Peripheral Nerve Blocks for Headache

What the procedure is

A peripheral nerve block places local anaesthetic, sometimes combined with a corticosteroid, around a nerve contributing sensation to the head and scalp. The greater occipital nerve contributes sensation at the back of the head and towards the crown; supraorbital and supratrochlear nerves supply the forehead and area around the eye. Anterior nerve blocks may be proposed as additional cranial blocks in some specialist services; the diagnosis, evidence and intended target should be explained. The injection does not cut the nerve or remove the underlying tendency to headache.

It is one possible part of a broader headache plan. The diagnosis should be reviewed, features suggesting a new secondary cause assessed, and acute and preventive treatments considered together. Because the informal phrase 'migraine injection' can refer to several treatments, ask for the exact medicine and nerve target proposed.

When it may be considered

Specialist assessment may consider a block for chronic or disabling migraine, selected periods of cluster headache, occipital neuralgia, or as one element of a plan for medication-overuse headache. A headache diary, frequency, previous treatment, associated conditions and pregnancy or breastfeeding all affect the decision.

A new sudden severe headache, fever with neck stiffness, altered awareness, seizure, new weakness or loss of vision or speech needs assessment for an emergency cause before a nerve block is considered. Frequent headache also calls for review of medication overuse and suitable preventive options.

Possible benefit and uncertainty

Some people have a temporary reduction in headache days or severity. Benefit may last days or weeks and occasionally longer. For a greater occipital nerve block specifically, Cambridge University Hospitals reports that about one person in three receives no useful benefit; this figure cannot be generalised to supraorbital or supratrochlear blocks. Leeds Teaching Hospitals notes that most studies of cranial blocks have small samples and response cannot be predicted reliably.

The procedure may not help, may not provide complete pain relief, and does not automatically replace other treatment. A decision to repeat it should consider previous response, cumulative steroid exposure and risk; it should not be understood as something that can be repeated without limit because one injection was tolerated. A diary can track headache days, severity, medicines and function.

What happens during and after it

The target is identified from examination and anatomical landmarks, sometimes with ultrasound. The skin is cleaned and medicine delivered through a fine needle. Although the procedure may be brief, the needle and injection can cause stinging, pressure, burning, discomfort or pain. Dizziness can occur, so the service may advise observation. Follow the treating team's instructions about driving, work, exercise and medicines.

Before the appointment, report allergies, anticoagulants, diabetes, active infection, possible pregnancy and every medicine used. Do not stop an anticoagulant unless the procedure team gives a specific plan; stopping without advice can itself cause harm. The right to decline or revisit alternatives remains part of consent.

Risks and when to seek help

Possible effects include injection-site pain, tenderness, bruising or bleeding, dizziness, a temporary headache flare, numbness and infection. An allergic reaction can occur. If steroid is included, additional effects can include a temporary rise in blood glucose, skin thinning or colour change, and a small patch of hair loss. Rare serious complications should be covered in individual consent.

Contact the clinical service promptly for spreading redness, warmth, discharge, fever or steadily worsening pain. Breathing difficulty, swelling of the face or tongue, collapse, new persistent weakness or altered consciousness needs emergency help. This guide cannot decide personal suitability and is not a substitute for procedure-specific consent.

References

1. Greater occipital nerve block for headache (opens in a new tab) — Cambridge University Hospitals NHS Foundation Trust
2. Cranial nerve blocks including greater occipital nerve blocks (opens in a new tab) — Leeds Teaching Hospitals NHS Trust
3. Techniques for facial blocks (opens in a new tab) — Gloucestershire Hospitals NHS Foundation Trust
4. Occipital nerve block (opens in a new tab) — The Dudley Group NHS Foundation Trust