Styloid/C1 transverse process juxtaposition as a cause of Eagle's syndrome

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.

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.

Eagle jugular syndrome accompanied by de novo brainstem cavernous malformation: a case-based systematic review

BACKGROUND

Eagle jugular syndrome (EJS), recently identified as a cause of cerebrovascular disease (CVD) due to venous obstruction by an elongated styloid process (SP), is reported here alongside a case of concurrent de novo cerebral cavernous malformation (CCM). This study aims to explore the potential causal relationship between EJS and de novo CCM through a comprehensive literature review.

METHOD

Systematic literature reviews, spanning from 1995 to 2023, focused on EJS cases with definitive signs and symptoms and de novo CCM cases with detailed clinical characteristics. Data on the pathophysiology and clinical manifestations of EJS, as well as potential risk factors preceding de novo CCM, were collected to assess the relationship between the two conditions.

RESULT

Among 14 patients from 11 articles on EJS, the most common presentation was increased intracranial hypertension (IIH), observed in 10 patients (71.4%), followed by dural sinus thrombosis in four patients (28.6%). In contrast, 30 patients from 28 articles were identified with de novo CCM, involving 37 lesions. In these cases, 13 patients developed CCM subsequent to developmental venous anomalies (43%), seven following dural arteriovenous fistula (dAVF) (23%), and two after sinus thrombosis (6%). In a specific case of de novo brainstem CCM, the development of an enlarged condylar emissary vein, indicative of venous congestion due to IJV compression by the elongated SP, was noted before the emergence of CCM.

CONCLUSION

This study underscores that venous congestion, a primary result of symptomatic EJS, might lead to the development of de novo CCM. Thus, EJS could potentially be an indicator of CCM development. Further epidemiological and pathophysiological investigations focusing on venous circulation are necessary to clarify the causal relationship between EJS and CCM.

Differences in the Osseous Ultrastructure in 2 Differing Etiologies of Eagle Syndrome. A Micro-CT Study

OBJECTIVES

Eagle syndrome is a rare disease caused by an elongated styloid process (type I) or ossified stylohyoid ligament (type II) and causes a heterogeneous symptom complex, ranging from pain in the throat and neck to neurological symptoms and neurovascular entrapment. The 2 different types present differing shapes and ultrastructures and cause different symptoms. This study aimed to distinguish the 2 types by investigating the structures by micro-computed tomography.

METHODS

Micro-computed tomography was performed and evaluated in n=10 resected styloid processes from patients diagnosed with Eagle syndrome. The tissues were measured for their shape, ratio of soft tissue and bone amounts, bone volume, and ultrastructure, and compared within the groups.

RESULTS

The shapes of the different types were different and the ultrastructure differed between the 2 groups, with an absence of trabecular architecture in type II. The area of bone to nonbone tissues in type I samples was significantly higher compared with type II (P=0.007). Alike these results, the bone volume and bone-to-soft tissue ratio were significantly higher in type I compared with type II (P=0.009).

CONCLUSIONS

The findings suggest that both the popular theories (hyperplasia and metaplasia) may be probable but each solely valid for 1 type of Eagle. Type I may derive from bone hyperplasia with cancellous bone formation and rather high bone density in the elongated styloid process. Type II most likely originates from ligament metaplasia into bone without a compact structure.

Styloid Jugular Nutcracker: The Possible Role of the Styloid Process Spatial Orientation-A Preliminary Morphometric Computed Study

Styloid Jugular Nutcracker (SJN, also known as Eagle Jugular Syndrome EJS) derives from a jugular stenosis caused by an abnormal styloid process, compressing the vessel in its superior portion (J3) against the C1 anterior arch. It could be considered a venous vascular variant of Eagle Syndrome (ES). Main clinical features of this ES variant are headache, pulsatile tinnitus and dizziness, possibly related to venous hypertension and impaired cerebral parenchyma drainage. In our opinion, conceptually, it is not the absolute length of the styloid bone that defines its abnormality, but its spatial direction. An elongated bone pointing outward far away from the midline could not compress the vein; vice versa, a short styloid process tightly adherent to the cervical spine could be pathological. To prove this hypothesis, we developed a semi-automatic software that processes CT-Angio images, giving quantitative information about distance and direction of the styloid process in three-dimensional space. We compared eight patients with SJN to a sample of healthy subjects homogeneous for sex and age. Our results suggest that SJN patients have a more vertically directed styloid, and this feature is more important than the absolute distance between the two bony structures. More studies are needed to expand our sample, including patients with the classic and carotid variants of Eagle Syndrome.

