Botulinum toxin type A in prophylactic treatment of migraine headaches: a preliminary study

The purpose of this study was to determine the safety and efficacy of botulinum toxin type A (BOTOX; Allergan, Irvine, USA) in migraine prophylaxis. We performed a double-blind, randomized, 90-day placebo-controlled study that enrolled 30 adult migraineurs. Patients received 50 units botulinum toxin type A (n=15) or placebo (n=15). Outcome measures were monthly frequency and duration of migraine attacks and the number of severe attacks. Botulinum toxin type A produced significantly greater reductions in the frequency of migraine attacks of any severity at Day 90 (-3.14 vs. -0.53; p<0.05) and in the frequency of severe migraine attacks at Days 60 (-1.4 vs. -0.54; p<0.05) and 90 (-1.8 vs. -0.20; p<0.02). One patient in the botulinum toxin type A group experienced mild, transient frontalis muscle weakness lasting approximately 30 days. Botulinum toxin type A injections were well tolerated and provided effective migraine prophylaxis in these patients.