What is Glossopharyngeal Neuralgia
Glossopharyngeal neuralgia is a rare condition in which there are repeated (recurring) attacks of intense pain in the throat, tongue, tonsils, and, sometimes, the ears.
This condition is usually lifelong (chronic), unless successfully treated with surgery.
Glossopharyngeal neuralgia (GPN) is a unilateral severe pain felt in the distribution of the glossopharyngeal nerve, the auricular (Jacobsen’s nerve) and pharyngeal branches of the vagus nerve. Pain occurs in the ear, the posterior third of the tongue, and the tonsillar fossa.
Glossopharyngeal neuralgia is a rare condition characterized by paroxysms of pain in the sensory division of the cranial nerve IX. Although the pain of glossopharyngeal neuralgia is similar to that of trigeminal neuralgia, it occurs 100 times less frequently. Glossopharyngeal neuralgia occurs more commonly in patients older than 50 years.
The pain is located in the tonsil, laryngeal region, and posterior tongue. The pain is unilateral in most patients, but can occur bilaterally 2% of the time.
Rarely, the pain of glossopharyngeal neuralgia is associated with bradyarrhythmias; in some patients, it is associated with syncope.
These cardiac symptoms are thought to be due to overflow of neural impulses from the glossopharyngeal nerve to the vagus nerve. Although rare, this unusual combination of pain and cardiac arrhythmia can be lethal.
How common is Glossopharyngeal Neuralgia
The incidence is about 0.2 to 0.7 per 100,000 patients, with most presenting older than 50 years of age and with a female:male ratio of 1:1.
GPN is a rare disorder, 1/100 as common as trigeminal neuralgia. It occurs most frequently in middle-aged men and women.
What are the causes?
This condition may be caused by pressure on nerves (glossopharyngeal nerveor vagus nerve) that come from the brain (cranial nerves). Sometimes, the cause is not known (idiopathic glossopharyngeal neuralgia).
The majority of GPN cases are idiopathic or are related to neurovascular compression of cranial nerves IX and X. Tumors involving the jugular foramen can cause GPN as well.
Eagle syndrome is another uncommon but well-described cause, where an elongated styloid process or ossified stylohyoid ligament compresses the glossopharyngeal nerve.
What increases the risk?
This condition is more likely to develop in people who are over the age of 40.
What are the symptoms of glossopharyngeal neuralgia
What is the typical clinical presentation of glossopharyngeal neuralgia?
This syndrome is characterized by paroxysmal jolts or lancinating, sharp pain in the pharynx.
Swallowing is often a trigger.
This pain emanates from a dysfunctional cranial nerve IX (glossopharyngeal nerve).
Some individuals experience syncope from the extreme pain and autonomic dysfunction.
The main symptom of this condition is severe, recurring pain in the ears, tonsils, and the back of the throat and tongue. Pain usually affects only one side of the body (unilateral). The specific location and frequency of the pain varies. You may have times when this condition is inactive (remission), and times when you have pain more frequently. Pain may:
- Come and go.
- Last for a few seconds or a few minutes at a time.
- Happen daily or once every few weeks.
In many cases, certain actions that involve the mouth and throat can trigger pain. These actions are different for each person. Pain can be triggered by:
- Chewing or swallowing.
- Eating spicy foods.
Typically severe stabbing pain along one side of the throat near the tonsillar area with occasional radiation to the ear lasting fractions of a second up to 2 minutes is present, which can be precipitated by swallowing, coughing, talking, or yawning.
Most patients are believed to have an artery compressing the nerve as it exits the medulla and travels through the subarachnoid space to the jugular foramen although secondary causes should be excluded by MRI and other testing (including tumors, multiple sclerosis, Paget’s disease, Sjögren’s syndrome, and other causes).
Pain is elicited by stimulating trigger points in the cutaneous distribution of the glossopharyngeal or vagus nerves, often with swallowing, chewing, yawning, or coughing. Note that while most triggers mimic those of trigeminal neuralgia, swallowing is specific to GPN. In “classic” GPN, patients are pain-free in between severe episodes that are brief and lancinating. In “symptomatic” GPN, an aching pain is present between the episodes of stabbing pain. Episodes often occur in clusters, and patients tend to sit leaning forward and drool during attacks. Syncope occurs in 10% of cases, due to hypersensitivity of the dorsal motor nucleus of the vagus nerve.
