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.

This topic will review the clinical features, diagnosis, and management of GN. Other types of cranial pain are discussed separately. (See "Overview of craniofacial pain".)

EPIDEMIOLOGY — The incidence rate of GN is 0.2 to 0.7 per 100,000 individuals in population studies [1-4]. GN occurs significantly less frequently than other cranial pain syndromes such as trigeminal neuralgia or occipital neuralgia [1,2].

GN occurs in males and females with no gender predilection [5] and is more common in older adults, with one series reporting symptom onset after age 50 in 57 percent [6].

PATHOPHYSIOLOGY

Anatomy of the glossopharyngeal nerve — The glossopharyngeal nerve (cranial nerve IX) is a mixed nerve (figure 1) that provides [7]:

●Somatic motor control to the stylopharyngeal muscle

●Visceral motor output to the parotid gland

●Somatic sensation to parts of the ear, upper pharynx, and posterior tongue

●Visceral sensory innervation to the carotid sinus and (taste) to the posterior tongue

Efferent fibers originate in the nucleus ambiguus and inferior salivary nucleus. Afferent fibers terminate at the solitary and spinal trigeminal nuclei. The nerve enters the subarachnoid space at the lateral aspect of the medulla and passes through the jugular canal and foramen, adjacent to the vagus and accessory nerves. The extracranial segment of the glossopharyngeal nerve contains six terminal branches each with distinct functional roles:

●Tympanic branch – Parasympathetic fibers to parotid gland and sensation from tympanic membrane and middle ear

●Carotid sinus branch – Parasympathetic innervation to the carotid body and baroreceptors (to monitor blood oxygen, carbon dioxide, pH, and blood pressure), along with the vagus nerve

●Pharyngeal branch – Sensation to the pharynx

●Tonsillar branch – Sensation to palatine tonsil

●Stylopharyngeal branch – Motor control to the stylopharyngeal muscle (to help elevate the pharynx for swallowing and talking)

●Lingual branch – Somatosensory and taste sensation of the posterior one-third of the tongue

Additional communicating branches provide accessory input to adjacent nerves. Anatomic dissections of the carotid sinus branch of the glossopharyngeal nerve have identified branches that communicate with the facial nerve, vestibulocochlear nerve, vagus nerve, sympathetic trunk, and superior cervical sympathetic ganglion [8,9].

Causes — The most common cause of GN is compression of the glossopharyngeal nerve root by an adjacent intracranial vascular structure. However, more proximal brainstem and distal neck compressive and noncompressive lesions may be implicated as well.

●Vascular compression – Vascular compression of the glossopharyngeal nerve is most often due to the posterior inferior cerebellar artery. Less commonly, compression can be by the anterior inferior cerebellar artery, vertebral artery, or a combination of these structures [10]. Venous compression at the root entry zone and concurrent arachnoiditis have also been reported [11].

Vascular compression leads to disruption of myelin integrity, reported as the cause in 76 of 78 cases of GN in one series [12]. Myelin disruption leads to ephaptic transmission in the nerve fibers, similar to pathophysiology described for classic trigeminal neuralgia.

●Other compressive lesions – While intracranial arterial compression is the most common cause of GN, neuralgic pain can also be triggered by other compressive irritation anywhere along the course of the glossopharyngeal nerve from the brainstem to the oropharynx. Some of the etiologies include:

•Arteriovenous malformation with draining vessels along the medulla extending into the jugular fossa [13] or dural arteriovenous fistula [14]

•Chiari I malformation [15-19]

•Tumors compressing along the pathway of the nerve:

-Intracranial lesions such as medullary tumors or tumors originating from the cerebellopontine (CP) angle [20-22], arachnoid cysts in the CP angle [23]

-Neck lesions such as esophageal tumors [24,25], masses in the parapharyngeal space [26], within or around the carotid sheath [27,28], or within the glossopharyngeal nerve [29]

-Oropharyngeal masses such as tongue carcinoma [30-32] and tonsillar carcinoma [33]

•Oropharyngeal infections, such as a lingual abscess [34], and intraoral and peritonsillar infections [35]

•Trauma, typically to the neck [36,37]

•Eagle syndrome – If the styloid process is over 25 mm or the stylohyoid ligament becomes calcified, it may cause compression of structures nearby, including the glossopharyngeal nerve. Patients may present with throat pain, dysphagia, odynophagia, globus, neck pain, and ear pain. Pain may be worse when turning the head [38]. Pain is common with palpation of the peritonsillar region intraorally [39], though this would be present with GN as well. In these cases, a bony prominence might be palpitated in the tonsillar fossa [40].

