Convexity subarachnoid hemorrhage revealed contralateral internal carotid artery dissection due to Eagle syndrome: a case report.

BACKGROUND: Atraumatic localized convexity subarachnoid hemorrhage (cSAH) is an uncommon form of nonaneurysmal subarachnoid hemorrhage characterized by bleeding limited to the cerebral convexities. Ipsilateral cSAH can result from a variety of causes, such as internal carotid artery stenosis, obstruction, and dissection, although concomitant contralateral cSAH is exceptionally rare. In this case, the initial findings of cSAH led us to discovering contralateral internal carotid artery dissection (ICAD) and an elongated styloid process (ESP). ESP is recognized as a risk factor for ICAD, which is a hallmark of Eagle syndrome. This sequence of findings led to the diagnosis of Eagle syndrome, illustrating a complex and intriguing interplay between cerebrovascular conditions and anatomical variations. CASE PRESENTATION: A 47-year-old Japanese woman experienced acute onset of headache radiating to her neck, reaching its zenith approximately two hours after onset. Given the intractable nature of the headache and its persistence for three days, she presented to the emergency department. Neurological examination revealed no abnormalities, and the coagulation screening parameters were within normal ranges. Brain computed tomography (CT) revealed right parietal cSAH, while CT angiography (CTA) revealed ICAD and an ESP measuring 30.1 mm on the left side, positioned only 1.4 mm from the dissected artery. The unusual occurrence of contralateral cSAH prompted extensive and repeated imaging reviews that excluded reversible cerebral vasoconstriction syndrome (RCVS), leading to a diagnosis of left ICAD secondary to Eagle syndrome. The patient underwent conservative management, and the dissected ICA spontaneously resolved. The patient has remained recurrence-free for two and a half years. CONCLUSIONS: Managing cSAH requires diligent investigation for ICAD, extending beyond its identification to explore underlying causes. Recognizing Eagle syndrome, though rare, as a potential etiology of ICAD necessitates the importance of evaluating ESPs. The method for preventing recurrent cervical artery dissection due to Eagle syndrome is controversial; however, conservative management is a viable option.

The External Carotid Artery and the Styloid Process.

BACKGROUND: The external carotid artery (ECA) is typically regarded as coursing between the styloid muscles to continue into the parotid space. The anatomical possibility of an ECA with an ascending parapharyngeal trajectory continuing posteriorly to an elongated styloid process (ESP), thus retrostyloid, to the parotid space is overlooked. It was, therefore, aimed to document the prevalence of this retrostyloid variant of the ECA's course. METHODS: We investigated a retrospective random cohort of 160 archived CT angiograms of 97 males and 63 females aged between 47 and 76. The presence of an ESP and the retrostyloid course of the ECA were bilaterally documented. RESULTS: An ESP was identified in 99/320 sides (30.94%), regardless of the ECA course. In the overall group, we obtained 35% null cases for the two variables on the right and 34.06% for the left. ESPs were identified in 8.75% on the right side and 10.31% on the left. The ECAs had retrostyloid courses in 6.25% on the right side and 5.63% on the left. Thus, of the 320 ECAs documented on both sides, 221 (69.06%) had no retrostyloid courses, and we did not identify any ESP in those cases. ESPs were detected in 19.06% of the sides but without retrostyloid ECAs, and retrostyloid courses of the ECAs were detected in 11.88%. CONCLUSIONS: The possibility of a retrostyloid course of the ECA should not be ignored. An ESP may misinform the surgeon about the main carotid artery located immediately deep to it.

Eagle syndrome: tissue characteristics and structure of the styloid process.

Eagle syndrome is a bone disease where elongation of the styloid process leads to throat and neck pain, and in severe cases neurovascular symptoms such as syncope and neuralgia. The pathophysiology of Eagle syndrome is poorly understood with various theories having been proposed how this elongation is caused. To better understand the pathophysiology, we performed a work-up in 6 patients presenting with Eagle syndrome. Patients mainly presented with pain on turning the neck (100%), foreign body sensation (67%), tension in the neck (67%), and dysphagia (50%). The typical length of the styloid process ranges from 25 to 30 mm; however, [18F]NaF (sodium fluoride) PET/CT showed elongated styloid processes with an average length of 52.1 ± 15.6 mm (mean ± SD) with increased turnover at the base of one of the styloid processes. The removed styloid processes were further examined by histology, micro-CT, quantitative backscatter electron imaging (qBEI), Fourier transform infrared spectroscopy (FTIR), and circularly polarized light imaging. Histology revealed one case of a fractured styloid process healing through callus formation and one case of pseudarthrosis. Bone mineral density and mineralization was similar in the styloid processes when compared to cortical bone samples derived from the mandibular bone of different patients. Circular polarized light microscopy showed a collagen orientation in the styloid process comparable to the cortical bone samples with a distinct separation of collagen structure between the mineralized structure and the surrounding soft tissue with FTIR analysis demonstrating a typical composition of bone. This altogether suggests that the elongated styloid processes in Eagle syndrome are mature bone, capable of endochondral repair, possibly growing from the base of the process through endochondral ossification, rather than being a form of secondary calcification of the stylohyoid ligament as previously postulated.

