Botulinum toxins in the treatment of migraine and tension-type headaches.

Botulinum toxins are promising preventive treatments for patients with moderate to severe episodic and chronic migraine and chronic daily headache. The recommended indications for botulinum toxins as preventive therapy lend themselves to the following patient types: those who demonstrate a lack of improvement from preventive (prophylactic) pharmacotherapy; those who experience severe and intolerable adverse events from preventive medications; those who refuse to use daily medications; those who have contraindications to acute migraine therapy, and elderly patients with chronic migraine. Both open-label and double-blind placebo-controlled studies using fixed-site, "follow the pain." or a combination approach have demonstrated significant reduction in migraine frequency, severity, and duration, as well as decreased use of acute medications. The most prominent reductions have been noted in those with reportedly the most severe migraine headaches. Large, well-designed, double-blind, placebo-controlled studies are recommended to further clarify optimum dosage and location of injection, reduce treatment frequency and duration, and address other primary headache disorders that may benefit from this therapy.