Comparison of two ultrasound-guided techniques for greater occipital nerve injections in chronic migraine: a double-blind, randomized, controlled trial

Background and objectives: Two ultrasound (US)-guided techniques for greater occipital nerve (GON) block have been described for the management of headache disorders: a "proximal or central" technique targeting the GON at the level of the second cervical vertebra and a "distal or peripheral" technique targeting the GON at the level of the superior nuchal line. In this multicenter, prospective, randomized control trial, we compared accuracy, effectiveness, and safety of these two techniques in patients with chronic migraines (CMs).

Methods: Forty patients with refractory CMs were randomized to receive either a proximal or distal US-guided GON block with bupivacaine and methylprednisolone acetate. The primary outcome was the difference in Numerical Rating Score (NRS) for headache intensity at 1 month. Secondary outcomes were effectiveness, performance, and safety-related. Effectiveness-related outcomes included NRS for headache intensity, number of headache days per week, patient satisfaction, quality of life, assessment of sleep quality, and sleep interruption. Performance-related outcomes included procedure time, accuracy of block, and patient discomfort. Safety-related outcomes included an assessment for adverse effects.

Results: NRS pain scores were significantly reduced at 24 hours and at 1 week postprocedure in both cohorts and at 1 and 3 months in the proximal group as compared with the baseline. There was no significant difference in NRS pain scores between the two cohorts at any of the follow-up time points. There was a significant reduction in number of headache days per week at 1 month in both groups, and a significant improvement in sleep interruption at 1 week in both groups. There were no significant adverse effects.

Conclusions: This study was designed to compare two different US-guided approaches for blocking the GON. Our results demonstrate that both distal and proximal techniques can provide a short-term improvement in headache intensity, reduction in number of headache days per week, and an improvement in sleep interruption. The proximal GON technique may confer more sustained analgesic benefit compared with the distal approach in patients with CM headaches.

Trial registration number: NCT02031822.