Neurological picture. Elongated styloid process (Eagle's syndrome) as a cause of atypical craniocervical pain

Neurological phenotypes and treatment outcomes in Eagle syndrome: systematic review and meta-analysis

Background

Eagle syndrome is caused by an elongated styloid process affecting carotid arteries and cranial nerves. Pain, dysphagia, tinnitus, paresthesia (classic subtype), and neurovascular events (vascular subtype) may be triggered by head movements or arise spontaneously. However, Eagle syndrome remains underappreciated in the neurological community. We aimed to determine the most common neurological and non-neurological clinical presentations in patients with Eagle syndrome and to assess the clinical outcome post-surgical resection in comparison to non-surgical therapies.

Methodology

We conducted a systematic review of patient-level data on adults with Eagle syndrome, following PRISMA guidelines. We extracted data on demographics, presenting symptoms, neurological deficits, radiological findings, and treatments, including outcomes and complications, from studies in multiple indexing databases published between 2000 and 2023. The study protocol is registered with PROSPERO.

Results

In total, 285 studies met inclusion criteria, including 497 patients with Eagle syndrome (mean age 47.3 years; 49.8% female). Classical Eagle (370 patients, 74.5%) was more frequent than vascular Eagle syndrome (117 patients, 23.5%, p < 0.0001). Six patients (1.2%) presented with both variants and the subvariant for four patients (0.8%) was unknown. There was a male preponderance (70.1% male) in the vascular subtype. A history of tonsillectomy was more frequent in classic (48/153 cases) than in vascular (2/33 cases) Eagle syndrome (Odds Ratio 5.2, 95% CI [1.2-22.4]; p = 0.028). By contrast, cervical movements as trigger factors were more prevalent in vascular (12/33 cases) than in classic (7/153 cases) Eagle syndrome (Odds Ratio 7.95, 95% CI [2.9-21.7]; p = 0.0001). Headache and Horner syndrome were more frequent in vascular Eagle syndrome and dysphagia and neck pain more prominent in classic Eagle syndrome (all p < 0.01). Surgically treated patients achieved overall better outcomes than medically treated ones: Eighty-one (65.9%) of 123 medically treated patients experienced improvement or complete resolution, while the same applied to 313 (97.8%) of 320 surgical patients (Odds Ratio 1.49, 95% CI [1.1-2.0]; p = 0.016).

Conclusions

Eagle syndrome is underdiagnosed with potentially serious neurovascular complications, including ischemic stroke. Surgical treatment achieves better outcomes than conservative management. Although traditionally the domain of otorhinolaryngologist, neurologist should include this syndrome in differential diagnostic considerations because of the varied neurological presentations that are amenable to effective treatment.

Eagle syndrome: toward a clinical delimitation

INTRODUCTION

Orofacial and cervical pain are a frequent reason for neurology consultations and may be due to multiple pathological processes. These include Eagle syndrome (ES), a very rare entity whose origin is attributed to calcification of the stylohyoid ligament or elongation of the temporal styloid process. We present a series of five patients diagnosed with ES.

METHODS

We describe the demographic and clinical characteristics and response to treatment of 5 patients who attended the headache units of 2 tertiary hospitals for symptoms compatible with Eagle syndrome.

RESULTS

The patients were 3 men and 2 women aged between 24 and 51, presenting dull, intense pain, predominantly in the inner ear and the ipsilateral tonsillar fossa. All patients had chronic, continuous pain in the temporal region, with exacerbations triggered by swallowing. Four patients had previously consulted several specialists at otorhinolaryngology departments; one had been prescribed antibiotics for suspected Eustachian tube inflammation. In all cases, the palpation of the tonsillar fossa was painful. Computed tomography scans revealed an elongation of the styloid process and/or calcification of the stylohyoid ligament in 3 patients. Four patients improved with neuromodulatory therapy (duloxetine, gabapentin, pregabalin) and only one required surgical excision of the styloid process.

CONCLUSIONS

Eagle syndrome is a rare and possibly underdiagnosed cause of craniofacial pain. We present 5 new cases that exemplify both the symptoms and the potential treatments of this entity.

Eagle syndrome: Toward a clinical delimitation

OBJECTIVES

Orofacial and cervical pain are a frequent reason for neurology consultations and may be due to multiple pathological processes. These include Eagle syndrome (ES), a very rare entity whose origin is attributed to calcification of the stylohyoid ligament or elongation of the temporal styloid process. We present a series of five patients diagnosed with ES.