●Other causes – Brainstem demyelination may be the cause of GN as well [41], though vascular compression might still be present in these cases [42].

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 [43]. Pain may be moderate to severe and attacks can recur several times each day, depending on the patient’s activity and triggers [6]. GN can occur in a pattern of episodes lasting weeks to months, alternating with longer periods of remission.

●Location of pain – GN pain typically occurs in the posterior tongue, pharynx, angle of the jaw, and sometimes deep in the ipsilateral ear. Pain is most commonly unilateral. However, bilateral GN was seen in approximately 12 percent of cases referred to a tertiary center for care [6]. Sides are typically affected at different times [44,45], with some cases reporting patients who have had sectioning of one glossopharyngeal nerve prior to the onset of symptoms on the contralateral side [44].

Similar neuralgic pain occurring in the anterior jaw or cheek may indicate co-occurring trigeminal neuralgia. One series describes co-occurrence of GN with trigeminal neuralgia in 12 percent of patients [6]. (See 'Differential diagnosis' below.)

●Triggers – Episodes of GN pain are frequently triggered by activities that activate the glossopharyngeal nerve, such as swallowing, coughing, or yawning.

●Associated features – Syncope may occur in approximately two percent of patients [6], and bradyarrhythmia, asystole, hypotension, and seizures have also been reported [46]. It is thought that these symptoms might be related to excessive impulses from the carotid sinus branch of the glossopharyngeal with resultant stimulation of the vagus nerve, either through direct branch connections or through reflex loops with the vagal nuclei of the medulla [47].

Occasionally, the paroxysmal pain may be associated with an urge to cough, possibly related to concurrent compression or involvement of the vagus nerve [48,49].

Some patients with frequent GN attacks provoked by swallowing may also report unintentional weight loss [50,51].

The presence of a fixed sensory deficit such as a loss of gag reflex or loss of sensation in the pharynx is atypical for GN and would be more suggestive of glossopharyngeal neuropathy. (See 'Differential diagnosis' below.)

DIAGNOSIS — The diagnosis of GN should be considered in patients with recurrent episodes of pain involving the jaw, tongue, and/or ear as well as those with face or neck pain and unexplained syncope. 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.

Diagnostic criteria — The International Classification of Headache Disorders, Third Edition (ICHD-3) criteria include [52]:

●Recurring paroxysmal attacks of unilateral pain in the distribution of the glossopharyngeal nerve (posterior tongue, pharynx, tonsillar fossa, angle of the jaw, and/or ear)

●Pain must have all four of the following characteristics:

•Lasting from a few seconds to two minutes

•Severe intensity

•Electric shock-like, shooting, stabbing, or sharp in quality

•Precipitated by swallowing, coughing, talking, or yawning

●Not better accounted for by another ICHD-3 diagnosis

Classification — Patients with symptoms that fulfill diagnostic criteria for GN may be classified by the underlying cause identified on imaging evaluation (or at surgery). (See 'Imaging' below.)

●Classical GN – Classical GN is when the neuralgia develops related to neurovascular compression of the glossopharyngeal nerve root.

●Secondary GN – Secondary GN is when the neuralgic pain is related to an underlying structural cause other than neurovascular compression, such as a brainstem demyelinating lesion or tumor in the parapharyngeal space or elsewhere along the glossopharyngeal nerve.

●Idiopathic GN – Idiopathic GN occurs when there is no evidence of neurovascular compression or other structural cause for the pain. In these cases, it is important to rule out mimics of GN. (See 'Differential diagnosis' below.)

Diagnostic evaluation — All patients whose symptoms fulfill diagnostic criteria for GN should undergo physical examination and diagnostic testing to confirm the diagnosis and determine the underlying etiology.

