Therapeutic use of botulinum toxin type A in treating neck and upper-back pain of myofascial origin: a pilot study

Efficacy of botulinum toxin in myofascial pain in neck and shoulder-systematic review and meta-analysis

While botulinum toxin injections (BTX-A) have been long used to treat myofascial pain (MFP) in the neck and shoulder region, the evidence of its effectiveness remained unclear. Thus, we aimed to examine the existing evidence on the efficacy of BTX-A injections for reducing MFP in the neck and shoulder areas. This was a systematic review of Medline, Embase, Cinahl, Scopus, and Central databases. Only randomized controlled trials were included. Random effects meta-analysis with effect size index as weighted mean difference (WMD) was applied. The search resulted in 100 records, of them seven were considered relevant and included in the meta-analysis. In total, the data from 261 patients were analyzed. Five trials focused on entire neck/upper back and shoulder pain, one on the infraspinatus muscle and one on the trapezius muscle. The dose of BTX-A varied from 20 to 400 UI. The risk of systematic bias was high for three trials and low for four trials. The pooled WMD was statistically significant [-10.22 (95% confidence interval (CI) -12.77 to -7.68)] on a scale from 0 to 100 in favor of BTX-A over sham. However, the difference was not clinically significant. Also, the meta-regression coefficient was insignificant [-0.01 (95% CI -0.04 to 0.02)]. The overall quality of evidence was moderate. In conclusion, there is moderate evidence that BTX-A injections are not more effective than saline injections to treat MFP in the neck and shoulder region. The effect of BTX-A did not exceed the level of clinical significance. So far, BTX-A cannot be recommended for clinical use when dealing with MFP in the neck and shoulder.

Intramuscular injections of botulinum toxin for the treatment of upper back myofascial pain syndrome: A systematic review of randomized controlled trials

BACKGROUND AND OBJECTIVE

Myofascial pain syndrome (MPS) is a chronic musculoskeletal disorder characterized by the presence of trigger points. Among the treatment options, botulinum toxin injections have been investigated. The aim of this paper was to provide a synthesis of the evidence on intramuscular botulinum toxin injections for upper back MPS.

DATABASES AND DATA TREATMENT

A systematic review of the literature was performed on the PubMed, Scopus and Cochrane Library, using the following formula: ("botulinum") AND ("musculoskeletal") AND ("upper back pain") OR ("myofascial pain").

RESULTS

Ten studies involving 651 patients were included. Patients in the control groups received placebo (saline solution) injections, anaesthetic injections + dry needling or anaesthetic injections. The analysis of the trials revealed modest methodological quality: one "Good quality" study, one "Fair" and the other "Poor". No major complications or serious adverse events were reported. Results provided conflicting evidence and did not demonstrate the superiority of botulinum toxin over comparators. Most of the included trials were characterized by a small sample size, weak power analysis, different clinical scores used and non-comparable follow-up periods. Even if there is no conclusive evidence, the favourable safety profile and the positive results of some secondary endpoints suggest a potentially beneficial action in pain control and quality of life.

CONCLUSION

The currently available studies show conflicting results. Their overall low methodological quality does not allow for solid evidence of superiority over other comparison treatments. Further insights are needed to properly profile patients who could benefit more from this peculiar injective approach.

SIGNIFICANCE

The randomized controlled trials included in this review compared using botulinum toxin to treat upper back MPS with placebo or active treatments (e.g., dry needling or anaesthetics) showing mixed results overall. Despite the lack of clear evidence of superiority, our study suggests that the use of botulinum toxin should not be discouraged. Its safety profile and encouraging results in pain control, motor recovery and disability reduction make it an interesting treatment, particularly in the subset of patients with moderate to severe chronic pain and active trigger points. To support the safety and efficacy of botulinum toxin, further high-quality studies are needed.

Fatter Is Better: Boosting the Vascularization of Adipose Tissue Grafts

Adipose tissue resorption after fat grafting is a major drawback in plastic and reconstructive surgery, which is primarily caused by the insufficient blood perfusion of the grafts in the initial phase after transplantation. To overcome this problem, several promising strategies to boost the vascularization and, thus, increase survival rates of fat grafts have been developed in preclinical studies in recent years. These include the angiogenic stimulation of the grafts by growth factors and botulinum neurotoxin A, biologically active gels, and cellular enrichment, as well as the physical and pharmacological stimulation of the transplantation site. To transfer these approaches into future clinical practice, it will be necessary to establish standardized procedures for their safe application in humans. If this succeeds, the surgical outcomes of fat grafting may be markedly improved, resulting in a significant reduction of the physical and psychological stress for the patients.

Treatment and management of myofascial pain syndrome

Myofascial Pain Syndrome (MPS) is a regional pain disorder that affects every age-group and is characterized by the presence of trigger points (TrPs) within muscles or fascia. MPS is typically diagnosed via physical exam, and the general agreement for diagnostic criteria includes the presence of TrPs, pain upon palpation, a referred pain pattern, and a local twitch response. The prevalence of MPS among patients presenting to medical clinics due to pain ranges anywhere from 30 to 93%. This may be due to the lack of clear criteria and guidelines in diagnosing MPS. Despite the prevalence of MPS, its pathophysiology remains incompletely understood. There are many different ways to manage and treat MPS. Some include exercise, TrP injections, medications, and other alternative therapies. More research is needed to form uniformly-accepted diagnostic criteria and treatments.

Comparative Effectiveness of Botulinum Toxin Injection for Chronic Shoulder Pain: A Meta-Analysis of Randomized Controlled Trials

Botulinum toxin (BoNT) injection is regarded as a promising treatment for musculoskeletal pain. However, its efficacy for treating chronic shoulder pain remains unclear. We investigated the effectiveness of BoNT injections for chronic shoulder pain by conducting a systematic search of electronic databases up to March 2020 for randomized control trials (RCTs) that used BoNT injections for chronic shoulder pain treatment. The primary outcome was the between-group comparison of pain reduction, quantified by the standardized mean difference (SMD). Nine RCTs comprising 666 patients were included and divided into two groups: one group with shoulder joint pain (n = 182) and the other group with shoulder myofascial pain (n = 484). Regarding shoulder joint pain, the efficacy of BoNT injections was similar to that of the reference treatment (SMD: −0.605, 95% confidence level [CI]: −1.242 to 0.032 versus saline; SMD: −0.180, 95% CI: −0.514 to 0.153 versus corticosteroids) at one month post-intervention, and was superior (SMD: −0.648, 95% CI: −0.1071 to −0.225 versus corticosteroids) between one and three months. Likewise, in terms of shoulder myofascial pain, the effectiveness of BoNT injections did not differ from the reference treatment (SMD: −0.212, 95% CI: −0.551 to 0.127 versus saline; SMD: 0.665, 95% CI: −0.260 to 1.590 versus dry needling and SMD: 1.093; 95% CI: 0.128 to 2.058 versus lidocaine) at one month post- intervention, and appeared superior (SMD: −0.314, 95% CI: −0.516 to −0.111 versus saline) between one and three months. Our meta-analysis revealed that BoNT injections could be a safe and effective alternative for patients with chronic shoulder pain.

