Facial Pain Due to Other Causes

Facial Pain Due to Other Causes

Facial pain may be caused by temporomandibular joint dysfunction in patients with malocclusion, abnormal bite, or faulty dentures. There may be tenderness of the masticatory muscles, and an association between pain onset and jaw movement is sometimes noted. This pattern differs from that of jaw (masticatory) claudication, a symptom of giant cell arteritis, in which pain develops progressively with mastication. Treatment of the underlying joint dysfunction relieves symptoms.

A relationship of facial pain to chewing or temperature changes may suggest a dental disturbance. The cause is sometimes not obvious, and diagnosis requires careful dental examination and radiographs. Sinusitis and ear infections causing facial pain are usually recognized by the history of respiratory tract infection, fever, and, in some instances, aural discharge. There may be localized tenderness. Radiologic evidence of sinus infection or mastoiditis is confirmatory.

Glaucoma is an important ocular cause of facial pain, usually localized to the periorbital region.

On occasion, pain in the jaw may be the principal manifestation of angina pectoris. Precipitation by exertion and radiation to more typical areas establish the cardiac origin.

When to Refer

• Worsening pain unresponsive to simple measures.
• Continuing pain of uncertain cause.
• For consideration of surgical treatment (trigeminal or glossopharyngeal neuralgia).

Postherpetic Neuralgia

Postherpetic Neuralgia

Herpes zoster (shingles) is due to infection of the nervous system by varicella-zoster virus. About 15% of patients who develop shingles suffer from postherpetic neuralgia. This complication seems especially likely to occur in the elderly, when the rash is severe, and when the first division of the trigeminal nerve is affected. It also relates to the duration of the rash before medical consultation. A history of shingles and the presence of cutaneous scarring resulting from shingles aid in the diagnosis. Severe pain with shingles correlates with the intensity of postherpetic symptoms.

The incidence of postherpetic neuralgia may be reduced by the treatment of shingles with oral acyclovir or famciclovir, but this is disputed; systemic corticosteroids do not help. Zoster vaccine markedly reduces morbidity from herpes zoster and postherpetic neuralgia among older adults. Management of the established complication is essentially medical. If simple analgesics fail to help, a trial of a tricyclic antidepressant (eg, amitriptyline, up to 100–150 mg/d) in conjunction with a phenothiazine (eg, perphenazine, 2–8 mg/d) is often effective. Other patients respond to carbamazepine (up to 1200 mg/d), phenytoin (300 mg/d), or gabapentin (up to 3600 mg/d), or pregabalin (up to 300 mg/d). A combination of gabapentin and morphine taken orally may provide better analgesia at lower doses of each agent than either taken alone. Topical application of capsaicin cream (eg, Zostrix, 0.025%) is sometimes helpful, perhaps because of depletion of pain-mediating peptides from peripheral sensory neurons, and topical lidocaine (5%) is also worthy of trial. The administration of live-attenuated zoster vaccine to patients over the age of 60 years is important in preventing the occurrence of herpes zoster and thus of postherpetic neuralgia.

Glossopharyngeal Neuralgia

Glossopharyngeal Neuralgia

Glossopharyngeal neuralgia is an uncommon disorder in which pain similar in quality to that in trigeminal neuralgia occurs in the throat, about the tonsillar fossa, and sometimes deep in the ear and at the back of the tongue. The pain may be precipitated by swallowing, chewing, talking, or yawning and is sometimes accompanied by syncope. In most instances, no underlying structural abnormality is present; multiple sclerosis is sometimes responsible. Oxcarbazepine and carbamazepine (see Table 24–3) are the treatments of choice and should be tried before any surgical procedures are considered. Microvascular decompression is generally preferred over destructive surgical procedures such as partial rhizotomy in medically refractory cases and is often effective without causing severe complications.

Atypical Facial Pain

Atypical Facial Pain

Facial pain without the typical features of trigeminal neuralgia is generally a constant, often burning pain that may have a restricted distribution at its onset but soon spreads to the rest of the face on the affected side and sometimes involves the other side, the neck, or the back of the head as well. The disorder is especially common in middle-aged women, many of them depressed, but it is not clear whether depression is the cause of or a reaction to the pain. Simple analgesics should be given a trial, as should tricyclic antidepressants, carbamazepine, oxcarbazepine, and phenytoin; the response is often disappointing. Opioid analgesics pose a danger of addiction in patients with this disorder. Attempts at surgical treatment are not indicated.

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.