Facial pain: trigeminal neuralgia.

Atypical facial pain is a loose term used to encompass a wide range of facial pain syndromes including those of dental and ear, nose and throat (ENT) aetiology. Often, it is associated with psychiatric conditions like depression and psychosomatic illnesses. This facial pain typically does not follow anatomical boundaries or its explainable by present day neurophysiological understanding. The pain is often constant with no remission and is aggravated by stress. Treatment is difficult and often directed to the psychiatric cause. Surgical treatment is contraindicated. Trigeminal neuralgia on the other hand, can be effectively treated. Pain in the trigeminal distribution is paroxysmal, precipitated by trigger factors and there is no pain in between attacks. The aetiology of trigeminal neuralgia is still unknown though current thinking is that there is a peripheral disturbance or damage with cerebral brainstem disinhibition of the trigeminal apparatus. This results in a paroxysmal discharge and reverberation of pain impulses when a trigger point is elicited. Therefore, anti-epileptic drugs like tegretol can be effective in controlling trigeminal neuralgia in the majority of patients, at least in the initial stages. For unknown reasons however, medical treatment either is not effective at all from the very beginning or fails after a few years. Surgery then becomes the only available therapeutic option. If the peripheral disturbance is due to an organic cause like a tumour, surgical approaches should be directed towards its removal. Often the pain will also resolve. If the trigeminal neuralgia is of the idiopathic variety, then the surgeon has a choice of either peripheral percutaneous retrogasserian ganglionectomies or central approaches like microvascular decompression and trigeminal tractotomy.