The pain of glossopharyngeal neuralgia is in the distribution of cranial nerve IX. In some patients, overflow pain may occur in areas innervated by the trigeminal nerve, upper cervical segments, or both. The pain is neuritic and is unilateral in 98% of patients. It is often described as shooting or stabbing, with a severe intensity level.
The pain of glossopharyngeal neuralgia is often triggered by swallowing, chewing, coughing, or talking. With the exception of trigger areas in the distribution of cranial nerve IX, the patient’s neurological examination should be normal. Because tumors at the cerebellopontine angle may produce symptoms identical to those of glossopharyngeal neuralgia, an abnormal neurological examination is cause for serious concern. Dull, aching pain that persists between the paroxysms of pain normally associated with glossopharyngeal neuralgia is highly suggestive of a space-occupying lesion and requires thorough evaluation.
How is Glossopharyngeal Neuralgia diagnosed?
This condition is diagnosed based on:
- The location of your pain.
- How you feel when you are given medicines that temporarily numb your nerves in a specific area (local anesthetics).
- Blood tests.
tests, such as:
- CT scan.
Evaluate the pharynx and hypopharynx by direct visualization to exclude tumor. Head and neck MRI study is the imaging of choice to evaluate the brain stem, palatine region, pharynx, and hypopharynx.
You may be referred to an ear, nose, and throat (ENT) specialist (otolaryngologist) or a health care provider who specializes in the nervous system (neurologist).
GPN is a clinical diagnosis. Imaging investigations can include magnetic resonance imaging (MRI) to assess for vascular compression and to rule out neoplastic lesions and demyelinating disease.
Computed tomography or plain films are also recommended to assess for Eagle syndrome. The diagnosis can often be confirmed by the cessation of pain with a nerve block at the jugular foramen or with application of topical anesthesia to the pharynx.
Magnetic resonance imaging (MRI) of the brain and brainstem should be performed in all patients thought to have glossopharyngeal neuralgia. MRI of the brain provides the best information regarding the cranial vault and its contents. MRI is highly accurate and helps identify abnormalities that may put the patient at risk for neurological disasters secondary to intracranial and brainstem pathology, including tumors and demyelinating disease.
MRI can also aid in the identification of blood vessels that may be compressing the glossopharyngeal nerve. Magnetic resonance angiography (MRA) may be helpful in identifying aneurysms responsible for neurological symptoms. In patients who cannot undergo MRI, such as patients with pacemakers, computed tomography (CT) is a reasonable second choice.
Clinical laboratory tests consisting of complete blood cell count, automated chemistry profile, and erythrocyte sedimentation rate are indicated to rule out infection, temporal arteritis, and malignancy that may mimic glossopharyngeal neuralgia.
Endoscopy of the hypopharynx with special attention to the piriform sinuses also is indicated to rule out occult malignancy. Differential neural blockade of the glossopharyngeal nerve may help strengthen the diagnosis of glossopharyngeal neuralgia.
Glossopharyngeal neuralgia is generally a straightforward clinical diagnosis that can be made on the basis of a targeted history and physical examination. Diseases of the eye, ears, nose, throat, and teeth may mimic trigeminal neuralgia or may coexist and confuse the diagnosis.
Tumors of the hypopharynx, including the tonsillar fossa and piriform sinuses, may mimic the pain of glossopharyngeal neuralgia, as may tumors at the cerebellopontine angle. Occasionally, demyelinating disease may produce a clinical syndrome identical to glossopharyngeal neuralgia.
The jaw claudication associated with temporal arteritis also sometimes confuses the clinical picture, as does trigeminal neuralgia.
How is Glossopharyngeal Neuralgia treated?
Treatment for this condition depends on the cause and severity of your symptoms. Treatment may include:
- Medicines that decrease nerve irritation, such as medicines to control seizures (anticonvulsants). This is commonly the first treatment method.
- Medicines that help relieve depression (antidepressants). These may be used to help relieve pain.
- Local anesthetics. These may be prescribed if other medicines are ineffective.
- Surgery to relieve pressure on the nerve (vascular decompression) or to cut the nerve (rhizotomy). This may be done if other treatments are ineffective.
