Neurogenic facial pain.

Neurogenic facial pain can be classified as either paroxysmal or persistent. Trigeminal neuralgia is the commonest example of the former, and postherpetic neuralgia, atypical facial pain, and tension head and facial pains are examples of the latter. The cause of many of these pains is poorly understood, the complex neuroanatomy of the head and neck being a contributory factor. Even when the aetiology is known, the mechanism whereby pain is produced is usually obscure. While treatment with drugs and surgical measures for trigeminal neuralgia are often satisfactory, and acupuncture for pain due to "muscle tension" may be beneficial, there is often little effective treatment for a considerable proportion of patients with neurogenic facial pain.