Interventional and surgical management of internal jugular venous stenosis: a narrative review

BACKGROUND

A small subset of patients with presumed idiopathic intracranial hypertension are found to have isolated internal jugular vein stenosis (IJVS).

OBJECTIVE

To review the current interventions used in patients who present with intracranial hypertension secondary to IJVS.

METHODS

In December 2020, we performed a literature search on Pubmed/Medline and Scopus databases for original articles studying surgical and endovascular interventions used for intracranial hypertension in the setting of internal jugular vein stenosis. No date, patient population, or study type was excluded.

RESULTS

All studies that included at least one case in which a surgical or endovascular intervention was used to treat IJVS were included. Selection criteria for patients varied, most commonly defined by identification of compression of the internal jugular vein. The 17 studies included in this review ranged from case reports to large single-center cohort studies. The most used surgical intervention was styloidectomy. Styloidectomy had an overall better outcome success rate (79%) than angioplasty/stenting (66%). No complications were recorded in any of the surgical cases analyzed. Outcome measures varied, but all studies recorded clinical symptoms of the patients.

CONCLUSION

Few current large cohort studies analyze surgical and endovascular interventions for patients with IJVS. Notably, the most common intervention is styloidectomy, followed by internal jugular vein stenting. By understanding the trends and experience of interventionalists and surgeons, more focused and larger studies can be performed to determine effective strategies with the best clinical outcomes.

Internal carotid artery dissection related to abnormalities of styloid process: is it only a matter of length?

INTRODUCTION

Vascular Eagle syndrome, due to impingement of the extracranial internal carotid artery (ICA) by the styloid process (SP), is an uncommon and not yet widely recognized cause of ICA dissection. Up to now, this diagnosis is still presumptive, based mainly on the length of the SP. However, given the discrepancy between the much higher prevalence of an elongated SP in the population compared to the reported rate of Eagle syndrome, other anatomical factors beyond the length itself of this bony structure seem to be involved.

MATERIAL AND METHODS

We performed a retrospective single center case-control study of ICA dissection related to abnormalities of styloid process and age- and sex-matched controls affected by ICA dissection not related to abnormal relationship with the styloid process. In our work instead of considering SP length as the main criteria to differentiate the two groups, we decided to consider styloid process-internal carotid artery distance (at the dissection point) as the main factor to define a styloid process related dissection (SPRD). In fact in some patients, the distance between the dissected artery and the bony prominence was virtual.

RESULTS

Our study showed that in patients with SPRD the styloid process angulation on the coronal plane tends to be more acute and that styloid process-C1 distance is significantly shorter at the side of the dissection. This data reinforces the idea that ICA dissection risk in the vascular Eagle syndrome has probably a multifactorial pathogenesis.

Styloidogenic-cervical spondylotic internal jugular venous compression, a vascular disease related to several clinical neurological manifestations: diagnosis and treatment-a comprehensive literature review