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 presentation and outcomes in a large surgical case series.

Objective: The purpose of this study is to describe both the common and uncommon symptoms associated with Eagle syndrome and share our experience treating a large group of patients with surgical intervention, primarily intraoral excision of the calcified stylohyoid ligament. Methods: This retrospective case series included 56 patients at least 18 years of age or older with a diagnosis of Eagle syndrome. All operations were conducted by a single surgeon at a tertiary medical center from 2015 to 2022. Charts were reviewed for demographics, prior medical/surgical history, symptoms, imaging results, operative details, and follow-up history. A phone survey inquired about presenting symptoms and symptom resolution following surgery. Results: The most common areas of pain were the ear (64.3%), underneath the angle of the mandible (50%), throat (46.4%), and neck (30.4%). Over 70% of patients reported tinnitus, dysphagia, and pain that were exacerbated by head rotation. Fifty-one of the 56 patients underwent surgical treatment, 92.2% via intraoral and 7.8% via cervical approaches. All patients (100%) reached in a phone survey stated that their symptoms resolved or improved after surgery. Conclusion: Eagle syndrome typically presents with common symptoms. However, healthcare providers must also be vigilant for less common manifestations, such as seizures or episodes of dizziness/fainting. These may be caused by calcification of the stylohyoid ligament. Intraoral surgical resection of the calcified ligament is a safe and effective treatment for most patients. Level of Evidence: Level 4.

Role of the Surgical Approach in the Treatment of Eagle Syndrome.

Introduction Eagle syndrome is a rare and an often misdiagnosed entity in otorhinolaryngology. Objective To determine the efficacy of the surgical treatment for Eagle syndrome. Methods The present prospective study included 25 patients who presented with complaints of pain in the throat, ear, and neck, as well as difficulty and/or pain while swallowing; they were assessed for Eagle syndrome. As per patient profile, we performed a clinical assessments along with orthopantomograms (OPGs), three-dimensional computed tomography (3D CT) scans, and cone beam computed tomography (CBCT). Pain was assessed pre- and postoperatively through the Numerical Rating Scale-11 (NRS-11), whose score ranges from 0 to 10. Microscopic tonsillo-styloidectomy was performed in cases in which the conservative treatment failed to relieve pain. Results The mean age of the entire study population was of 36.08 ± 7.19 years, and the male-to-female ratio was of 1.08:1. Referred otalgia was the commonest (44%) complaint. Radiologically, out of 25 patients, 20 patients presented elongated styloid processes. The longest symptomatic styloid process measured radiographically was of 64.7 mm while the shortest was of 28.2 mm. Out of 20 patients, 12 underwent surgery. The postoperative pain assessment through the NRS-11 was performed on day 0 (3.83 ± 0.83), day 7 (1.5 ± 0.52), week 4 (0.5 ± 0.52), and week 12 (0.41 ± 0.51). By 12 weeks, 7 patients were symptom-free, while 5 patients still reported mild pain. Conclusion Eagle syndrome associated with an elongated styloid process is not a rarity, but it often goes undiagnosed. Microscopic tonsillo-styloidectomy shows excellent results in the management of patients with Eagle syndrome.

Eagle's Syndrome: A Fortunate Discovery in a Symptomatic Patient.

Eagle's syndrome is a condition characterized by an elongated styloid process or a calcified stylohyoid ligament, which can lead to a plethora of symptoms, such as neck and facial pain upon movement, dysphagia, pharyngeal foreign body sensation, headache, and vertigo-like sensations. This pathology may affect one or both of a patient's styloid processes (unilateral or bilateral), with most of these cases going undiagnosed due to the vague nature of their symptoms. Nonetheless, the diagnosis of Eagle's syndrome must derive from the combined findings of both clinical examination and radiographic imaging. Symptomatic patients may require conservative or surgical treatment.

