Eagle Syndrome

What is Eagle Syndrome?

Eagle syndrome was coined by Watt W. Eagle, a specialist in ear, nose, and throat disorders at Duke University, who reported the first instances in 1937. It’s a rare ailment caused by an unusually long or misshapen bone in the throat, called the styloid process, which affects the working of surrounding structures. This results in facial and neck pain, typically worsened by moving the neck. Some people also refer to Eagle syndrome as stylohyoid syndrome, styloid syndrome, or styloid-carotid artery syndrome.

What Causes Eagle Syndrome?

The root causes of Eagle syndrome are still under discussion. Dr. Watt Eagle initially suggested that surgical damage (like having your tonsils removed) or long-term local irritation could lead to inflammation or damage to the styloid process and its surrounding ligaments, causing an overly-active bone growth.

Later, in 1975, Lentini proposed another theory that leftover cartilage-like tissues could transform into bone during a traumatic or stressful event. Epifanio, in 1962, hinted that the bone growth in the styloid process might also be related to hormonal imbalances in women going through menopause, as these women also sometimes had bone growth in other ligaments within their bodies.

Gokce C et al. reported in 2008 that patients with advanced kidney disease who had abnormal levels of calcium, phosphorus, and vitamin D typically experienced misplaced bone growth. This could lead to the elongation of the styloid process, which then resulted in Eagle syndrome.

In 2015, Sekerci conducted a study using data from 542 patients and observed a potential connection between the presence of an arcuate foramen (a small opening in the skull) and an elongated styloid process via three-dimensional CT scans.

Risk Factors and Frequency for Eagle Syndrome

The styloid process, part of the skull, is typically about 2.5 cm long. Anything longer than this is usually considered abnormally long. Through studies conducted on 80 cadavers, the styloid process has been found to range in length from 1.52 to 4.77 cm. Interestingly, about 4% of the general population are found to possess an elongated styloid process, but only a fraction of these, around 4%, actually experience symptoms due to this elongation. So, in real terms, only around 0.16% of people have a symptomatic elongated styloid process. This condition is more common in females, with a ratio of 3 females to every male affected. Moreover, it typically presents in people who are over 30 years old and usually affects both sides of the skull, even though there are cases where only one side is affected.

The normal length of the styloid process is about 2.5 cm.
Styloid processes longer than 2.5 cm are considered abnormally long.
In a study, the length was found to vary between 1.52 to 4.77 cm.
About 4% of people have an elongated styloid process, yet only 4% of these people experience symptoms.
Thus, the real occurrence of symptomatic elongated styloid process is about 0.16%.
The condition is more common in females, with a 3:1 female-to-male ratio.
It’s typically found in people over 30 years of age.
Usually, both sides of the skull are affected, but there are cases where only one side is affected.

Signs and Symptoms of Eagle Syndrome

Eagle syndrome is a condition often seen in people in their 30s or 40s. It seems to affect women more frequently and symptoms can vary from mild discomfort to acute pain. There are two categories of symptoms, each related to a different cause of the syndrome.

The first category, known as “classic Eagle syndrome,” is usually found in patients who have suffered trauma to the throat or have had their tonsils removed. The root of the pain is thought to come from tension or pressure on certain cranial nerves during the healing process. Although this can result in pain attacks similar to glossopharyngeal neuralgia, most patients experience a constant, dull throat pain. This pain is concentrated on one side of the throat and can be referred to the ear and is often worsened by turning the head. Other symptoms within this category can include:

Feeling like there’s something stuck in the throat
Difficulty swallowing
Painful swallowing
Ear pain
Headaches
Pain in the areas supplied by the external and internal carotid arteries
Pain when turning the neck or chewing
Facial pain
Ringing in the ears

A bulge may sometimes be felt in the throat, which can make the symptoms worse. Usually, these symptoms occur on one side, but there may be instances where both sides are afflicted.

The second category of symptoms stems from a condition called vascular Eagle syndrome or stylocarotid syndrome. This happens when the styloid process, a small bone in the skull, presses against an artery in the neck, leading to pain. Turning the head could potentially compress the artery further and cause more pain. Other symptoms can include:

Transient Ischemic Attacks (mini-strokes)
Vertigo (a sense of spinning)
Passing out

In this case, there’s usually no history of tonsil removal. Depending on which artery is irritated, the pain experienced can either be referred to above the eye socket or below the eye socket.