The efficacy and safety of Botulinum Toxin Type A in painful knee osteoarthritis: a systematic review and meta-analysis

Objective

A systematic review and meta-analysis was carried out to evaluate the efficacy and safety of Botulinum Toxin Type A in painful knee osteoarthritis.

Methods

The EMBASE and MEDLINE databases were searched to identify randomized controlled trials (RCTs) of Botulinum Toxin Type A in the treatment of painful knee osteoarthritis. The references of included literature were also searched.

Results

Five articles involving 5 RCTs including 314 patients were included in this analysis. There was a significant difference between Botulinum Toxin Type A and placebo in the visual analog scale (VAS) pain scale and Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) questionnaire score in both the short-term (≤4 weeks) and long-term (≥8 weeks) treatment period. There were no serious adverse events in the Botulinum Toxin Type A groups.

Conclusions

This meta-analysis suggests that Botulinum Toxin Type A is effective and safe in the painful knee OA treatment. However, high-quality randomized controlled studies are still needed to further confirm our findings.

Effect of Local Anesthetic Versus Botulinum Toxin-A Injections for Myofascial Pain Disorders: A Systematic Review and Meta-Analysis

OBJECTIVE

Myofascial pain is a chronic pain disorder characterized by the presence of painful localized regions of stiff muscle and/or myofascial trigger points. Intramuscular myofascial trigger point injections are considered first-line treatments for myofascial pain. Common injectates include local anesthetics and botulinum toxin-A (BTX-A). The objective of this systematic review was to compare the effectiveness of local anesthetics and BTX-A on pain intensity in patients with myofascial pain.

METHODS

A comprehensive systematic search of 3 databases, EMBASE, CENTRAL, and Medline was conducted. The search was comprised of words to describe "myofascial pain" and "injections." We performed a meta-analysis comparing local anesthetic and BTX-A injections across these follow-up week periods: 0 (immediately following the injection), 1 to 2, 3 to 4, 5 to 6, 7 to 8, 9 to 10, 11 to 12, 16, 18, 24 weeks with local anesthetics and BTX-A as subgroups. We also performed subgroup analyses comparing the effectiveness of local anesthetic injections and BTX-A injections at various muscle locations and comparing the effectives of single versus multiple injection sessions.

RESULTS

In total, 33 studies were included. A qualitative analysis suggested that local anesthetics and BTX-A were inconsistently effective at mitigating pain across all follow-up periods. The meta-analyses revealed that local anesthetic injections were more effective than BTX-A at mitigating pain intensity. Multiple injection sessions of local anesthetics were more beneficial than a single session.

CONCLUSIONS

Additional studies are needed to determine sources of heterogeneity mediating the observed differences in effectiveness of local anesthetic and BTX-A injections among the studies. Additional replicative studies are also needed to delineate the relative efficacy and effectiveness of local anesthetic and BTX-A injection. The quantitative results of this study suggest that patients overall experience more pain relief with local anesthetic injections.

Therapeutic uses and efficacy of botulinum toxin in orofacial medicine

Introduction: Botulinum toxin, primarily known for its use in cosmetic surgery, is also used for therapeutic purposes in many medical fields. It works as a muscle relaxant and inhibits glandular secretions. In the orofacial sphere, the use of this toxin is proposed in particular for disabling myofascial pain and aberrant salivary disorders. Methodology: A critical analysis of the literature, based on PUBMED data, concerning the orofacial indications of botulinum toxin was carried out. Results: The literature is abundant regarding the therapeutic interest of this toxin for several oral pathologies, but scientific merits vary markedly from one indication to another. Discussion: The musculorelaxant and antisecretory action of this toxin appears to be demonstrated in the case of bruxism, limitation of the mouth opening and in hypersialorrhea. On the other hand, its medical benefit is still not supported by scientific evidence for masseter hypertrophy, tonicity of the levator labii superioris muscles, sialocele fistulae and Frey's syndrome. Conclusion: Additional high-level studies, unbiased, randomized controlled trials, are required to eliminate the uncertainties that persist about the clinical impact of botulinum toxin and to justify the development of recommendations for good practice valid and credible.

Alternatives to Opioids in the Pharmacologic Management of Chronic Pain Syndromes: A Narrative Review of Randomized, Controlled, and Blinded Clinical Trials

Chronic pain exerts a tremendous burden on individuals and societies. If one views chronic pain as a single disease entity, then it is the most common and costly medical condition. At present, medical professionals who treat patients in chronic pain are recommended to provide comprehensive and multidisciplinary treatments, which may include pharmacotherapy. Many providers use nonopioid medications to treat chronic pain; however, for some patients, opioid analgesics are the exclusive treatment of chronic pain. However, there is currently an epidemic of opioid use in the United States, and recent guidelines from the Centers for Disease Control (CDC) have recommended that the use of opioids for nonmalignant chronic pain be used only in certain circumstances. The goal of this review was to report the current body of evidence-based medicine gained from prospective, randomized-controlled, blinded studies on the use of nonopioid analgesics for the most common noncancer chronic pain conditions. A total of 9566 studies were obtained during literature searches, and 271 of these met inclusion for this review. Overall, while many nonopioid analgesics have been found to be effective in reducing pain for many chronic pain conditions, it is evident that the number of high-quality studies is lacking, and the effect sizes noted in many studies are not considered to be clinically significant despite statistical significance. More research is needed to determine effective and mechanism-based treatments for the chronic pain syndromes discussed in this review. Utilization of rigorous and homogeneous research methodology would likely allow for better consistency and reproducibility, which is of utmost importance in guiding evidence-based care.

Botulinum toxin type A for the treatment of head and neck chronic myofascial pain syndrome: A systematic review and meta-analysis

BACKGROUND

The authors conducted a systematic review to study the efficacy of botulinum toxin type A (BoTN-A) in the treatment of myofascial pain syndrome.

TYPES OF STUDIES REVIEWED

The authors identified randomized, double-masked, placebo-controlled studies on June 1, 2016, from PubMed, Web of Science, and the Cochrane Library. Three of the authors assessed the studies for risk of bias. Outcomes included pain reduction on a visual analog scale, the number of responders, and the posttreatment pain threshold to applied pressure using algometry.

RESULTS

The initial search strategy yielded 253 unduplicated references, which the authors reduced to 13 relevant studies. The authors included 11 studies in the meta-analyses as the investigators of those studies had reported similar outcomes. Pooled results showed a nonsignificant improvement in the posttreatment intensity of pain in the BoTN-A group compared with the placebo group at 4 to 6 weeks (standardized difference in means [SDM], -0.110; 95% confidence interval [CI], -0.344 to 0.124; P = .356) and a significant improvement at 2 to 6 months (SDM, -0.360; 95% CI, -0.623 to -0.096; P = .008). The number of study participants who responded to treatment was not statistically significantly different between the groups (risk ratio, 1.346; 95% CI, 0.922-1.964; P = .123) nor was the increase of pain threshold to pressure (algometry) at 2 months (SDM, 0.131; 95% CI, -0.178 to 0.440; P = .405). The study investigators reported no major adverse events.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Pain was reduced significantly in the group that received BoTN-A compared with the placebo group at 2 to 6 months but not at 4 to 6 weeks (with moderate quality of the evidence). Additional studies with larger numbers of participants are needed to confirm these results.