Ischemic stroke due to stylocarotid artery syndrome: a case report and review.

Stylocarotid artery syndrome (SAS) is a rare variant of Eagle's syndrome that may lead to transient ischemic attack or stroke. The underlying pathophysiological mechanism involves compression of the internal carotid artery by an elongated styloid process (ESP), potentially resulting in vascular occlusion or dissection. An ESP exceeding 2.5 cm is deemed elongated, with a length of 3.0 cm considered clinically significant. Although the prevalence of ESP ranges from 4.0% to 7.3%, symptomatic cases are rare; symptoms are present in only approximately 4.0% of individuals with an ESP. Unlike the typical symptoms of Eagle's syndrome, SAS may not cause pharyngeal discomfort, the sensation of a foreign body in the throat, dysphagia, or facial pain. This absence of characteristic symptoms as well as the development of central nervous system symptoms often leads patients to seek care from neurologists instead of otolaryngologists, increasing the likelihood of misdiagnosis or underdiagnosis. We herein report a unique case of ischemic stroke caused by SAS and present a literature review on cases of SAS-associated ischemic stroke published in the past decade. The reporting of this study conforms to the CARE guidelines.

Transoral Robotic Surgery for Eagle Syndrome: A Systematic Review.

Objectives: Transoral robotic surgery (TORS) is gaining popularity and has been introduced for the treatment of Eagle syndrome. This review aims to evaluate the safety and efficacy of TORS for the treatment of Eagle syndrome. Methods: A systematic review of the English language literature using multiple databases was completed for studies describing TORS for Eagle syndrome. The quality of studies and risk of bias were evaluated using the MINORS scoring system. Results: Out of 1495 articles screened, 4 studies met criteria for inclusion in the final analysis. Across all studies, there was a 100% surgical success rate. In total, every patient had some level of symptom improvement with 84% of patients having complete symptom improvement and 16% having partial improvement. Reported estimated blood loss averaged 12.5 mL. A total of 94.7% of patients had no surgical complications and no cases were complicated by postoperative bleeding. Operative time averaged 65 minutes. The average length of stay was 2.1 days. A total of 92% of patients resumed their diet on postoperative day 1, with the remainder resuming on postoperative day 2. MINORS criteria scoring suggested moderate risk of bias in all studies. Conclusion: Based on limited quality evidence, this review suggests that TORS is a safe and effective surgical approach in the treatment of Eagle syndrome with low complication rates. Further large-scale prospective studies are warranted.

Internal carotid artery pseudoaneurysm after neck manipulation in a patient with Eagle syndrome.

Key Clinical Message: Contraindications of spinal manipulative therapy (SMT) have been proposed, which mandate rigorous control for its safe practice when manipulating the upper spine. Here, we report a vascular complication of Neck Manipulation in Eagle syndrome (ES) patient. Abstract: SMT is used to treat musculoskeletal conditions such as back pain and neck pain by applying force to the spinal joints. Here, we report a rare but devastating complication of SMT, where a young male patient, 22 years old, with ES, had a large pseudoaneurysm from the internal carotid artery (ICA) after SMT from an unlicensed practitioner, treated successfully with endograft. Clinicians administering SMT should consider an elongated styloid process as a potential contraindication to this therapy.

Accuracy in the Diagnostics of Styloid Process - Panoramic Radiograph vs. Computed Tomography: A Comparative Study.

BACKGROUND/AIM: The styloid process (SP) becomes clinically relevant when it shows enlargement (>30 mm) in the sense of an elongated SP (ESP) and/or increasing calcification leading to Eagle Syndrome (ES). Panoramic radiograph (PR) or computed tomography (CT) are part of the routine diagnostics in ES. Currently, CT is considered the gold standard. The aim of this study was to investigate the accuracy in the diagnostics/measurements of SP/ESP throughout a comparative study between PR and CT. Furthermore, in addition to measuring established parameters, this study aimed to determine the currently unexamined width in the base and tip of the SP. PATIENTS AND METHODS: The present study examined the radiological findings of bilateral SP in 100 patients who received both PR and CT on the same day. Measurements of the length of the SP and width at the basis and tip were performed. Furthermore, calcification patterns, Langlais classification and the prevalence of ESP were analyzed. RESULTS: There was a highly significant correlation between PR and CT measuring SP for every parameter. Males showed significantly longer SP than females among the age group between 18-75 years. The results of the length measurements of the SP (male: right SP=32.98 mm; left SP=35.21 mm; female: right SP=30.31 mm; left SP=30.92 mm) significantly exceeded the values of comparable studies. CONCLUSION: Consequently, it can be concluded that PR provides accurate measurements when compared to CT for measuring and diagnosing SP/ESP/Eagle syndrome. This study was one of the first to examine the width of the SP in the base and tip, thus these measurements can serve as a baseline for further studies. Since the mean lengths of SP exceeded 30.0 mm in the present study, these findings raise the question of whether the cut-off of 30.0 mm is adequate for the diagnosis of ESP.

