Botulinum Toxin Type A Injections for Cervical and Shoulder Girdle Myofascial Pain Using an Enriched Protocol Design

Abstract

Background Myofascial pain syndrome is a regional condition of muscle pain and stiffness and is classically characterized by the presence of trigger points in affected musculature. Botulinum toxin type A (BoNT-A) has been shown to have antinociceptive properties and elicit sustained muscle relaxation, thereby possibly affording even greater relief than traditional strategies. Our goal in this study was to determine whether direct injection of BoNT-A into painful muscle groups is effective for cervical and shoulder girdle myofascial pain. Methods An enriched protocol design was used wherein 114 patients with cervical and shoulder girdle myofascial pain underwent injection of BoNT-A to determine their response to the drug. Fifty-four responders were then enrolled in a twelve-week, randomized, double-blind, placebo-controlled trial. Pain scales and quality of life measures were assessed at baseline and at routine follow-up visits until completion of the study after 26 weeks. Results Injection of BoNT-A into painful muscle groups improved average visual numerical pain scores in subjects who received a second dose of BoNT-A compared to placebo (p = 0.019 (0.26, 2.78)). Subjects who received a second dose of BoNT-A had a reduced number of headaches per week (p = 0.04 (0.07, 4.55)). Brief Pain Inventory interference scores for general activity and sleep were improved (p = 0.046 (0.038, 3.7) and 0.02 (0.37, 4.33), respectively) in those who received a second dose of BoNT-A. Conclusion Botulinum toxin type A injected directly into painful muscle groups improves average pain scores and certain aspects of quality of life in patients suffering from severe cervical and shoulder girdle myofascial pain.

Epidemiology, Diagnosis, and Treatment of Neck Pain

“…92-94 A more recent study of 114 previous responders that used an enriched protocol design found modest benefit in some but not most outcome measures for some variables that persisted through 26 weeks. 95 In 2 controlled studies performed in patients with low back pain, the results were mixed regarding the effectiveness of botulinum toxin. 96,97 The authors found there was inconclusive evidence to support the use of botulinum toxin injections for myofascial pain syndrome.…”

Safety and Efficacy of PrabotulinumtoxinA (Nabota®) Injection for Cervical and Shoulder Girdle Myofascial Pain Syndrome: A Pilot Study

“…They are typically performed several times per week. However, botulinum toxin can be administered in a single injection that lasts for many months [ 2 , 3 , 4 ].…”

“…Zhou et al [ 5 ] described the potential effects of botulinum toxin in myofascial pain syndrome, and Nicol et al [ 4 ] reported that botulinum toxin improved pain and quality of life in patients with cervical and shoulder girdle myofascial pain syndrome.…”

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

“…After excluding 108 duplicated articles and 439 non-relevant articles by screening titles and abstracts, 19 studies were deemed eligible for subsequent evaluation. Ten were further excluded because four lacked a control group [10,[13][14][15], five targeted myofascial pain in regions other than shoulder areas [16][17][18][19][20], and one used an enriched protocol design to assess the effect of repeated BoNT injections [14] (Figure 1). The final meta-analysis consisted of seven 2-armed [21][22][23][24][25][26][27], one 3-armed [28], and one 4-armed [29] trials.…”