Effects of Botulinum Toxin Landmark-Guided Intra-articular Injection in Subjects With Knee Osteoarthritis

BACKGROUND

Increasing evidence has suggested that botulinum toxin A (BoNT/A) can inhibit the release of selected neuropeptide transmitters from primary sensory neurons. Thus, intra-articular (IA) injection therapies with BoNT/A may reduce pain in patients with knee osteoarthritis (OA).

OBJECTIVE

To investigate the effects of landmark-guided IA injection of BoNT/A on patients with knee OA.

DESIGN

A prospective randomized controlled trial.

SETTING

A rehabilitation clinic of a private teaching hospital.

PATIENTS

A total of 46 patients with symptomatic knee OA (mostly Kellgren-Lawrence grade 2-3).

METHODS

The patients were randomly assigned to 1 of the following groups: BoNT/A group (BoNT/A injection; n = 21) or control group (education only; n = 20). The patients in the BoNT/A group received an IA injection of 100 units of BoNT/A into the affected knee.

MAIN OUTCOME MEASURES

The short-term (1 week posttreatment) and long-term (6 months posttreatment) effects were evaluated using a pain visual analogue scale (VAS) and questionnaires concerning functional status, including the Lequesne and Western Ontario and McMaster Universities (WOMAC) indexes.

RESULTS

The between-group comparison revealed significant differences with regard to the pain VAS score at 1 week (P < .001) and at 6 months (P = .001) posttreatment. Similar findings for the between-group comparison were observed for the WOMAC and Lequesne indexes at 6 months (P < .05) posttreatment. The pain VAS score in the BoNT/A group significantly decreased from 5.05 ± 1.12 (pretreatment) to 2.89 ± 1.04 at 1 week (P < .001) and 3.45 ± 1.70 at 6 months posttreatment (P < .001) but not in the control group (P = .476).

CONCLUSIONS

The IA injection of BoNT/A provided pain relief and improved functional abilities in patients with knee OA in both the short- and long-term follow-up.

LEVEL OF EVIDENCE

I.

Treatment of myofascial pain syndrome with lidocaine injection and physical therapy, alone or in combination: a single blind, randomized, controlled clinical trial

BACKGROUND

Myofascial pain syndrome (MPS) of the shoulder girdle and cervical region is a common musculoskeletal problem that is often chronic or recurrent. Physical therapy (PT) and lidocaine injections (LI) are two treatments with demonstrated effectiveness compared to a control group, however little is known about their combined value. The objective of this study was to determine whether LI into trigger points combined with a PT program would be more effective than each separate treatment alone in improving pain, function, and quality of life in a group of patients with MPS of the shoulder girdle and cervical region.

METHODS

A single-blind, randomized, controlled clinical trial (RCT) was conducted with three parallel groups in the Departments of Physical Medicine and Rehabilitation of two urban hospitals in Medellin, Colombia. One hundred and twenty seven patients with shoulder girdle MPS for more than 6 weeks and pain greater than 40 mm on the visual analog scale (VAS) were assigned to 1 of 3 intervention groups: PT, LI, or the combination of both (PT + LI). The primary outcome was VAS pain rating at 1-month post-treatment. The secondary outcomes included VAS pain rating at 3 months, and, at both 1 and 3 months post-treatment: (a) function, evaluated by hand-back maneuver and the hand-mouth maneuver, (b) quality of life, as measured by sub-scales of the Short Form - 36 (SF-36), and (c) depressive symptoms, as measured by the Patient Health Questionnaire - 9 (PHQ-9). Independent t-tests were used to compare outcomes between groups at 1 month and 3 months post-treatment.

RESULTS

In the per protocol analysis, there were no significant intergroup differences in VAS at 1 month PT + LI, 40.8 [25.3] vs. PT, 37.8 [21.9], p = 0.560 and vs. LI, 44.2 [24.9], p = 0.545. There were also no differences between groups on secondary outcomes except that the PT and PT + LI groups had higher right upper limb hand-back maneuver scores compared to the LI alone group at both 1 and 3 months (p = 0.013 and p = 0.016 respectively).

CONCLUSIONS

The results of this RCT showed that no differences in pain ratings were observed between the individual treatments (PT or LI) compared to the combined treatment of PT and LI. In general, no difference in primary or secondary outcomes was observed between treatments.

TRIAL REGISTRATION

NTC01250184 November 27, 2010.

WITHDRAWN: Botulinum toxin for subacute/chronic neck pain

Withdrawn due to non‐compliance with The Cochrane Collaboration’s Commercial Sponsorship Policy

The editorial group responsible for this previously published document have withdrawn it from publication.

WITHDRAWN: Medicinal and injection therapies for mechanical neck disorders

Withdrawn due to non‐compliance with The Cochrane Collaboration’s Commercial Sponsorship Policy

The editorial group responsible for this previously published document have withdrawn it from publication.

Botulinum toxin for myofascial pain syndromes in adults

BACKGROUND

This is an updated version of the original Cochrane review published in Issue 4, 2012. Myofascial pain syndrome (MPS) is a regional muscular pain syndrome characterised by the presence of trigger points, which are painful points in one or more muscles. The pain can be felt at the site where the trigger point is located or it can be felt away from that place when the muscle is pressed (referred pain). Botulinum toxin is a protein produced by the bacterium Clostridium botulinum and is a potent neurotoxin that eventually inhibits muscle contractions. It is capable of selectively weakening painful muscles and interrupting the pain cycle.

OBJECTIVES

To assess the effectiveness and safety of botulinum toxin A (BTXA) in the treatment of myofascial pain syndrome (MPS), excluding MPS in neck and head muscles.

SEARCH METHODS

This is an updated version of the original Cochrane review published in Issue 4, 2012. The search strategy for the update was the same as in the original review and we searched CENTRAL in The Cochrane Library (2013, Issue 11 of 12), MEDLINE (Ovid) (2012 to 29 November 2013) and EMBASE (Ovid) (2012 to 27 November 2013). The search strategy was composed of terms for myofascial pain and botulinum toxin. For the original review, we also searched the Cochrane Pain, Palliative and Supportive Care (PaPaS) Review Group Specialised Register until December 2011, PubMed (from 1966 to 2011) and LILACS (from 1982 to 2011). There was no language restriction.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) involving botulinum toxin for treating participants with MPS. We excluded studies with MPS of the neck and head from this review as they have already been assessed in existing systematic reviews. We considered a diagnosis of MPS to be based on the identification of trigger points in the taut band through palpation of sensitive nodules, local twitch response and specific patterns of referred pain associated with each trigger point.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened identified studies, extracted data, assessed trial quality and analysed results using the Cochrane PaPaS Review Group criteria.

MAIN RESULTS

Four studies with a total of 233 participants, comparing BTXA with placebo, met the inclusion criteria. In one study with 145 participants, significant improvement rates of pain intensity scores and duration of daily pain were demonstrated when comparing BTXA with placebo. The three other studies showed that there was no statistically significant difference between BTXA and placebo in pain intensity.

