Venous Sinus Stenosis

Venous Sinus Stenosis: What You Need to Know

Venous sinus stenosis (VSS) is a condition where the large veins in the brain that carry blood from the brain to the heart (venous sinuses) become narrowed, blocking blood flow. This narrowing can cause increased pressure in the skull, resulting in various symptoms like headaches, vision changes, pulsatile tinnitus (a rhythmic pulsing sound in the ear), and, in some cases, serious neurological issues. The most serious complication is the development of blood clots. Because of the complex nature of venous sinus stenosis and its potential risks, specialized expertise and care are crucial for accurate diagnosis and proper treatment.

Dural venous sinus stenosis can be characterized as either intrinsic or extrinsic stenosis. Intrinsic stenosis refers to internal filling defects such as prominent arachnoid granulations that narrow the sinus. Extrinsic stenosis involves external compression of the sinus by adjacent brain parenchyma.

What Causes Venous Sinus Stenosis?

There are two reasons why the venous sinuses can become narrowed:

Intrinsic Stenosis:

This is when the narrowing is caused by something inside the sinus itself. Common causes of intrinsic stenosis include:

• Enlarged arachnoid granulations.
  • These are the valves that allow cerebrospinal fluid to flow through the venous sinuses from the brain to the bloodstream. If they grow big enough, they can block the flow of blood.
• Blood clot.
  • A clot inside the sinus can cause a partial or complete blockage.
• Fibrous septae.
  • Some people are born with bands of connective tissue inside the venous sinuses. This tissue, which can develop in the form of bridges, tunnels, or pockets, can narrow the passageway and restrict blood flow.
• Venous sinus wall thickening.
  • Chronic stress, inflammation, or scarring that results from infections or other conditions can cause the walls of the sinuses to thicken, reducing blood flow from the brain.

Extrinsic stenosis:

This means the sinuses are being compressed from the outside, causing them to narrow. Factors that can compress the venous sinuses include

• Intracranial hypotension.
  • Excess cerebrospinal fluid can increase pressure, causing the venous sinuses to collapse against the skull, restricting blood flow.
• Tumors.
  • Growths that develop in or near the venous sinuses can compress the area.
• Infections.
  • Inflammation caused by conditions like meningitis can cause swelling in parts of the brain that put pressure on the venous sinuses.

Risk Factors

Venous sinus stenosis primarily affects young women with obesity of childbearing age; however, men can also be affected. Other risk factors include blood clotting disorders, pregnancy, inflammatory bowel disease, certain types of cancer, and obesity.

If not treated, venous sinus stenosis can lead to a range of complications, including headaches, vision problems, and a rhythmic pulsing in the ear. More significantly, there is a risk of developing blood clots, called venous sinus thrombosis. Blood clots can cause brain swelling, bleeding, or stroke. 

Common Symptoms

• Symptoms can vary depending on the severity of the narrowing and the location, but can include:
• Severe, chronic headache
• Blurred or double vision
• Tinnitus (ringing in the ears)
• Dizziness or vertigo
• Nausea and/or vomiting
• Mental confusion or memory problems
• Weakness or numbing in part of the body

How Venous Sinus Stenosis Is Diagnosed

Venous sinus stenosis is typically diagnosed through  a physician’s clinical evaluation and the use of imaging technology, which can include:

Magnetic resonance venography (MRV): This technology uses magnetic resonance imaging (MRI) to visualize the veins and blood flow. This technique allows the physician to identify any abnormalities or blockages in the blood vessels, including venous stenosis.

Computed tomography venography (CTV): This technology uses X-ray and contrast dye to provide a 3D image of the veins. This technique allows the physician to examine the extent and severity of any vein abnormalities.

Cerebral angiography: This technology uses X-ray and a contrast dye to highlight blood vessels on X-ray images. This technique allows the physician to see details of blood vessels in the brain. 

Treatment Options

Depending on a patient’s symptoms and their severity, venous stenosis can be managed with medications such as anticoagulants or anti-inflammatory drugs. When patients experience intracranial hypertension or pulsatile tinnitus that doesn’t improve with medication, advanced procedures may be considered, including a minimally invasive endovascular procedure called stenting.

Venous Sinus Stenting: What to Expect

Venous sinus stenting involves placing a small mesh tube in the narrowed vein to widen it and restore normal blood flow. The patient is placed under general anesthesia for the procedure. The physician makes a small incision in the groin or arm to insert a thin, flexible tube called a catheter, which is guided toward the narrowed vein using X-ray imaging. Once the catheter reaches the vein, the physician inflates a balloon at the tip to open the narrowing and position the stent. The catheter is then removed.

After the procedure, some patients spend the night in the hospital for monitoring. Headache is a common complication following stenting and resolves within a few days of the procedure. Rare complications can include blood clots, bleeding in the brain, and infection. Most patients experience a significant reduction in symptoms following stenting. 

Living with Venous Sinus Stenosis

People who have venous sinus stenting can experience a significant improvement in quality of life. Some people can experience a recurrence of the stenosis, so regular follow-up is important. Experiences will vary based on individual symptoms and severity, making expert management an important component. New Jersey Brain and Spine neurosurgeons have expertise in tailoring effective treatment plans for patients with venous sinus stenosis. 

When to See a Doctor

If you have persistent headaches, vision changes, or tinnitus, especially if they don’t improve with rest and over-the-counter medications, contact the specialists at New Jersey Brain and Spine. These symptoms may be related to intracranial hypertension and venous sinus stenosis. Early diagnosis and treatment can help improve symptoms and prevent serious complications.