Glossopharyngeal Neuralgia: Still Rare, Still Elusive 2023

The incidence rate of glossopharyngeal neuralgia is less than 1 per 100,000. Still, the rare pain disorder can be debilitating and frightening, and its diagnosis elusive. These factors make awareness crucial for clinicians, including those in primary care.

Glossopharyngeal neuralgia is caused by irritation of the ninth cranial nerve, the glossopharyngeal nerve. A small blood vessel or growth at the base of the skull might be pressing on it; infections of the throat or mouth could also press on it. Most cases are idiopathic.¹

The incidence of glossopharyngeal neuralgia rises with age, and is most common in adults aged 50 years and older, according to Dr. Kaye. Women are as likely as men to develop the condition, he said. Age is considered the main risk factor.

Symptoms of glossopharyngeal neuralgia include acute, abrupt onset of repeated episodes of sharp, severe, and stabbing unliteral pain in the area of the sensory distribution of auricular and pharyngeal branches of the glossopharyngeal and vagus cranial nerves, Dr. Kaye explained. “These areas include the mastoid, the back of the throat, the posterior one-third of the tongue, and back of the nose.”

Many things can trigger the pain, so clinicians should be aware of additional patient descriptions that may suggest the condition, including:¹

• tinnitus
• sudden movement of the head
• touching the external surface of the ear
• coughing, sneezing, swallowing
• talking, laughing, chewing

Painful Episodes

It’s also important to realize that glossopharyngeal neuralgia is an “excruciatingly painful” condition, said Seena Patel, DMD, MPH, associate professor and director of oral medicine at the A.T. Still University’s Arizona School of Dentistry and Oral Health, Mesa, and a dentist in Phoenix. She has published several papers on the treatment of orofacial neuropathic conditions.

The pain can be so intense that some people say they avoid eating, drinking, and chewing, leading to unwanted weight loss.

Trigeminal Neuralgia and Other Differential Diagnosis

Many conditions can mimic glossopharyngeal neuralgia, Dr. Kaye said. “The differential diagnosis list is long and includes trigeminal neuralgia, temporal arteritis, Jacobson’s neuralgia, superior laryngeal neuralgia, and myofascial pain dysfunction syndrome, and other conditions. Eagle’s syndrome presents very similarly to glossopharyngeal neuralgia. It occurs when an elongated styloid process impinges on branches and fibers of the glossopharyngeal nerve, causing the same symptoms.”

Most people with glossopharyngeal neuralgia have unilateral pain, but some report bilateral pain. When unilateral, pain is often reported on the left side of the body while trigeminal neuralgia (a common misdiagnosis) is often reported on the right. Some patients have both conditions.¹

Ruling out infections such as strep throat is necessary as well, Dr. Patel said.

It’s also important to address any patient fears upfront. In Dr. Patel’s experience, patients often first fear that they have cancer, so it’s important to rule out the absence of any masses.

In his report, Dr. Kaye noted that idiopathic glossopharyngeal neuralgia may be associated with compression of the cranial nerve IX “by a vessel or dysfunction of the central pons, whereas secondary glossopharyngeal neuralgia can result from trauma, neoplasm, infection of the throat, or malformations,” among many other causes. It points to a need to get an extensive imaging workup to rule out other pathological processes.¹

Taking a careful history is also important. For instance, some people may have undergone surgery that damaged their glossopharyngeal nerve, Dr. Patel said. One such example is a carotid endarterectomy.²

At least one case report suggests that glossopharyngeal neuralgia may occur secondary to COVID-19. In 2022, researchers described the case of a 54-year-old patient diagnosed with the condition who potentially contracted it secondary to COVID-19, fitting in with new knowledge that COVID-19 infection may induce neurological symptoms and complications.³

“Treatment for this disease can be broken down into three distinct categories that can be initiated in any order based on the severity of symptoms, but most commonly follow one,” Dr. Kaye said.¹

Treatment usually begins with a highly conservative or pharmacological approach, including carbamazepine and gabapentin. According to Dr. Kaye, those are the first-line medical treatments.

Next, if medication does not provide relief, minimally invasive therapies can be tried. “For those not responding to pharmacotherapy, pulsed radiofrequency is the newest minimally invasive therapy, under CT guidance,” Dr. Kaye said. Directing pulses at the nerve change how the nerve transmits electrical signals and reduces the pain.

In addition, physical therapy, including hot and cold compression, and psychotherapy can help some patients, Dr. Kaye noted.

The last resort, she said, is surgery. The two surgical options are microvascular decompression and rhizotomy.¹

Because the condition is rare, studies on the various treatment options are not plentiful and the studies that have been published usually involve small numbers and sometimes are case reports of one.

Among the studies cited by Dr. Kaye:

• One woman diagnosed at age 48 began taking gabapentin at 400 mg 6 times a day for 2 months. After stopping it, she was asymptomatic for 4 years.⁴
• In a study of 30 patients treated with CT-guided radiofrequency ablation, 93.3% had satisfactory pain relief at 12 months. While satisfaction dropped over the follow-up, 54.8% still had satisfactory pain relief at the 10-year mark.⁵
• Microvascular decompression can be linked with post-op delirium, a complication Dr. Kaye cited,⁶ but studies overall have found it to be an effective and safe treatment. In one study of 228 individuals who were treated with the approach, 89.5% had excellent relief immediately post-op; of the 107 followed for 5 years, 86.9% said the result was excellent at that point.⁷
• Rhizotomy alone may provide relief, as does rhizotomy in combination with partial vagus nerve rhizotomy, but the combined approach had 9 times higher complication rates long-term, at 35.8%.⁸

“All of these treatments have pretty good track records,” Dr. Kaye said.

“I would recommend every primary care doctor develop a professional relationship with a local interventional pain physician,” Dr. Kaye said. Primary care physicians can try medical management and recommend a visit with a fellowship-trained interventional pain physician who can provide minimally invasive pain techniques, and then, if needed, also recommend a surgeon if surgical management is needed.