AUTHORS' CONCLUSIONS

Since the first publication of this review, no new studies were found. There is inconclusive evidence to support the use of botulinum toxin in the treatment of MPS based on data from four studies with a total of 233 participants, which we considered were of sufficient quality to be included in this review. Meta-analyses were not possible due to the heterogeneity between studies. We suggest that in future studies the same methodology to assess pain, a standardised dose of treatment, follow-up of at least four months (to observe the maximum and minimum curve of the drug effect) and appropriate data presentation should be used. More high-quality RCTs of botulinum toxin for treating MPS need to be conducted before firm conclusions on its effectiveness and safety can be drawn.

Physician-delivered injection therapies for mechanical neck disorders: a systematic review update (non-oral, non-intravenous pharmacological interventions for neck pain)

Background:

Controversy persists regarding medicinal injections for mechanical neck disorders (MNDs).

Objectives:

To determine the effectiveness of physician-delivered injections on pain, function/disability, quality of life, global perceived effect and patient satisfaction for adults with MNDs.

Search Methods:

We updated our previous searches of CENTRAL, MEDLINE and EMBASE from December 2006 through to March 2012.

Selection Criteria:

We included randomized controlled trials of adults with neck disorders treated by physician-delivered injection therapies.

Data Collection and Analysis:

Two authors independently selected articles, abstracted data and assessed methodological quality. When clinical heterogeneity was absent, we combined studies using random-effects models.

Results:

We included 12 trials (667 participants). No high or moderate quality studies were found with evidence of benefit over control. Moderate quality evidence suggests little or no difference in pain or function/disability between nerve block injection of steroid and bupivacaine vs bupivacaine alone at short, intermediate and long-term for chronic neck pain. We found limited very low quality evidence of an effect on pain with intramuscular lidocaine vs control for chronic myofascial neck pain. Two low quality studies showed an effect on pain with anaesthetic nerve block vs saline immediately post treatment and in the short-term. All other studies were of low or very low quality with no evidence of benefit over controls.

Authors' Conclusions:

Current evidence does not confirm the effectiveness of IM-lidocaine injection for chronic mechanical neck pain nor anaesthetic nerve block for cervicogenic headache. There is moderate evidence of no benefit for steroid blocks vs controls for mechanical neck pain.

Effects of far-infrared irradiation on myofascial neck pain: a randomized, double-blind, placebo-controlled pilot study

OBJECTIVES

The objective of this study was to determine the relative efficacy of irradiation using a device containing a far-infrared emitting ceramic powder (cFIR) for the management of chronic myofascial neck pain compared with a control treatment.

DESIGN

This was a randomized, double-blind, placebo-controlled pilot study.

PARTICIPANTS

The study comprised 48 patients with chronic, myofascial neck pain.

INTERVENTION

Patients were randomly assigned to the experimental group or the control (sham-treatment) group. The patients in the experimental group wore a cFIR neck device for 1 week, and the control group wore an inert neck device for 1 week.

MAIN OUTCOME MEASUREMENT

Quantitative measurements based on a visual analogue scale (VAS) scoring of pain, a sleep quality assessment, pressure-pain threshold (PPT) testing, muscle tone and compliance analysis, and skin temperature analysis were obtained.

RESULTS

Both the experimental and control groups demonstrated significant improvement in pain scores. However, no statistically significant difference in the pain scores was observed between the experimental and control groups. Significant decreases in muscle stiffness in the upper regions of the trapezius muscles were reported in the experimental group after 1 week of treatment.

CONCLUSIONS

Short-term treatment using the cFIR neck device partly reduced muscle stiffness. Although the differences in the VAS and PPT scores for the experimental and control groups were not statistically significant, the improvement in muscle stiffness in the experimental group warrants further investigation of the long-term effects of cFIR treatment for pain management.

Pharmacological Interventions Including Medical Injections for Neck Pain: An Overview as Part of the ICON Project

OBJECTIVES

To conduct an overview (review-of-reviews) on pharmacological interventions for neck pain.

SEARCH STRATEGY

Computerized databases and grey literature were searched from 2006 to 2012.

SELECTION CRITERIA

Systematic reviews of randomized controlled trials (RCT) in adults with acute to chronic neck pain reporting effects of pharmacological interventions including injections on pain, function/disability, global perceived effect, quality of life and patient satisfaction.

DATA COLLECTION & ANALYSIS

Two independent authors selected articles, assessed risk of bias and extracted data The GRADE tool was used to evaluate the body of evidence and an external panel provided critical review.

MAIN RESULTS

We found 26 reviews reporting on 47 RCTs. Most pharmacological interventions had low to very low quality methodologic evidence with three exceptions. For chronic neck pain, there was evidence of: a small immediate benefit for eperison hydrochloride (moderate GRADE, 1 trial, 157 participants);no short-term pain relieving benefit for botulinum toxin-A compared to saline (strong GRADE; 5 trial meta-analysis, 258 participants) nor for subacute/chronic whiplash (moderate GRADE; 4 trial meta-analysis, 183 participants) including reduced pain, disability or global perceived effect; andno long-term benefit for medial branch block of facet joints with steroids (moderate GRADE; 1 trial, 120 participants) over placebo to reduce pain or disability;

REVIEWERS' CONCLUSIONS

While in general there is a lack of evidence for most pharmacological interventions, current evidence is against botulinum toxin-A for chronic neck pain or subacute/chronic whiplash; against medial branch block with steroids for chronic facet joint pain; but in favour of the muscle relaxant eperison hydrochloride for chronic neck pain.

Improvement in anxiety and pain after whole body whirlpool hydrotherapy among patients with myofascial pain syndrome

Objective

To evaluate the effect of the Whirlpool hydrotherapy on pain and anxiety in chronic myofascial pain syndrome (MPS) patients, compared to the conventional hydrocollator pack therapy.

Methods

Forty-one subjects who have MPS in the upper trapezius muscles without depression were recruited. The patients were randomly assigned into two groups: the whirlpool therapy group whose bodies were immersed in a whirlpool bath at 34℃-36℃ for 30 minutes; the hydrocollator group who took a 30-minute application of a standard hot hydrocollator pack. Patients in both groups received therapy three days a week for 2 weeks and underwent several evaluations at baseline and after treatment. The variables we analyzed during evaluations were as follows: the primary outcome we considered was pain severity using a visual analogue scale. And the secondary outcomes examined included anxiety using the Korean version of the Beck Anxiety Inventory and quality of life (QoL) using the Korean version of the World Health Organization QoL Assessment, Brief Form. All follow-up values were compared with the baseline values.

Results

The baseline parameters did not show significant differences between two groups. And after 2-week treatment, both groups revealed significant improvement in anxiety levels and QoL, as well as in pain. However, the improvement on pain (p=0.002) and anxiety (p=0.010) was significantly greater in the whirlpool group, compared to the hydrocollator group.

Conclusion

The whirlpool hydrotherapy can be used as a more effective therapeutic method to reduce pain and anxiety in chronic MPS patients without depression.