The treatment is similar to trigeminal neuralgia. Try oxcarbazepine or carbamazepine as first line.
Carbamazepine is considered first-line treatment for glossopharyngeal neuralgia. Rapid response to this drug essentially confirms a clinical diagnosis of glossopharyngeal neuralgia.
Despite the safety and efficacy of carbamazepine compared with other treatments for glossopharyngeal neuralgia, much confusion and unfounded anxiety surround its use. This medication, which may be the patient’s best chance for pain control, is sometimes discontinued because of laboratory abnormalities erroneously attributed to it.
Baseline screening laboratory tests, consisting of a complete blood cell count, urinalysis, and automated chemistry profile, should be obtained before starting the drug.
Carbamazepine should be started slowly, if the pain is not out of control, at a starting dose of 100 to 200 mg at bedtime for 2 nights; the patient should be cautioned regarding side effects, including dizziness, sedation, confusion, and rash.
The drug is increased in 100- to 200-mg increments, given in equally divided doses over 2 days, as side effects allow, until pain relief is obtained or a total dose of 1200 mg per day is reached. Careful monitoring of laboratory parameters is mandatory to avoid the rare possibility of life-threatening blood dyscrasia.
At the first sign of blood count abnormality or rash, this drug should be discontinued. Failure to monitor patients started on carbamazepine can be disastrous because aplastic anemia can occur.
When pain relief is obtained, the patient should be kept at that dosage of carbamazepine for at least 6 months before considering tapering of this medication. The patient should be informed that under no circumstances should the dosage of drug be changed or the drug refilled or discontinued without the physician’s knowledge.
In the uncommon event that carbamazepine does not control a patient’s pain adequately, gabapentin may be considered. As with carbamazepine, baseline blood tests should be obtained before starting therapy. Gabapentin should be started with a 300-mg dose at bedtime for 2 nights; the patient should be cautioned about potential side effects, including dizziness, sedation, confusion, and rash.
The drug is increased in 300-mg increments, given in equally divided doses over 2 days, as side effects allow, until pain relief is obtained or a total dose of 2400 mg per day is reached. At this point, if the patient has experienced partial pain relief, blood values are measured and the drug is carefully titrated using 100-mg tablets. More than 3600 mg per day is rarely required.
Baclofen has been reported to be of value in some patients who fail to obtain relief from carbamazepine and gabapentin. Baseline laboratory tests should be obtained before starting baclofen.
The drug is started with a 10-mg dose at bedtime for 2 nights; the patient should be cautioned about potential adverse effects, which are the same as those of carbamazepine and gabapentin. The drug is increased in 10-mg increments, given in equally divided doses over 7 days, as side effects allow, until pain relief is obtained or a total dose of 80 mg daily is reached. This drug has significant hepatic and central nervous system side effects, including weakness and sedation. As with carbamazepine, careful monitoring of laboratory values is indicated during the initial use of this drug.
When treating patients with any of the drugs mentioned, the clinician should inform the patient that premature tapering or discontinuation of the medication may lead to the recurrence of pain. It becomes more difficult to control pain thereafter.
Glossopharyngeal Nerve Block
The use of glossopharyngeal nerve block with local anesthetic and a steroid serves as an excellent adjunct to drug treatment of glossopharyngeal neuralgia. This technique rapidly relieves pain while medications are being titrated to effective levels.
The initial block is performed with preservative-free bupivacaine combined with methylprednisolone. Subsequent daily nerve blocks are done in a similar manner, substituting a lower dose of methylprednisolone.
This approach also may be used to obtain control of breakthrough pain. Ultrasound guided needle placement may improve the efficacy of this technique and help avoid needle-related complications.
Radiofrequency Destruction of the Glossopharyngeal Nerve
The destruction of the glossopharyngeal nerve can be carried out by creating a radiofrequency lesion under biplanar fluoroscopic guidance. This procedure is reserved for patients who have failed to respond to all the treatments mentioned for intractable glossopharyngeal neuralgia and who are not candidates for microvascular decompression of the glossopharyngeal root.
Gamma knife ablation has also been used in this patient population. Ultrasound guided electrode placement may improve the efficacy of this technique and help avoid needle-related complications.
