Glossopharyngeal Neuralgia

INTRODUCTION

Glossopharyngeal neuralgia (GN) is a rare condition characterized by recurrent, brief, shock-like pains in the jaw, tongue, and/or ear, typically triggered by activities such as coughing or swallowing that activate the glossopharyngeal nerve.

●Definition and causes – GN is a rare condition characterized by recurrent, brief, shock-like pains in the jaw, tongue, and/or ear, typically triggered by activities such as coughing or swallowing that activate the glossopharyngeal nerve. The main cause of GN is compression of the glossopharyngeal nerve root (figure 1) by an adjacent intracranial vascular structure. However, more proximal brainstem and distal neck compressive and noncompressive lesions may be implicated as well.

●Clinical features – Symptoms of GN are characterized by unilateral paroxysmal pain, typically sharp, stabbing, or electrical shock-like in quality. GN attacks are brief, typically from one second up to two minutes in duration and may recur several times each day. Episodes of GN pain are frequently triggered by swallowing, coughing, or yawning.

Syncope occurs in approximately 2 percent of patients with GN.

●Diagnosis and evaluation – The diagnosis of GN is made in patients whose clinical features fulfill diagnostic criteria. Diagnostic evaluation is warranted for all patients to exclude other causes to symptoms and to classify GN subtypes by identifying underlying compressive or other structural causes.

●Differential diagnosis – The differential diagnosis of GN includes other conditions which may present with recurrent pain involving the tongue, throat, jaw, and/or ear. These include

•Glossopharyngeal neuropathy

•Trigeminal neuralgia

•Nervus intermedius neuralgia

•Superior laryngeal neuralgia

•Gastroesophageal reflux

Some conditions may present either as GN mimics when symptoms are similar to GN or as secondary causes of GN when symptoms are due to compression of the glossopharyngeal nerve. These conditions include oral cavity tumors, carotid body tumors, and oropharyngeal infections.

●Treatment

•Initial pharmacotherapy – We suggest initial therapy with carbamazepine or oxcarbazepine (Grade 2C) based on their efficacy in trigeminal and other forms of cranial neuralgia.

For patients who do not respond to initial therapy, we offer an alternative agent, such as gabapentin. Other options for GN include pregabalin, phenytoin, lamotrigine, levetiracetam, and ketamine.

•Surgical options for refractory GN – For patients with GN who do not respond to or tolerate a trial of at least two medications, we suggest referral to a surgeon to discuss surgical and procedural options such as microvascular decompression (MVD), rhizotomy, and stereotactic radiosurgery (SRS) (Grade 2C).

•Patients with syncope – Patients with GN who develop syncope should be referred for cardiac evaluation to assess for additional contributing factors and for symptomatic management. Pharmacotherapy or surgical decompression for neuropathic symptoms may also be effective for some patients with syncopal episodes triggered by GN.

●Prognosis – The prognosis of GN is variable with some patients reporting spontaneous remission or effective pain relief with pharmacotherapy while others have refractory or recurrent pain despite medication trials and surgical interventions.