Botulinum toxin and other new approaches to migraine therapy.

The number of migraine treatments and our understanding of migraine pathophysiology are both increasing. Newer treatments focus on migraine prevention. Botulinum toxin (BTX) is a potent neurotoxin used primarily to treat diseases associated with increased muscle activity. Recently, BTX was found to have antinociceptive effects that are probably independent of its muscle-relaxant action. Clinical trials support the efficacy of BTX type A (and possibly also type B) in the treatment of migraine. The anticonvulsant topiramate was recently shown to be effective for migraine prevention. At the low doses used for this indication, cognitive side effects are not a major concern. Another new approach to migraine prevention is angiotensin type 1 (AT1) receptor blockade. The high tolerability of the AT1 receptor blocker candesartan warrants further studies to assess its role in migraine prevention.