A critical appraisal of the evidence for botulinum toxin type A in the treatment for cervico-thoracic myofascial pain syndrome

Myofascial pain syndrome (MPS) is a musculoskeletal condition characterized by regional pain and muscle tenderness associated with the presence of myofascial trigger points (MTrPs). The last decade has seen an exponential increase in the use of botulinum toxin (BTX) to treat MPS. To understand the medical evidence substantiating the role of therapeutic BTX injections and to provide useful information for the medical practitioner, we applied the principles of evidence-based medicine to the treatment for cervico-thoracic MPS. A search was conducted through MEDLINE (PubMed, OVID, MDConsult), EMBASE, SCOPUS and the Cochrane database for the period 1966 to 2012 using the following keywords: myofascial pain, muscle pain, botulinum toxin, trigger points, and injections. A total of 7 trials satisfied our inclusion criteria and were evaluated in this review. Although the majority of studies found negative results, our analysis identified Gobel et al.'s as the highest quality study among these prospectively randomized investigations. This was due to appropriate identification of diagnostic criteria, excellent study design and objective endpoints. The 6 other identified studies had significant failings due to deficiencies in 1 or more major criteria. We conclude that higher quality, rigorously standardized studies are needed to more appropriately investigate this promising treatment modality.

Botulinum toxin for the treatment of myofascial pain syndromes involving the neck and back: a review from a clinical perspective

Introduction. Botulinum toxin inhibits acetylcholine (ACh) release and probably blocks some nociceptive neurotransmitters. It has been suggested that the development of myofascial trigger points (MTrP) is related to an excess release of ACh to increase the number of sensitized nociceptors. Although the use of botulinum toxin to treat myofascial pain syndrome (MPS) has been investigated in many clinical trials, the results are contradictory. The objective of this paper is to identify sources of variability that could explain these differences in the results. Material and Methods. We performed a content analysis of the clinical trials and systematic reviews of MPS. Results and Discussion. Sources of differences in studies were found in the diagnostic and selection criteria, the muscles injected, the injection technique, the number of trigger points injected, the dosage of botulinum toxin used, treatments for control group, outcome measures, and duration of followup. The contradictory results regarding the efficacy of botulinum toxin A in MPS associated with neck and back pain do not allow this treatment to be recommended or rejected. There is evidence that botulinum toxin could be useful in specific myofascial regions such as piriformis syndrome. It could also be useful in patients with refractory MPS that has not responded to other myofascial injection therapies.

Myofascial pain syndrome: a treatment review

Myofascial pain syndrome (MPS) is defined as pain that originates from myofascial trigger points in skeletal muscle. It is prevalent in regional musculoskeletal pain syndromes, either alone or in combination with other pain generators. The appropriate evaluation and management of myofascial pain is an important part of musculoskeletal rehabilitation, and regional axial and limb pain syndromes. This article reviews the current hypotheses regarding the treatment modalities for myofascial trigger points and muscle pain. Through a critical evidence-based review of the pharmacologic and nonpharmacologic treatments, the authors aim to provide clinicians with a more comprehensive knowledge of the interventions for myofascial pain.

Botulinum toxin for myofascial pain syndromes in adults

BACKGROUND

Myofascial pain syndrome (MPS) is a regional muscular pain syndrome characterised by the presence of trigger points, which are painful points in one or more muscles. The pain can be felt at the site where the trigger point is located or it can be felt away from that place when the muscle is pressed (referred pain). Botulinum toxin is a protein produced by the bacterium Clostridium botulinum and is a potent neurotoxin that eventually inhibits muscle contractions. It is capable of selectively weakening painful muscles and interrupting the pain cycle.

OBJECTIVES

To assess the effectiveness and safety of botulinum toxin in treating MPS, excluding MPS in neck and head muscles.

SEARCH METHODS

The search strategy was composed of terms for myofascial pain and botulinum toxin. We searched the Cochrane Pain, Palliative and Supportive Care (PaPaS) Review Group's Specialised Register until December 2011, CENTRAL (Cochrane Database of Systematic Reviews 2011, Issue 4), PUBMED (from 1966 to 2011), EMBASE (from 1980 to 2011) and LILACS (from 1982 to 2011). There was no language restriction.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) involving botulinum toxin for treating participants with MPS. We excluded studies with MPS of the neck and head from this review, as they have already been assessed in existing systematic reviews. We considered a diagnosis of MPS to be based on the identification of trigger points in the taut band through palpation of sensitive nodules, local twitch response and specific patterns of referred pain associated with each trigger point.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened identified studies, extracted data, assessed trial quality and analysed results using the Cochrane PaPaS Review Group criteria.

MAIN RESULTS

Four studies with a total of 233 participants, comparing botulinum toxin A (BTXA) with placebo, met the inclusion criteria. In one study with 145 participants, a significant improvement rate of pain intensity scores, as shown by the mean difference (MD) of -0.23 (95% confidence interval (CI) -0.26 to -0.20; P value < 0.00001) and duration of daily pain (MD -1.11; 95% CI -1.37 to -0.85; P value < 0.00001), was demonstrated when comparing BTXA with placebo. The three other studies showed that there was no statistically significant difference between BTXA and placebo in pain intensity.

AUTHORS' CONCLUSIONS

There is inconclusive evidence to support the use of botulinum toxin in the treatment of MPS based on data from four studies with a total of 233 participants, which we considered adequate to be included in this review. Meta-analyses were not possible due to the heterogeneity between studies. We suggest that in future studies the same methodology to assess pain, a standardised dose of treatment, follow-up of at least four months (to observe the maximum/minimum curve of the drug effect) and appropriate data presentation should be used. More high-quality RCTs of botulinum toxin for treating MPS need to be conducted before firm conclusions on its effectiveness and safety can be drawn.

Treatment of refractory pain with botulinum toxins--an evidence-based review

OBJECTIVES

To provide updated information on the role of botulinum toxins in the treatment of refractory pain based on prospective, randomized, double-blind, placebo-controlled studies. DESIGN OF THE REVIEW: Class I and class II articles were searched online through PubMed (1966 to the end of January 2011) and OvidSP including ahead-of-print manuscripts.

RESULTS

Level A evidence (two or more class I studies-established efficacy): pain of cervical dystonia, chronic migraine, and chronic lateral epicondylitis. Level B evidence (one class I or two class II studies-probably effective and recommended): post-herpetic neuralgia, post-traumatic neuralgia, pain of plantar fasciitis, piriformis syndrome, and pain in total knee arthroplasty. Level C evidence (one class II study-possibly effective, may be used at discretion of clinician): allodynia of diabetic neuropathy, chronic low back pain, painful knee osteoarthritis, anterior knee pain with vastus lateralis imbalance, pelvic pain, post-operative pain in children with cerebral palsy after adductor hip release surgery, post-operative pain after mastectomy, and sphincter spasms and pain after hemorrhoidectomy. Level U evidence (efficacy not proven due to diverse class I and II results): myofascial pain syndrome and chronic daily headaches. Studies in episodic migraine and tension headaches have shown treatment failure (level A-negative).

CONCLUSION

Evidence-based data indicate that administration of botulinum toxin in several human conditions can alleviate refractory pain. The problems with some study designs and toxin dosage are critically reviewed.

Botulinum toxin for subacute/chronic neck pain

BACKGROUND

Neck disorders are common, disabling and costly. Botulinum toxin (BoNT) intramuscular injections are often used with the intention of treating neck pain.

OBJECTIVES

To systematically evaluate the literature on the treatment effectiveness of BoNT for neck pain, disability, global perceived effect and quality of life in adults with neck pain with or without associated cervicogenic headache, but excluding cervical radiculopathy and whiplash associated disorder.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, AMED, Index to Chiropractic Literature, CINAHL, LILACS, and EMBASE from their origin to 20 September 2010.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials in which BoNT injections were used to treat subacute or chronic neck pain.

