Background: The effectiveness of greater occipital nerve block (GONB) in patients with primary
headache syndromes is controversial. Few studies have been evaluated the usefulness of GONB in
patients with migraine without aura (MWOA).
Objective: To compare the effectiveness of ultrasound-guided GONB using bupivacaine 0.5%
and placebo on clinical improvement in patients with refractory MWOA in a randomized, doubleblinded clinical trial.
Study Design: A prospective, randomized, placebo-controlled, double-blind pilot trial.
Setting: Physical medicine and rehabilitation and neurology departments of a University Hospital.
Methods: Thirty-two patients with a diagnosis of MWOA according to the International
Classification of Headache Disorders-II criteria were included in the study. Twenty-three patients
(2 men, 21 women) completed the study. They were randomly assigned to receive either GONB
with local anesthetic (bupivacaine 0.5% 1.5 mL) or greater occipital nerve (GON) injection with
normal saline (0.9% 1.5 mL). Ultrasound-guided GONB was performed to more accurately locate
the nerve. All procedures were performed using a 7 – 13 MHz high-resolution linear ultrasound
transducer. The treatment group was comprised of 11 patients and the placebo group was
comprised of 12 patients. The primary outcome measure was the change in the headache severity
score during the one-month post-intervention period. Headache severity was assessed with a visual
analogue scale (VAS) from 0 (no pain) to 10 (intense pain).
Results: In both groups, a decrease in headache intensity on the injection side was observed
during the first post-injection week and continued until the second week. After the second week,
the improvement continued in the treatment group, and the VAS score reached 0.97 at the end
of the fourth week. In the placebo group after the second week, the VAS values increased again
and nearly reached the pre-injection levels. The decrease in the monthly average pain intensity
score on the injected side was statistically significant in the treatment group (P = 0.003), but not
in the placebo group (P = 0.110). No statistically significant difference in the monthly average pain
intensity score was observed on the uninjected side in either group (treatment group, P = 0.994;
placebo group, P = 0.987). No serious side effect was observed after the treatment in either group.
Only one patient had a self-limited vaso-vagal syncope during the procedure.
Limitations: This trial included a relatively small sample. This may have been the result of
the inclusion of only those patients who correctly completed their pain diaries. Another major
limitation is the short follow-up duration. Patients were followed for one month after the injection,
thus relatively long-term effects of the injection have not been observed.
Conclusions: Ultrasound guided GONB with 1.5 mL of 0.5% bupivacaine for the treatment
of migraine patients is a safe, simple, and effective technique without severe adverse effects. To
increase the effectiveness of the injection, and to implement the isolated GONB, ultrasonography
guidance could be suggested.
Key words: Migraine, greater occipital nerve, occipital nerve block, ultrasound-guided