Botulinum toxin A is a remarkably versatile treatment with a steadily expanding list of indications, which include strabismus, hemifacial spasm, focal dystonias such as spasmodic torticollis, dysphonia and writer's cramp, as well as adult and childhood spasticity. Recent innovations include its use in some types of pain, in autonomic and gastrointestinal disorders, and in cosmetic medicine, such as hyperhidrosis, hypersalivation, rectal fissure, achalasia and facial wrinkles. Botulinum toxin is arguably the safest and most effective treatment in movement disorders since the introduction of...