Physical examination — Direct inspection and/or palpation of the neck, ear and tympanic membrane, and oropharynx may identify swelling or other evidence of an underlying mass lesion.

For patients with odynophagia or those unable to tolerate oropharyngeal examination, a topical anesthetic agent may be applied to the posterior oropharynx and peritonsillar region. Transient symptom relief in the region of the previous trigger zone is suggestive of the diagnosis of GN. A 10 percent cocaine solution was used in the past [6], but this has been gradually replaced with lidocaine as the preferred anesthetic.

Referral to an otolaryngologist may be helpful to evaluate for tongue or pharyngeal masses and other pathology that might cause a secondary GN [53].

Imaging — We suggest imaging of the brain and soft tissues of the neck for all patients with GN to identify underlying structural causes and to exclude other causes of symptoms. For most patients, we prefer magnetic resonance imaging (MRI) of the brain and soft tissues of the neck with contrast. High-resolution computed tomography (CT) of the head and neck may also be performed when bony pathology is suspected or as an alternative imaging study if MRI is contraindicated.

Brain imaging can help identify vascular compression adjacent to the glossopharyngeal nerve. The most common vessel involved is the posterior inferior cerebellar artery, followed by the anterior inferior cerebellar artery, vertebral artery, or a combination of these.

Imaging of the soft tissues of the neck may identify a secondary cause of neuralgic pain in the tongue, pharynx, parapharyngeal region, or neck. CT of the neck may also show an elongated styloid process, suggestive of Eagle syndrome [39,53]. Plain radiographs of the skull or cervical spine may be another option to evaluate for an elongated styloid process [54].

Cardiovascular testing — Patients with GN who report associated cardiovascular symptoms such as lightheadedness, palpitations, or syncope warrant cardiovascular evaluation, including ambulatory electrocardiogram (ECG) monitoring to assess for associated bradyarrhythmia. A wide variety of ECG findings have been reported in patients with GN, including bradycardia (27 to 45 per minute), asystole (up to six to eight seconds), negative T-wave changes, T-P interval prolongation, and sinus arrest with nodal rhythm [54]. (See "Syncope in adults: Clinical manifestations and initial diagnostic evaluation", section on 'Initial testing' and "Syncope in adults: Risk assessment and additional diagnostic evaluation", section on 'Selected additional testing'.)

DIFFERENTIAL DIAGNOSIS — The differential diagnosis of GN includes other conditions which may present with recurrent pain involving the tongue, throat, jaw, and/or ear.

●Painful glossopharyngeal neuropathy – Pain from glossopharyngeal neuropathy tends to be continuous or near-continuous, sometimes with superimposed paroxysms of pain, unlike the triggered transient attacks in GN [52]. Neuropathy of the glossopharyngeal nerve can be associated with loss of taste sensation to the posterior one-third of the tongue with loss of sensitivity to the posterior tongue, palate, and pharynx. There may be an absent gag reflex on the affected side and impaired swallowing. Compression from internal carotid artery dissection [55] and traumatic cases have been reported (eg, following endoscopy, tonsillectomy, carotid endarterectomy, intubation, and aesthetic procedures) [56,57].

●Trigeminal neuralgia – Trigeminal neuralgia is characterized by paroxysmal, brief, shock-like pain in the face. It is typically easy to differentiate trigeminal neuralgia from GN as trigeminal neuralgia tends to be triggered by light touch to the face rather than the pharynx. Confusion can arise when patients are asked about whether brushing their teeth or whether swallowing is a trigger for pain. In trigeminal neuralgia, brushing the gumline typically triggers pain, typically during the oral phase of swallowing (where the tongue is forming the food bolus). By contrast, with GN, brushing teeth can trigger pain when the toothbrush gets too close to the back of their mouth (touching their posterior tongue or eliciting a gag motion), and it is the pharyngeal phase of swallowing (when food is passing by the oropharynx) that is likely to trigger pain. (See "Trigeminal neuralgia".)

Trigeminal neuralgia can be comorbid with GN. (See 'Clinical features' above.)

