Review ArticleEagle syndrome: A comprehensive review
Introduction
Eagle Syndrome is a rare and poorly understood clinical condition that presents with a myriad of symptoms that typically include pain in the anterolateral neck. These symptoms are associated with an abnormal styloid process. Fig. 1 shows a schematic of normal anatomy along with an elongated styloid process. Eagle initially described a pain syndrome associated with an elongated styloid process in 1937 as “stylalgia” [1]. Eagle subsequently expanded on his initial descriptions [2], [3], [4], [5], [6]. Historically stylohyoid pain syndromes have been delineated based upon their etiology, i.e. acquired versus congenital. Eagle syndrome proper has been described as a pain syndrome associated with an elongated styloid. The congenital variant, often described as stylohyoid syndrome has been described as a syndrome with pain and symptoms of carotid compression (presyncope, syncope, and even transient ischemic events) caused by an ossified stylohyoid ligament. Subsequent studies have expanded Eagle syndrome to include a myriad of symptoms beyond pain. Furthermore the literature has also blurred the demarcation between the acquired and congenital syndromes.
Eagle syndrome is an important clinical condition for the otolaryngologist to recognize. This is due to the variety of presentations, potentially serious complications, and the fact that Eagle syndrome is often amenable to treatment. In this paper we present an updated review of the literature regarding Eagle/stylohyoid syndrome and discuss current/emerging treatment modalities.
Section snippets
Methods
For this study we aimed to identify all full-text, peer-reviewed publications pertaining to Eagle Syndrome in otolaryngology or head and neck surgery. The searches were conducted in the Ovid MEDLINE, Google Scholar, PubMed, and NCBI databases there were no regional restrictions. However only English language results were reviewed. The following search terms were used: “Eagle Syndrome”, “styloid syndrome”, “stylocarotid syndrome”, “stylohyoid syndrome”, “styloid-carotid artery syndrome”, and
Background
Abnormalities in the stylohyoid complex were first identified in animals by Vesalius in 1543 [7]. The first description in humans was published by Marchetti in 1656 [8]. Watt Eagle first described the combination of pain associated with an abnormal stylohyoid complex in 1937 and later reported a case series of over 200 patients [1], [5]. Eagle found that about 4% of patients that have abnormalities with their stylohyoid complex have pain [5]. He described two different presentations the classic
Example case illustration
A 56-year old female presented to the clinic with a 2-year history of right-sided throat pain and globus sensation. The patient denied dysphagia, weight loss, or other associated symptoms. The patient had tried several courses of anti-inflammatory medication and antibiotics without sufficient relief. A complete head and neck examination including fiberoptic laryngoscopy was performed, and the only pertinent finding was pain in the right neck with deep palpation. Intraoral palpation of the right
Epidemiology
There have been many studies since the identification of Eagle Syndrome that have sought to determine the incidence and prevalence of this condition. The variability in determining the epidemiology of this condition is likely due to differences in the diagnostic criteria in radiologic imaging. Some have suggested that the accepted length of the normal styloid process is approximately 2.5 cm, with 3 cm regarded as the upper limit of normal [10], [11]. Radiologically, some studies have used
Embryology/pathophysiology/etiology
The development of the stylohyoid complex develops from the Reichert cartilage of the second branchial arch early on during the embryologic development. As development progresses the second branchial arch becomes four separate segments, the stylohyal, ceratohyal, hypohyal, and basihyal. The stylohyal develops with the tympanohyal to become the styloid process. Through ossification the stylohyal develops into the stylohyoid ligament, while the hypohyal develops into the minor horn of the hyoid
Clinical presentation
Eagle first described two syndromes associated with elongation/aberrant ossification of the stylo-hyoid apparatus. The first, classic Eagle syndrome was described as pain, dysphagia, and a foreign body sensation that presents immediately after tonsillectomy. Eagle also described stylocarotid sydrome in which an elongated styloid compresses the carotid artery and results in pain (parietal/periorbital), visual disturbances, and syncope [3], [4], [6].
Subsequent studies have documented that an
Diagnostic work up
The diagnosis begins with a history that raises the clinical suspicion for Eagle syndrome Physical exam coupled with the patient history can guide further work-up. Pharyngeal palpation, especially of the tonsil or within the tonsillar fossa can be diagnostic. Relief of symptoms upon infiltration of lidocaine into the anterior pillar and into the tonsillar fossa can be diagnostic for Eagle syndrome [16].
Imaging is another useful tool in both diagnosis and treatment of an elongated styloid. Plain
Conservative management
The management of Eagle syndrome is commonly divided into conservative methods of medical management or more definitive surgical treatment.
Basic medical therapy can be further divided into first-line analgesics such as NSAIDs and alternative management consisting of a combination of anticonvulsants, antidepressants, local injections and manipulation [38]. For patients who refuse surgery, Han et all report on a viable multi-drug approach with gabapentin, tianeptine, tramadol, and acetaminophen,
Conclusion
Eagle syndrome has a large variety of clinical presentations as evidenced by the multitude of nonspecific symptoms. As a result, it is important to understand the diagnostic workup, relevant imaging, and ultimate treatment options. With advances in medical management and surgical approaches to the styloid process, Eagle syndrome has become recognized more readily and has an established group of treatment options.
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