Trigeminal neuralgia: the diagnosis and management of this excruciating and poorly understood facial pain.

Trigeminal neuralgia is defined as sudden, usually unilateral, severe, brief, stabbing recurrent episodes of pain within the distribution of one or more branches of the trigeminal nerve, which has a profound effect on quality of life. The diagnosis is made on history alone, and time needs to be taken to elicit the key features and differentiate from toothache or one of the trigeminal autonomic cephalalgias. Most trigeminal neuralgia is idiopathic, but a small percentage is due to secondary causes-for example, tumours or multiple sclerosis-which can be picked up on CT or MRI. Recently published international guidelines suggest that carbamazepine and oxcarbazepine are the first-line drugs. There is limited evidence for the use of lamotrigine and baclofen. If there is a decrease in efficacy or tolerability of medication, surgery needs to be considered. A neurosurgical opinion should be sought early. There are several ablative, destructive procedures that can be carried out either at the level of the Gasserian ganglion or in the posterior fossa. The only non-destructive procedure is microvascular decompression (MVD). The ablative procedures give a 50% chance of patients being pain free for 4 years, compared with 70% of patients at 10 years after MVD. Ablative procedures result in sensory loss, and MVD carries a 0.2-0.4% risk of mortality with a 2-4% chance of ipsilateral hearing loss. Surgical procedures result in markedly improved quality of life. Patient support groups provide information and support to those in pain and play a crucial role.