Microvascular Decompression of the Glossopharyngeal Root
Microvascular decompression of the glossopharyngeal root, also referred to as the Jannetta procedure, is the major neurosurgical procedure of choice for intractable glossopharyngeal neuralgia. It is based on the theory that glossopharyngeal neuralgia is a compressive mononeuropathy analogous to trigeminal neuralgia.
The operation consists of identifying the glossopharyngeal root close to the brainstem and isolating the offending compressing blood vessel. A sponge is interposed between the vessel and nerve, relieving the compression and the pain
What are the surgical options for treatment of glossopharyngeal neuralgia?
Surgical treatment is reserved for cases of drug inefficacy or intolerance. Microvascular decompression of the cranial nerves IX and X is first line, often producing excellent results.
If no vascular compression is present, sectioning of the nerve IX and upper rootlets of nerve X can be performed. Other options include percutaneous radiofrequency rhizotomy and radiosurgery. In the event of Eagle syndrome, the pain can be cured by resection of the styloid process.
Antiepileptic medications such as carbamazepine and gabapentin are commonly used to treat GPN. If syncope is a prominent feature of the disease, atropine can also be used.
Other anticonvulsants or baclofen may be tried.
Anesthetic block of the glossopharyngeal nerve is short lived in efficacy.
In recalcitrant cases, microvascular decompression may be pursued.
Follow these instructions at home:
- Take over-the-counter and prescription medicines only as told by your health care provider.
- Do not drive or operate heavy machinery while taking prescription pain medicine.
- Keep track of things that trigger your pain. Avoid triggers when possible.
- Keep all follow-up visits as told by your health care provider. This is important.
Contact a health care provider if:
- You have pain that gets worse or does not get better with medicine.
- You feel light-headed or dizzy.
- You feel nauseous or you vomit.
- You have difficulty balancing.
Get help right away if:
- You have severe pain.
- You vomit or faint during an attack of pain.
- Your hearing or vision changes.
- You lose feeling in your face.
- You cannot move your face.
The pain of glossopharyngeal neuralgia is severe and can lead to suicide; therefore it must be considered a medical emergency, and strong consideration should be given to hospitalizing such patients.
If a dull ache remains after the intense, paroxysmal pain of glossopharyngeal neuralgia subsides, this is highly suggestive of persistent compression of the nerve by a structural lesion such as a brainstem tumor or schwannoma. Glossopharyngeal neuralgia is almost never seen in persons younger than 30 years unless it is associated with multiple sclerosis, and all such patients should undergo MRI to identify demyelinating disease.
The major complications associated with glossopharyngeal nerve block are related to trauma to the internal jugular and carotid artery. Hematoma formation and intravascular injection of local anesthetic with subsequent toxicity are significant problems for the patient.
Blockade of the motor portion of the glossopharyngeal nerve can result in dysphagia secondary to weakness of the stylopharyngeus muscle. If the vagus nerve is inadvertently blocked, as it often is during glossopharyngeal nerve block, dysphonia secondary to paralysis of the ipsilateral vocal cord may occur.
Reflex tachycardia secondary to vagal nerve block is also observed in some patients. Inadvertent block of the hypoglossal and spinal accessory nerves during glossopharyngeal nerve block will result in weakness of the tongue and trapezius muscle.
The glossopharyngeal nerve is susceptible to trauma from the needle, hematoma, or compression during injection procedures. Such complications, although usually transitory, can be quite upsetting to the patient.
Although uncommon, risk for infection is ever present, especially in patients who have cancer and are immunocompromised. Early detection of infection is crucial to avoiding potentially life-threatening sequelae.
The pain of glossopharyngeal neuralgia is among the most severe pain that humans can experience and must be considered a medical emergency.
The uncontrolled pain of glossopharyngeal neuralgia has led to suicide, and hospitalization of such patients should be strongly considered. Between attacks of glossopharyngeal neuralgia, the patient is relatively pain free.
If a dull ache remains after the intense pain subsides, this is highly suggestive of a persistent compression of the nerve by a structural lesion, such as a brainstem tumor or schwannoma.
Glossopharyngeal neuralgia is almost never seen in individuals younger than 30 years unless it is associated with multiple sclerosis, and all such patients should undergo MRI with sequences designed to identify demyelinating disease.
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