Internal jugular vein (IJV) stenosis is associated with several central nervous system disorders such as Ménière or Alzheimer’s disease. The extrinsic compression between the styloid process and the C1 transverse process, is an emerging biomarker related to several clinical manifestations. However, nowadays a limited number of cases are reported, and few information are available about treatment, outcome and complications. Our aim is to collect and identify clinical-radiological characteristics, diagnosis and treatment of the styloidogenic internal jugular venous compression. We performed a comprehensive literature review. Studies reporting patients suffering from extracranial jugular stenosis were searched. For every patient we collected: demography, clinical and radiological characteristics and outcome, type of treatment, complications. Thirteen articles reporting 149 patients were included. Clinical presentation was non-specific. Most frequent symptoms were headache (46.3%), tinnitus (43.6%), insomnia (39.6%). The stenosis was monolateral in 51 patients (45.9%) and bilateral in 60 (54.1%). Anticoagulants were the most common prescribed drug (57.4%). Endovascular treatment was performed in 50 patients (33.6%), surgery in 55 (36.9%), combined in 28 (18.8%). Improvement of general conditions was reported in 58/80 patients (72.5%). Complications were reported in 23% of cases. Jugular stenosis is a complex and often underestimated disease. Conservative medical treatment usually fails while surgical, endovascular or a combined treatment improves general conditions in more than 70% of patients.

Eagle's syndrome, elongated styloid process and new evidence for pre-manipulative precautions for potential cervical arterial dysfunction

INTRODUCTION

Safety with upper cervical interventions is a frequently discussed and updated concern for physical therapists, chiropractors and osteopaths. IFOMPT developed the framework for safety assessment of the cervical spine, and this topic has been discussed in-depth with past masterclasses characterizing carotid artery dissection and cervical arterial dysfunction. Our masterclass will expand on this information with knowledge of specific anatomical anomalies found to produce Eagle's syndrome, and cause carotid artery dissection, stroke and even death. Eagle's syndrome is an underdiagnosed, multi-mechanism symptom assortment produced by provocation of the sensitive carotid space structures by styloid process anomalies. As the styloid traverses between the internal and external carotid arteries, provocation of the vessels and periarterial sympathetic nerve fibers can lead to various neural, vascular and autonomic symptoms. Eagle's syndrome commonly presents as neck, facial and jaw pain, headache and arm paresthesias; problems physical therapists frequently evaluate and treat.

PURPOSE

This masterclass aims to outline the safety concerns, assessment and management of patients with Eagle's syndrome and styloid anomalies. By providing evidence of this common anomaly found in almost one-third of the population, hypothesis generation and clinical reasoning with patients presenting with head and neck symptoms can improve.

IMPLICATIONS

Including styloid anomalies as potential hypotheses for patients with head and neck complaints can assist therapists in safe practice and expedite referral. The authors recommend updating the IFOMPT framework to incorporate Eagle's syndrome, a comprehensive autonomic assessment, and palpation of the stylohyoid complex to avoid potentially serious complications from conceivably hazardous interventions.

Styloidogenic Jugular Venous Compression Syndrome: Clinical Features and Case Series

BACKGROUND

Styloidogenic jugular venous compression syndrome (SJVCS) is a rare cause of idiopathic intracranial hypertension (IIH).

OBJECTIVE

To elucidate the pathophysiology and the hemodynamics of SJVCS.

METHODS

We conducted a retrospective review of medical records, clinical images, dynamic venography, and manometry for consecutive patients with SJVCS undergoing microsurgical decompression from April 2009 to October 2017. Patients with IIH with normal venography and manometry findings served as controls.

RESULTS

Data were analyzed for 10 patients with SJVCS who presented with headaches. Neck flexion exacerbated headaches in 7 patients. Eleven patients with IIH provided control data for normal intracranial venous pressure and styloid process anatomy. Patients with SJVCS had bilateral osseous compression of venous outflow. The styloid processes were significantly longer in patients with SJVCS than in those with IIH (mean [standard deviation (SD)] distance, 31.0 [10.6] vs 19.0 [14.1] mm; P < .01). The styloid process-C1 lateral tubercle distance was shorter in patients with SJVCS than in those with IIH (mean [SD] distance, 2.9 [1.0] vs 9.9 [2.8] mm; P < .01). Patients with SJVCS had significantly higher global venous pressure and a higher pressure gradient across the stenosis site than controls (mean [SD] pressure, 2.86 [2.61] vs 0.13 [1.09] cm H2O; P = .09). All 10 patients with SJVCS experienced venous pressure elevation during contralateral neck turning (mean [SD] pressure, 4.29 [2.50] cm H2O). All 10 patients with SJVCS underwent transcervical microsurgical decompression, and 9 experienced postoperative improvement or resolution of symptoms. One patient had transient postoperative dysphagia and facial drooping, and another patient reported jaw numbness.