Adaptive treatment strategy for a vestibular schwannoma in a patient with vascular Eagle syndrome: illustrative case.

BACKGROUND: Eagle syndrome, an uncommon condition, causes symptoms due to neural and/or vascular compression from an elongated styloid process or calcified stylohyoid ligament and can also complicate other planned surgical procedures. OBSERVATIONS: A 42-year-old female with loss of balance, dizziness, and ataxic gait underwent cranial magnetic resonance imaging (MRI), revealing a right-sided Koos grade IV vestibular schwannoma. Initially, a retrosigmoid craniotomy for tumor resection was planned. However, preoperative MRI and computed tomography (CT) showed a dilated right-sided mastoid emissary vein, tortuous scalp and paraspinal veins, and bilateral elongated styloid processes. CT angiography and digital subtraction angiography indicated Eagle syndrome-related compression of both internal jugular veins and concurrent occlusion of the left internal jugular vein at the jugular foramen. Consequently, given the risk of damaging venous structures, Gamma Knife radiosurgery was chosen over resection. LESSONS: This case highlights the importance of adapting treatment plans based on patient-specific anatomical and pathological factors. In situations in which traditional surgery poses risks to sensitive structures such as the venous system, alternative approaches like radiosurgery offer safer yet effective options. Comprehensive risk-benefit evaluations are crucial for such decisions.

Evaluation of Styloid Process Elongation in Madinah, Saudi Arabia: A Retrospective Radiographic Investigation.

OBJECTIVES: This study aimed to identify the prevalence of an elongated styloid process and analyze the presence of its calcification in the Saudi population using panoramic radiographs. METHODS: The Taibah Outpatient Dental Clinic's OPG radiographs for 962 patients who attended screening clinics between December 2022 and October 2023 were all included in the study. Patients' demographics, such as age, gender, and nationality, as well as radiological data, were included in the following study variables: the presence of an elongated styloid on both sides of a panoramic radiograph, right side styloid length, left side styloid length, right side distal end thickness, and left side distal end thickness. RESULTS: The study evaluated 438 (45.5%) processes found in individuals aged 16-80 years old. The elongated process length ranged from 30.0 to 40.1 mm, and the diameter ranged from 0.81 to 7.79 mm at the origin to 0.56-3.79 mm at the end. There was no statistically significant difference in process length across genders or age groups. The diameters of the styloid bones on the left side vary significantly across genders at the start and completion of the process. CONCLUSION: The prevalence of elongated styloids in the studied population was 4.26%. The radiological evaluation of the styloid process is a crucial stage in dental surgery planning.

Surgical management of stylocarotid Eagle syndrome in a patient with bilateral internal carotid artery dissection: illustrative case.

BACKGROUND: Eagle syndrome is characterized by an elongated styloid process, which can cause acute neurological symptoms when the projection impinges on local structures. One method by which Eagle syndrome can cause acute stroke is via internal carotid artery dissection. OBSERVATIONS: A patient presented with acute aphasia and right-arm weakness. Imaging revealed a left internal carotid artery dissection, which was treated with stenting. Three years later, the patient presented with left-sided weakness, and imaging revealed a new right internal carotid artery dissection. Closer review of the patient's imaging revealed bilateral elongated styloid processes. The patient subsequently underwent staged bilateral styloidectomy and returned to his prior baseline postoperatively. LESSONS: This case report describes a patient with Eagle syndrome who had two internal carotid artery dissections separated by several years. A literature review revealed that styloidectomy is well tolerated in patients with carotid dissection due to Eagle syndrome. Patients with carotid dissection due to Eagle syndrome remain at risk for contralateral dissection, and prophylactic contralateral styloidectomy should be considered.

Stylohyoid Chain Syndrome (Eagle Syndrome) in Conjunction with Carotid Artery Dissection: A Case Report of Surgical Treatment.

