A 62-year-old woman presented to the general surgery clinic for evaluation of an anterior neck mass. She complained of hoarseness and dysphagia to both solid and liquids. Significantly, at the time of initial evaluation, the patient was unable to tolerate flexible laryngoscopy. Thyroid examination found significant enlargement with extension below the sternal notch. On the basis of this clinical picture, total thyroidectomy was elected. Triple endoscopy was performed in the operating room demonstrating normal anatomy throughout. The operating surgeons made specific note of the identification and sparing of both the superior and recurrent laryngeal nerves on the right side but made no comment about the left superior laryngeal nerve. The procedure was otherwise unremarkable, and the parathyroids were reimplanted into the sternocleidomastoids bilaterally. The patient was discharged on postoperative day 2 without notable complications.

At a follow-up appointment 1 week status after thyroidectomy, the patient complained of continued dysphagia and hoarseness as well as a sensation of “tightness” in her throat. At 1 month of follow-up, the patient began to describe severe episodic odynophagia. Codeine-acetaminophen 5/325 was trialed unsuccessfully for pain control. Further workup was pursued, including requested consultation with 3 separate specialties. Several attempts were made to visualize any lesions, including computed tomographic imaging of the chest and neck as well as repeat flexible laryngoscopy. All proved negative. Over a half-dozen separate diagnoses were considered. The final service consulted was otolaryngology, after symptoms had persisted 7 months postoperative.

Initial otolaryngology (ENT) evaluation, in fact, revealed progressive worsening of all symptoms since the beginning of treatment. Odynophagia had replaced dysphagia as the most prominent symptom. Pain was exacerbated by food at either extreme of temperature. There was accompanying hoarseness. On the suspicion of a laryngeal pathogenesis, the patient was scheduled for evaluation by speech pathology. Their examination revealed maximum phonation time that was significantly below age-adjusted average, apparently because of spasm of some sort. The patient was also observed to have significant difficulty handling her secretions secondary to pain. However, a barium study demonstrated functionally normal swallowing.

By this point, the patient had lost 30 lb secondary to severe odynophagia in spite of adherence to a puree diet. In light of the repeated normal workups, we, at this point, began to suspect a cranial nerve neuralgia and trialed gabapentin 300 mg bid. The patient reported a 50% symptom reduction on gabapentin at follow-up. Physical examination at that time demonstrated tenderness in the middle portion of the thyrohyoid membrane. Injection of 0.5 mL 1% lidocaine at the right superior laryngeal nerve was trialed. The patient reported relief within 30 seconds of administration. Four months after the trialed nerve block, the patient reports that her pain is still well-controlled with continued use of gabapentin. She is now tolerating a normal diet and has regained 17 lb.

Characteristics of superior laryngeal neuralgia have been described as an idiopathic syndrome of paroxysmal pain generally confined to one side of the laryngeal region (left greater than right) and may radiate to the infraauricular area. Bilateral involvement has been described as with other cranial nerve neuralgias. The sharp pain may radiate to the posterior auricular area from minutes to hours and can be variable both in intensity and intervals. The act of swallowing may elicit pain, which leads the patient to avoid food and result in significant weight loss . Straining the voice, singing, or turning of the head are other prominent triggering factors for some patients.

Pain is characteristically elicited with pressure over the entry point of the superior laryngeal nerve through the thyrohyoid membrane. Since the introduction of local anesthetic block as a confirming diagnostic maneuver in the 1950s , the diagnosis has been associated with a variety of conditions. Anesthetizing the larynx with topical anesthetic is an alternative method for confirming the diagnosis .

Seasonal occurrence in the fall and winter months has been noted by a number of authors since the first case series by Avellis . The report of Beck and Zimmerlin of 18 patients that occurred during the influenza epidemic of 1959 to 1960 provides circumstantial evidence of a possible viral association. Later reports have found similar associations .

Recently, hoarseness has been emphasized as a prominent symptom , although most descriptions do not list this as a significant symptom with the prominent exception of a report of 18 cases attributed to an influenza epidemic that had hoarseness as a common symptom . The largest reported series only found 2 of 21 with vocal symptoms (variable or breaking voice), and there is but 1 older report lists a single patient with hoarseness .

Reported cases can be categorized into 2 broad categories: central and peripheral causes. The central causes are described as identical to tic douloureux or glossopharyngeal neuralgia except for the involved nerve and its distribution. Findings suggestive of the central origin are the characteristic searing pain with a trigger point often within the larynx similar to tic douloureux or glossopharyngeal neuralgia. Electromicroscopic examination of the superior laryngeal nerve after sectioning is normal in central etiologies , whereas it would not be expected to be with peripheral involvement. The secondary causes, more accurately termed superior laryngeal nerve neuritis , are characterized by peripheral pathology, which gives rise to pain in the same characteristic distribution because of irritation or inflammation. Both central and peripheral causes are relieved by superior laryngeal nerve blockade. Swallowing problems appear to be more common with central causes than peripheral etiologies, although experience is limited and such distinctions may prove unwarranted . Causes of peripheral etiologies may include scarring from previous carotid artery surgery , deviation of the hyoid bone , microsurgery tonsillectomy , lateral pharyngeal divertculum , and trauma .

