Eagle syndrome

The slender styloid process (Gk. stylus = pillar, instrument for writing (incidentally the root of the word "style")) is seldom seen on most cadaveric skulls since it frequently snaps during dissection.  Technically part of the temporal bone (a.k.a. the "temporal stylus"), the styloid is a point of attachment for multiple small muscles... basically any muscle that originates with the prefix "stylo-" (stylohyoid m., styloglossus m., stylopharyngeal m.).  Just posterior to the styloid process is the stylomastoid foramen, which transmits the exiting CN VII and a small stylomastoid artery.

The skull base ala CT axial views.  The temporal styloid process is circled in red.

Fractures of the styloid have been reported as case reports, but the main contribution of the styloid process to pathology is through Eagle's syndrome in which an elongated styloid process, or a calcified stylohyoid ligament causes chronic neck pain or globus sensation.  The styloid normally measures somewhere around 2-3 cm and in the proper setting, an elongated styloid may contribute to localized pain.  Eagle syndrome can occur unilaterally or bilaterally and cause a variety of nonspecific symptoms including dysphagia, headache, pain on rotation of the neck, pain on extension of the tongue, or dysphonia.  Below is a lateral radiograph of Eagle's syndrome demonstrating a heavily ossified stylohyoid ligament, and beneath that, axial CT images of the same patient.

Heavily calcified structure extending from the skull base to the hyoid is compatible with a stylohyoid ligament calcification (Eagle Syndrome)

Axial CT images of the patient above demonstrate an ossified left stylohyoid ligament.  Compression and entrapment of adjacent structures is not too difficult to imagine with a ossified ligament this flagrant.

One source believes the ultimate source of pathology due to the elongation is entrapment of the glossopharyngeal (CN IX) nerve.


1. Prasad KC, Kamath MP, et al.  "Elongated Styloid Process (Eagle's Syndrome): A clinical study" Journal of Oral and Maxillofacial surgery. 60:2 (Feb 2002) pp. 171-175.
2. Murtagh RD, Caracciolo JT, Fernandez G. "CT Findings associated with Eagle's Syndrome" AJNR Am J Neuroradiol 22:1401–1402, August 2001
3. Slavin KV. "Eagle syndrome: entrapment of the glossopharyngeal nerve? Case report and review of the literature J Neurosurg 97:216–218, 2002