Overview of Glossopharyngeal Neuralgia
Glossopharyngela neuralgia (GPN) is a rare pain syndrome characterized by intermittent severe shock-like pains that occur in the back of the throat, tongue and/or ear in the distribution of the glossopharyngeal nerve. The syndrome is very similar to
trigeminal neuralgia in the electric shock-like nature of the pain and its being triggered by stimulation of the area where the pain is felt. The glossopharyngeal nerve supplies sensation to the back of the throat and tongue and portions of the ear.
Symptoms of Glossopharyngeal Neuralgia
Most patients experience pain in the back of the throat and tongue and ear. Occasionally the pain is fairly restricted to the ear. The pain is sharp and sudden in onset and occurs for a short period of time during which the patient often must stop their activities including talking. The pain can be triggered by eating or swallowing. In some patients there is stimulation of related nerves that result in temporary slowing (bradycardia) or complete absence of heart beats (asystole) that can lead to sudden temporary loss of consciousness (syncope) or rarely seizures. The episodes of pain start as brief episodes that may be absent for months or years but tend to become more frequent over time.
Causes of Glossopharyngeal Neuralgia
The cause of most cases of GPN is not known (idiopathic) although these tend to be associated with compression of the glossopharyngeal nerve by a blood vessel. In rare cases GPN is associated with a lesion that compresses the nerve in its course outside the brain (secondary GPN) such as a destructive tumor of the skull base.
Diagnosis of Glossopharyngeal Neuralgia
The diagnosis is primarily based on the description of the location and pattern of the patient’s pain. The diagnosis is supported by the stopping of pain for several hours with the application of local anesthetic to the back of the throat during a flare up, but this test is rarely necessary. MR imaging is routinely performed to ensure that there is not a tumor or other mass lesion associated with the pain that would require a different approach to treat the pain. The MRI also allows the identification of blood vessels that may be compressing the glossopharyngeal nerve, although this is not necessary to proceed with a surgical procedure.
Complications of Glossopharyngeal Neuralgia
In the absence of the rare symptomatic heart rate changes during attacks of pain (see "Diagnosis" section), there are no long-term medical or neurologic complications from GPN. The major disability of GPN occurs from the significant impact it has on quality of life and psychological well-being.