Background: Botulinum toxin type A (BoNT-A) for the treatment of patients with various forms of migraine has been studied, but there is a paucity of data regarding the use of BoNT-A in Asian headache patients. Our study was designed to evaluate the efficacy of BoNT-A in the treatment of transformed migraine (TM) in a population of Taiwanese patients.
Methods: We retrospectively analyzed 30 patients who underwent BoNT-A treatment for TM from July 2003 to May 2004. Of 30 patients, 14 had palpable muscle tenderness (or tender points) in the pericranial region and 16 did not. All patients received injections into the corrugator, procerus, frontalis, and temporalis muscles (a total of 30 U), while a subset of TM patients with tender points (6 of 14 patients) also received injections to additional muscles based on a follow-the-tenderness approach (mean dose, 45 U).
Results: Twenty-seven of the 30 patients (90%) surveyed reported effective relief of their symptoms with BoNT-A treatment (at least a 50% reduction in the number of headache days or in headache intensity). The greatest reduction in headache days per month and headache intensity was found in TM patients with tender points who received a mean dose of 45 U compared to those who received fixed-site dosing of 30 U.
Conclusion: Our results suggest that BoNT-A may be an effective prophylactic treatment for TM in Taiwanese patients. Interestingly, similar efficacy was demonstrated in TM patients with tender points compared to those without tender points when an additional dose of BoNT-A was injected into the tender muscles in the former.