Trigeminal Neuralgia

Essentials of Diagnosis

• Brief episodes of stabbing facial pain.
• Pain is in the territory of the second and third division of the trigeminal nerve.
• Pain exacerbated by touch.

General Considerations

Trigeminal neuralgia ("tic douloureux") is most common in middle and later life. It affects women more frequently than men.

Clinical Findings

Momentary episodes of sudden lancinating facial pain occur and commonly arise near one side of the mouth and shoot toward the ear, eye, or nostril on that side. The pain may be triggered or precipitated by such factors as touch, movement, drafts, and eating. Indeed, in order to lessen the likelihood of triggering further attacks, many patients try to hold the face still while talking. Spontaneous remissions for several months or longer may occur. As the disorder progresses, however, the episodes of pain become more frequent, remissions become shorter and less common, and a dull ache may persist between the episodes of stabbing pain. Symptoms remain confined to the distribution of the trigeminal nerve (usually the second or third division) on one side only.

Differential Diagnosis

The characteristic features of the pain in trigeminal neuralgia usually distinguish it from other causes of facial pain. Neurologic examination shows no abnormality except in a few patients in whom trigeminal neuralgia is symptomatic of some underlying lesion, such as multiple sclerosis or a brainstem neoplasm, in which case the finding will depend on the nature and site of the lesion. Similarly, CT scans and radiologic contrast studies are often normal in patients with classic trigeminal neuralgia.

In a young patient presenting with trigeminal neuralgia, multiple sclerosis must be suspected even if there are no other neurologic signs. In such circumstances, findings on evoked potential testing and examination of cerebrospinal fluid may be corroborative. When the facial pain is due to a posterior fossa tumor, CT scanning and MRI generally reveal the lesion.

Treatment

The drugs most helpful for treatment are oxcarbazepine (although not approved by the US Food and Drug Administration [FDA] for this indication) or carbamazepine, with monitoring by serial blood counts and liver function tests. If these medications are ineffective or cannot be tolerated, phenytoin should be tried. (Doses and side effects of these drugs are shown in Table 24–3.) Baclofen (10–20 mg three or four times daily) or lamotrigine (400 mg orally daily) may also be helpful, either alone or in combination with one of these other agents. Gabapentin may also relieve pain, especially in patients who do not respond to conventional medical therapy and those with multiple sclerosis. Depending on response and tolerance, up to 2400 mg/d is given in divided doses.

Posted in: Facial Pain,Trigeminal Neuralgia