The patient suffers paroxysms of intense, stabbing pain, lasting only seconds, in the trigeminal nerve distribution. It is unilateral, affecting the mandibular and maxillary divisionsmost often, and the ophthalmic division only rarely. The face may screw up with pain (hence tic doloureux). Pain may recur many times day and night, and can often be precipitated by touching the skin of the affected area, by washing, shaving, eating or talking. Mainly a condition of those over 50 years old.

Cause

- Mostly idiopathic.

- Trigeminal sensory or motor deficits are not demonstrated unless the cause is structural e.g. MS (consider especially in the young), vascular malformation, or a cerebello-pontine angle tumour.

Treatment

- In idiopathic neuralgia, aim for pain relief (may need high doses). spontaneous remissions occur.

- Drugs to try include carbamazepine (start at 100mg/12h PO, max 400mg/8h) and phenytoin (200-400mg/24h PO).

- If drugs fail, surgery may be necessary. this may be directed at the peripheral nerve, the trigeminal ganglion or the nerve root. the nerve root may be compressed by tortuous blood vessels as it enters the brainstem and surgical decompression is then useful.