Difficult-to-Control Headaches: The Role of Pericranial Nerve Blocks

What are difficult-to-control headaches?

Chronic headaches that fail to respond to standard treatment represent one of the most complex challenges in clinical neurology. When preventive medications — such as beta-blockers, antiepileptics, or tricyclic antidepressants — cannot adequately reduce the frequency or intensity of episodes, we speak of a refractory or difficult-to-control headache.

This scenario affects a significant subset of patients with chronic migraine and can severely impact quality of life: missed work, analgesic dependence, repeated emergency visits, and a cycle of pain that seems endless.

The role of the peripheral nervous system in migraine

Migraine is not simply "a severe headache." It is a complex neurological disorder involving both the central and peripheral nervous systems. In chronic migraine, a phenomenon called central sensitization develops: the nervous system becomes abnormally reactive, amplifying pain signals even in response to stimuli that would not normally be painful.

In this context, the nerves running along the surface of the skull — the pericranial nerves — can become active pain sources or pathways that perpetuate the sensitization cycle. Temporarily blocking them can interrupt that cycle and provide lasting relief.

What are pericranial nerve blocks?

A pericranial nerve block involves the infiltration of a local anesthetic — typically lidocaine or bupivacaine, sometimes combined with a short-acting corticosteroid — at precise anatomical points on the skull and face.

The goal is twofold:

• Interrupt the active episode: it acts as a "reset" for the local nervous system, cutting the ongoing pain cycle short.
• Reduce the frequency of future episodes: in patients with chronic migraine, periodic treatments can significantly decrease the number of headache days per month.

The procedure is outpatient: no hospitalization is required, it takes 10–20 minutes, and the vast majority of patients tolerate it well with minimal discomfort at the injection site.

Pericranial nerves and where they are found

The pericranial nerves most frequently used in headache management include the following:

Greater Occipital Nerve

The most clinically relevant. It emerges between the C1 and C2 vertebrae, ascends through the back of the neck, and distributes over the entire posterior scalp up to the vertex. It is located approximately 3 cm lateral to the midline, at the level of the external occipital protuberance. It is the nerve most frequently blocked in chronic migraine, occipital neuralgia, and cervicogenic headache.

Lesser Occipital Nerves

Branches of the cervical plexus that innervate the lateral and posterior scalp behind the ear. They are blocked alongside the greater occipital nerve when pain extends into that region.

Supraorbital and Supratrochlear Nerves

Branches of the frontal nerve — the ophthalmic division of the trigeminal nerve — that emerge through the supraorbital and supratrochlear notches along the upper orbital rim. They innervate the forehead, the anterior scalp, and the periorbital region. Particularly useful in migraines with predominantly frontal pain, cluster headaches, and certain frontal neuralgias.

Auriculotemporal Nerve

A branch of the mandibular nerve that courses through the anterior temporal region. It is blocked when pain is predominantly located at the temple.

Who can benefit?

The most appropriate candidates are patients with:

• Chronic migraine (≥15 headache days/month) that has not responded adequately to two or more preventive treatments
• Status migrainosus: a prolonged episode (>72 hours) that does not respond to usual treatment
• Occipital neuralgia: lancinating pain in the distribution of the greater occipital nerve
• Cluster headache in an active period, used as bridge therapy while preventive treatment is adjusted
• Cervicogenic headache with a prominent occipital component
• Migraine with significant cutaneous allodynia (scalp or facial sensitivity to touch during attacks)

How long does the effect last? Do they need to be repeated?

Relief may begin within the first 30 minutes after application. Duration varies from patient to patient: some experience improvement for weeks, others for months. In those who respond well, blocks are scheduled periodically — every 4 to 12 weeks, depending on the case — as part of a comprehensive management plan.

Nerve blocks do not cure migraine, but they can be a very valuable tool for reducing disease burden and improving quality of life while long-term treatment is optimized.

Nerve blocks as part of a comprehensive plan

The best results are achieved when blocks form part of a complete therapeutic strategy that includes:

• Optimization of preventive treatment — if the current regimen is insufficient, several options are available, including anti-CGRP monoclonal antibodies
• Appropriate acute treatment — triptans or other medications based on each patient's profile
• Identification of triggering and perpetuating factors — sleep, stress, dietary habits, analgesic overuse
• OnabotulinumtoxinA (Botox) for chronic migraine, when indicated
• Close neurological follow-up

Refractory headache is treatable. If you have been dealing with headaches that do not respond to standard treatment for months or years, a specialized neurological evaluation may open possibilities you have not yet explored.