CONCLUSION

SJVCS is a novel clinical entity causing IIH. Patients should be evaluated with dynamic venography with manometry. Surgical decompression with removal of osseous overgrowth is an effective treatment in select patients.

Styloidogenic compression of the internal jugular vein, a new venous entrapment syndrome?

Internal jugular vein (IJV) thrombosis is mainly related to central venous catheter, malignancy, and ovarian hyperstimulation syndrome. We report a case of IJV thrombosis possibly related to IJV compression between the styloid process and the first cervical vertebra (C1) transverse process. To support this hypothesis, we perform radiological assessment of the IJV and examine its relationship with the styloid process and C1 transverse process in 34 controls. Our results showed a strong correlation between IJV diameter and styloid process-C1 transverse process distance. Compared to control subjects, our patient had a short styloid process-C1 transverse process distance, which suggests its involvement in IJV thrombosis.

The eagle jugular syndrome

BACKGROUND

The elongation of the styloid process is historically associated with two variants of the Eagle syndrome. The classic one, mainly characterized by pain and dysphagia, and the carotid variant characterized by pain and sometimes by cerebral ischemia. We observed a further variant characterized by a styloid elongation coursing adjacent to the transverse process of C1, causing significant compression of the internal jugular vein.

METHODS

We reviewed all the cases of Eagle syndrome, including the jugular variant, admitted in our Hospital in the last six years. We compared symptomatology, associated comorbidities and imaging. Data were statistically analyzed.

RESULTS

Overall 23 patients were admitted to the Hospital for symptomatic elongation of the styloid process, 11 male and 12 females. The jugular variant of the Eagle syndrome is clinically delineated by significant differences, as compared to the classic variant and carotid variants. Headache was the more prominent symptom (p < .009) as well as a documented peri-mesencephalic hemorrhage was the more significant comorbidity (p < .0003). The group classic-carotid variant was characterized by ipsilateral pain respect to the jugular variant (p < .0003). CT angiography with venous phase extended to the neck veins and imaging reconstruction is highly recommended as imaging technique, complemented by color-Doppler ultrasound.

CONCLUSIONS

The elongation of the styloid process may have different paths which creates compression on the surrounding anatomical structures. There may be a possible association of jugular impingement by an elongated styloid process with symptoms.

TRIAL REGISTRATION

Protocol n°45-2013.

An unusual internal carotid artery compression as a possible cause of Eagle syndrome - A novel hypothesis and an innovative surgical technique

Background:

Eagle syndrome (ES) is a rare symptomatic condition generally caused by an elongated styloid process (SP) or calcification of the stylohyoid complex. On the diagnosis is made, its treatment remains subjective since the indications for surgical intervention are still not standardized. Although styloidectomy is the surgical treatment of choice, no consensus exists regarding the transcervical or/and transoral route. Here, we report our experience in a patient with bilateral internal carotid artery (ICA) dissection caused by ES, who underwent innovative surgical technique.

Case Description:

A 53-year-old man, with the right-sided middle cerebral artery acute stroke, underwent computed tomography angiography 3 days after a successful endovascular treatment. The study showed a bilateral ICA dissection with bilateral hypertrophic SPs and a close relationship of ICAs with both SPs anteriorly and C1 transverse process posteriorly. Considering the occurrence of ICA compression by a styloid/C1 transverse process juxtaposition, the patient underwent the left partial C1 transversectomy by an extraoral approach. A temporary paresis of the ipsilateral lower lip lasted 1 month, with a partial remission after 3 months. The patient reported significant improvement of symptoms with a good esthetics and functional outcome.

