Botulinum toxin in the treatment of blepharospasm and hemifacial spasm.

Blepharospasm and hemifacial spasm are the two most common craniofacial movement disorders. Blepharospasm is a syndrome characterized by excessive or continuous eye closure related to overactivity of the orbicularis oculi and adjacent muscles bilaterally. Hemifacial spasm is a peripherally-induced movement disorder typically caused by vascular compression of cranial nerve VII (CN VII) leading to involuntary unilateral contractions of muscles used in facial expression. Treatment options for both conditions include medications, botulinum toxin, and various surgical interventions. This article summarizes the existing medical literature which indicates that botulinum toxin is the treatment of choice for blepharospasm and hemifacial spasm.