What is Jugular Foramen Syndrome?
The jugular foramen is a pair of openings found on each side of the base of the skull. They are located on the sides of the large opening known as the foramen magnum. Several vital passages go through these openings or foramen – the glossopharyngeal or nerve IX, the vagus or nerve X, the spinal accessory nerve or nerve XI, and the internal jugular vein.
Inside the foramen, a thin bridge made of fibrous bone separates it into two sections. This bridge connects two parts of two different bones in the skull – the temporal bone and the occipital bone. The part in front (anteromedial compartment or pars nervosa) contains nerve IX, an offshoot of nerve IX called Jacobson’s nerve, and the lower part of the petrosal sinus. The part at the back (posterolateral component or pars venosa) houses the internal jugular vein, the jugular bulb, nerves X and XI, an offshoot of nerve X called Arnold’s nerve, and the rear part of the ascending pharyngeal artery.
There’s a condition called the jugular foramen syndrome, also known as JFS. It happens when the nerves IX, X, and XI, which pass through the jugular foramen, become paralyzed. This condition was first described by Vernet in the Paris Medical Journal back in 1917.
What Causes Jugular Foramen Syndrome?
Jugular foramen syndrome is a condition that might be caused by several different factors. These have been mentioned in medical research and can be grouped in categories.
Firstly, some people might have it from birth due to a condition known as primary cholesteatoma. This is a skin growth that happens in the middle ear, behind the eardrum.
Secondly, it might be due to issues with the blood vessels. This can happen because of uneven and enlarged jugular foramen, that is the passage in the base of the skull through which the jugular vein and several nerves exit, a high or bulging jugular bulb, which is a dilation in the internal jugular vein, a blockage of the internal jugular vein, swellings in the carotid artery or vertebral artery that supply blood to the brain, neck and face, or a pouch-like structure formed in the jugular vein, also known as a diverticulum.
Thirdly, it might be due to inflammation, specifically from conditions like giant cell arteritis, which is an inflammation of the arteries’ walls, or Wegener’s granulomatosis, an uncommon disease characterized by inflammation of the blood vessels.
Fourth, infections such as the chickenpox or shingles virus, herpes virus, or an abscess in the throat can trigger it.
Fifth, tumors either benign or malignant, can cause it. Benign tumors include paraganglioma, a rare neuroendocrine neoplasm, schwannomas of lower cranial nerves, which are tumors of the covering of nerves, tumors of the meninges or the covering of the brain and spinal cord, benign cysts, neurofibromas, or a very rare malignant growth in the skull bone. Malignant tumors might include metastasis, squamous cell cancer, a cancer of plasma cells called multiple myeloma, a cancer of the cartilage known as chondrosarcoma, or lymphomas – a group of cancers of a specific type of white blood cells.
Lastly, it could be due to trauma such as a penetrating injury or fractures involving the base of the skull.
Risk Factors and Frequency for Jugular Foramen Syndrome
Jugular foramen syndrome is a rare condition, and because of this, it’s hard to know exactly how often it occurs. The most common cause of jugular foramen syndrome is metastatic disease, a condition where cancer cells spread from the original tumor to other parts of the body. This is often overlooked when diagnosing patients. Metastasis commonly occurs in the later stages of diseases like breast, lung, kidney, and prostate cancer, when the disease has spread to the base of the skull.
However, when it comes to the primary hidden illnesses that can lead to jugular foramen syndrome, paragangliomas are the most common, followed by schwannomas and meningiomas. Some recent research even suggests that these primary illnesses occur more frequently than the spreading of cancer cells.
Signs and Symptoms of Jugular Foramen Syndrome
Jugular foramen syndrome, often shortened to JFS, is a conditioned linked to issues in the nerves of your head neck. The most common symptoms include a hoarse voice or trouble swallowing, known medically as dysphagia. It’s also commonly associated with persistent pain around the area of the ear and headaches.