●Nervus intermedius neuralgia – Nervus intermedius neuralgia is paroxysmal, brief, shock-like pain in the ear (often deep in the ear canal but may also include the auricle). Patients with nervus intermedius neuralgia do not typically report pharyngeal pain, unlike those with GN. However, a variant of GN with pain restricted to the ear may be difficult to distinguish from nervus intermedius neuralgia until patients subsequently develop pharyngeal pain that can help discriminate between these conditions [58]. (See "Nervus intermedius neuralgia".)

●Superior laryngeal neuralgia – Superior laryngeal neuralgia is described as paroxysmal shock-like pain located in the paralaryngeal region, often on one side of the anterior neck near the thyrohyoid membrane. Pain is triggered by laryngeal movement such talking, coughing, straining the voice, swallowing, or, rarely, head turning [59]. There may be hoarseness or cough.

Superior laryngeal neuralgia has been described after viral infections and as a rare complication of carotid endarterectomy and other surgeries [60]. In one series of pain in this region, 4 of 28 patients were found to have a vocal cord granuloma [61]. It can be difficult to differentiate superior laryngeal neuralgia from GN, though a pharyngeal trigger would not be expected in superior laryngeal neuralgia. For example, pain with food or liquid touching the posterior tongue or throat would be consistent with GN, but pain elicited by the movement of the larynx upward during swallowing would be more suggestive of superior laryngeal neuralgia. Sometimes a blockade with a local anesthetic may be both diagnostically helpful and therapeutic [59,60].

●Gastroesophageal reflux – Pain from the esophagus may also present as lancinating pain referred to the throat and ear initially with substernal pain coming on later in the course [62,63]. In some cases, the pain may be due to laryngopharyngeal reflux. Pain from gastroesophageal reflux may be worse at night and responsive to omeprazole. (See "Clinical manifestations and diagnosis of gastroesophageal reflux in adults".)

Some oropharyngeal 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 include (see 'Causes' above):

●Oral cavity tumors – Some tumors at the base of the tongue may cause mouth and jaw pain as well as referred ear pain. Distinguishing features suggestive of oral cavity tumors include mouth ulcers or bleeding, dysarthria, and leukoplakia. (See "Overview of the diagnosis and staging of head and neck cancer", section on 'Clinical presentation'.)

●Carotid body tumor – Carotid body tumors are uncommon tumors that typically present as a painless pulsatile swelling in the neck or angle of the mandible. However, some can be painful [64,65] and may have recurrent bradycardia or syncope, sometimes triggered with a head turn (eg, carotid sinus syndrome), mimicking the recurrent syncope that can occur with GN [66]. (See "Differential diagnosis of a neck mass".)

●Oropharyngeal infections – Oral or pharyngeal infections such as abscesses may present with mouth and referred ear pain similar to GN. Additional discriminating features may include fever, odynophagia, trismus, and a neck mass. (See "Deep neck space infections in adults", section on 'General clinical features'.)

TREATMENT — The management of GN includes initial pharmacotherapy and interventional procedures for refractory symptoms. Management is similar to treatment options for trigeminal neuralgia due to shared underlying mechanisms and because available data on treatment of GN are limited to case series and reports [67-69].

Pharmacotherapy and interventional options used for pain relief may also be effective for patients with associated triggered bradyarrhythmia or syncope [54,70,71]. (See 'Management for patients with syncope' below.)

Pharmacotherapy — We suggest initial therapy with either carbamazepine or oxcarbazepine for patients with GN, based on efficacy for trigeminal neuralgia and other forms of cranial neuralgia [6]. Clinical experience suggests these agents provide effective pain relief for 20 to 30 percent of patients. Carbamazepine is more well studied for these conditions, but oxcarbazepine may be better tolerated [46,72]. For patients who do not respond to initial therapy, we offer a trial of an alternative medication.

●Carbamazepine – We typically start at 100 to 200 mg twice daily, with a gradual increase in increments of 200 mg daily as tolerated and necessary for pain relief. A typical maintenance dose is 600 to 800 mg daily in divided doses (either 12-hour extended-release tablets in twice daily dosing or immediate-release chewable tablets in four-times daily dosing). In our clinical experience, some older patients respond better to smaller doses of immediate-release more frequently (eg, 200 mg chewable tablets four times daily) than larger doses of extended-release taken less frequently (eg, 400 mg extended-release twice daily). The maximum dose recommended for neuropathic pain is around 1200 mg daily; however, some patients do tolerate higher doses when given for other indications (eg, epilepsy and bipolar disorder).

