Background: The objective of the study was to determine whether botulinum toxin type A injections can serve as a prognosticator for migraine surgery success.
Methods: Patients who underwent migraine surgery from 2000 to 2010 by the senior author (B.G.) were reviewed. Patients were included if they had botulinum toxin type A injection before surgery; had completed postinjection, postsurgery Migraine Headache Questionnaires; and had at least 1-year follow-up. Outcome variables include patient demographics and Migraine Headache Index. Treatment success was defined as at least a 50 percent reduction in Migraine Headache Index.
Results: One hundred eighty-eight patients were included; 144 reported successful migraine headache reduction after injection (success group) and 44 did not (failure group). The groups were well matched for age, migraine headache characteristics, and number of surgical sites (p > 0.05). The surgery success rate was significantly higher in the success group overall (90.3 percent versus 72.3, p = 0.003), and in patients who reported botulinum toxin type A success and subsequent same-site surgery (97.9 percent versus 71.4 percent, p < 0.0001). Botulinum toxin type A success was prognostic for surgery success at the frontal trigger site (trigger site I) (92.5 percent versus 69.2 percent, p = 0.012), the temporal trigger site (trigger site II) (95.5 percent versus 73.3 percent, p = 0.005), and the occipital trigger site (trigger site IV) (95.9 percent versus 62.5 percent, p = 0.0003). Six patients had exclusively septum or turbinate (site III) surgery, and all failed injections.
Conclusions: Positive botulinum toxin type A response is a significant predictor of migraine surgery success. When injections fail, nonmuscular abnormalities should be considered.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.