DATA COLLECTION AND ANALYSIS

A minimum of two review authors independently selected articles, abstracted data, and assessed risk of bias, using the Cochrane Back Review Group criteria. In the absence of clinical heterogeneity, we calculated standardized mean differences (SMD) and relative risks, and performed meta-analyses using a random-effects model. The quality of the evidence and the strength of recommendations were assigned an overall grade for each outcome.

MAIN RESULTS

We included nine trials (503 participants). Only BoNT type A (BoNT-A) was used in these studies.High quality evidence suggests there was little or no difference in pain between BoNT-A and saline injections at four weeks (five trials; 252 participants; SMD pooled -0.07 (95% confidence intervals (CI) -0.36 to 0.21)) and six months for chronic neck pain. Very low quality evidence indicated little or no difference in pain between BoNT-A combined with physiotherapeutic exercise and analgesics and saline injection with physiotherapeutic exercise and analgesics for patients with chronic neck pain at four weeks (two trials; 95 participants; SMD pooled 0.09 (95% CI -0.55 to 0.73)) and six months (one trial; 24 participants; SMD -0.56 (95% CI -1.39 to 0.27)). Very low quality evidence from one trial (32 participants) showed little or no difference between BoNT-A and placebo at four weeks (SMD 0.16 (95% CI -0.53 to 0.86)) and six months (SMD 0.00 (95% CI -0.69 to 0.69)) for chronic cervicogenic headache. Very low quality evidence from one trial (31 participants), showed a difference in global perceived effect favouring BoNT-A in chronic neck pain at four weeks (SMD -1.12 (95% CI: -1.89 to -0.36)).

AUTHORS' CONCLUSIONS

Current evidence fails to confirm either a clinically important or a statistically significant benefit of BoNT-A injection for chronic neck pain associated with or without associated cervicogenic headache. Likewise, there was no benefit seen for disability and quality of life at four week and six months.

[Types of topical treatment for peripheral neuropathic pain : Mechanism of action and indications]

The term "peripheral neuropathic pain syndromes" summarizes several chronic pain syndromes, which can occur focally or generalized in the peripheral nervous system in the course of an impairment of afferent neurons. Controlled clinical trials gave distinct indications for systemic treatments with antidepressants, anticonvulsants and opioid analgesics in several neuropathic pain syndromes. In addition to these systemic therapies, there are also two topical treatment options: topical application of lidocaine and capsaicin. An important cause of sensitization phenomena of afferent nociceptors is the upregulation of sodium channels and thermosensor channels. In the context of a partial nerve lesion that leaves behind partially preserved or regenerated afferent nerve fibres, just these channels could be used as target structures for topical medications. Topically applied drugs are absorbed systemically only in minute quantities, so systemic side effects are negligible. Pharmacological interactions with systematically acting substances are also virtually absent; thus, topically applied substances are especially appropriate for add-on therapy in addition to systemic pain medication.

Botulinum toxin injections for low-back pain and sciatica

BACKGROUND

Adequate relief from low-back pain (LBP) is not always possible. Emerging evidence suggests a role for botulinum neurotoxin (BoNT) injections in treating pain disorders. Proponents of BoNT suggest its properties can decrease muscle spasms, ischemia and inflammatory markers, thereby reducing pain.

OBJECTIVES

To determine the effects of botulinum toxin injections in adults with LBP.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2009, issue 3) and MEDLINE, EMBASE, and CINAHL to August 2009; screened references from included studies; consulted with content experts and Allergan. We included published and unpublished randomised controlled trials without language restrictions

SELECTION CRITERIA

We included randomised trials that evaluated BoNT serotypes versus other treatments in patients with non-specific LBP of any duration.

DATA COLLECTION AND ANALYSIS

Two review authors selected the studies, assessed the risk of bias using the Cochrane Back Review Group criteria, and extracted the data using standardized forms. We performed a qualitative analysis due to lack of data.

MAIN RESULTS

We excluded evidence from nineteen studies due to non-randomisation, incomplete or unpublished data. We included three randomised trials (N =123 patients). Only one study included patients with chronic non-specific LBP; the other two examined unique subpopulations. Only one of the three trials had a low risk of bias and demonstrated that BoNT injections reduced pain at three and eight weeks and improved function at eight weeks better than saline injections. The second trial showed that BoNT injections were better than injections of corticosteroid plus lidocaine or placebo in patients with sciatica attributed to piriformis syndrome. The third trial concluded that BoNT injections were better than traditional acupuncture in patients with third lumbar transverse process syndrome. Both studies with high risk of bias had several key limitations. Heterogeneity of the studies prevented meta-analysis. There is low quality evidence that BoNT injections improved pain, function, or both better than saline injections and very low quality evidence that they were better than acupuncture or steroid injections.

AUTHORS' CONCLUSIONS

We identified three studies that investigated the merits of BoNT for LBP, but only one had a low risk of bias and evaluated patients with non-specific LBP (N = 31). Further research is very likely to have an important impact on the estimate of effect and our confidence in it. Future trials should standardize patient populations, treatment protocols and comparison groups, enlist more participants and include long-term outcomes, cost-benefit analysis and clinical relevance of findings.

The role of botulinum toxin in management of pain: an evidence-based review

PURPOSE OF REVIEW

In the present review we discuss the role of botulinum neurotoxins (BoNTs) in the management of different pain conditions, with evidence-based data on the toxins' efficacy on pain and its mechanisms.

RECENT FINDINGS

Experimental in-vitro studies have reported promising results of a novel recombinant chimera of BoNT A and E that inhibits the calcitonin gene-related peptide exocytosis from brainstem sensory neurons. Animal studies in neuropathic pain rat models have reported an analgesic effect of BoNT A given after the neuropathic procedure and a bilateral antinociceptive effect to the unilateral noxious stimuli. There is a growing body of evidence that BoNTs are effective in myofascial pain syndrome, neuropathic pain, and joint pain. The pre-existing evidence that BoNTs are ineffective in migraine or other headache disorders has not yet been challenged. In other pain syndromes, studies published in the last review year have not contributed significantly in either demonstrating or invalidating the research that has so far proved inconclusive.

SUMMARY

The role of BoNTs in management of pain is not yet well established. Larger studies in neuropathic pain, joint pain, and myofascial pain syndrome are needed to fully ascertain the role for BoNT therapy in those areas.

Botulinum toxin intramuscular injections for neck pain: a systematic review and metaanalysis

OBJECTIVE

To assess the effect of intramuscular botulinum toxin type A (BoNT-A) injections on pain, function/disability, global perceived effect, and quality of life (QOL) in adults with neck pain (NP).

METHODS

We searched Central, Medline, and Embase databases up to June 2010. A minimum of 2 authors independently selected articles, abstracted data, and assessed risk of bias and clinical applicability. We estimated standard mean differences (SMD) with 95% CI, relative risks (RR), and performed metaanalyses (SMD(p)) using a random-effects model for nonheterogeneous data. The approach of the Grading of Recommendations Assessment, Development, and Evaluation working group summarizes the quality of evidence.