Conclusion:

A styloid/C1 transverse process juxtaposition should be considered as an alternative pathogenetic mechanism in vascular ES. When a posterior ICA compression by C1 transverse process is present, a bone reshaping of C1 rather than a conventional styloidectomy can be considered an efficacious treatment which allows a good preservation of the styloid muscles and ligaments.

Surgical Management of Stylohyoid Pain (Eagle’s) Syndrome: A 5-Year Experience

Objectives:

(1) To define patient demographics and common symptoms in patients who undergo styloidectomy for stylohyoid pain syndrome (Eagle’s syndrome). (2) To evaluate the effectiveness of styloidectomy in reducing symptoms of Eagle’s syndrome.

Methods:

Retrospective chart review and prospective case series. We retrospectively gathered demographic data on all patients at a single institution who underwent styloidectomy during a 5-year period. Using a patient symptom survey, we also gathered prospective data on a cohort of these patients presenting during the second half of the timeframe.

Results:

Thirty-two patients underwent styloidectomy for Eagle’s syndrome between November 2010 and June 2015. Of these patients, 22 (68.8%) were female, 29 (90.6%) were Caucasian, and 10 (31.3%) reported history of tonsillectomy. Mean age was 46.0 years, and mean BMI was 26.1 kg/m2. Nineteen patients completed the prospective survey. Average styloid length was 45.3 mm. Most severe preoperative symptoms were neck pain, otalgia, globus, facial pain, headache, and discomfort with neck turning. Thirteen of 17 individual symptoms demonstrated significant decrease in symptom scores after styloidectomy. Aggregate symptom scores also showed significant decrease postsurgically. Longer styloid length correlated with increased scores for dysphagia and odynophagia but not with conglomerate symptom scores.

Conclusions:

Patients with Eagle’s syndrome were mostly female, Caucasian, and had near-normal BMI. There is wide variability in presenting symptoms of Eagle’s syndrome, but nearly all demonstrate improvement after styloidectomy. Thus, in appropriately selected patients, styloidectomy can effectively and reliably produce improvement in patient symptoms.

Moving target: transient rotational stenosis precipitating jugular bow hunter's syndrome

A 60-year-old man presented with a 10-month history of of stereotypical spells characterized by vertigo, tinnitus, blurred vision, left hemibody numbness, and occasional syncope, precipitated by turning his head leftwards. Cerebral angiography and CT angiography of the head and neck with provocative maneuvers did not demonstrate vertebral artery narrowing. However, there was narrowing of the left internal jugular vein due to extrinsic compression from the sternocleidomastoid with leftward head rotation in the setting of hypoplasia of the right internal jugular vein. The patient underwent a cervical venogram which confirmed the finding. Manometric evaluation demonstrated a gradient of 29 mm Hg across the stenosis with the head turned leftwards compared with 1 mm Hg in the neutral position. The patient was treated with myectomies of the left sternocleidomastoid, posterior belly of the digastric, stylohyoid and omohyoid and styloid process removal. Following surgery, the patient reported complete resolution of symptoms. Repeat venography demonstrated resolution of the stenosis and pressure gradient.

Moving target: transient rotational stenosis precipitating jugular bow hunter's syndrome

A 60-year-old man presented with a 10-month history of of stereotypical spells characterized by vertigo, tinnitus, blurred vision, left hemibody numbness, and occasional syncope, precipitated by turning his head leftwards. Cerebral angiography and CT angiography of the head and neck with provocative maneuvers did not demonstrate vertebral artery narrowing. However, there was narrowing of the left internal jugular vein due to extrinsic compression from the sternocleidomastoid with leftward head rotation in the setting of hypoplasia of the right internal jugular vein. The patient underwent a cervical venogram which confirmed the finding. Manometric evaluation demonstrated a gradient of 29 mm Hg across the stenosis with the head turned leftwards compared with 1 mm Hg in the neutral position. The patient was treated with myectomies of the left sternocleidomastoid, posterior belly of the digastric, stylohyoid and omohyoid and styloid process removal. Following surgery, the patient reported complete resolution of symptoms. Repeat venography demonstrated resolution of the stenosis and pressure gradient.