Occipital Neuralgia

What is Occipital Neuralgia?

It is a severe headache. It is due to pain from irritation, usually trauma, to the greater occipital nerve.

The greater occipital nerve sits at the back of the skull, and the nerve is usually very tender to touch. The pain is a sharp, shooting pain, and can be associated with altered sensation over the back of the skull.

To clinch the diagnosis, the pain must be relieved by injection of local anaesthetic to "freeze" the nerve. In a typical case, I often will treat first with non-steroidals and / or Gabaepntin before going for occipital nerve blockade.

You can read a fairly typical case history here.

Other than previous trauma, no cause is usually found.

The problem is that other conditions can mimic occipital neuralgia. It is only one of many causes of pain in the back of the head.

These include temporal arteritis (the inflamed occipital artery sits very close to the occipital nerves and sets off the pain), or inflammation or disease of the atlanto-axial joints (these are the joints between neck and skull that support the head).

Examination reveals tenderness over the entry point of the greater occipital nerve.

You can locate the entry point by finding the inion.

(1) Place a finger in the middle of the back of your neck.

(2) Slide the finger up towards the head.

(3) The first bony prominence you feel as you move up is the inion.

Approximately one inch to the side and one inch down from that point are the entry points of the greater occipital nerve (there is one on each side). (See picture below)

If you test pin prick sensation over the back of the skull you can find increased sensitivity to the pain of pin-prick in the affected area.

In others you find reduced sensitivity to pin prick. Other than that examination is normal.

It worth checking neck rotation and looking at head posture for clues of atlanto-axial joint disease.

There is also a rare condition called the Neck Tongue Syndrome which causes sudden severe pain in the back of the head and neck associated with brief sensory disturbance in the tongue.

Other conditions to consider

On the one hand, the situation of a patient with severe shooting pain in the occiput (Back of head) is well recognised.

What is not so commonly known is that there is very little experimental evidence to support the theory (which I just wrote above) that entrapment of the greater occipital nerve in the subcutaneous tissues is the cause of the condition.

Some experts e.g. Bogduk, suggests that occipital neuralgia is more likely to be a manifestation of c2 root pain i.e. c2 neuralgia.

Certainly, if there is abnormal neck rotation or other neurological signs to suggest structural neurological disease, then a structural cause deeper inside should be sought.

The list of associations with occipital neuralgia includes these (all only case reports i.e. isolated cases):

1. Myelitis, including multiple sclerosis relapse
2. Vascular malformation of cervico-medullary junction
3. Neurosyphilis
4. Intracranial Hypotension with sagging of cerebellar tonsils
5. Occipital nerve or foramen magnum schwannoma (a benign tumour of the nerve sheath)
6. Herpes zoster of the maxillary division of trigeminal nerve
7. Posterior Inferior Artery vascular loop compression

In my own practice I can recall cases of high cervical myelitis having some occipital pain, but I have never aggressively chased the other diagnoses as neurological signs have not been prominent enough for me to justify imaging.

Occipital Neuralgia Treatment

1. Anti-inflammatory medicines
• Indomethacin
• Diclofenac
• Ibuprofen
• Cox-II inhibitors
2. Anti-convulsants
• Gabapentin
• Pregabalin
• Carbamazepine (Tegretol)
3. Nerve block injection
A nerve block usually consists of a mix of 40-80 mg of methylprednisolone and lidocaine or bupivicaine which is injected around the entry points of the greater occipital nerves. Local hair loss is the only commonly reported side-effect (about 2% risk). If the person with occipital neuralgia symptoms has diabetes, their blood sugar may increase in the week following methylprednisolone injection.