MATERIAL AND METHODS

We describe the demographic and clinical characteristics and response to treatment of 5 patients who attended the headache units of two tertiary hospitals for symptoms compatible with Eagle syndrome.

RESULTS

The patients were three men and two women aged between 24 and 51, presenting dull, intense pain, predominantly in the inner ear and the ipsilateral tonsillar fossa. All patients had chronic, continuous pain in the temporal region, with exacerbations triggered by swallowing. Four patients had previously consulted several specialists at otorhinolaryngology departments; one had been prescribed antibiotics for suspected Eustachian tube inflammation. In all cases, the palpation of the tonsillar fossa was painful. Computed tomography scans revealed an elongation of the styloid process and/or calcification of the stylohyoid ligament in three patients. Four patients improved with neuromodulatory therapy (duloxetine, gabapentin, pregabalin) and only one required surgical excision of the styloid process.

CONCLUSIONS

Eagle syndrome is a rare and possibly underdiagnosed cause of craniofacial pain. We present five new cases that exemplify both the symptoms and the potential treatments of this entity.

Complete ossification of the stylohyoid chain as cause of Eagle's syndrome: a very rare case report

AIM

To report on a patient with Eagle's syndrome with a complete and very large ossification of the stylohyoid complex on the right side that to our best knowledge has never been published previously.

BACKGROUND

Eagle's syndrome is characterized by a set of symptoms that are caused by the irritation of the neurovascular and soft-tissues caused by an elongated styloid process or ossification of stylohyoid ligament.

CASE DESCRIPTION

Because of the high discomfort and pain degree as well as limitations of mandibular and head mobility and also the thickness of the ossifed stylohyoid chain, the patient was treated surgically by removing the hypertrophic segment.

CONCLUSION

These symptoms subsided completely after the surgical excision of the anomaly. The elongated styloid process on the left side was symptom free.

CLINICAL SIGNIFICANCE

Eagle's syndrome symptoms are not specific and can mimic those of other disorders, the syndrome must be included in the differential diagnosis of patients with pain in the orofacial, pharyngeal and cervical area.

Eagle's syndrome: embryology, anatomy, and clinical management

BACKGROUND

Eagle's syndrome refers to a rare constellation of neuropathic and vascular occlusive symptoms caused by pathologic elongation or angulation of the styloid process and styloid chain. First described in 1652 by Italian surgeon Piertro Marchetti, the clinical syndrome was definitively outlined by Watt Eagle in the late 1940s and early 1950s.

METHODS

This article reviews how underlying embryologic and anatomic pathology predicts clinical symptomatology, diagnosis, and ultimately treatment of the syndrome.

RESULTS

The length and direction of the styloid process and styloid chain are highly variable. This variability leads to a wide range of relationships between the chain and the neurovascular elements of the neck, including cranial nerves 5, 7, 9, and 10 and the internal carotid artery. In the classic type of Eagle's syndrome, compressive cranial neuropathy most commonly leads to the sensation of a foreign body in the throat, odynophagia, and dysphagia. In the carotid type, compression over the internal carotid artery can cause pain in the parietal region of the skull or in the superior periorbital region, among other symptoms.

CONCLUSIONS

Careful recording of the history of the present illness and review of systems is crucial to the diagnosis of Eagle's syndrome. After the clinical examination, the optimal imaging modality for styloid process pathology is spiral CT of the neck and skull base. Surgical interventions are considered only after noninvasive therapies have failed, the two most common being intraoral and external resection of the styloid process.

Eagle's syndrome: a review of the literature

Eagle's syndrome represents symptoms brought on by compression of regional structures by elongation of the styloid process or ossification of the stylohyoid or stylomandibular ligaments. Watt Eagle described it for the first time in 1937, dividing it into two subtypes: the "classic syndrome" and the "stylo-carotid artery syndrome." Many theories have been put forth regarding its pathogenesis. Depending on the underlying pathogenetic mechanism and the anatomical structures compressed or irritated by the styloid process, symptoms vary greatly, ranging from cervicofacial pain to cerebral ischemia. The syndrome generally follows tonsillectomy or trauma. Diagnosis is confirmed by radiological findings. Palpation of the styloid process in the tonsillar fossa and infiltration with anesthesia are also used in making the diagnosis. The treatment is primarily surgical; however, some conservative treatments have also been used. The current literature on Eagle's syndrome is reviewed, highlighting its often underestimated frequency and its clinical importance.