Testing for Eagle Syndrome

Eagle syndrome is diagnosed mainly through a detailed medical history and physical exam. People with this condition often have throat pain that spreads to their neck, ear, or face. Since this kind of pain can be caused by numerous different conditions, such as certain cancers, nerve pain, or jaw joint dysfunction, these other ailments need to be ruled out first.

Eagle syndrome typically shows up as a constant, throbbing pain because of a longer than usual bone called the styloid process. This pain often gets worse when a person swallows and can often be duplicated by pressing on a certain area in the back of the throat. Another condition, called insertion tendonitis, might seem similar, but it usually causes tenderness over a different part of the throat.

A health professional can check for a long or “elongated” styloid process by using their index finger to apply gentle pressure in the back of the throat. If this causes pain that spreads to the ear, face, or head, it is likely that the person has an elongated styloid process.

Typically, a normal-length styloid process can’t be felt through this method. If someone does have an elongated styloid process, this can then be confirmed through imaging techniques. Of these, CT scans are the most accurate. These produce 3D pictures of the neck, which can accurately measure the length of the bone and associated ligament.

In adults, the normal length of the styloid is roughly an inch (or 2.5 cm). If it’s longer than this, such as over 1.2 inches (or 3 cm), it’s considered to be elongated. Using this measurement, about 4% of people have an elongated styloid, but only a small percentage of these actually have symptoms.

Different imaging techniques like OPG or CT can be used to look at the styloid process and the ligament around it. If there is concern that the long bone is pressing on blood vessels and potentially causing a lack of blood flow and symptoms, then an angiogram (an imaging technique that uses X-rays to view the body’s blood vessels) should be performed. The person’s head would be positioned in a way that brings on the symptoms to best show any narrowing of the carotid artery (a major blood vessel in the neck).

Treatment Options for Eagle Syndrome

The Eagle syndrome, also known as the elongated styloid process syndrome, can be treated in several ways, either with non-invasive methods or by surgery. Non-invasive, or conservative treatments, include painkillers, anti-depressants, drugs used for controlling seizures, injections of steroids and a local anesthetic called lidocaine, a sedative drug known as diazepam, anti-inflammatory drugs, and applying heat to the affected area. However, trying to manually break the elongated styloid process is usually not effective and could accidentally damage nearby important structures like nerves and blood vessels.

If these medications aren’t effective, surgery may be considered. The best results are often achieved by shortening the styloid process surgically. This can be done in two ways — through the mouth (intraoral approach), or through an external incision on the throat (external approach).

Operating through the mouth has its advantages. It’s simpler, takes less time, can be done under local anesthesia, and doesn’t leave a visible external scar. However, it also has its drawbacks. It can be hard to reach the area, especially if there’s bleeding or deep neck infections. It may also be difficult to see the area being worked on, particularly in patients who can’t open their mouths very wide. There’s also a risk of accidentally injuring major nerves and blood vessels, and problems with speech and swallowing due to swelling after the operation.

Meanwhile, the external approach has its own advantages and disadvantages. The biggest advantage is that it provides a better view of the styloid process and nearby structures. This method also allows for the removal of a partially hardened stylohyoid ligament. However, it takes more time, has a risk of injury to the facial nerve and its branches, leaves a notable scar on the neck, and requires longer recovery time.

It’s important to note, though, that the decision between the two surgical approaches would likely depend on the surgeon’s preferred practice. It’s also worth mentioning that in about 20% of patients, surgery might not eradicate the condition completely.

The occurrence of certain health problems may cause similar symptoms and make diagnosis challenging. The conditions could include:

Arthritis in the neck (cervical arthritis)
A lump (mass) in the neck area
Incorrectly fitted dental implants
Migraine (a type of severe headache)
Outpouching in the food pipe (esophageal diverticula)
Ear infection (otitis)
Potential tumors (abnormal lump or growth of cells)
Problems with the salivary gland
Inflammation of blood vessels in the temples (temporal arteritis)
A nerve-related facial pain condition (trigeminal neuralgia)

It is essential for the doctor to thoroughly examine these potential causes and carry out suitable tests to give an accurate diagnosis.

Frequently asked questions

Eagle Syndrome is a rare ailment caused by an unusually long or misshapen bone in the throat called the styloid process, which affects the working of surrounding structures. This results in facial and neck pain, typically worsened by moving the neck.

The real occurrence of symptomatic elongated styloid process is about 0.16%.