Evidence of efficacy of carbamazepine for GN is limited, based on indirect data for trigeminal neuralgia and other forms of neuralgia. The dosing, adverse effects, and efficacy of carbamazepine are discussed in greater detail separately. (See "Trigeminal neuralgia", section on 'Carbamazepine'.)

●Oxcarbazepine – We start oxcarbazepine at 600 mg daily in two divided doses and increase as tolerated by 300 mg every third day as tolerated and necessary up to a total dose of 1200 to 1800 mg daily.

The dosing, adverse effects, and efficacy of oxcarbazepine are discussed in greater detail separately. (See "Trigeminal neuralgia", section on 'Oxcarbazepine'.)

●Alternative options – For patients who do not respond to or tolerate initial therapy with carbamazepine and/or oxcarbazepine, we offer an alternative medication such as gabapentin. Alternative options may also be used adjunctively for patients with a partial response to carbamazepine or oxcarbazepine.

Several medications that have been used for other forms of neuralgia have also shown some benefit in case reports of patients with GN. Options include:

•Gabapentin [67,73]

•Pregabalin [74-76]

•Phenytoin [6]

•Lamotrigine [47,77]

•Levetiracetam [78]

•Ketamine [79]

●Parenteral options as bridge therapy – Glossopharyngeal nerve block with an anesthetic plus a glucocorticoid can be performed by a pain specialist to provide temporary relief from pain while starting on an oral medicine or waiting for surgical assessment [80]. Intravenous fosphenytoin was reported to be useful in a small series of patients with refractory GN awaiting neurosurgical treatment [81].

Surgery and procedures for medically 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. The choice of procedure will be influenced by underlying cause, potential adverse effects for the technique, patient preference, and expertise of the local center.

●Microvascular decompression without vagoglossopharyngeal sectioning – Microvascular decompression (MVD) of the glossopharyngeal nerve is performed by craniotomy and involves separation of vascular structures from the glossopharyngeal and vagal nerve complex. Pledgets are typically placed between the vessel and the nerve to prevent recurrence of compression. MVD may be preferred for patients with evidence of significant neurovascular compression on neuroimaging.

Significant or complete pain relief is reported in 90 to 100 percent of patients immediately following MVD [11,20,82-84]. In one series of 46 patients, 45 (98 percent) were pain-free at the one-year follow-up [20]. Combining three other series with available long-term follow-up after MVD, 71 of 75 patients (95 percent) remained pain-free for more than 10 years after surgery [82,83,85]. However, other reports indicate the long-term effects may be less durable for some patients. In a study of 97 patients with GN who had MVD, 29 patients (30 percent) had eventual pain recurrence, with almost all cases (96 percent) occurring in the first five years after surgery [11]. Predictors of favorable response to surgery include the presence of throat pain at the initial presentation and high degree of neurovascular conflict on preoperative imaging [11,84].

Complications may occur in approximately 26 percent of patients following craniotomy and MVD [11] and include dysphagia, hoarseness, facial weakness, ipsilateral hearing loss, and cerebrospinal fluid leak, as well as uncommon severe complications (intracranial hematoma, brainstem infarct, and death) [11,82,84,85]. Most complications are mild and transient, but approximately 9 percent can have permanent deficits [11].

●Rhizotomy of glossopharyngeal nerve with or without rhizotomy of upper vagal nerve rootlets – Glossopharyngeal nerve sectioning or rhizotomy (ie, intracranial sectioning or percutaneous radiofrequency thermocoagulation) can be performed alone or along with the upper vagus nerve rootlets. In one series of 96 patients available for follow-up after rhizotomy, long-term "excellent" relief of pain was noted in 76 percent at the one-year follow-up and 44 percent at 10-year follow-up [86].

