Eagle Syndrome and the Artery and Vein Compression Connection
What is Eagle Syndrome?
The Styloid Process is a thin, slender bone of the skull found just below the ears on both sides. It serves as an attachment site for muscles associated with the tongue and the throat. Eagle’s Syndrome is a rare clinical condition where the styloid bone grows or its ligaments become calcified which can cause compression of the arteries and/or veins.
“Eagle syndrome is caused by an elongated styloid process or calcified stylohyoid ligament. The stylocarotid variant with neurologic symptoms is rare and presents a diagnostic challenge. Patients may present with…
- Transient ischemic attacks (i.e. a temporary disruption in the blood supply to part of the brain- The disruption in blood supply results in a lack of oxygen to the brain)
- Syncope (i.e. unconscious and go limp, then soon recover)
- or less well defined symptoms, like episodic dizziness
“To the best of our knowledge, Eagle syndrome with arterial and venous compression due to elongated styloid process has not been previously presented in the literature.” Turkey Reference
“Eagle’s syndrome is a condition of orofacial pain related to the elongated styloid process or the calcification of the stylohyoid ligament. It affects around 4-10% of the population…. over 30 mm may be the cause of the Eagle’s syndrome.” Europe PMC Reference
“Elongated styloid process or calcified stylohyoid ligament is thought to contribute to pain on swallowing (odynophagia) and neck pain through compression of glossopharyngeal nerve.” University of Alberta (Canada) Reference”
What Symptoms Does Eagle Syndrome Produce?
Clinical presentation may include headache, anxiety and neck discomfort, head noises, hearing loss, memory loss, visual disorders, and difficulty of sleep. Other symptoms may include difficulty swallowing, feeling of something stuck in the throat, and facial pain.
Eagle syndrome is a rare entity that causes recurrent throat pain, neck pain, dysphagia (swallowing difficulties), or facial pain due to an elongated styloid process or calcified stylohyoid ligament. Clinical findings related to lower cranial nerve compression have also been reported. Reference
Patients with Eagle syndrome typically present with dysphagia, dysphonia, cough, voice changes, otalgia, sore throat, facial pain, foreign body sensation, headache, vertigo, and neck pain. Korean Reference
What Causes Eagle Syndrome?
It was found that some of the patients diagnosed with Craniocervical Instability also have Eagle syndrome. The elongation of the styloid process is not the only causative factor, but the process itself could present a specific orientation of the styloid process causing an impression on the jugular vein.
Eagle syndrome is also seen in some patients after throat trauma or tonsillectomy (removal of tonsils).
What Tests Confirm eagle syndrome?
- Cone Beam CT / CT scanning with 3D reconstruction is recommended to visualize elongated styloid process
- Other tests include: Contrast enhanced MRV, CT venography, and Catheter Venography
Figure 3: CE-MRV (contrast-enhanced magnetic resonance venography) showing severe bilateral IJVS, surrounded by abnormally distorted vertebral venous plexuses (A, white arrow). In 3D reconstruction of CT scanning, the J3 segments of the bilateral IJV were obviously compressed by the adjacent lateral mass of C1 and styloid process (B, red arrow).
Which Specialist Treats Eagle Syndrome Patients?
The neurologist and the neurosurgeon are the specialist doctors who take care of patients with Eagle syndrome.
What are the Conservative and Surgical Treatment Methods for Eagle Syndrome?
- Conservative Treatment: Postural awareness
- Orthobiologic Injections that cause strengthening of the longus capitis, suboccipital and, levator scapula muscles to pull the occipital facets anteriorly
- Surgical Options: Internal jugular vein stenting, Styloidectomy
Case Study: Eagle Syndrome Surgery / Styloidectomy Treatment by Osborne Head & Neck Institute
“Kevin, an information security consultant by day, and a racing enthusiast by night suffers from Eagle’s Syndrome. Kevin has experienced terrible neurological symptoms and seeks a way to feel whole again. Having gone to Dr. Osborne to remove the styloid process on one side, he returns to have surgery on the other side.” – Physician – Patient Video
Eagle syndrome, both surgical and conservative treatment show promising results. Conservative management also includes ultrasound-guided steroid injections (note: relatively new research indicates steroid injections are not advisable more than 3 times due to nerve damage and bone death reference) or long-lasting anaesthetics into the lesser cornu of the hyoid or the inferior aspect of the tonsillar fossa in order to relieve symptoms.
Surgical methods involve removing the elongated styloid process, for which two different approaches have been proposed: the extraoral or transcervical and the intraoral or transpharyngeal approach.7 Starting with conservative management and, if that fails, going for the surgical option, appears to be a sound approach.” UAE Reference
“Medical therapy is first-line treatment for Eagle syndrome… In cases that do not respond to medical therapies, surgery is indicated. Different medications may be used in medical management of Eagle syndrome based on the respective etiology, including analgesics, anticonvulsants, antidepressants, and local infiltration with steroids or long-acting local anesthetic agents20. Nonsurgical treatment of Eagle syndrome with gabapentin, tianeptine, tramadol, acetaminophen, local lidocaine injection and stellate ganglion block has also been reported…” Korea Reference
What is an Internal Jugular Vein?
