Nerve blocks for headache work best in cluster headache, where the evidence for a greater occipital nerve block is reasonable. For other headache types the evidence is weaker. There, the block’s main value is often diagnostic (finding the source) rather than therapeutic. Both of those are worth saying plainly.
Cluster headache: the strongest case
A systematic review and meta-analysis looked at greater occipital nerve block for cluster headache. At one month, the pooled proportion of pain-free patients was 50% (95% CI 24–76). Across the two included randomized controlled trials, the relative risk of pain freedom in active versus control groups was 4.86 (95% CI 1.35–17.55).1
Those confidence intervals are wide, which is honest: this is a small evidence base. But the direction is consistent and the effect is large. The block is typically used as a transitional treatment, not a standalone one. It interrupts a bout while a preventive medication is brought up to an effective dose.
A 2024 double-blind randomized trial of methylprednisolone and lidocaine versus placebo as transitional treatment in episodic cluster headache supported the same role.2 See occipital nerve block.
Occipital neuralgia: the block is the test
Here the logic is different and cleaner. Say numbing a specific nerve abolishes pain in the area that nerve supplies. Then that nerve is implicated. If numbing it does not, the pain is coming from somewhere else.
That makes a block useful whichever way it turns out, which is unusual in medicine. A block that fails is not a failed treatment. It is a redirected diagnosis. See occipital neuralgia or migraine.
Cervicogenic headache: diagnostic by definition
ICHD-3 (the international headache classification) explicitly accepts it as evidence of cause when a diagnostic block of a cervical structure (a part of the neck) or its nerve supply abolishes the headache.3 The block is written into the diagnostic criteria. See is your headache coming from your neck.
Migraine: more mixed
Occipital nerve blocks are used in migraine and many people report benefit. But the trial evidence is less consistent than in cluster. The clearest use is where the neck or the back of the head contributes — scalp tenderness, neck-triggered attacks, pain running from the base of the skull — rather than in migraine generally.
We will tell you when the case is thinner. See migraine treatment.
The condition that makes any of this interpretable
All of the above assumes the injection reached the intended target. Placed by surface landmarks alone, it goes where the anatomy usually is — and anatomy varies. Around the head and neck, the structures you are avoiding sit millimeters from the ones you are aiming at.
This is why every injection here is placed under ultrasound or fluoroscopic guidance. It is not a refinement. It is what makes a negative result mean something. A failed landmark block tells you nothing. A failed guided block tells you the pain is coming from elsewhere.
It also means there is no fixed series of three. The interval is set by how long the last block held and by what is happening clinically, not by a schedule.
Common questions
How long does a nerve block last?
The anesthetic wears off in hours, but relief frequently outlasts it by weeks. That is longer than the drug’s action alone explains. Duration varies widely between people. See occipital nerve block.
Is it just a steroid injection?
Not necessarily. The injected medicine is local anesthetic, sometimes with a corticosteroid depending on the reason for the block. For a purely diagnostic block, anesthetic alone is often the point. See image guidance.
What if the block doesn’t help?
Then, as long as it was image-guided, that is useful information rather than a wasted appointment. The pain is coming from somewhere other than the structure we blocked, and the diagnosis moves. See image guidance.
Do I need sedation?
No. Occipital and superficial trigeminal blocks take seconds, and an SPG block involves no needle at all. You drive yourself home.
How many can I have?
There is no fixed course. We time the next one by how long the last one held and by clinical need — see occipital nerve block.
Nerve blocks work best when the right nerve is chosen and the needle is placed under imaging. Both are standard in our headache treatment in St. Louis; see ultrasound and fluoroscopic guidance.
Sources
- Zhang H, et al. Efficacy and safety of greater occipital nerve block for the treatment of cluster headache: a systematic review and meta-analysis. 2020. PMID 32781922. pubmed.ncbi.nlm.nih.gov
- Chowdhury D, Kordcal SR, Nagane R, Duggal A. ANODYNE study: a double-blind randomized trial of greater occipital nerve block of methylprednisolone and lignocaine versus placebo as a transitional preventive treatment for episodic cluster headache. Cephalalgia, 2024. journals.sagepub.com
- Headache Classification Committee of the International Headache Society. ICHD-3, 11.2.1 Cervicogenic headache. ichd-3.org