The specific symptoms a patient experience rely on which parts are affected by JFS. These include:
- Compression of the vagus nerve: Initial effects include voice changes, like hoarseness or a nasal-sounding voice due to paralysis in the larynx (voice box). As the issue progresses, one side of the soft palate may become paralyzed, causing the uvula (the dangly bit at the back of the mouth) to deviate to the healthy side.
- Dysfunction of the glossopharyngeal nerve: Symptoms can include numbness on one side of the back of the tongue, less spit from the salivary gland on the same side, and a missing or reduced gag reflex.
- Problems in the accessory nerve: This can result in difficulties lifting the shoulder, moving the arm away from the center of the body, and turning the head to the opposite side, due to weakened muscles.
Blockage of the veins and sinuses in the area can cause headaches and a condition called papilledema, which is swelling in the optic nerve due to increased pressure within the skull.
Doctors diagnosing JFS will be on the lookout for specific issues, this could include noticing:
- Problems with the palatal and gag reflexes
- A drooping shoulder
- Vocal cord palsy on one side
- Weakness in the sternocleidomastoid and trapezius muscles, located in the neck and back respectively
- Fasciculation (muscle twitches) or winging of the scapula (shoulder blade sticking out)
- Other symptoms involving the cranial nerves or the brainstem
- Cerebellar signs (coordination and balance issues, for example)
- Checking the mouth and exterior of the ear canal for signs of rashes or lumps
Moreover, unique conditions have been associated with JFS, such as the Glossopharyngeal neuralgia syncope syndrome and a symptom known as pulsatile tinnitus, which is a rhythmic noise that only you can hear, often syncing with your heartbeat.
Testing for Jugular Foramen Syndrome
There are various tests that can be done to identify the cause of jugular foramen syndrome, a rare condition affecting certain nerves in the brain:
1. A brain scan using Magnetic Resonance Imaging (MRI), with a special dye to highlight any abnormalities. This is the most common test if jugular foramen syndrome is suspected. Additional MRI scans of the blood vessels (MRA and MRV) can give more information about blood supply to the tumor and the surrounding veins.
2. Digital Subtraction Angiography (DSA) is a special type of X-ray of the blood vessels. This is necessary for patients with lesions (abnormal changes in body tissue) that have a high blood supply. In such cases, patients may need pre-surgery treatment to reduce the blood supply to the lesion.
3. A CT scan of the base of the skull along with angiogram. This imaging helps identify any bone erosion and blood vessel invasion by a tumour and helps doctors plan for surgery.
4. Indirect laryngoscopy, a procedure to check your larynx (voice box). This helps determine the extent of any vocal cord paralysis, which may suggest the need for a tracheostomy, a surgery to create a hole in your windpipe for breathing, after the main surgery.
In addition to the above, your healthcare provider may suggest several lab tests:
1. General tests including a total blood count, erythrocyte sedimentation rate (a test that measures inflammation in your body), and C-reactive protein (a protein that increases in your blood when there’s inflammation in your body).
2. Tests to check for specific types of antibodies that can indicate certain autoimmune conditions.
3. Tests for Varicella-zoster virus (the chickenpox virus) and Herpes Simplex Virus.
4. Tests of your cerebrospinal fluid, the fluid around your brain and spinal cord, for any abnormalities.
5. A Polymerase chain reaction test (a test that is used to amplify select parts of DNA), to detect varicella-zoster virus.
6. Nerve conduction studies and electromyography (tests that measure the electrical activity of muscles and nerves) for the sternocleidomastoid and trapezius muscles if the diagnosis is uncertain.
A common finding in glomus jugulare tumors (a slow-growing, benign tumor that can be found at the base of your skull), is a ‘moth-eaten’ pattern of bone destruction shown on a CT scan, ‘salt-and-pepper’ pattern on long delayed MRI images, and a ‘dropout’ phenomenon in time-intensity curves on a contrast MRA.
