Characteristics of patients with myofascial pain syndrome of the low back

The objective of this study is to determine characteristics of patients with myofascial pain syndrome (MPS) of the low back and the degree to which the low back pain in the patients examined can be attributed to MPS. Twenty-five subjects with myofascial trigger point(s) [MTrP(s)] on the low back participated in this cross-sectional study. The location, number, and type of selected MTrPs were identified by palpation and verified by ultrasound. Pain pressure threshold, physical function, and other self-reported outcomes were measured. Significant differences were found in Group 1 (Active), 2 (Latent), 3 (Atypical, no twitching but with spontaneous pain), and 4 (Atypical, no twitching and no spontaneous pain) of participants in the number of MTrPs, current pain, and worst pain in the past 24 h (p = .001-.01). There were interaction effects between spontaneous pain and twitching response on reports of physical function, current pain, and worst pain (p = .002-.04). Participants in Group 3 reported lower levels of physical function, and higher levels of current pain and worst pain compared to those in Group 4. Participants in Group 1 and 2 had similar levels of physical function, current pain, and worst pain. The number of MTrPs is most closely associated with the level of pain. Spontaneous pain report seems to be a decisive factor associated with poor physical function; however, twitching response is not.

A model for personalized diagnostics for non-specific low back pain: the role of the myofascial unit

Low back pain (LBP) is the leading cause of disability worldwide. Most LBP is non-specific or idiopathic, which is defined as symptoms of unknown origin without a clear specific cause or pathology. Current guidelines for clinical evaluation are based on ruling out underlying serious medical conditions, but not on addressing underlying potential contributors to pain. Although efforts have been made to identify subgroups within this population based on response to treatment, a comprehensive framework to guide assessment is still lacking. In this paper, we propose a model for a personalized mechanism-based assessment based on the available evidence that seeks to identify the underlying pathologies that may initiate and perpetuate central sensitization associated with chronic non-specific low back pain (nsLBP). We propose that central sensitization can have downstream effects on the "myofascial unit", defined as an integrated anatomical and functional structure that includes muscle fibers, fascia (including endomysium, perimysium and epimysium) and its associated innervations (free nerve endings, muscle spindles), lymphatics, and blood vessels. The tissue-level abnormalities can be perpetuated through a vicious cycle of neurogenic inflammation, impaired fascial gliding, and interstitial inflammatory stasis that manifest as the clinical findings for nsLBP. We postulate that our proposed model offers biological plausibility for the complex spectrum of clinical findings, including tissue-level abnormalities, biomechanical dysfunction and postural asymmetry, ecological and psychosocial factors, associated with nsLBP. The model suggests a multi-domain evaluation that is personalized, feasible and helps rule out specific causes for back pain guiding clinically relevant management. It may also provide a roadmap for future research to elucidate mechanisms underlying this ubiquitous and complex problem.

Evidence for an association of serum microanalytes and myofascial pain syndrome

BACKGROUND

Myofascial Pain Syndrome (MPS) is a common pain disorder. Diagnostic criteria include physical findings which are often unreliable or not universally accepted. A precise biosignature may improve diagnosis and treatment effectiveness. The purpose of this study was to assess whether microanalytic assays significantly correlate with characteristic clinical findings in people with MPS.

METHODS

This descriptive, prospective study included 38 participants (25 women) with greater than 3 months of myofascial pain in the upper trapezius. Assessments were performed at a university laboratory. The main outcome measures were the Beighton Index, shoulder range of motion, strength asymmetries and microanalytes: DHEA, Kynurenine, VEGF, interleukins (IL-1b, IL-2, IL-4, IL-5, IL-7, IL-8, IL-13), growth factors (IGF-1, IGF2, G-CSF, GM-CSF), MCP-1, MIP-1b, BDNF, Dopamine, Noradrenaline, NPY, and Acetylcholine. Mann-Whitney test and Spearman's multivariate correlation were applied for all variables. The Spearman's analysis results were used to generate a standard correlation matrix and heat map matrix.

