An elongated styloid process or calcified stylohyoid ligament is relatively uncommon in imaging studies, occurring in approximately 4% of the general population. However, only about 4% of people with these anatomical changes develop pain symptoms consistent with Eagle syndrome, or only about 0.16% of the general population. Symptomatic Eagle syndrome is therefore considered rare. The condition can occur at any age but is most frequently recognized in adults and is reported 3 times more often in women than men.

Eagle syndrome results from an abnormality of the styloid process or stylohyoid ligament. The styloid process is normally a 2.5 cm narrow projection of bone located beneath the ear. In some individuals, it becomes longer than usual (>3 cm) or develops an abnormal orientation that allows it to contact nearby structures. The stylohyoid ligament may also become partially or completely ossified, meaning that soft connective tissue is replaced by bone-like material.

The precise reason these changes occur is not always known, but some associations have been made: 

• In some cases, symptoms develop after trauma or surgery involving the throat or tonsils. Removal of the tonsils, known as tonsillectomy, has historically been associated with Eagle syndrome, possibly because scar tissue or changes in local anatomy cause an elongated or calcified structure to irritate nearby nerves

• Genetic predisposition

• Part of the normal aging process, as bones begin to calcify and ossify over time, which is the hardening or loss of flexibility in connective tissues in the body

• Chronic conditions affecting the jaw or neck, such as temporomandibular joint (TMJ) dysfunction, may exert excessive force on the ligaments and muscles attached to the styloid process. Over time, this strain may cause the bone to elongate.

Symptoms vary according to which structures are affected. The most common symptom is persistent or intermittent pain in the throat or upper neck that may radiate to the ear, jaw, face, or tongue. Patients may describe the pain as sharp, aching, or a foreign-body sensation, as though something is stuck in the throat. Pain may become worse with swallowing, chewing, turning the head, yawning, or opening the mouth.

Other symptoms can include difficulty or discomfort when swallowing, known as dysphagia; painful swallowing, known as odynophagia; facial or jaw pain; ear pain despite a normal ear examination; headache; ringing in the ears, known as tinnitus; and a sensation of pressure in the throat or neck. Some individuals can feel a hard structure in the tonsillar region when the area is examined.

A less common form, sometimes called the vascular form of Eagle syndrome, occurs when the elongated styloid process contacts or compresses the carotid artery or nearby blood vessels. The carotid arteries are major blood vessels that carry oxygen-rich blood from the heart toward the brain. Vascular compression can potentially cause dizziness, fainting, transient neurological symptoms, or, rarely, a stroke. Sudden neurological symptoms require emergency medical evaluation.

Diagnosis is based on the patient's symptoms, physical examination, and imaging studies. Because throat, jaw, ear, and facial pain can have many causes, clinicians generally consider other conditions before attributing symptoms to Eagle syndrome.

During an examination, a clinician may carefully palpate, or feel, the tonsillar region. Reproduction of the patient's characteristic pain when pressure is applied over the styloid process can support the diagnosis. However, an elongated styloid process alone does not establish that it is causing symptoms because many people have an elongated process without experiencing pain.

Computed tomography (CT) is the primary imaging technique used to evaluate Eagle syndrome. CT uses X-rays and computer processing to create detailed cross-sectional images of bones and other structures. Three-dimensional CT reconstruction can provide particularly useful information about the length, orientation, and relationship of the styloid process to surrounding structures.

A panoramic dental X-ray, also called a panoramic radiograph, may identify an elongated styloid process or calcified stylohyoid ligament, although it provides less anatomical detail than CT.

When vascular Eagle syndrome is suspected, CT angiography may be performed. CT angiography combines CT imaging with a contrast material injected into a blood vessel to visualize the arteries and determine whether the styloid process is contacting or compressing the carotid artery. Magnetic resonance angiography, which uses magnetic resonance imaging to visualize blood vessels, may also be considered in selected cases.

A local anesthetic injection may sometimes be used as a diagnostic aid. A local anesthetic is a medication that temporarily blocks pain signals. If injection around the styloid process temporarily eliminates the characteristic pain, this can provide additional evidence that the structure is responsible for the symptoms.

Treatment depends on the severity of symptoms and whether important nerves or blood vessels are affected. Individuals with an elongated styloid process but no symptoms generally do not require treatment.

For mild symptoms, conservative treatment may include pain-relieving medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), which reduce pain and inflammation. Other approaches may include physical therapy, local anesthetic injections, or corticosteroid injections. Corticosteroids are medications that reduce inflammation and may provide temporary symptom relief.

For persistent or severe symptoms, surgical removal or shortening of the elongated styloid process may be considered. This procedure is called styloidectomy. Surgery can be performed through an incision inside the mouth, known as the transoral approach, or through an incision in the neck, known as the external approach. The choice depends on the anatomy, surgeon preference, and whether vascular structures need to be carefully exposed. Surgery is generally intended to relieve pressure or irritation of nearby structures.

The prognosis for Eagle syndrome is generally favorable when the condition is correctly identified and appropriately treated. Some individuals have mild symptoms that can be managed with conservative treatment, while others have persistent pain that requires surgery. Surgical treatment can provide substantial or complete relief for many symptomatic patients, although symptoms can occasionally persist or recur.

The presence of an elongated styloid process does not necessarily indicate a serious disease because many people with this anatomical variation never develop symptoms. Vascular involvement is uncommon but can carry more serious risks because compression or injury of a carotid artery can potentially impair blood flow to the brain. Individuals experiencing sudden weakness, numbness, difficulty speaking, vision loss, severe dizziness, or other signs suggestive of a stroke should seek emergency medical attention.

1. Cleveland Clinic - Eagle syndrome  

2. Saccomanno S, Greco F, DE Corso E, Lucidi D, Deli R, D'Addona A, Paludetti G. Eagle's Syndrome, from clinical presentation to diagnosis and surgical treatment: a case report. Acta Otorhinolaryngol Ital. 2018 Apr;38(2):166-169. doi: 10.14639/0392-100X-1479. PMID: 29967562; PMCID: PMC6028820

3. https://ostrowonline.usc.edu/eagles-syndrome/

4. Regenex - Eagle syndrome 

5. Egierska D, Perszke M, Kurianowicz I. Eagle’s syndrome. Pol Merkur Lekarski. 2021 Dec 16;49(294):458-460. PMID: 34919094.