The 2025 American Headache Society guidelines give the greater occipital nerve (GON) block a level A recommendation for ED migraine treatment, boldly calling it a “must offer” therapy for migraine patients requiring parenteral treatment.
- Mechanism:
- The GON, a branch of the C2 spinal nerve, innervates the posterior scalp and converges with trigeminal afferents at the C2 dorsal horn. Blocking the GON dampens trigeminal signaling at this convergence point, reducing acute migraine pain. Since central sensitization drives migraine chronicity, benefits often outlast the local anesthetic, persisting for weeks to months.
- Efficacy:
- A meta-analysis of over 400 patients showed a mean reduction of 3.6 headache days/month and lower pain severity scores versus controls, with greater benefit from scheduled, recurring blocks. For acute migraine, one large study found 82% of patients reported moderate-to-significant relief.
- How to:
- Positioning:
- Seat the patient with the head flexed slightly forward. Avoid any lateral or rotational movement, which may distort landmarks.
- Landmark-based:
- Palpate the external occipital protuberance and mastoid process. The GON runs about one-third of the distance (2-4 cm) between them, just medial to the occipital artery (which is often palpable). Prep the skin, advance the needle while aspirating until you hit bone, withdraw slightly, then inject 1-3 mL of 1% lidocaine or 0.5% bupivacaine with a fanning technique.
- Ultrasound-guided (more precise):
- Place a linear probe with sterile cover transversely over the occipital protuberance, then slide down to the C2 spinous process, which has a characteristic bifid appearance. Moving laterally from here, identify the GON between the semispinalis capitis and obliquus capitis inferior fascial plane, medial to the occipital artery (consider color Doppler to confirm). Inject 1-3 mL of anesthetic into this fascial plane, avoiding injection into the nerve fascicles themselves.
- Adjuncts?
- Dexamethasone mixed with local anesthetic has evidence of benefit with cervicogenic headache and occipital neuralgia, but has no proven added benefit for migraine specifically.
- Positioning:
Bottom Line: Consider adding the GON block to your toolkit for migraine treatment in the ED.
References
- Robblee, J., Minen, M. T., Friedman, B. W., Cortel-LeBlanc, M. A., Cortel-LeBlanc, A., & Orr, S. L. (2026). 2025 guideline update to acute treatment of migraine for adults in the emergency department: The American Headache Society evidence assessment of parenteral pharmacotherapies. Headache: The Journal of Head and Face Pain, 66(1), 53-76.
- Palamar, D., Uluduz, D., Saip, S., Erden, G., Unalan, H., & Akarirmak, U. (2015). Ultrasound-guided greater occipital nerve block: an efficient technique in chronic refractory migraine without aura?. Pain Physician, 18(2), 153.
- NYSORA. https://nysora.com/pain-management/ultrasound-guided-greater-occipital-nerve-block/