome and required a fasciotomy and femoro-popliteal artery bypass. She also had soft tissue infections requiring several debridements, skin grafts and hyperbaric oxygen treatments. She subsequently developed a left foot drop with neuropraxia. She was admitted to acute inpatient rehabilitation 5 months post-injury. Physical examination on admission was significant for dysesthesia of the left foot, left equinavarus contracture, and limited range of motion at the knee (0 to 30°). This patient had a history significant for obesity and an ACL reconstruction in 2001. The remainder of her history is non-contributory. The patient was fitted with a knee brace and short leg brace, and was referred to orthopedic surgery for Achilles tendon release. Setting: Acute inpatient rehabilitation. Results: The patient was advanced to independent ambulation with a rolling walker. Discussion: This is the first reported case, to our knowledge, of multiple non-traumatic ligamentous tears in a postpartum female. Conclusions: Several studies have shown a correlation between serum relaxin levels during the menstrual cycle with increased incidence of ACL rupture in female athletes. Preventative measures and patient education focusing on the reduction of risk factors could include target muscle strengthening preand post-partum, activity modification and possibly prophylactic bracing. Further studies could investigate a correlation between risk of injury with peripartum hormone changes in various populations, including the general population, those with previous ACL reconstruction, and in hypermobile patients.

Ultrasound Imaging and Elastography for Characterizing Muscle Tissue in Myofascial Pain Syndrome

home from the EC the same day or kept overnight in the EC observation unit. A difference in length of stay between the two groups was identified in the upper quartile of patients, which included the patients admitted to the hospital for more than one day. There were 338 patients in the Control group who were admitted longer than one day for a total of 2033 hospital days. There were 51 patients in the PM&R Consult group admitted for more than one day for a total of 243 hospital days. The mean LOS for patients admitted more than one day was 6.01 days for the Control group and 4.76 days for the PM&R Consult group. When the mean LOS for the PM&R Consult group was applied to the Control group it equated to a savings of 424 hospital days. A Wilcoxon two-sample test was performed to compare the similarity of the length of stay data in the two groups. The Wilcoxon twosample test results indicated that for patients admitted longer than one day the LOS was significantly lower in the PM&R Consult group (p< .0001). Conclusions: The length of stay for patients admitted to the hospital for more than one day with back pain was significantly less for patients who received a PM&R consultation in the EC.