Migraine is the most common neurological disorder, and contributes to disability and large healthcare costs in the United States and the world.The treatment of migraine until recently has focused on medications, both abortive and prophylactic, but treatment 6love luzern of chronic migraine has been revolutionized with the introduction of botulinum toxin injection therapy.In this review, we explore the current understanding of migraine pathophysiology, and 22 k light ride the evolution of the use of botulinum toxin therapy including proposed pathophysiological mechanisms through animal data.We also discuss the similarities and differences between three injection techniques.