Glossopharyngeal neuralgia is a syndrome that consists of episodic ear and throat pain in the distribution of the ninth cranial nerve (AKA Glossopharyngeal nerve). This pain syndrome usually develops in individuals over 40 years old.
Glossopharyngeal neuralgia is classically described as “stabbing,” or “electrical shock-like” in nature. Episodes are typically brief, lasting a couple of seconds up to a few minutes and can be quite debilitating. They can occur in the tongue, throat, ear, and tonsils on one side of the head, but in rare cases may be bilateral. Painful attacks may occur spontaneously but are more often associated with a specific stimulus such as chewing, speaking, coughing, swallowing or laughing. The attacks can occur frequently throughout the day or once every couple of weeks and they can also disturb sleep.
It is typically caused by compression of the glossopharyngeal nerve. Compression of the nerve by an adjacent artery and/or vein can occur near the brainstem. Compression of the nerve more distally in the neck by an elongated styloid process (a bone in the neck) can cause this pain syndrome as well, and this is called Eagle syndrome. Additionally, Glossopharyngeal neuralgia can be caused by a tumor or infection in the region of ninth cranial nerve or by multiple sclerosis.
The diagnosis is made on clinical grounds alone; that is, no specific test can be done to prove the diagnosis in any given patient. The pattern of episodic ear and/or throat pain, often triggered by touching the palate or tonsil is strongly suggestive of the disorder. High resolution MRI or CT imaging of the brainstem may reveal the presence of vascular compression, tumors, or demyelinating lesions involving the ninth cranial nerve. High resolution CT scanning of the neck can reveal the presence of an elongated styloid process, suggestive of Eagle syndrome.
Trigeminal neuralgia is a related disorder in which there is pain in the face. Distinguishing the two disorders is done based upon the location of the pain. Pain that distinctly involves the ear or throat is the classic distribution seen in glossopharyngeal neuralgia.
The first line treatment for Glossopharyngeal Neuralgia is pharmacological. The anticonvulsant medications, including the seizure medications oxcarbazepine, carbamazepine, gabapentin, and pregabalin are all appropriate choices. Some antidepressants can also be helpful either alone or in combination with the seizure medications. If these medications are ineffective or have intolerable side effects, a variety of other medications may be used.
Should pharmacologic management be ineffective, surgical intervention is indicated. The first-choice treatment is typically microvascular decompression (MVD), as it has the highest initial and long-term success rates. Patients unable to tolerate such an operation due to advanced age or other medical problems may consider one of the many less invasive options including Gamma Knife radiosurgery.
Resection of the elongated styloid process through a minimally-invasive approach through the tonsil or neck can successfully cure the pain in Eagle syndrome. Nerve sectioning techniques in the neck can effectively treat this disorder as well, especially when the pain does not involve the ear. Neurostimulation techniques, such as high cervical spinal cord stimulation and motor cortex stimulation, may be used when other treatment methods are ineffective.