Greater Occipital Nerve Block for Migraine Prophylaxis

Migraine is a common disease with lifetime prevalence in women and men of 33% and 12% respectively. Chronic migraine affects 2% of the US population and is highly disabling. There are no FDA approved medications for the treatment of chronic migraine. Although some patients benefit from a daily prophylactic medication, others continue to suffer from severe, frequent, debilitating headaches. Limited efficacy, poor compliance, side effects and drug-drug interactions may explain why more than 80% of migraineurs in the population are not prescribed daily prophylactic medications. Occipital nerve injections with corticosteroids and/or local anesthetics have been employed for the acute and prophylactic treatment of migraine, cervicogenic headache and cluster headache for decades. A long-acting anesthetic and corticosteroid are often combined, although anesthetic agents have also been used alone. However, there are no randomized controlled trials evaluating the preventive efficacy of occipital nerve block in subjects with migraine. Patients were equally randomized to receive either 2.5 ml 0.5% bupivacaine plus 0.5 ml 20 mg methylprednisolone over the ipsilateral (unilateral headache) or bilateral (bilateral headache) occipital nerve or 2.75 ml normal saline plus 0.25 ml 1% lidocaine without epinephrine (placebo). The GON injection site was at the medial third of the distance between the occipital protuberance and the mastoid process. Patients were evaluated after the 4-week baseline diary completion phase to undergo the injection, and for 4 weeks after the injection. Therefore, there were 3 patient visits in this study: screening, injection and 4-week follow-up. In an effort to ensure adequate blinding, 0.25 ml of short-acting 1% lidocaine without epinephrine was used as the placebo arm. In order to ensure adequate blinding of the investigator, each syringe and needle hub was covered with opaque tape so as to ensure blinding of the investigator providing the injection. A total of four investigators provided injections. The blinded investigator who evaluated the study subject 4 weeks after injection may or may not be the same as the investigator who provided the injection.