(1) Background: "Eagle Syndrome", also known as "stylalgia" or a "stylohyoid chain anomaly", typically manifests with ipsilateral orofacial pain, a foreign body sensation in the throat, and ear-related symptoms. Despite these common presentations, its potential association with carotid artery dissection is not widely acknowledged. (2) Methods: This article presents an extremely rare case of a patient diagnosed with an ischemic stroke in the left hemisphere, followed by the dissection of the left internal carotid artery, initially with an unidentified cause. Subsequent examinations revealed elongated left styloid processes directly compressing the dissected artery. (3) Results: After initial treatment involving pharmacological and mechanical thrombectomy, styloidectomy restored blood flow to the internal carotid artery. The patient remained symptom-free during a 12-month follow-up. (4) Conclusions: This case emphasizes the importance of considering anatomical variations within the stylohyoid chain when assessing young individuals with neurological symptoms. Furthermore, it underscores the potential benefits of early surgical intervention in reducing the morbidity and mortality associated with this condition.

Bilateral carotid dissection due to Eagle syndrome.

Eagle syndrome is defined as a collection of symptoms affecting the cervical and cranial regions, resulting from an elongated styloid process or ossified stylohyoid ligament encroaching on surrounding structures and causing a variety of symptoms. Classically, Eagle syndrome presents as neck, throat, or ear pain. Carotid artery dissection is a rare complication of Eagle syndrome. We report the case of a 40-year-old man who presented with bilateral internal carotid artery dissection secondary to pathological elongation of the styloid processes.

Transoral robotic styloidectomy for Eagle syndrome: A systematic review.

OBJECTIVES: The aim of the study is to conduct a systematic review of the existing literature on styloidectomy performed through transoral robotic surgery (TORS) in Eagle syndrome (ES). DESIGN AND SETTING: Two independent reviewers (RC and AC) conducted a systematic review of PubMed and Embase databases, seeking articles on TORS performed for ES treatment. The search was conducted in July 2023. The review was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PARTICIPANTS: The review included a total of 17 adult patients, comprising 12 females and 5 males, with an average age of 52.2 years, all diagnosed with ES. MAIN OUTCOME MEASURES: For each patient, we assessed the overall length of the styloid process, the affected side, total intervention duration, hospitalization duration, pre and postoperative Visual Analogue Scale (VAS) scores, and the presence of minor and major complications. RESULTS: We identified 4 articles describing 17 instances of TORS as a surgical treatment for ES in the literature, totaling 18 styloidectomies. The mean age of the patients was 52.2 years, with 12 females and 5 males. The average operation time, inclusive of the docking phase, was 68.8 minutes. Sixteen patients (94.1% of the total) experienced complete symptom disappearance or near-complete resolution after surgery. One patient (5.9%) showed improvement categorized as 'non-meaningful.' Only one case of minor complication was reported among the 17 procedures (5.9%).

Eagle jugular syndrome presenting with intracranial hypertension - Diagnosis and illustration of pathophysiology by multi-modality imaging.

Eagle jugular syndrome is an uncommon condition caused by compression of an elongated styloid process onto the internal jugular vein. Its presentation is non-specific but may represent in severe clinical consequences including venous thrombosis and intracranial haemorrhage. Thorough understanding of local anatomy is important in understanding the pathogenesis and establishing the diagnosis. Our case reported here illustrates the use of multimodality imaging, including dynamic Computer tomography manoeuvre, in identifying the site of obstruction and guidance towards successful surgical treatment.

"Winged" Eagle's syndrome: neurophysiological findings in a rare cause of spinal accessory nerve palsy. Illustrative cases.

BACKGROUND: Eagle's syndrome (ES) classically describes dysphagia, globus sensation, and otalgia from an elongated and calcified styloid process or stylohyoid ligament. Compression of the spinal accessory nerve (SAN) has not been reported as an associated feature of ES or related variants. OBSERVATIONS: The authors describe two cases of an atypical "winged" variant with SAN palsy resulting from compression by a posteriorly angulated or calcified styloid process. Both patients exhibited lateral scapular winging and atrophy of the trapezius and sternocleidomastoid muscles. Electrophysiological studies demonstrated motor unit preservation; therefore, surgical exploration, styloidectomy, and SAN decompression were performed through a transcervical approach. Postoperatively, both patients had improvements in pain and shoulder mobility, the return of muscle strength, and electrophysiological evidence of trapezius reinnervation. LESSONS: Compression of the SAN, which can be identified both clinically and on electrodiagnostic testing, is an atypical finding that can result from a posteriorly angulated or calcified styloid process. This winged variant of ES should be included in the differential for SAN palsy, and a multidisciplinary approach is recommended for assessment and management.