A single injection of BtB was effective and safe for treating cervical dystonia. Long-term uncontrolled studies suggested that further injection cycles continue to work for most patients. 
Future research should explore technical factors such as the optimum treatment intervals and use of image or electromyographic guidance for administration. Other issues include service delivery, quality of life, long-term efficacy and safety, and the relative indications for BtA, BtB and other treatments such as deep brain stimulation
Botulinum toxin type B: a double-blind, placebo-controlled, safety and efficacy study in cervical dystonia.
We enrolled and treated 122 patients with idiopathic cervical dystonia in a double-blind, placebo-controlled safety and efficacy study of botulinum toxin type B (BotB). Both A-responsive and A-resistant patients were enrolled. Patients received intramuscular injections of either BotB (2,500 U, 5,000 U, or 10,000 U) or placebo. The primary outcome measure of efficacy was the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score at 4 weeks following study drug administration. Secondary measures of efficacy were TWSTRS-Severity, -Disability, and -Pain subscale scores, and Analog Pain Assessment, Investigator Global Assessment, Patient Global Assessment, and Sickness Impact Profile scores. Duration of effect was estimated with an intent-to-treat analysis of responders. Safety measures included clinical parameters, laboratory tests, and adverse events. The primary and most of the secondary analyses indicated a statistically significant treatment effect and a dose response. BotB is safe, well tolerated, and efficacious in the treatment of cervical dystonia at the doses tested.