RESULTS

Mean age of participants was 32 years (20-61). Eight (21%) had widespread pain (Widespread Pain Index ≥ 7). Thirteen (34%) had MPS for 1-3 years, 14 (37%) 3-10 years, and 11 (29%) for > 10 years. The following showed strong correlations: IL1b,2,4,5,7,8; GM-CSF and IL 2,4,5,7; between DHEA and BDNF and between BDNF and Kynurenine, NPY and acetylcholine. The heat map analysis demonstrated strong correlations between the Beighton Index and IL 5,7, GM-CSF, DHEA. Asymmetries of shoulder and cervical spine motion and strength associated with select microanalytes.

CONCLUSION

Cytokine levels significantly correlate with selected clinical assessments. This indirectly suggests possible biological relevance for understanding MPS. Correlations among some cytokine clusters; and DHEA, BDNF kynurenine, NPY, and acetylcholine may act together in MPS. These findings should be further investigated for confirmation that link these microanalytes with select clinical findings in people with MPS.

Quantitative Ultrasound Texture Feature Changes With Conservative Treatment of the Trapezius Muscle in Female Patients With Myofascial Pain Syndrome

OBJECTIVE

We set out to assess whether quantitative ultrasound could be used to assess changes that occur after physical therapy in patients experiencing myofascial pain syndrome.

METHODS

We consecutively recruited female subjects experiencing myofascial pain syndrome of the neck and shoulder region and provided 10 sessions of conservative physical therapy. A control group was recruited for textural analyses. We measured change in pain ratings, range of motion, and ultrasound texture features before and after the intervention and after 3 mos.

RESULTS

We recruited 63 female myofascial pain syndrome subjects and 20 healthy controls. After treatment, the mean blob size (an ultrasound texture feature) value for each subject decreased from 30.84 ± 5.00 to 25.86 ± 5.67 on the right and decreased from 31.70 ± 5.51 to 28.08 ± 5.53 on the left (P < 0.0005). The blob count showed a significant increase only on the left side (P < 0.01). Corresponding to this were reductions in pain and disability scores after treatment and at 3 mos compared with retreatment (P < 0.0005 for all checkpoints). Cervical range of motion values were significantly increased only at 3 mos compared with pretreatment except for mean flexion range of motion.

CONCLUSIONS

Ultrasound texture feature of blob size and count changes correspond to routine clinical outcomes after conservative physical therapy of myofascial pain syndrome in female individuals.

Granisetron vs. lidocaine injection to trigger points in the management of myofascial pain syndrome: a double-blind randomized clinical trial

OBJECTIVES

Granisetron and lidocaine injections have been used for the management of myofascial pain syndrome. This study was aimed to compare the efficacy of granisetron and lidocaine injections to trigger points of upper trapezius in the management of myofascial pain syndrome.

METHODS

We performed a double-blind randomized clinical trial in an outpatient clinic of physical medicine and rehabilitation at a teaching hospital. A total of 40 patients aged ≥18 with neck pain due to myofascial pain syndrome were included. They had pain for at least one month with the intensity of at least 30 mm on a 100 mm visual analog scale. Each participant received a single dose of 1 mL lidocaine 2% or 1 mg (in 1 mL) granisetron. The solutions were injected into a maximum of three trigger points of the upper trapezius. We instructed all patients to remain active while avoiding strenuous activity for three or four days, and to perform stretch exercise and massage of their upper trapezius muscles. We assessed the patients before the interventions, and one month and three months post-injection. The primary outcome was the Neck Disability Index and the secondary outcome was the Neck Pain and Disability Scale.

RESULTS

Both interventions were successful in reducing neck pain and disability (all p-values <0.001). However, the neck pain and disability responded more favorably to lidocaine than granisetron (p=0.001 for Neck Disability Index, and p=0.006 for Neck Pain and Disability Scale). No significant side-effect was recognized for both groups.

CONCLUSIONS

Both lidocaine and granisetron injections to trigger points are effective and safe for the management of the syndrome and the benefits remain at least for three months. However, lidocaine is more effective in reducing pain and disability. The injections are well-tolerated, although a transient pain at the site of injections is a common complaint. One mL of lidocaine 2% is more effective than 1 mg (in 1 mL) granisetron for injecting into the trigger points of the upper trapezius in myofascial pain syndrome.