RESULTS

We selected 14 trials. High-quality evidence suggested BoNT-A was no better than saline at 4 weeks [4 trials/183 participants; SMD(p) -0.21 (95% CI -0.50 to 0.07)] and 6 months for chronic NP. Moderate-quality evidence showed a similar effect for subacute/chronic whiplash-associated disorder (WAD) on pain [4 trials/122 participants; SMD(p) -0.21 (95% CI -0.57 to 0.15)], disability, and QOL. Very low-quality evidence indicated BoNT-A combined with exercise and analgesics was not significant for chronic NP reduction at 4 weeks [3 trials/114 participants; SMD(p) -0.08 (95% CI -0.45 to 0.29)] but was at 6 months [2 trials/43 participants; SMD(p) -0.66 (95% CI -1.29 to -0.04)].

CONCLUSION

Current evidence does not confirm a clinically or statistically significant benefit of BoNT-A used alone on chronic NP in the short term or on subacute/chronic WAD pain, disability, and QOL. Larger trials, subgroups, and predictors of responses defined a priori (to facilitate selection of patients most likely to benefit) and factorial designs to explore BoNT as an adjunct treatment to physiotherapeutic exercise and analgesics are needed.

The efficacy of botulinum toxin type A in managing chronic musculoskeletal pain: a systematic review and meta analysis

BACKGROUND

Botulinum toxin type A (BoNTA) is a neurotoxin that acts by inhibiting the release of neurotransmitters acetylcholine at neuromuscular junctions, thus reducing muscular contractions. Recent evidence suggests that BoNTA can reduce nociceptive activities of sensory neurons in animal models by inhibiting release of certain neuropeptides. Despite the therapeutic benefit of BoNTA in alleviating painful muscle spasms, its efficacy in other musculoskeletal pain conditions is less clear.

OBJECTIVE

We aim to examine the efficacy of BoNTA in reducing chronic musculoskeletal pain.

METHODS

Studies for inclusion in our report were identified using MEDLINE, EMBASE, PUBMED, Cochrane Central Register of Controlled Trials, CINAHL, and reference lists of relevant articles. Studies were considered eligible for inclusion if they were randomized controlled trials (RCTs), evaluating the efficacy of BoNTA injections in pain reduction. All studies were assessed and data were abstracted independently by paired reviewers. The outcome measures were baseline and final pain scores as assessed by the patients. The internal validity of trials was assessed with the Jadad scale. Disagreements were resolved through discussions.

MAIN RESULTS

Twenty-one studies were included in the systematic review and 15 of them were included in the final meta-analysis. There was a total of 706 patients in the meta-analysis, represented from trials of plantar fasciitis (n = 1), tennis elbow (n = 2), shoulder pain (n = 1), whiplash (n = 3), and myofascial pain (n = 8). Overall, there was a small to moderate pain reduction among BoNTA patients when compared to control (SMD = -0.27, 95% CI: -0.44 to -0.11). When the results were analyzed in subgroups, only tennis elbow (SMD = -0.44, 95% CI: -0.86 to -0.01) and plantar fasciitis (SMD = -1.04, 95% CI: -1.68 to -0.40) demonstrated significant pain relief. Although not in the meta-analysis, one back pain study also demonstrated positive results for BoNTA. Lastly, BoNTA was effective when used at ≥ 25 units per anatomical site or after a period ≥ 5 weeks.

CONCLUSION

In our meta-analysis, BoNTA had a small to moderate analgesic effect in chronic musculoskeletal pain conditions. It was particularly effective in plantar fasciitis, tennis elbow, and back pain, but not in whiplash or shoulder pain patients. However, more evidence is required before definitive conclusions can be drawn. On the other hand, there is convincing evidence that BoNTA lacks strong analgesic effects in patients with myofascial pain syndrome. A general dose-dependent and temporal response with BoNTA injections was also observed.

Re-engineering clostridial neurotoxins for the treatment of chronic pain: current status and future prospects

Clostridial neurotoxins from the botulinum neurotoxin (BoNT) family are protein complexes, derived from the bacterium Clostridium botulinum, which potently inhibit acetylcholine release and result in a reversible blockade of the neuromuscular junction. This feature led to the clinical development of BoNT-A for a number of neuromuscular disorders. BoNT-A toxins are commercially available as three different preparations: Dysport/Azzalure, Botox/Vistabel, and Xeomin/Bocouture. Although BoNT-A preparations have not yet been approved for the treatment of pain, a substantial body of preclinical and clinical evidence shows that BoNT-A is effective in treating a number of different types of pain. It is thought to exert an analgesic effect both via muscle-relaxant properties and also directly, via inhibition of nociceptive neuropeptides. This review explores the mechanistic basis of this analgesic effect, summarizing current knowledge of the structure-function relationship of BoNT and discussing effects on both motor and pain neurons. For a complete picture of the analgesic properties of BoNT-A, clinical evidence of efficacy in myofascial pain and neuropathic pain is considered in tandem with a mechanistic rationale for activity. Patients experiencing chronic pain are clear candidates for treatment with a modified clostridial endopeptidase that would provide enduring inhibition of neurotransmitter release. A strong preclinical evidence base underpins the concept that re-engineering of BoNT could be used to enhance the analgesic potential of this neurotoxin, and it is hoped that the first clinical studies examining re-engineered BoNT-A will confirm this potential.

Comparison of miniscalpel-needle release, acupuncture needling, and stretching exercise to trigger point in myofascial pain syndrome

OBJECTIVE

Myofascial pain syndrome (MPS) is one of the most common causes of chronic musculoskeletal pain. Several methods have been recommended for the inactivation of trigger points (TrPs). We carried out this study to investigate the effectiveness of miniscalpel-needle (MSN) release and acupuncture needling and self neck-stretching exercises on myofascial TrPs of the upper trapezius muscle.

METHODS

Eighty-three TrPs in 43 patients with MPS were treated and randomly assigned to 3 groups: group 1 received MSN release in conjunction with self neck-stretching exercises; group 2 received acupuncture needling treatment and performed self neck-stretching exercises; and group 3, the control group, was assigned self neck-stretching exercises only. The therapeutic effectiveness was evaluated using subjective pain intensity (PI) with a visual analog scale, pressure pain threshold (PPT), and contralateral bending range of motion (ROM) of cervical spine at pretreatment, 2 weeks, and 3 months after treatment.

RESULTS

The improvement of PI, PPT, and contralateral bending ROM of cervical spine was significantly greater in group 1 and 2 than that in control group at 2 weeks and 3 months follow-up. Compared with group 2, patients in group 1 had a statistically significant reduction in PI, an increase in PPT, contralateral bending ROM of cervical spine at 3 months follow-up.

DISCUSSION

The effectiveness of MSN release for MPS is superior to that of acupuncture needling treatment or self neck-stretching exercises alone. The MSN release is also safe, without severe side effects in treatment of MPS.

Comparison of 3 needle sizes for trigger point injection in myofascial pain syndrome of upper- and middle-trapezius muscle: a randomized controlled trial

OBJECTIVES

To investigate (1) the relation between needle diameter and treatment efficacy of myofascial pain syndrome and (2) the relation between needle diameter and pain intensity during injection.

DESIGN

Randomized controlled trial.

SETTING

University-affiliated tertiary-care hospital.

