Clinical application of botulinum toxin in otolaryngology, head and neck practice (brief review).

Botulinum toxin (Botox) is useful in controlling the symptoms of patients with movement disorders. Application of Botox serves to (1) inhibit hypertonicity, (2) enhance the action of the antagonistic muscles, and (3) avoid an impingement in order to reestablish "the balance of forces". In accordance with the principles mentioned above, Botox can be used to treat dystonias of the larynx (adductor laryngeal spasmodic dysphonia, abductor laryngeal spasmodic dysphonia), laryngeal granulomas, laryngeal joint dislocation, cricopharyngeal spasm, and posterior glottic synechiae. In addition, extra-laryngeal disorders such as blepharospasm, hemifacial spasm, oromandibular dystonia, and spasmodic torticollis respond well to Botox. The effects of Botox are reversible and have specific localized activity. Hence, Botox has served as a powerful diagnostic method in exploring the underlying mechanism of various types of dystonias and provides some therapeutic benefits before pursuing surgical options. Here we review the literature and describe our experiences with Botox, including such topics as preparing and storing Botox, identifying the target muscles under EMG-guidance, choosing an appropriate dose, and outlining the applications of Botox in Otolaryngology, Head and Neck Surgery practice.