Onabotulinum toxin A treatment of cervicogenic headache: A randomised, double-blind, placebo-controlled crossover study

Aims: Preliminary reports regarding injections in the neck of onabotulinum toxin A have been positive in cervicogenic headache (CeH). The aim was to perform the first methodologically rigorous trial. Methods: A randomised, placebo-controlled, patient-, injector- and evaluator-blinded crossover study included 28 adult patients with a long-standing and treatment-resistant CeH. After a baseline period, injections of either onabotulinum toxin A or placebo were given in fixed sites in the neck muscles on the pain side. Second injections were given after >= 8 weeks. Patients were thereafter followed for another 8 weeks. A detailed headache calendar was filled in, and patients were followed with quality-of-life (QoL) questionnaires, algometry and neck mobility measurements. Results: There was no significant difference between verum and placebo in a mixed linear model analysis (p = 0.084) with regard to the primary end-point, reduction of days with moderate to severe headache. Six patients withdrew from the study before the second injections, but an intention-to-treat (ITT) analysis gave a similar result (p = 0.27). There were no significant differences favouring verum in any of the secondary efficacy measures. Side-effects of onabotulinum toxin A were minor and short-lasting. Conclusion: Onabotulinum toxin A in neck muscles does not seem to be beneficial in CeH.