Botulinum Toxin Treatment of Movement Disorders.

Botulinum neurotoxins (BoNTs) are now among the most widely used therapeutic agents in clinical medicine with indications applied to the fields of movement disorders, pain disorders, and autonomic dysfunction. In this literature review, the efficacy and utility of BoNTs in the field of movement disorders are assessed using the criteria of the Guideline Development Subcommittee of the American Academy of Neurology. The literature supports a level A efficacy (established) for BoNT therapy in cervical dystonia and a level B efficacy (probably effective) for blepharospasm, hemifacial spasm, laryngeal dystonia (spasmodic dysphonia), task-specific dystonias, essential tremor, and Parkinson rest tremor. It is the view of movement disorder experts, however, that despite the level B efficacy, BoNTs should be considered treatment of first choice for blepharospasm, hemifacial spasm, laryngeal, and task-specific dystonias. The emerging data on motor and vocal tics of Tourette syndrome and oromandibular dystonias are encouraging but the current level of efficacy is U (undetermined) due to lack of published high-quality studies.