Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A-resistant cervical dystonia. Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A-responsive cervical dystonia.
To determine the safety and efficacy of botulinum toxin type B (BoNT/B) in patients with type A-resistant cervical dystonia (CD).
                Local intramuscular injections of BoNT are an effective therapy for CD. After repeated use, some patients become resistant to therapy. BoNT/B, effective in type A toxin-responsive patients, is proposed as an alternative therapy for type A-resistant patients.
                The authors performed a 16-week, double-blind, placebo-controlled trial of BoNT/B in type A-resistant patients with CD. After resistance to therapy was confirmed with the frontalis-type A test, placebo or 10,000 U BoNT/B was administered in a single session into two to four clinically involved muscles. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) was the primary efficacy measurement. TWSTRS-Total, three visual analog scales (Patient Global Assessment of Change, Principal Investigator Global Assessment of Change, Patient Analog Pain Assessment), and adverse events were assessed at baseline and weeks 2, 4, 8, 12, and 16.
                A total of 77 patients participated (38 placebo, 39 active). Improvements in severity, disability, and pain were documented in the BoNT/B-treated group. TWSTRS-Total scores were improved in the BoNT/B-treated group at weeks 4 (p = 0.0001), 8 (p = 0.0002), and 12 (p = 0.0129). All three visual analog scales demonstrated improvements at week 4 (p < 0.0001, 0.0001, and 0.001). A Kaplan-Meier analysis supported a duration of effect of 12 to 16 weeks in the active group. Dry mouth and dysphagia were self-limited adverse effects, reported more commonly in the BoNT/B group.
                Botulinum toxin type B (BoNT/B) (NeuroBloc) is safe and efficacious for the management of patients with type A-resistant cervical dystonia with an estimated duration of treatment effect of 12 to 16 weeks. To determine the safety and efficacy of botulinum toxin type B (BoNT/B) in patients with cervical dystonia (CD).
                BoNT/B is a form of chemodenervation therapy for the treatment of patients with CD.
                The authors performed a 16-week, randomized, multicenter, double-blind, placebo-controlled trial of BoNT/B in patients with CD who continue to respond to botulinum toxin type A. Placebo, or 5,000 U or 10,000 U of BoNT/B was administered in two to four muscles involved clinically in CD. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score at week 4 was the primary efficacy measure. Clinical assessments and adverse events were recorded for treatment day 1 and at weeks 2, 4, 8, 12, and 16.
                A total of 109 patients were enrolled randomly across all three treatment groups. The mean improvement in the TWSTRS-Total scores in each group at week 4 was 4.3 (placebo), 9.3 (5,000 U), and 11.7 (10,000 U). For the prospectively defined primary contrast (10,000 U versus placebo), highly significant differences were noted for the primary (TWSTRS-Total, baseline to week 4, p = 0.0004) and supportive secondary (Patient Global Assessment, baseline to week 4, p = 0.0001) outcome measures. Improvement in pain, disability, and severity of CD occurred for patients who were treated with BoNT/B when compared with placebo-treated patients. Overall, improvements associated with BoNT/B treatment were greatest for patients who received the 10,000-U dose. The duration of treatment effect for BoNT/B was 12 to 16 weeks for both doses.
                Botulinum toxin type B (NeuroBloc) is safe and efficacious at 5,000 U and 10,000 U for the management of patients with cervical dystonia.
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.