Is botulinum toxin useful in treating headache? Yes.

Recent scientific data support an effect of botulinum neurotoxin (BoNT) on pain and headache. BoNT was shown to affect the release of neurotransmitters that are important in pain transmission and in migraine pathogenesis. Data from both animal and clinical studies suggest that the toxin may have an analgesic effect that is independent from its effect on muscle tone. The high tolerability and long duration of action of the drug make it appealing as a potential prophylactic treatment for headache patients. Results of controlled trials on the efficacy of BoNT in the treatment of episodic migraine (EM) are mostly negative, although some subgroups of patients (eg, those with high attack frequency) may respond to the drug. Studies of patients with chronic daily headache have been inconclusive, although (as with the EM studies) specific subgroups of patients appear to benefit from the drug. BoNT is probably ineffective for the treatment of chronic tension-type headache. There are anecdotal reports on a positive effect of BoNT in patients with other types of headache (eg, nummular headache). Factors that may affect the response of patients to BoNT include headache characteristics, disease duration, the use of concurrent preventive medications, and the presence or absence of medication overuse. The authors' clinical experience shows that some headache patients benefit significantly from BoNT treatment. The challenge for future studies is to identify those patients who will best respond to the drug.