Rhizotomy can be done with or without MVD. In a systemic review of observational series, rhizotomy alone was associated with immediate pain relief in 79 to 100 percent of patients, while MVD combined with rhizotomy was associated with immediate relief in 86 to 100 percent of patients [10]. However, adverse events were more frequent among patients who underwent MVD combined with rhizotomy while more patients in the rhizotomy-only group required medication postoperatively [10].

Complications of rhizotomy include hoarseness, dysphagia, numbness of the tongue and pharynx, and abnormal taste sensation [86]. Notably, percutaneous radiofrequency thermocoagulation for GN is more technically difficult than gasserian thermocoagulation for trigeminal neuralgia due to the location of the nerve and high risk of injury to adjacent structures [87].

●Stereotactic radiosurgery – For patients who are unable to undergo open surgical procedures or who have failed previous open procedures, stereotactic radiosurgery (SRS) is an option. SRS involves the delivery of a therapeutic dose of radiation from multiple nonparallel radiation beams that converge on the target lesion. Typically, the target is either the cisternal portion of the glossopharyngeal nerve or the distal nerve at the level of the glossopharyngeal meatus (where the glossopharyngeal nerve passes through dura over the jugular foramen). These targets are chosen to minimize radiation dosing to the brainstem and vagus nerve [88]. (See "Stereotactic cranial radiosurgery".)

Onset of pain relief with SRS tends to start around 2 to 11 weeks after treatment [89,90]. There is a low rate of complications reported, mainly involving hypoesthesia of the pharynx [10,89,90].

There is limited information available on long-term follow-up after SRS for GN. Similar to the experience with trigeminal neuralgia, SRS for GN may have a higher recurrence rate at the one-year follow-up. One small series of patients reported 71 percent of patients were pain-free at one year [88], while another reported 82 percent pain-free at one year but also described 10 of their 21 patients as having a recurrence (mean 13.6 months), with three patients receiving a second radiosurgery procedure [90].

Management for 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. Some patients with GN who have recurrent symptomatic bradyarrhythmia or syncope may warrant pacemaker implantation [91]. However, such patients with pain and syncope whose neuropathic symptoms respond to pharmacotherapy or surgical decompression may also report resolution of syncopal episodes [71,92,93]. (See "Reflex syncope in adults and adolescents: Clinical presentation and diagnostic evaluation", section on 'Initial evaluation' and "Reflex syncope in adults and adolescents: Treatment".)

PROGNOSIS — The prognosis in GN is variable with some patients reporting spontaneous remission or effective pain relief with pharmacotherapy. However, other patients have refractory or recurrent pain despite medication trials and surgical interventions. In a series of 217 patients with GN seen from 1922 to 1977, 161 patients experienced spontaneous remissions, ranging from less than six months (50 patients) to more than five years (20 patients) [6]. Predictors of poor prognosis in GN include bilateral pain, severe attacks, and absence of a compressive lesion on diagnostic imaging [5,11].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Neuropathic pain".)

SUMMARY AND RECOMMENDATIONS

●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. (See 'Introduction' above and 'Causes' above.)

●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. (See 'Clinical features' above.)

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. (See 'Diagnosis' above.)

•Examination – We perform direct inspection and/or palpation of the neck, ear and tympanic membrane, and oropharynx to assess for swelling or other evidence of an underlying mass lesion. (See 'Physical examination' above.)

•Imaging – We suggest imaging of the brain and soft tissues of the neck for all patients with GN to identify underlying structural causes and to exclude other causes of symptoms. For most patients, we prefer MRI of the brain and soft tissues of the neck with contrast. High-resolution CT of the head and neck may also be performed when bony pathology is suspected and as an alternative imaging study when MRI is contradicted. (See 'Imaging' above.)

•Cardiovascular testing – Patients with GN who report associated cardiovascular symptoms such as lightheadedness, palpitations, or syncope warrant cardiovascular evaluation. (See 'Cardiovascular testing' above.)

●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 (see 'Differential diagnosis' above):

•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. (See 'Differential diagnosis' above and 'Causes' above.)

●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. (See 'Pharmacotherapy' above.)

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). (See 'Surgery and procedures for medically refractory GN' above.)

•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. (See 'Management for patients with syncope' above.)

●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. (See 'Prognosis' above.)