Treatment of cervical dystonia with botulinum toxin.

Cervical dystonia (CD) is the most common form of dystonia encountered in a movement disorders clinic. The treatment of this focal dystonia has improved markedly with the advent on botulinum toxin (BTX) injections, which has now become the treatment of choice. Initial studies, even double-blind controlled trials, failed to show robust effect, largely as a result of poor design, often using fixed dosage and site of administration. When the BTX treatment is customized to the needs of the individual patients and the most involved muscles are targeted, the effects can be quite dramatic and the improvement usually lasts 3 to 4 months. Experience and improved skills can largely prevent the adverse effects such as dysphagia and neck weakness. Although there is no evidence that BTX slows the progression of the disease, as a result of early intervention with BTX, many of the long-term complications of CD, such as contractures and radiculopathy, have been largely eliminated.