Eagle’s syndrome, also known as stylohyoid syndrome, styloid syndrome, is caused by an elongated or disfigured styloid process, or a calcified stylohyoid ligament (Egierska D et al 2021). The abnormality or elongation leads to orofacial and cervical pain that are often triggered by neck movements. An elongated styloid process is incidental in about 4% of the general population, but only about 4% of these present with symptoms that are attributable to elongation of styloid (Pinheiro TG et al 2013).
It usually presents with the complaint of dull and throbbing pain that aggravates with swallowing and can be replicated by palpation of the tonsillar fossa. Insertion tendonitis can mimic Eagle’s syndrome. Other symptoms may include the foreign body sensation in the pharynx (55%), dysphagia, painful deglutition, ear pain, headache, pain on cervical rotation, pain on chewing, facial pain, and tinnitus. It typically presents to ear, nose, and throat (ENT) specialists due to the location of presenting symptoms. Orofacial pain clinics get these patients due to mixed symptoms. “Classic Eagle syndrome” is usually encountered in patients after pharyngeal trauma or tonsillectomy. It is characterized by pain located in the fifth, seventh, eighth, ninth, and tenth cranial nerves area. (Bokhari MR et al 2022)
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Several possible mechanisms for the pathogenesis of pain in Eagle syndrome have been proposed. The first considers that the elongated styloid process causes compression of cranial nerves, most commonly the glossopharyngeal nerve.
- Then there is a possibility of compression of the internal carotid artery by the styloid process, which can lead to transient ischemic attacks.
- Compression of the sympathetic nerves running along the artery, leading to multiple symptoms is another cause.
- Or it can be due to reactive hyperplasia which associates the elongation with either overgrowth of the styloid process or ossification of the stylohyoid ligament complex due to trauma.
The pain in Eagle Syndrome often resembles glossopharyngeal neuralgia but is dull and more constant, however, we should understand that cases with sharp intermittent pain along the path of the glossopharyngeal nerve have also been reported. Other differentials may include: (Bokhari MR et al 2022)
- Cervical arthritis
- Cervical mass
- Faulty dental prostheses
- Esophageal diverticula
- Salivary gland disease
- Temporal arteritis
- Trigeminal neuralgia
Let’s think outside the box:
Pain in the throat that may radiate to the neck, ear, or face is often nonspecific and can be as a result of several other conditions, such as, malignancies, various neuralgias, cerebral venous thrombosis of unknow etiology, stroke and temporomandibular joint dysfunction. These should be considered before considering Eagle’s syndrome. (Zhang, F. et al 2019)
How to diagnose?
Good history is the stepping stone for diagnosing. An elongated styloid process can be felt by intraoral palpation. A 3-D CT can show precise measurements of the length of the styloid process and the ossified stylohyoid ligament. The method to measure the length of styloid process is explained by Goldstein and Scopp (Prasad KC et al,2002). The normal length of the adult styloid is approximately 2.5 cm, greater than 3cm or 30 mm is considered elongated. (Gokce C 2008)
Conservative treatments include analgesics, antidepressant medications, anticonvulsants, trans pharyngeal steroid injection and lidocaine, nonsteroidal anti-inflammatory drugs. Surgical shortening of the styloid process either via an intraoral or external produces better long-term results. (Han MK et al 2013)
Let’s see some cases from the literature: (Searle E et al 2021)
- A 42-year-old female presented with chief complaint of a 6-year history of parietal/facial pain, with hyperacusis, and some intra-oral symptoms. There was no history of trauma or infection; she had regular dental check-ups and no pathology was found.
- The patient had suffered 6 years of disabling pain until this condition was correctly diagnosed and treated. It started with face and scalp pain, swelling, and intolerance of loud noises. After no response to antibiotics, the patient was referred to a neurologist who diagnosed chronic headache with migraine features.”
Both these patients had Eagles syndrome. Such patients generally have a history of chronic pain. Significant knowledge of this disease is crucial to deliver adequate treatment. The importance of diagnosing this uncommon disease should be emphasized, given that correct clinical-surgical treatment is frequently delayed. The diagnosis of Eagle’s syndrome is clinical as well as radiographic, and the definitive treatment in cases of refractory pain is surgical.
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- Egierska D, Perszke M, Kurianowicz I. Eagle’s syndrome. Pol Merkur Lekarski. 2021 Dec 16;49(294):458-460. PMID: 34919094.
- Bokhari MR, Graham C, Mohseni M. Eagle Syndrome. 2022 Jul 10. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 28613540.
- Pinheiro TG, Soares VY, Ferreira DB, Raymundo IT, Nascimento LA, Oliveira CA. Eagle’s Syndrome. Int Arch Otorhinolaryngol. 2013 Jul;17(3):347-50. doi: 10.7162/S1809-977720130003000017. PMID:
25992033; PMCID: PMC4423332.
- Searle E, Searle A. An overview of Eagle’s syndrome. Br J Pain. 2021 Nov;15(4):388-392. doi: 10.1177/2049463720969741. Epub 2020 Nov 4. PMID: 34840786; PMCID: PMC8611296.
- Scheller, Konstanze & Eckert, Alexander & Scheller, Christian (2013). Transoral, retromolar, para-tonsillar approach to the styloid process in 6 patients with Eagle’s syndrome. Medicina oral, patologia oral y cirugia bucal. 19. 10.4317/medoral.18749.
- Prasad KC, Kamath MP, Reddy KJ, Raju K, Agarwal S. Elongated styloid process (Eagle’s syndrome): a clinical study. J Oral Maxillofac Surg. 2002 Feb;60(2):171-5. doi: 10.1053/joms.2002.29814. PMID: 11815916.
- Han MK, Kim DW, Yang JY. Non Surgical Treatment of Eagle’s Syndrome – A Case Report -. Korean J Pain. 2013 Apr;26(2):169-72. doi: 10.3344/kjp.2013.26.2.169. Epub 2013 Apr 3. PMID: 23614080;
- Zhang, F., Zhou, H., Guo, Z., & Yang, Y. (2019). Eagle Syndrome as a Cause of Cerebral Venous Sinus Thrombosis. Canadian Journal of Neurological Sciences, 46(3), 344-345. doi:10.1017/cjn.2019.17