Botulinum toxin A and chronic low back pain: a randomized, double-blind study. BOTOX and physical therapy in the treatment of piriformis syndrome.
To investigate the efficacy of botulinum toxin A in chronic low back pain and associated disabilities.
                Thirty-one consecutive patients with chronic low back pain who met the inclusion criteria were studied: 15 received 200 units of botulinum toxin type A, 40 units/site at five lumbar paravertebral levels on the side of maximum discomfort, and 16 received normal saline. Each patient's baseline level of pain and degree of disability was documented using the visual analogue scale (VAS) and the Oswestry Low Back Pain Questionnaire (OLBPQ). The authors reevaluated the patients at 3 and 8 weeks (visual analogue scale) and at 8 weeks (OLBPQ).
                At 3 weeks, 11 of 15 patients who received botulinum toxin (73.3%) had >50% pain relief vs four of 16 (25%) in the saline group (p = 0.012). At 8 weeks, nine of 15 (60%) in the botulinum toxin group and two of 16 (12.5%) in the saline group had relief (p = 0.009). Repeat OLBPQ at 8 weeks showed improvement in 10 of 15 (66.7%) in the botulinum toxin group vs three of 16 (18.8%) in the saline group (p = 0.011). No patient experienced side effects.
                Paravertebral administration of botulinum toxin A in patients with chronic low back pain relieved pain and improved function at 3 and 8 weeks after treatment. This study evaluates the efficacy of botulinum toxin A injections used in conjunction with physical therapy for the treatment of piriformis syndrome.
                This a double-blind, placebo controlled clinical trial using electrophysiologic criteria for patient selection and a visual analog scale to assess treatment efficacy in relieving pain.
                As measured on the visual analog scale, patients injected with botulinum toxin A experienced more relief from pain than patients receiving lidocaine with steroid (P < 0.05) and more relief than patients receiving placebo (P = 0.001).
                Injection with botulinum toxin A is an effective adjunct to physical therapy in the treatment of piriformis syndrome. H-reflex prolongation by flexion, adduction, and internal rotation (FAIR test) beyond 1.86 msec (3 SD) of the mean is a clinical indication of piriformis syndrome.
We identified three studies that investigated the merits of BoNT for LBP, but only one had a low risk of bias and evaluated patients with non-specific LBP (N = 31). Further research is very likely to have an important impact on the estimate of effect and our confidence in it. Future trials should standardize patient populations, treatment protocols and comparison groups, enlist more participants and include long-term outcomes, cost-benefit analysis and clinical relevance of findings.