Reply to Dr. Merry’s Letter to the Editor

We appreciate the interest and thoughtful questions from Dr. Merry. Dr. Merry, like many others over many decades, has employed occipital nerve blocks (ONBs) for the acute and preventive treatment of migraine and other headache disorders. We do not doubt his assertion that some of his patients have responded to ONBs. We have the same experience. However, placebo response rates may be high and sustained in migraine trials, particularly with more invasive procedures. Despite the complexity in conducting such a trial, including protecting the blind, we felt it important to embark on the first randomized placebo-controlled study in an attempt to bring some evidence to a practice employed by many clinicians. We also appreciate the variability in the location of the greater occipital nerve from patient to patient and the need to confirm adequate anesthesia. In this study, the procedure was standardized and performed in a way to maximize the distribution of the solution at the skull base. Anesthesia was assessed both in active- and placebo-treated patients. Adequate anesthesia was confirmed in all active-treated patients. No patient in the study underwent a second injection. All patients in the active group achieved anesthesia over the occiput, though the distribution and extent of the anesthesia was not assessed. We hope this study leads to future studies evaluating the efficacy of occipital nerve blockade for the acute treatment of migraine and other headache disorders, and that studies with alternative designs are initiated to explore the preventive effect of ONBs in patients with headache disorders.