Effect of Local Anesthetic Versus Botulinum Toxin-A Injections for Myofascial Pain Disorders

Abstract

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.

Trigger Point Injection Therapy in the Management of Myofascial Pain Syndrome in the Maxillofacial Area

“…Продолжительность периода ремиссии после инъекций в триггерные точки, достигнутая в данном исследовании, согласуется со сведениями об эффективности инъекционных методик в триггерные точки у пациентов с МБС лица, представленными в специальной литературе [14,16].…”

Botulinum toxin for chronic pain: What's on the horizon?

“…34 However, in randomized controlled double-blind studies comparing BoNT to placebo, local anesthetics, and steroids, there were no significant differences in pain scores. 35,36 The majority of studies have been landmark based or used the site of maximal tenderness as guidance for injections, but there is some evidence that targeted injections focusing on specific muscle groups may improve benefit. 5 This usually requires the use of imaging for guidance.…”

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

“…However, their meta-analysis included stroke patients with hemiplegic shoulders, so the results might not be well-representative of the general population. Conversely, Ahmed et al demonstrated that the local anesthetic injections were more effective than BoNT injections [11]. Nevertheless, their patients had heterogeneous symptoms and some of them presented with myofascial pain over all body regions.…”

“…In recent years, BoNT injections have been increasingly used to treat mild musculoskeletal disorders, like tennis elbow, knee osteoarthritis, and refractory joint pain [8][9][10]. However, its effects remain inconclusive regarding chronic shoulder pain based on available systemic reviews and meta-analyses [11,12]. Wu et al concluded that BoNT injections were effective in treating shoulder pain compared with placebo injections [12].…”