Botulinum toxin type A for migraine prophylaxis in the Japanese population: an open-label prospective trial.

OBJECTIVE: To evaluate the efficacy and tolerability of Botulinum Toxin Type A (BoNT-A) for migraine prophylaxis.

METHODS: Nineteen Japanese adult patients (50 +/- 10 years old), who met the International Classification of Headache Disorders 2nd Edition (ICHD II) criteria for migraine and had five or more migraine attacks a month, were enrolled in this open-label prospective study. A total of 50 units of BoNT-A were injected in 19-fixed sites of the muscles including procerus, corrugator, frontalis, temporalis and occipitalis. All participants were advised to stop taking preventive medicine from one month before and three months after BoNT-A injection. Migraine disability assessment (MIDAS), migraine questionnaire and headache diary were used for the evaluation of efficacy. Seven patients received repeated injection combined with prophylactic medication.

RESULT: We excluded five patients from the analysis because four patients had medication overuse headache and one continued preventive medicine. Mean MIDAS score decreased significantly two months after the injection. Thirteen of 14 patients stated subjective improvement after the injection on the migraine questionnaire. The amount of analgesics consumption or headache frequency did not change after injection, but the frequency of severe migraine attacks decreased significantly. No serious adverse event was reported. Repeated injections also showed significant reduction in MIDAS score three months after the second and third injections.

CONCLUSION: BoNT-A injection was an effective and safe treatment for migraine prophylaxis among the Japanese population. A randomized placebo control trial is necessary to confirm its efficacy.