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

Objective: To determine the efficacy of botulinum toxin type A (BTX-A) in treating neck and upper-back pain of myofascial origin. Design: A randomized, double-blind, placebo-controlled pilot study. Setting: Outpatient physical medicine and rehabilitation clinic of a university-affiliated tertiary hospital. Participants: A total of 29 subjects enrolled from among 45 screened patients. No subject withdrawal due to serious adverse events occurred. Intervention: Subjects were evaluated at baseline, received a 1-time injection of either BTX-A (treatment group) or saline (control group), and were followed up at 2 weeks and at months 1, 2, 3, 4, and 6. Main Outcome Measures: Visual analog scale (VAS) for pain, the Neck Disability Index (NDI), and the Medical Outcome Study 36-Item Short-Form Health Survey (SF-36). Results: Improvements in the VAS and NDI scores were seen in the treatment group but were not significant when compared with the controls. Statistically significant improvements for the treatment group were seen in the SF-36 bodily pain (at months 2 and 4) and mental health (at month 1) scales but not in the other scales, nor in the summary measures. No serious adverse events were reported. Conclusions: Trends toward improvements in VAS and NDI scores of the BTX-A group are encouraging, but they were possibly due to a placebo effect and were not statistically significant. The BTX-A subjects, at certain time points, showed statistically significant improvements in the bodily pain and mental health scales of the SF-36 compared with controls. Our study had limited power and population base, but the results could be used to properly power follow-up studies to further investigate this topic.