Glossopharyngeal neuralgia is a chronic pain syndrome that causes intense, shooting pains in the back of the tongue and throat, tonsillar areas, and middle ear.
Glossopharyngeal neuralgia may be due to inflammation or compression of either the glossopharyngeal nerve or the vagus nerve, another nerve that innervates (stimulates) the same basic areas. The condition usually comes on quite suddenly, and may wax and wane in severity over time. This condition may occur in conjunction with trigeminal neuralgia (a pain syndrome affecting the face).
Glossopharyngeal neuralgia usually strikes people over the age of 40. It is a relatively rare condition, affecting about 0.7/100,000 individuals per year.
Causes and symptoms
The cause of glossopharyngeal neuralgia is not completely understood, although it seems that conditions (tumors, infections, injuries, or blood vessels located close to the glossopharyngeal nerve) that put pressure on the glossopharyngeal nerve may sometimes be responsible for its development. Individuals with diabetes or multiple sclerosis may also develop glossopharyngeal neuralgia. Episodes of pain may be brought on by swallowing, sneezing, chewing, clearing the throat, eating spicy foods, drinking cold liquids, speaking, laughing, or coughing.
Glossopharyngeal neuralgia causes sudden, intense pains in the throat, mouth, tongue, jaw, ear, and neck. The pains have been described as excruciating and electric shock-like, and usually last from seconds to several minutes. Because the glossopharyngeal nerve also affects heart rate and blood pressure, some patients experience abnormal heart rhythms during episodes of pain. The heart rate may become so slow, in fact, that the patient faints.
The diagnosis is usually strongly suspected from the patient's characteristic description of the pain episodes. Often, the doctor can trigger an episode by gently touching the back of the throat with a cotton swab. The test is then repeated after application of a topical anesthetic has been used to numb the throat. If the pain episodes are caused by glossopharyngeal neuralgia, touching the back of the anesthetized throat with a cotton swab will not trigger an episode of pain.
CT or MRI may reveal inflammation of the glossopharyngeal nerve or the presence of an abnormality (such as a tumor) that is exerting pressure on the nerve. Angiography involves introducing dye into the vascular system, in order to take x-ray, CT, or MRI images that may reveal the location of a blood vessel that is exerting pressure on the glossopharyngeal nerve.
Neurologists and otorhinolaryngologists treat glossopharyngeal neuralgia.
Carbamazepine , phenytoin, gabapentin , baclofen, and tricyclic antidepressants may be used to ameliorate the pain of glossopharyngeal neuralgia. When a blood vessel is identified as compressing the glossopharyngeal nerve, surgery may be performed to move the vessel or to position a Teflon felt pad between the blood vessel and the nerve, in order to attempt to mitigate any pressure that is exerted on the nerve. In severe cases of glossopharyngeal neuralgia that don't respond to other treatments, surgery that severs the glossopharyngeal nerve may be the only treatment that relieves the sufferer's pain.
The prognosis of glossopharyngeal neuralgia varies, depending on the underlying cause of the disorder. Some individuals are completely relieved of the pain episodes after surgery; others continue to have periodic exacerbations throughout their lives.
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Hermanowicz, Neal. "Cranial Nerves IX (Glossopharyngeal) and X (Vagus)." In Textbook of Clinical Neurology, edited by Christopher G. Goetz. Philadelphia: W. B. Saunders Company, 2003.
Rozen, Todd D. "Trigeminal neuralgia and glossopharyngeal neuralgia." Neurologic Clinics 22, no. 1 (February 2004).
NINDS Glossopharyngeal Neuralgia Information Page. National Institute of Neurological Disorders and Stroke (NINDS). November 6, 2002 (June 2, 2004). <http://www.ninds.nih.gov/health_and_medical/disorders/glossopharyngeal_neuralgia.htm>
Rosalyn Carson-Dewitt, MD