RESUMEN
BACKGROUND: Low back pain is a major cause of disability and can result in substantial morbidity and high healthcare costs. Botulinum toxin has been used successfully to alleviate pain for a number of conditions caused by muscle contractions or spasms. OBJECTIVES: The aim of this study was to investigate the efficacy of botulinum toxin type A (BoNT-A; Dysport®, Ipsen, UK) for treating chronic low back pain (CLBP). PATIENTS AND METHODS: This was a single-blind, randomized clinical trial study. Fifty patients with CLBP received either BoNT-A (40 Ipsen units per injection) or saline in 5 sites in the paraspinal muscles (n = 25 per group). A visual analogue system (VAS) was used to measure pain levels at baseline and at 4 and 8 weeks post-injection. Disability was assessed using the Oswestry low back pain disability questionnaire at baseline and at 8 weeks post-injection. RESULTS: After 4 weeks, 76% of patients in the BoNT-A group reported pain relief compared to 20% in the saline group (P < 0. 005). Additionally, greater pain relief was experienced by patients in the BoNT-A group at 8 weeks (64% vs. 12%; P < 0. 001). By week 8, significant functional improvement (a minimum two-grade improvement between baseline and post-treatment assessments) was demonstrated in a higher number of patients receiving BoNT-A than in the saline group (68% vs. 12% , respectively; P < 0. 005). Patients experienced only minor side effects. CONCLUSIONS: BoNT-A improves CLBP with a low incidence of side effects and can be used as a therapeutic tool in the management of these patients.
