Eagle syndrome

Eagle syndrome (also termed stylohyoid syndrome, styloid syndrome, stylalgia, styloid-stylohyoid syndrome, or styloid–carotid artery syndrome) is an uncommon condition commonly characterized but not limited to sudden, sharp nerve-like pain in the jaw bone and joint, back of the throat, and base of the tongue, triggered by swallowing, moving the jaw, or turning the neck. First described by American otorhinolaryngologist Watt Weems Eagle in 1937, the condition is caused by an elongated or misshapen styloid process (the slender, pointed piece of bone just below the ear) and/or calcification of the stylohyoid ligament, either of which interferes with the functioning of neighboring regions in the body, such as the glossopharyngeal nerve.

Signs and symptoms

Possible symptoms include:

Classic Eagle syndrome is present on only one side; however, it may rarely be present on both sides.

In vascular Eagle syndrome, the elongated styloid process comes in contact with the internal carotid artery below the skull. In these cases, turning the head can cause compression of the artery or a tear inside the blood vessel, which restricts blood flow and can potentially lead to a transient ischemic attack or stroke. Sometimes, compression of the internal jugular vein can also occur and might lead to increased intracranial pressure.

Cause

Eagle syndrome occurs due to elongation of the styloid process or calcification of the stylohyoid ligament, potentially compressing the nearby carotid artery or glossopharyngeal nerve. However, the cause of the elongation hasn't been known clearly. It could occur spontaneously or could arise since birth. Usually normal stylohyoid process is 2.5–3 cm in length, if the length is longer than 3 cm, it is classified as an elongated stylohyoid process.