Clinical diagnosis
Case 177
【Progress】
He came back to the local clinic with CT findings our radiologist interpreted. Regrettably, we had no information about his progress thereafter.
【Discussion】
Styloid process is a cylindrical bone extending from the lower surface of the petrous portion of the temporal bone. Its length is approximately 2.5 cm (1-3). Elongated styloid process is defined when its length is more than 3 cm (1). Three muscles and two ligaments arise from styloid process; styloglossus, stylopharyngeus and stylohyoid muscles: stylomandibular and stylohyoid ligaments (4, 5). The styloglossus and stylohyoid are innovated by XII nerve. The styloglossus makes the tip of tongue retract and/or elevate. The stylohyoid makes hyoid bone elevate during swallowing. The stylopharyngeus is innovated by IX nerve. It makes larynx elevate and pharynx dilate during swallowing. The stilomandibular and stylohyoid ligaments also facilitate in the movement of mandible and hyoid bone during swallowing. Then, styloid bone helps swallowing indirectly by supporting these muscles and ligaments.
Styloid process forwards from the inferior part of petrous temporal bone towards tonsil fossa. Tonsil fossa exists between palatoglossal arch and palatopharyngeal arch. Styloid process runs below the ear and between external carotid artery and internal carotid artery. There are cranial nerves of IX, X, XI and XII running around carotid arteries. When styloid process extends, it may impinge on these nerves.
Eagle syndrome is a condition of otalgia, face pain, throat pain, foreign body sensation like bone stuck without infection (5–8). Pain on swallowing and foreign body sensation are the most common symptoms of these. The symptoms are typically caused by elongated styloid process. Eagle described this syndrome in 1937 and categorized in two forms; the first form is attributed to the scar following surgical tonsillectomy: the second form is caused by styloid process impinging on nerve and carotid artery (5). At present, the mechanism of Eagle syndrome is as follows; elongated styloid process impinge on cranial nerves of glossopharyngeal nerve and/or trigeminal branch nerve; elongated styloid process impinges on carotid artery followed by irritation of sympathetic nerves; elongated styloid process directly attach to oropharyngeal mucosa; fracture of styloid process or calcified stylohyoid ligament; scar in post tonsillectomy periods (1,6－8). The diagnosis is based on medical history and physical examination. Intraoral palpation can touch styloid process in tonsillar fossa when styloid process is elongated (1, 8). Further compression of tonsillar fossa by the second finger causes pain radiate to not only throat but also to ear, face and head (1, 8). These findings indicate Eagle syndrome most likely.
In our case, his main symptom is pain of throat and lower neck. Although it was not clear that he previously underwent surgical tonsillectomy, face CT showed elongated styloid process of 5.1cm in length which reached the surface of tonsillar surface. CT is the golden standard modality for finding out elongated styloid process.
【Summary】
We present an eighteen-year-old male suffering from pain of throat and lower neck in the right side. Laboratory test revealed no inflammation. Face CT showed elongated styloid process extends to the tonsillar surface. It should be in borne in mind that styloid process is the origin of three muscles (styloglossus, stylopharyngeus and stylohyoid muscles) and two ligaments (stylomandibular and stylohyoid ligaments) which work together during smooth swallowing. Then, styloid bone helps swallowing indirectly by supporting these muscles and ligaments. Eagle syndrome is a condition of otalgia, face pain, throat pain, foreign body sensation like bone stuck. The mechanism of Eagle syndrome is as follows: the elongated styloid process impinges on cranial nerve of IX, X, XI and XII or impinges on carotid artery irritating sympathetic nerve nearby or impinges on the surface of tonsillar fossa.
【References】
1.Piagkou M, et al. Eagle's syndrome: a review of the literature. Clin Anat. 2009 Jul;22(5):545-58.
2.Vadgaonkar R, et al. Morphological study of styloid process of the temporal bone and its clinical implications. Anat Cell Biol. 2015 Sep;48(3):195-200.
3.Patil S, et al. Morphometric study of the styloid process of temporal bone. J Clin Diagn Res. 2014 Sep;8(9):AC04-6.
4.Laccourreye O, et al. Styloglossus muscle: a critical landmark in head and neck oncology. Eur Ann Otorhinolaryngol Head Neck Dis. 2018 Dec;135(6):421-425.
5.Eagle W. Elongated styloid process: report of two cases. Arch Otolaryngol. 1937;25:584–586.
6.Das S, et al. Anomalous styloid process and its clinical implications. Bratisl Lek Listy. 2008;109(1):31-3. [PubMed]
7.Ghosh LM, et al. The syndrome of elongated styloid process. Auris Nasus Larynx. 1999 Apr;26(2):169-75.
8.Casale M, et al. Atypical chronic head and neck pain: don't forget Eagle's syndrome. Eur Rev Med Pharmacol Sci. 2008 Mar-Apr;12(2):131-3.
2020.1.15