Signs and symptoms of Eagle Syndrome can vary depending on the category of the syndrome. In the first category, known as "classic Eagle syndrome," symptoms can include feeling like there's something stuck in the throat, difficulty swallowing, painful swallowing, ear pain, headaches, pain in the areas supplied by the external and internal carotid arteries, pain when turning the neck or chewing, facial pain, and ringing in the ears. Patients with classic Eagle syndrome may also experience a constant, dull throat pain that is concentrated on one side of the throat and can be referred to the ear. In some cases, a bulge may be felt in the throat, which can worsen the symptoms. In the second category, known as vascular Eagle syndrome or stylocarotid syndrome, symptoms can include transient ischemic attacks (mini-strokes), vertigo (a sense of spinning), and passing out. Unlike the first category, there is usually no history of tonsil removal in patients with vascular Eagle syndrome. Depending on which artery is irritated, the pain experienced can either be referred to above the eye socket or below the eye socket. It is important to note that Eagle syndrome is more commonly seen in women in their 30s or 40s.

The root causes of Eagle syndrome are still under discussion, but they can include surgical damage or long-term local irritation, leftover cartilage-like tissues transforming into bone, hormonal imbalances in women going through menopause, abnormal levels of calcium, phosphorus, and vitamin D in patients with advanced kidney disease, and the presence of an arcuate foramen.

The doctor needs to rule out the following conditions when diagnosing Eagle Syndrome: - Arthritis in the neck (cervical arthritis) - A lump (mass) in the neck area - Incorrectly fitted dental implants - Migraine (a type of severe headache) - Outpouching in the food pipe (esophageal diverticula) - Ear infection (otitis) - Potential tumors (abnormal lump or growth of cells) - Problems with the salivary gland - Inflammation of blood vessels in the temples (temporal arteritis) - A nerve-related facial pain condition (trigeminal neuralgia)

The types of tests that are needed for Eagle Syndrome include: 1. Medical history and physical exam to assess symptoms and rule out other conditions. 2. Index finger pressure test in the back of the throat to check for pain that spreads to the ear, face, or head. 3. Imaging techniques like CT scans to accurately measure the length of the styloid process and associated ligament. 4. Angiogram to view the blood vessels and check for any narrowing of the carotid artery. 5. Other imaging techniques like OPG (orthopantomogram) may be used to look at the styloid process and ligament around it. It's important to note that the specific tests ordered may vary depending on the individual case and the healthcare provider's judgment.

Eagle Syndrome can be treated through non-invasive methods or by surgery. Non-invasive treatments include painkillers, anti-depressants, drugs for controlling seizures, injections of steroids and lidocaine, diazepam, anti-inflammatory drugs, and applying heat to the affected area. However, manually breaking the elongated styloid process is usually not effective and could cause damage to nearby nerves and blood vessels. If these treatments are not effective, surgery may be considered. The best results are often achieved by surgically shortening the styloid process, which can be done through the mouth or through an external incision on the throat. Each approach has its own advantages and disadvantages, and the decision between the two would depend on the surgeon's preferred practice.

When treating Eagle Syndrome, there can be side effects associated with the different treatment methods. The side effects can vary depending on the specific treatment used. Here are some potential side effects: - Non-invasive treatments: - Painkillers: potential side effects include drowsiness, dizziness, upset stomach, and constipation. - Anti-depressants: potential side effects include nausea, drowsiness, weight gain, and sexual dysfunction. - Drugs used for controlling seizures: potential side effects include dizziness, drowsiness, and coordination problems. - Injections of steroids and lidocaine: potential side effects include temporary pain at the injection site, allergic reactions, and infection. - Diazepam (sedative drug): potential side effects include drowsiness, dizziness, and confusion. - Anti-inflammatory drugs: potential side effects include stomach irritation, ulcers, and increased risk of bleeding. - Applying heat to the affected area: potential side effects are minimal. - Surgery: - Intraoral approach: potential side effects include difficulty reaching the area, risk of injuring nerves and blood vessels, and problems with speech and swallowing due to swelling. - External approach: potential side effects include longer recovery time, risk of injury to the facial nerve and its branches, and a notable scar on the neck. It's important to note that these side effects may not occur in every patient, and the decision to pursue a specific treatment should be made in consultation with a healthcare professional.

The prognosis for Eagle Syndrome is generally good. With proper diagnosis and treatment, symptoms can be managed and controlled. Surgical intervention may be necessary in severe cases, but most individuals with Eagle Syndrome can find relief through conservative measures such as pain management and lifestyle modifications.

An ear, nose, and throat (ENT) specialist or an otolaryngologist.

Ear Nose and Throat