According to a study published in Headache, greater occipital nerve blocks (GONB) with bupivacaine were not as effective as intravenous (IV) metoclopramide as a first-line treatment for migraineurs who presented to emergency departments.
According to a study published in Headache, greater occipital nerve blocks (GONB) using bupivacaine were not as effective as intravenous (IV) metoclopramide as a first-line treatment for migraineurs who presented to emergency departments (ED).
Each year, more than 1 million individuals in the United States present to EDs for acute treatment of migraine, but less than 25% of patients with migraine in the ED achieve headache relief and remain headache free for 48 hours.
Recently, GONB have been used to treat acute migraine, and some data suggest that the blocks may provide rapid and sustained relief with minimal adverse effects. “This procedure is hypothesized to work by decreasing transmission through the trigeminocervical complex (TCC), an important way-station in migraine pathogenesis,” the authors wrote, although clinical evidence supporting the mechanism is limited.
To determine whether GONB using bupivacaine would alleviate pain as well as or better than IV metoclopramide, researchers conducted a randomized, double-dummy, clinical trial comparing the 2 treatments.
Eligible participants presented to 2 EDs of the Montefiore Medical Center in the Bronx, New York. All patients were 18 years or older and visited EDs for an acute headache of moderate or severe intensity meeting International Classification of Headache Disorders, 3rd edition criteria. Pregnant or lactating patients were excluded from the study, along with individuals who had previously been treated with GONB.
Patients were randomized 1:1 to either receive a total of 6 mL of bupivacaine 0.5%, injected adjacent to the greater occipital nerve bilaterally (3 mL each side), in addition to an intravenous drip containing normal saline placebo (administered over 15 minutes), or a sham GONB consisting of 6 mL of normal saline, injected adjacent to the greater occipital nerve bilaterally (3 mL each side), in addition to an intravenous drip containing 10 mg metoclopramide, also administered over 15 minutes.
All patients, clinicians, and research associates who assessed outcomes were blinded to the treatments administered. Over 2.5 years, 1358 patients were screened for participation while 99 were ultimately randomized to receive GONB (n = 51) or metoclopramide (n = 48). Efficacy was measured by improvement on a pain scale ranging from 0 to 10 completed both at baseline and after 1 hour.
“While GONB was not as efficacious as intravenous metoclopramide, an exploratory analysis suggested that in experienced hands, GONB and intravenous metoclopramide may have comparable efficacy,” researchers said.
For example, poor 1-hour pain outcomes were common when the provider had previously performed fewer than 7 GONB, while patients receiving the treatment from providers who had completed 7 or more GONB “almost uniformly reported >50% relief of pain.” The association established between health care provider experience and outcomes thus marks a limitation to the study. Researchers also caution against generalizing findings to the entire population of migraineurs presenting to EDs, as a large number of patients screened for the study did not meet inclusion criteria.
Friedman BW, Irizarry E, Williams A, et al. A randomized, double-dummy, emergency department-based study of greater occipital nerve block with bupivacaine vs intravenous metoclopramide for treatment of migraine. Headache. Published online September 27, 2020. doi:10.1111/head.13961