The cause is often unknown but sometimes is an abnormally positioned artery that puts pressure on (compresses) the glossopharyngeal nerve.
People have brief attacks of excruciating pain, affecting one side of the tongue or throat and sometimes an ear.
Doctors diagnose the disorder based on what the pain is like and whether a local anesthetic applied to the back of the throat eliminates the pain.
Certain antiseizure drugs or antidepressants, baclofen, or a local anesthetic may relieve the pain, but surgery is sometimes needed.
(See also Overview of the Cranial Nerves Overview of the Cranial Nerves Twelve pairs of nerves—the cranial nerves—lead directly from the brain to various parts of the head, neck, and trunk. Some of the cranial nerves are involved in the special senses (such as seeing... read more .)
Glossopharyngeal neuralgia, a rare disorder, usually begins after age 40 and occurs more often in men.
The vagus (10th cranial) nerve malfunctions at the same time because the vagus nerve and the glossopharyngeal (9th cranial) nerve exit the skull together. Thus, the problem affecting the glossopharyngeal nerve usually also affects the vagus nerve. The vagus nerve helps control the heartbeat. When the vagus nerve malfunctions, the pulse may be abnormal, and abnormal heart rhythms Overview of Abnormal Heart Rhythms Abnormal heart rhythms (arrhythmias) are sequences of heartbeats that are irregular, too fast, too slow, or conducted via an abnormal electrical pathway through the heart. Heart disorders are... read more (arrhythmias) may occur.
Causes of Glossopharyngeal Neuralgia
Often, the cause of glossopharyngeal neuralgia is unknown.
But sometimes glossopharyngeal neuralgia occurs when
An abnormally positioned artery compresses the glossopharyngeal nerve near where the nerve exits the brain stem.
The long, pointed bone at the base of the skull (styloid process) is abnormally long and compresses the nerve.
Rarely, the cause is a tumor in the brain or neck, an abscess, a bulge ( aneurysm Aneurysms of Arteries in the Arms, Legs, and Heart An aneurysm is a bulge (dilation) in the wall of an artery. (See also Aortic Branch Aneurysms and Brain Aneurysms.) Aneurysms may occur in any artery. Aneurysms are most common in the aorta... read more ) in an artery in the neck (carotid artery), or multiple sclerosis Multiple Sclerosis (MS) In multiple sclerosis, patches of myelin (the substance that covers most nerve fibers) and underlying nerve fibers in the brain, optic nerves, and spinal cord are damaged or destroyed. The cause... read more .
Symptoms of Glossopharyngeal Neuralgia
In glossopharyngeal neuralgia, attacks are brief and occur intermittently, but they cause excruciating pain. Attacks may be triggered by a particular action, such as chewing, swallowing, talking, yawning, coughing, or sneezing. The pain usually begins at the back of the tongue, back of the throat, or the area near the tonsils. Sometimes pain spreads to the ear or the area at the back of the jaw. The pain may last several seconds to a few minutes and usually affects only one side of the throat and tongue.
If the vagus nerve malfunctions, disturbing the heart rate, people may faint.
Diagnosis of Glossopharyngeal Neuralgia
A doctor's evaluation
A test using a cotton-tipped applicator and an anesthetic
Magnetic resonance imaging
Sometimes computed tomography or x-rays
Glossopharyngeal neuralgia is distinguished from trigeminal neuralgia Trigeminal Neuralgia Trigeminal neuralgia is severe facial pain due to malfunction of the 5th cranial nerve (trigeminal nerve). This nerve carries sensory information from the face to the brain and controls the... read more (which causes similar pain) based on the pain’s location or results of a specific test. For the test, a doctor touches the back of the throat with a cotton-tipped applicator. If pain results, the doctor applies a local anesthetic to the back of the throat. If the anesthetic eliminates the pain, glossopharyngeal neuralgia is likely.
Magnetic resonance imaging (MRI) is done to check for tumors. Computed tomography (CT) may be done or x-rays are taken to determine whether the styloid process is abnormally long.
A local anesthetic may be applied to back of the throat to help with diagnosis and to rule out other possible causes of the pain. Nerve blocks Other treatments can also help doctors confirm the diagnosis. They can identify the affected nerve because they are used to disrupt a specific nerve pathway that transmits or enhances pain signals.
Treatment of Glossopharyngeal Neuralgia
A local anesthetic
The same drugs used to treat trigeminal neuralgia— antiseizure drugs Antiseizure drugs In seizure disorders, the brain's electrical activity is periodically disturbed, resulting in some degree of temporary brain dysfunction. Many people have unusual sensations just before a seizure... read more (carbamazepine, oxcarbazepine, gabapentin, or phenytoin), baclofen, and tricyclic antidepressants Heterocyclic (including tricyclic) antidepressants Agomelatine, a new type of antidepressant, is a possible treatment for major depressive episodes. Several types of drugs can be used to treat depression: Selective serotonin reuptake inhibitors... read more may help.
If these drugs are ineffective, applying a local anesthetic (such as lidocaine) to the back of the throat may provide temporary relief (as well as confirm the diagnosis).
However, for permanent relief, surgery may be needed. The glossopharyngeal nerve is separated from the artery that is compressing it by placing a small sponge between them (called vascular decompression).
Taking the Pressure Off a Nerve
When pain results from an abnormally positioned artery pressing on a cranial nerve, the pain can be relieved by a surgical procedure called vascular decompression. This procedure may be done to treat trigeminal neuralgia, hemifacial spasms, or glossopharyngeal neuralgia.
If the trigeminal nerve is compressed, an area on the back of the head is shaved, and an incision is made. The surgeon cuts a small hole in the skull and lifts the edge of the brain to expose the nerve. Then the surgeon separates the artery from the nerve and places a small sponge between them.
A general anesthetic is required, but the risk of side effects from the procedure is small. Side effects include facial numbness, facial weakness, double vision, infection, bleeding, alterations in hearing and balance, and paralysis.
Usually, this procedure relieves the pain, but in about 15% of people, pain recurs.