Myofascial pain syndrome is a common painful condition encountered in the general population. Previous studies evaluating the efficacy of
botulinum toxin for the treatment of
myofascial pain syndrome are limited, with variable results. This prospective study investigated the efficacy and safety of direct injection of
Prabotulinumtoxin A (Nabota®) into painful muscle groups for cervical and shoulder girdle myofascial
pain. Twelve patients with chronic
myofascial pain syndrome of the neck and shoulder underwent an injection of
Prabotulinumtoxin A. Painful muscles containing trigger points were injected in the mid-belly.
Pain scores and quality of life measurements were assessed at baseline, as well
as 6 weeks and 12 weeks post-injection. Safety and tolerability were also assessed. This trial is registered under clinical research information service (CRIS) number KCT0001634. Patients injected with
Prabotulinumtoxin A showed a significant improvement in
pain at 12 weeks (p < 0.001). At 6 weeks, the
pain had not significantly improved compared with baseline (p = 0.063). However, at that time, 41.7% of patients were characterized as
Prabotulinumtoxin A responders, with a 30% reduction in
pain rating score compared to baseline. In the Neck Disability Index scores, the patients demonstrated significant improvement at both 6 weeks and 12 weeks. No serious adverse effects occurred during the study.
Prabotulinumtoxin A injection into chronically painful muscles associated with cervical and shoulder girdle
myofascial pain syndrome resulted in an improvement in
pain scores and quality of life lasting at least 12 weeks. Additionally, the
injections were well tolerated. As these are preliminary findings in a pilot study, future studies should carefully consider using randomized, controlled, prospective trials.