Therapeutic uses of botulinum toxin.

Botulinum toxin was introduced as a safe and effective treatment for strabismus and other disorders of the extraocular muscles in the early 1980s. Approved by the U.S. Food and Drug Administration for use in the treatment of strabismus, blepharospasm and seventh cranial nerve disorders, botulinum toxin has also been shown to be effective in the treatment of a wide range of disorders associated with involuntary muscle contraction and spasm, including focal dystonia, hemifacial spasm and spasmodic torticollis. Neurologic syndromes associated with excessive muscle contraction or involuntary movement, disturbances of sphincter function and musculoskeletal pain are other conditions that can be successfully treated with botulinum toxin.