The Internal Jugular Vein is a major blood vessel that lies along each side of the neck and functions to return non-oxygenated blood from the brain, face, and neck back to the heart. The vein begins at the lower part of the skull and moves down in the neck passing between the styloid process of the skull and the transverse process of the atlas bone (C1). It ends behind the collar bone (the clavicle) by joining another vein (the subclavian vein). The IJV has three segments, the lower (J1), the middle (J2), and the upper segment (J3).
What are Possible IJV Abnormalities?
Degenerative disorders of the cervical spine like cervical spondylosis can result in the disk bulging outward, this can put pressure on the blood vessels and nerves in the neck, including the IJV. The IJV may also get blocked by a clot of blood (thrombus) or be compressed between the styloid process of the skull and the transverse process of C1 in patients with craniocervical instability.
Common IJV abnormalities in Craniocervical Instability Patients?
In Craniocervical Instability (CCI) the upper neck bones can move or shift due to loose or damaged ligaments. This instability can lead to compression of the Jugular Vein.
What Symptoms does IJV Compression Produce?
Common symptoms include Headache, weakness, problems with perception of body position, CSF excess with or without compensatory leak [Higgins 2019], craniovascular hypertension, brain swelling, hypertensive seizures, difficulty to see (dysopsia), and inability to speak clearly (dysarhria).
How can Eagle Syndrome Cause Internal Jugular Vein (IJV) Compression?
Eagle’s Syndrome is a rare clinical condition where the styloid bone grows or its ligaments become calcified which can cause compression of the Jugular Vein. The Styloid Process is a thin, slender bone of the skull found just below the ears on both sides. It serves as an attachment site for muscles associated with the tongue and the throat.
What are Possible Abnormalities?
Calcification of the ligaments or elongation of the Styloid bone are the main causes of compression of the Jugular Vein.
Common Abnormalities in CCI patients and Causes Of Eagle Syndrome?
It was found that some of the patients diagnosed with CCI have also Eagles syndrome. The elongation of the styloid process is not the only causative factor, but the process itself could present a specific orientation of the styloid process causing an impression on the jugular vein.
Eagle syndrome is also seen in some patients after throat trauma or tonsillectomy (removal of tonsils).
What Tests Confirm IJV compression?
Different imaging techniques are used to confirm the diagnosis of IJV compression this include:
- Magnetic Resonance Venography (MRV), which is an imaging test that is used to visualize veins in the body.
- Computed tomographic venography (CTV), which is an x-ray-based examination that uses an injection of contrast material to show how blood flows through your veins.
- Catheter venography (CV), in which a catheter is inserted into your veins then a contrast material is injected which makes your veins visible on the x-ray image.
- Magnetic Resonance Imaging (MRI),
- Cervical duplex ultrasound.
- Single‐photon emission computed tomography (SPECT), is a type of nuclear imaging test that uses a radioactive substance and a special camera to create 3D pictures.
Figure 2: Neuroimaging features of right IJVS induced by the C1 transverse mass. Sagittal (A), axial (B), and MRV (C) revealing the right IJV‐J3 segment stenosis accompanied by substantially abnormal collateral veins
What Specialist Treats Patients of IJV Compression due to Eagles syndrome?
The neurologist and the neurosurgeon are the specialist doctors who take care of patients with internal jugular vein compression and Eagle syndrome.
What are Conservative and Surgical Management methods for Eagle Syndrome Causing IJV Compression?
Treatment options for Jugular Vein Compression depend upon the symptoms and the severity of the compression. The treatment options could be:
- Medical treatment includes using blood thinners (anticaugulants), statins to lower cholesterol in the body, and antithromotics
- Endovascular treatment: comprise dilating the compressed segment of the vein (balloon angioplasty), putting a small tube in the vessel to hold it open (stenting), or both balloon angioplasty + stenting
- Surgery: includes cutting out the elongated styloid (styloidectomy), or C1 transverse process (C1 tubercolectomy), or both styloidectomy and C1 tubercolectomy
- A combined treatment (styloidectomy and stenting)
What is a Cerebral Artery?
- Ding J‐Y, Zhou D, Pan L‐Q, et al. Cervical spondylotic internal jugular venous compression syndrome. CNS Neurosci Ther. 2019;00:1–8. https ://doi. org/10.1111/cns.13148
- Bai C, Wang Z, Guan J, Jin K, Ding Y, Ji X, Meng R. Clinical characteristics and neuroimaging findings in eagle syndrome induced internal jugular vein stenosis. Ann Transl Med 2020;8(4):97. doi: 10.21037/atm.2019.12.93
- Scerrati A, Norri N, Mongardi L, Dones F, Ricciardi L, Trevisi G, Menegatti E, Zamboni P, Cavallo MA, De Bonis P. Styloidogenic-cervical spondylotic internal jugular venous compression, a vascular disease related to several clinical neurological manifestations: diagnosis and treatment—a comprehensive literature review. Ann Transl Med 2021;9(8):718. doi: 10.21037/atm-20-7698
- Jugular outlet syndrome (JOS), a common sequela of chronic upper cervical dysfunction https://www.researchgate.net/publication/337465853