Introduction
The association of an elongated styloid process with pharyngeal and cervical pain is known as Eagle syndrome and was first described in 1937. Eagle syndrome is characterized as a dull, aching pain localized to one or both sides of the throat with referred otalgia. Some pain may occur on swallowing or protrusion of the tongue or on rotating the head, and some patients complain of a foreign body sensation in their throat.
The etiology of styloid elongation and ossification of the stylohyoid ligament complex is unclear. Elongation of the styloid process occurs in approximately 4% of the population, but only a small percentage of patients with this finding are symptomatic (<10%). Eagle syndrome occurs more frequently in women than in men and is usually found in patients older than 30 years. Symptoms are often unilateral despite bilateral elongation.
The pathophysiology of Eagle syndrome is generally thought to be secondary to compression by the abnormal styloid of vascular and nervous structures, in particular the glossopharyngeal nerve and carotid artery. “Classic Eagle syndrome” is associated with tonsillectomy or pharyngeal trauma. “Stylocarotid syndrome” is characterized by compression of the carotid artery by an elongated styloid process that deviates medially.
The differential diagnosis of this condition includes cranial nerve neuralgias (e.g., trigeminal, glossopharyngeal, sphenopalatine, superior laryngeal, and primary geniculate neuralgias), temporomandibular joint disease, chronic pharyngotonsillitis, unerupted or impacted molar teeth, cervical osteoarthritis, and tumors in the oropharynx.
Key Operative Learning Points
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The diagnosis of Eagle syndrome is a diagnosis of exclusion.
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A transoral approach is preferred if the styloid process is palpable intraorally.
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A transcervical approach is preferred if there is complete calcification of the stylohyoid ligament.
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Intraoral visualization can be enhanced with endoscopy (nasal endoscope).
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Injury to the carotid artery and facial nerve can be avoided by maintaining the plane of dissection on the styloid process.
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A bone rongeur is used to resect the styloid process close to its origin at the skull base.
Preoperative Period
History
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Unilateral (or bilateral) pain in the throat or neck
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Dull, nagging pain that may be exacerbated by swallowing or turning the head
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Lack of other symptoms associated with cranial nerve deficits
Physical Examination
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Inspection of the oral cavity and pharynx (including nasopharynx and hypopharynx) is normal with no mucosal lesions.
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Palpation of the tonsillar fossa reveals a hard thin mass in the area of the tonsillar fossa and reproduces the patient’s symptoms.
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Cranial nerve function is intact.
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Infiltration of lidocaine in the region of the tonsillar fossa may abolish the symptoms.
Imaging
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Plain film radiograph. Individual styloid processes can be difficult to view due to superimposition of the surrounding structures.
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Panorex. Both styloid processes can be seen in detail.
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Computed tomography (CT) scan. CT provides excellent visualization of bony detail. If performed with contrast, CT also screens for other pathology in the differential diagnosis. A CT angiogram demonstrates the relationship of the carotid artery to the styloid process.
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Three-dimensional (3D) reconstruction of CT scan ( Fig. 38.1 ). Superb visualization of the styloid processes and calcified stylohyoid ligaments and their relationship to other structures is provided by a 3D reconstruction. This study is helpful in planning the surgical approach.
Fig. 38.1
Three-dimensional computed tomography of patient with Eagle syndrome demonstrates elongated styloid processes (right greater than left). Medial angulation (asterisks) may also be associated with Eagle syndrome.
Reprinted with permission from: Kent DT, Rath TJ, Snyderman CH. Conventional and 3-dimensional computerized tomography in Eagle’s syndrome, glossopharyngeal neuralgia, and asymptomatic controls. Otolaryngol Head Neck Surg 2015;153(1):41–47.
Indications
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Unilateral or bilateral throat or neck pain that does not respond to conservative measures (analgesics)
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Palpable styloid process with reproduction of symptoms
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Infiltration of lidocaine abolishes symptoms
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Absence of other pathology
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Radiographic evidence of enlarged or angulated styloid process
Contraindications
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Limited opening of the mouth
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Complete calcification of the stylohyoid ligament
Preoperative Preparation
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Preoperative imaging with CT scan
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Discussion with the patient that removal of the elongated styloid process does not always abolish the pain. There are other causes of these symptoms.
Operative Period
Anesthesia
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General anesthesia with muscle relaxants.
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Oral RAE tube to prevent kinking; positioned in the midline to accommodate retractors.
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Nasotracheal intubation through the contralateral nasal cavity is an excellent alternative to keep the tube out of the surgical field.
Positioning
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Supine with head and neck extended (Rose position)
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Reverse Trendelenburg position (15 degrees) to decrease bleeding
Perioperative Antibiotic Prophylaxis
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Penicillin
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If the patient is allergic to penicillins, use clindamycin.
Monitoring
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Facial nerve monitoring is optional.
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Navigation system. Image-based navigation (CT angiogram) can be helpful to localize the styloid process and the adjacent internal carotid artery.
Instruments and Equipment to Have Available
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McIvor or Dingman mouth retractor
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Zero-degree Hopkins rod endoscope (optional)
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Extended needle tip electrocautery
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Bipolar electrocautery
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Yankauer tonsil suction
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Cottle elevator
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Hurd or malleable retractors
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Kerrison bone rongeur (2 to 3 mm)
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“Needle-nose” bone rongeur (straight fine-tip rongeur)
Key Anatomic Landmarks
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The styloid process is anterior to the stylomastoid foramen.
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The stylopharyngeus, stylohyoid, and styloglossus muscles all take their origin from the styloid process of the temporal bone.
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The facial nerve is posterior and lateral to the styloid process.
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The internal carotid artery is medial to the styloid process.
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An elongated styloid process is palpable in the tonsillar fossa and posterior floor of mouth.
Prerequisite Skills
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Tonsillectomy (see Chapter 192 ).
Operative Risks
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Injury to the facial nerve. Excessive use of electrocautery or aggressive resection of the styloid process to its attachment at the skull base risks injury to the facial nerve.
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Injury to the carotid artery. Dissection of the soft tissues medial to the styloid process risks injury to the internal carotid artery.
Surgical Technique
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The mouth retractor is placed with the tongue and the endotracheal tube in the midline. The tongue can be placed slightly to the contralateral side to provide greater access to the posterior floor of mouth.
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If tonsils are present, a tonsillectomy is performed on the surgical side.
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The tonsillar fossa is palpated to identify the elongated styloid process. The surrounding tissues are infiltrated with several milliliters of 0.5% xylocaine with 1:200,000 epinephrine.
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Using the suction tip or Hurd retractors, the soft tissues are pushed laterally and posteriorly to tent the tissues over the styloid process ( Fig. 38.2 ). The constrictor muscle is then incised with electrocautery down to the styloid process.