PARTICIPANTS

Volunteers (N=77) with myofascial pain syndrome affecting upper- and middle-trapezius muscles with at least 3 months' duration of pain.

INTERVENTION

Participants were randomly assigned to receive trigger point injections on 1 side of the trapezius with a 21-, 23-, or 25-gauge needle. After a 1-time injection, participants were followed up for 14 days. Participants and the assessor were blinded for group assignment.

MAIN OUTCOME MEASURES

Treatment efficacy was measured with the visual analog scale (VAS; at pretreatment, and posttreatment on days 1, 4, 7, 14) for neck and upper-back pain, the Neck Disability Index (NDI; at pretreatment, and posttreatment on days 7, 14), and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36, at pretreatment and posttreatment on days 7, 14) for health-related quality of life. Pain intensity during injection was evaluated immediately after injection with VAS.

RESULTS

VAS scores for posttreatment on days 4, 7, and 14 decreased significantly compared with pretreatment scores in all groups; NDI scores on days 7 and 14 decreased significantly compared with pretreatment scores in all groups; SF-36 scores on days 7 and 14 decreased significantly compared with pretreatment scores in the 21- and 23-gauge needle groups; and SF-36 score on day 14 showed significant difference between the 21- and 25-gauge needle groups. For pain intensity during injection, VAS scores indicated no significant difference between the 3 groups.

CONCLUSIONS

No difference between the needle types was observed in terms of VAS or NDI, or in terms of pain intensity felt by patients during injection. In terms of SF-36 scores, injections with 21- or 23-gauge needles were found to be more effective. However, a well-controlled investigation is needed to explore the effect of needle thickness on health-related quality of life.

Botulinum toxin enhances the implantation effect of adipocytes in C57/BL6 mice

BACKGROUND

Recently, many plastic surgeons have been using adipogenic-differentiated cell implantation for remodeling scars in patients. However, this technique is not a long-term solution because implanted cells disappear gradually. Therefore, we investigated a method to increase the grafted cell preservation rate by using an effective adjuvant, botulinum toxin.

METHODS

The adipogenic-differentiated cells were subcutaneously injected in the dorsal area of C57/BL6 mice with or without botulinum toxin. Two and six weeks later we analyzed the residual volume and confirmed the characteristics of the implanted cells by real-time RT-PCR and immunohistochemistry.

RESULTS

Two and six weeks after transplantation we found that the residual volume of the transplantation site was higher in the botulinum toxin-treated group than in the untreated group. We also confirmed that the residual transplanted area has characteristics of adipogenic tissue by histological analysis. Next, to determine the mechanism related to the enhanced preservation rate of grafted cells via treatment with botulinum toxin, we performed immunohistochemical staining for the angiogenesis-related marker CD31. We found that CD31 expression was higher in the botulinum toxin-treated group than in the untreated group.

CONCLUSION

We have shown that in vivo grafted adipocyte cell preservation can be enhanced by treatment with botulinum toxin as an adjuvant. We suggest that botulinum toxin further increases this graft preservation rate by enhancing angiogenesis.

Nonsurgical interventional therapies for low back pain: a review of the evidence for an American Pain Society clinical practice guideline

STUDY DESIGN

Systematic review.

OBJECTIVE

To systematically assess benefits and harms of nonsurgical interventional therapies for low back and radicular pain.

SUMMARY OF BACKGROUND DATA

Although use of certain interventional therapies is common or increasing, there is also uncertainty or controversy about their efficacy.

METHODS

Electronic database searches on Ovid MEDLINE and the Cochrane databases were conducted through July 2008 to identify randomized controlled trials and systematic reviews of local injections, botulinum toxin injection, prolotherapy, epidural steroid injection, facet joint injection, therapeutic medial branch block, sacroiliac joint injection, intradiscal steroid injection, chemonucleolysis, radiofrequency denervation, intradiscal electrothermal therapy, percutaneous intradiscal radiofrequency thermocoagulation, Coblation nucleoplasty, and spinal cord stimulation. All relevant studies were methodologically assessed by 2 independent reviewers using criteria developed by the Cochrane Back Review Group (for trials) and by Oxman (for systematic reviews). A qualitative synthesis of results was performed using methods adapted from the US Preventive Services Task Force.

RESULTS

For sciatica or prolapsed lumbar disc with radiculopathy, we found good evidence that chemonucleolysis is moderately superior to placebo injection but inferior to surgery, and fair evidence that epidural steroid injection is moderately effective for short-term (but not long-term) symptom relief. We found fair evidence that spinal cord stimulation is moderately effective for failed back surgery syndrome with persistent radiculopathy, though device-related complications are common. We found good or fair evidence that prolotherapy, facet joint injection, intradiscal steroid injection, and percutaneous intradiscal radiofrequency thermocoagulation are not effective. Insufficient evidence exists to reliably evaluate other interventional therapies.

CONCLUSION

Few nonsurgical interventional therapies for low back pain have been shown to be effective in randomized, placebo-controlled trials.

Botulinum neurotoxins in the treatment of refractory pain

The proper management of pain is a critical issue in the practice of medicine. Despite the availability of a large number of analgesic medications, management of pain that is refractory to conventional treatments remains a challenge for both clinicians and surgeons. Botulinum neurotoxin (BoNT) has recently emerged as a potential novel approach to control pain. Animal studies have revealed a number of mechanisms by which BoNTs can influence and alleviate chronic pain, including inhibition of pain peptide release from nerve terminals and sensory ganglia, anti-inflammatory and antiglutaminergic effects, reduction of sympathetic neural discharge, and inhibition of muscle spindle discharge. In humans, prospective, placebo-controlled, double-blind studies have also provided evidence for effectiveness of BoNT therapy in a number of painful disorders. These include cervical dystonia, pelvic pain, low back pain, plantar fasciitis, postsurgical painful spasms, myofascial pain syndromes, migraine, and chronic daily headaches. Long-term studies on cervical dystonia and low back pain have demonstrated safety and sustained efficacy after repeated injections. This Review focuses on the analgesic effects of BoNT and the mechanisms of its pain control as revealed by animal models, and provides evidence-based data on the efficacy of BoNT therapy in various pain syndromes in humans.

Ultrasound-guided injection of botulinum toxin A in the treatment of iliopsoas spasticity

PURPOSE

Intramuscular injection of botulinum toxin A (BTX-A) is a common treatment for iliopsoas muscle spasticity, but it is not easy to position the needle in this muscle without guidance. In this paper we describe an ultrasound-guided technique for the intramuscular injection of BTX-A to treat spasticity of the iliopsoas muscle. Its effectiveness was assessed in 10 patients.

METHOD AND MATERIALS

The ultrasound-guided technique for BTX-A injection was used on 10 patients. The needle was inserted into the muscle belly at an angle of 45° along the longitudinal axis of the muscle when allowed by patient's condition.

RESULTS

In all cases, the iliopsoas muscle was easily identified and both the iliac and psoas components were assessed. Introduction of the needle and drug injection were entirely carried out under ultrasonographic guidance. The procedure was successful in all patients, even in those with a high-grade spasticity, and general anesthesia was not required.

CONCLUSIONS

This ultrasound-guided technique allows accurate guidance for the injection of BTX-A, and it can be considered as an alternate supportive therapy in patients with spasticity and dystonia.