Treatment Options for Jugular Foramen Syndrome
The treatment of Jugular Foramen Syndrome (JFS) depends on the cause of the condition:
1. Surgery: This is the standard care for various benign (non-cancerous) tumors such as schwannomas, meningiomas, non-invasive paragangliomas, and others. Complete removal of the tumor can potentially cure the condition. However, sometimes only a portion of the tumor can be removed to protect vital areas of the brain, critical blood vessels, and cranial nerves (nerves that originate from the brain). Dealing with large paragangliomas that have extended into the brain requires a team of various healthcare professionals. There are also procedures for handling increased pressure within the skull due to narrowed or blocked veins.
Radiotherapy: This refers to the use of high-energy rays to treat diseases. Stereotactic radiosurgery, which precisely targets the treatment area, may be used to treat paragangliomas smaller than 3 cm in diameter. The technology allows for a safe treatment option that reduces disease-related complications. For larger tumors measuring more than 3 to 4 cm, a similar method is used but the dose is divided into multiple smaller doses delivered over a period of time, which is also known as dose fractionation.
Radiotherapy is sometimes used after surgery to manage residual disease when it wasn’t possible to remove the entire tumor.
Embolization: This is a procedure that involves blocking the blood supply to extensively vascular tumors like paragangliomas, which can help reduce the blood loss during surgery.
Medications: These may include anticoagulants, which prevent blood clots, for jugular vein thrombosis (a condition where a blood clot formed in the jugular vein). For viral infections, Acyclovir (an antiviral medication) and steroids (medications that reduce inflammation) are used.
What else can Jugular Foramen Syndrome be?
There are several different forms of the medical condition known as jugular foramen syndrome. Each type relates to dysfunction in specific cranial nerves:
- Jackson syndrome: Impairs the functioning of cranial nerves X, XI, and XII.
- Collet–Sicard syndrome: Affects cranial nerves IX, X, XI, and XII.
- Villaret syndrome: Affects cranial nerves IX, X, XI, and XII, along with causing a condition affecting one side of the body known as Horner syndrome.
- Tapia syndrome: Impairs cranial nerves X and XII.
- Avellis syndrome: Causes vocal cord and palatal paralysis, along with a different condition on the opposite side of the body where there’s a loss of pain and temperature sensations, but touch sensations are preserved.
- Schmidt syndrome: Causes a lesion of the vagal nerve as well as both the bulbar and spinal accessory nuclei.
What to expect with Jugular Foramen Syndrome
The outlook for someone experiencing compression at the jugular foramen (the opening in the base of the skull where nerves and blood vessels pass through), depends on the cause of the compression. If it is due to a non-cancerous (benign) condition, complete removal through surgery might be possible, thereby potentially curing the problem.
For patients with compression caused by the spread of cancer (metastatic compression), their survival usually depends on the progression and severity of the original cancer, as well as how much this cancer has spread elsewhere in the body.
If the compression is due to an infection or blood vessel-related issue (vascular causes), the right treatment could bring adequate relief. However, if the compression leads to the loss of function in the lower cranial nerve (a condition known as palsy), following an injury (post-traumatic), the majority of cases don’t achieve complete recovery.
Possible Complications When Diagnosed with Jugular Foramen Syndrome
Common complications that might happen to patients with jugular foramen syndrome, particularly after surgery, include:
- Vocal cord paralysis
- Aspiration pneumonia, which might be prevented by extubating later, placing a breathing tube in some cases, and starting rehabilitation quickly
- Exposure keratopathy, or eye problems, if the facial nerve is involved – this might require closing part of the eyelid (tarsorrhaphy)
- Leakage of cerebrospinal fluid, the fluid around the brain and spine
Preventing Jugular Foramen Syndrome
If you have Juvenile Fibromyalgia Syndrome (JFS), it’s crucial to understand your condition and what causes it. If surgery is required, you’ll receive counseling to prepare you for what to expect. The possibility of needing a tracheostomy, which is a procedure to create an opening in the neck to assist with breathing, or a feeding gastrostomy, a procedure where a tube is inserted in your stomach to assist with feeding, may be discussed before surgery if required. These steps are crucial to help manage your condition effectively.
