Definition: Eagle's syndrome is defined as secondary glossopharyngeal neuralgia due to elongated styloid process, resulting from abnormal stylohyoid chain ossification. The styloid chain consists of the styloid process, the stylohyoid ligament, and the lesser cornu of the hyoid bone
In his classic description Eagle described two clinical features caused by elongated styloid process. They are
1. The classical stylohyoid syndrome
2. Stylocarotid syndrome
Classical stylohyoid syndrome: According to Eagle almost invariable occurred after tonsillectomy. It presented with a dull ache in the lateral pharyngeal wall and ipsilateral ear. The pain classically starts during the first week following tonsillectomy. This will have to be differentiated from the classic post tonsillectomy neuralgia. Post tonsillectomy pain becomes progressively less during the first week following surgery, where as in classical stylohyoid syndrome the neuralgia remains at the same intensity level.
Stylocarotid syndrome: This syndrome develops spontaneously, and is associated with cervical pain, ocular and facial pain. This pain is caused due to irritation of the carotid artery. Cervical pain caused by this condition should be differentiated from that of carotidynia, which is associated with tenderness of neck over the carotid bifurcation. MRI scan of neck is diagnostic in carotidynia. These scans demonstrated abnormal enhancing tissue around the offending vessel. The resolution of symptoms was associated with the image returing to normal.
Classically the normal styloid process is about 1 inch long. It is generally accepted as elongated if the length exceeds 4 cms. Elongated styloid process can be unilateral or bilateral. Orothopantomograms are helpful in identifying this condition. It should be remembered that ony 4% of patients with elongated styloid process are symptomatic.
Most of the time the diagnosis of elongated styloid process is made on the operating table following tonsillectomy. It will be seen occupying the tonsillar fossa after removal of the tonsil tissue.
The elongated styloid process may suffer fracture following whiplash injury to neck.
Management: Surgical management of the elongated styloid process is the preferred management modality. It can be removed via intra oral approach.
X-ray skull lateral view showing elongated styloid process