Occipital Neuralgia

Occipital neuralgia is a paroxysmal neuropathic pain in the distribution of the greater, lesser or third occipital nerves, caused by irritation or entrapment of the nerves in the upper cervical region, with severe lancinating pain that may be accompanied by dysaesthesia or allodynia of the scalp.

• Greater occipital nerve (C2) supplies the posterior scalp to the vertex; lesser occipital nerve (C2/C3) supplies the lateral occiput and behind the ear; third occipital nerve (C3) supplies the lower occiput.
• Causes: entrapment through the semispinalis and trapezius muscles, cervical spondylosis, C1/2 arthropathy, trauma (whiplash), tight hair styles or helmets, diabetic and inflammatory neuropathy, tumour of the upper cervical cord or posterior fossa, Chiari malformation, and varicella zoster.
• Often idiopathic; incidence about 3 per 100 000.
• It is frequently mislabelled; true occipital neuralgia is rarer than migraine or cervicogenic headache with occipital pain.

• Unilateral or bilateral paroxysms of stabbing, shooting, electric shock like pain lasting seconds to minutes in the occipital region, radiating towards the vertex, behind the ear or the eye, with a dull ache between attacks.
• Trigger: neck movement, brushing hair, pressure on the scalp or occipital nerves, cold wind.
• Tenderness and a positive Tinel sign over the greater occipital nerve (midway between the occipital protuberance and the mastoid) reproduce the pain.
• Scalp allodynia, hypoaesthesia or dysaesthesia in the nerve territory.
• Possible ipsilateral lacrimation and photophobia, causing confusion with migraine and cluster headache.
• Neck stiffness; cervical range of motion often reduced.
• Red flags: progressive course, neurological deficit, weight loss, fever, rash (zoster), constitutional symptoms, or tenderness of the temporal arteries (older adults).

• Clinical: paroxysmal pain in the occipital nerve distribution, tenderness over the nerve, and complete but temporary relief with a local anaesthetic block of the nerve (lidocaine 1 to 2 percent 2 to 3 mL at the nerve, which confirms the diagnosis).
• MRI of the cervical spine and posterior fossa (or MR angiography) when onset is atypical, in patients with neurological signs, or if intervention is planned.
• Blood tests: ESR and CRP (giant cell arteritis if over 50 years), fasting glucose or HbA1c, vitamin B12, and thyroid function.
• Differentials: cervicogenic headache, migraine with occipital pain, cluster headache, tension type headache, giant cell arteritis, C2 radiculopathy, Chiari malformation, upper cervical spine lesions, herpes zoster, posterior fossa tumour, vertebral artery dissection.

Conservative

• Heat, gentle neck stretching and massage; physiotherapy; correct posture and ergonomic adjustments; avoid tight headgear and hairstyles.
• Paracetamol 1 g orally up to four times daily or ibuprofen 400 mg three times daily with food for up to 2 weeks (maximum 4 g paracetamol daily).

Nerve block (first line intervention and diagnostic)

• Greater occipital nerve block: lidocaine 1 to 2 percent 2 to 3 mL combined with methylprednisolone 40 to 80 mg or triamcinolone 40 mg, injected at the nerve (repeat after 4 to 6 weeks if relief is partial; maximum 3 to 4 injections in a year). Relief lasts weeks to months in about 60 to 90 percent. Risks: bleeding, scalp atrophy and alopecia, infection, dizziness, vasovagal reaction, and (rarely) intravascular injection. Avoid in infection at the site and anticoagulation without precautions.

Neuropathic medicines

• Carbamazepine 100 mg orally twice daily, increasing by 100 to 200 mg every 3 days to 200 mg three times daily (maximum 1200 mg daily); check sodium, FBC and liver function at baseline, 2 and 4 weeks, then every 6 months; test HLA-B*1502 before starting in patients of Han Chinese, Thai or other Asian ancestry (risk of Stevens-Johnson syndrome); many drug interactions (reduces oral contraceptive efficacy).
• Gabapentin 300 mg orally at night, increasing over 1 to 2 weeks to 300 to 600 mg three times daily (maximum 3600 mg daily; reduce in renal impairment).
• Pregabalin 75 mg twice daily, increasing to 150 mg twice daily (maximum 300 mg twice daily; renal dose adjustment).
• Amitriptyline 10 mg at night, increasing to 50 to 75 mg.
• Muscle relaxant: baclofen 5 mg three times daily increasing weekly to 10 to 20 mg three times daily if muscle spasm contributes.

Refractory cases (specialist)

• Pulsed radiofrequency to the C2 dorsal root ganglion or the occipital nerve, nerve decompression, occipital nerve stimulation, or botulinum toxin injection.

Follow up

• Review at 4 to 6 weeks; refer to neurology or pain medicine when block and two medicines have not controlled pain, or when imaging is abnormal.

Special groups

• Pregnancy: use heat, physiotherapy, paracetamol, and nerve block with lidocaine alone; avoid carbamazepine, gabapentinoids and steroid injections unless specialist advice is available.
• Renal impairment: reduce gabapentin and pregabalin by creatinine clearance.