Glossopharyngeal neuralgia

Glossopharyngeal neuralgia (GPN) is characterized by a severe lancinating pain in the posterior pharynx, tonsillar fossa, and base of the tongue. It is induced frequently by swallowing and yawning. GPN has not been described previously in MS patients. The authors report four MS patients with GPN. Three responded to carbamazepine and one resolved during treatment with adrenocorticotrophin hormone (ACTH) and cyclophosphamide. Withdrawal of carbamazepine after 1 week in one patient resulted in recurrence of pain. GPN may be associated with MS and responds to carbamazepine.

Glossopharyngeal neuralgia is believed to be caused by irritation of the ninth cranial nerve. Symptoms usually begin in people over 40 years of age. In most cases, the source of irritation is never discovered. Nevertheless, tumors or infections of the throat and mouth, compression of the glossopharyngeal nerve by neighboring blood vessels, and other lesions at the base of the skull can sometimes cause this type of neuralgia (nerve pain).

Symptoms include severe pain in the areas connected to the ninth cranial nerves. This includes the throat, tonsillar region, posterior third of the tongue, nasopharynx (back of nose and throat), larynx, and ear. The pain is episodic and may be severe. It can sometimes be triggered by swallowing, chewing, speaking, laughing, or coughing.

Tests should be done to identify an abnormality at the base of the skull, particularly tumors. These may include X-rays, CAT scan of the head, and head MRI. Sometimes the MRI may show evidence of inflammation of the glossopharyngeal nerve. To determine whether a blood vessel is compressing the nerve, some pictures of the brain arteries can be obtained using techniques, such as magnetic resonance angiography (MRA) or conventional angiography (X-rays of the arteries with a dye). Occasionally, certain blood tests may be needed when the diagnosis is not clear, to rule out other causes of peripheral nerve problems (neuropathy), such as high blood sugar.

Treatment is aimed at controlling pain. Unfortunately, over-the-counter pain killers (such as aspirin or acetaminophen) are not very effective for the relief of neuralgia. The most effective drugs are actually anti-seizure medications, like carbamazepine, gabapentin, and phenytoin. Some anti-depressants like amitriptyline are sometimes tried with variable degrees of success.

In severe cases, when pain is difficult to treat, surgery aiming at decompressing the glossopharyngeal nerve may be required, which is generally considered effective. If a cause of the neuralgia is identified, the treatment of choice is the control of the underlying problem.