Carbamazepine is the most commonly used medication with good effectiveness reported, although failures have been reported . Prolonged treatment has not been necessary in a significant number of the case reports and series . Where this reflects a difference in etiology or variation in responsiveness remains to be determined. Repeated injections of commonly used concentrations of local anesthetics have been noted to be an effective treatment in isolated cases . Recent reports suggest that injections of high doses of local anesthetics have been successfully used as effective treatment in resistant cases . Extrafascicular administration of local anesthetics can induce wallerian degeneration with Schwann cell injury and axonal dystrophy in animal models . Presumably repeated injections can induce enough compromise of superior laryngeal nerve function to treat the neuralgia, offering the possibility of titration of compromise rather than the complete loss of function that results from surgical sectioning or alcohol injection for recalcitrant cases . Nerve section has been uniformly effective. Incision of the thyrohyoid membrane so as to relax any compression on the superior laryngeal nerve has been suggested as an alternative to nerve sectioning without supportive evidence for its effectiveness .

The differential diagnosis of condition mimicking superior laryngeal nerve syndrome includes neoplastic and inflammatory lesion of the larynx. Most can be excluded by visualization of the larynx, which is normal. The paroxysmal pain of neuralgias of surrounding cranial nerves differs in the localization of the pain and trigger zone distributions. Pain in the anterior neck may also be attributed to limited number of thyroid conditions. The most common of these is De Quervain thyroiditis, accounting for 5% of all adult thyroid disease. Although its pain is also unilateral, it is typically accompanied by elevations in C-reactive protein or erythrocyte sedimentation rate, and in 50% of cases has at least some period of thyrotoxicosis . It may also represent an atypical presentation of Hashimoto’s thyroiditis , even absent the classic anti-thyroid peroxidase antibodies. Trigeminal neuralgia is unlikely because the pain does not extend above the mandible. The glossopharyngeal nerve is uninvolved because the tonsil or pharynx does not trigger an attack. Classically, luetic disease or laryngeal tuberculosis may cause similar symptoms but can readily be excluded with testing. Carotidynia is a condition that may mimic superior laryngeal nerve syndrome. Classically, episodic throbbing pain in the anterior cervical triangle with tenderness of the carotid artery associated with vascular headache or migraines has been described with carotidynia . Tenderness of the carotid artery on the side of the cephalgia is commonly encountered with migrainous involvement . Digital pressure over the carotid bifurcation that elicits pain can be a helpful diagnostic maneuver to distinguish carotidynia from superior laryngeal nerve neuralgia.

A number of tendon insertion syndromes, generally diagnosable by palpation and selective nerve blocks, can also cause throat pain. Ernest syndrome creates a temporomandibular joint disorder–like spectrum of symptoms, the key finding of which is reproducible pain on palpation of the stylomandibular joint insertion. Management is typically a conservative course of steroid injections . In contrast, Eagle syndrome should have pain elicited by transoral palpation of the styloid in the region of the tonsillar fossa. It requires styloidectomy to resolve the discomfort, as more conservative options are ineffective. The pain of this disorder is characterized as a dull, background odynophagia with stabbing pain, punctuating attempts to swallow or turn the head. A radiologically abnormal styloid may be suggestive but not diagnostic because case series have demonstrated that as few as 4% of patients with this finding are actually symptomatic . Hyoid syndrome produces a very similar constellation of symptoms, but pain can be elicited by rocking the hyoid bone. Tenderness is maximal at the greater cornu of the hyoid. It may also be unique in eliciting dizziness or vertigo . Superior pharyngeal constrictor syndrome is an irritation of the myosfascial tissue at the insertion of the pterygomandibular raphe during swallowing. Unlike the other syndromes described, trauma is not a common precipitating factor. Pain may be localized to the posterior-lateral pharyngeal wall using a cotton swab . Local anesthetic/steroid injections into the superior pharyngeal constrictor offer a 90% success rate . The pain of glossopharyngeal neuralgia is sharp, a few seconds in duration, and most commonly localized to the tonsillar fossa. Swallowing is a common trigger. Treatment is initially pain control with anticonvulsants and, if refractory, nerve transaction. The site of intervention is dependent on whether the symptoms are primarily oropharyngeal or otologic in nature .

Superior laryngeal neuralgia is an uncommon cause of pain in the neck that warrants prompt treatment. Because of its uncommon occurrence, it is often not considered until extensive evaluation has been undertaken. Pressure over the area where the superior laryngeal nerve penetrates the thyrohyoid membrane is strongly supportive of the diagnosis and should be sought early in the diagnostic evaluation when visualization of the larynx does not suggest any etiology for the persistent pain. Anterior neck pain diagnoses need not be a diagnosis of exclusion. In fact, a strong case can be made for the use of diagnostic palpation and selective nerve blocks to first identify and confirm the diagnosis of many anterior cervical pain syndromes when the etiology of the pain is not apparent when the initial head and neck examination is negative before a more comprehensive evaluation including imaging studies is obtained.