The role of botulinum toxin as a therapeutic agent is expanding rapidly in otolaryngology. Botulinum toxin is a protease that blocks the release of acetylcholine from nerve terminals. Its effects are transient and nondestructive, and largely limited to the area in which it is administered. These
Botulinum neurotoxin (BoNT) is produced by Clostridium botulinum as a complex of proteins containing the neurotoxin itself and other nontoxic proteins. Activation of the neurotoxin occurs upon proteolytic cleavage into the heavy and light chains. This di-chain moiety is essential for neurotoxin and