Central Nervous System Vasculitis

What is vasculitis?

Vasculitis is the inflammation (swelling) of the blood vessels, the network of hollow tubes that carry blood throughout the body. Vasculitis can affect very small blood vessels (capillaries), medium-size blood vessels (arterioles and venules) or large blood vessels (arteries and veins). If blood flow in a vessel with vasculitis is reduced or stopped, the parts of the body that receive blood from that vessel begin to die.

What is central nervous system vasculitis?

Central nervous system (CNS) vasculitis is inflammation of blood vessel walls in the brain or spine. (The brain and the spine make up the central nervous system.) CNS vasculitis often occurs in the following situations:

• Accompanied by other autoimmune diseases such as systemic lupus erythematosus, dermatomyositis and rarely, sarcoidosis and rheumatoid arthritis.
• Infection, such as viral or bacterial.
• Systemic (affecting the whole body) vasculitic disorders, which include granulomatosis with polyangiitis GPA), eosinophilic granulomatosis with polyangiitis (EGPA), microscopic polyangiitis, cryoglobulinemic vasculitis and Behçet's syndrome).

It can also occur without any associated systemic disorder. In this case, the vasculitis is only confined to the brain or the spinal cord and it’s referred to as primary angiitis of the CNS (PACNS).

Is central nervous system vasculitis dangerous?

CNS vasculitis is a serious condition. The inflamed vessel wall can block the flow of oxygen to the brain, causing a loss of brain function and ultimately strokes. In some cases, CNS vasculitis is life-threatening. It’s important to get treatment for this condition.

What causes vasculitis?

In most cases, the exact cause is unknown, but the immune system (which helps keep the body healthy) plays a role. While the immune system usually works to protect the body, it can sometimes become "overactive" and attack the body. In most cases of vasculitis, something causes an immune or "allergic" reaction in the blood vessel walls.

Substances that cause allergic reactions are called antigens. Sometimes certain medicines or illnesses can act as antigens and start this process.

What are the symptoms of vasculitis?

Symptoms of vasculitis include:

• Skin rashes.
• Fatigue (tiredness).
• Weight loss.
• Weakness.
• Fever.
• Joint pains.
• Abdominal (stomach) pain.
• Kidney problems (including dark or bloody urine).
• Nerve problems (including numbness, weakness and pain).

What causes central nervous system vasculitis?

How the vessels in the brain become inflamed is not entirely clear. In some vasculitic diseases, abnormal antibodies (autoantibodies) attack white blood cells, which attack vessel walls and cause inflammation and destruction of the vessel wall. Infection caused by a virus can also cause CNS vasculitis.

What are the symptoms of central nervous system vasculitis?

Symptoms of CNS vasculitis can include the following:

• Severe headaches that last a long time.
• Strokes or transient ischemic attacks ("mini-strokes").
• Forgetfulness or confusion.
• Weakness.
• Problems with eyesight.
• Seizures.
• Encephalopathy (swelling of the brain), that can manifest as change is mood or personality and decrease level of consciousness.
• Sensation abnormalities.

How is vasculitis diagnosed?

The diagnosis of vasculitis, including CNS vasculitis, is based on a person's medical history, symptoms, a complete physical examination and the results of special laboratory tests. Blood abnormalities that are found in vasculitis include:

• Anemia (a shortage of red blood cells).
• A high white blood cell count.
• A high platelet (which allows blood to clot) count.
• Kidney or liver problems.
• Elevation of inflammatory markers.
• Special markers in the blood that can be present in certain types of vasculitis.

(In PACNS, when the vasculitis is only confined to the brain or spinal cord, the above symptoms and signs are often lacking and people see the symptoms of CNS vasculitis only.)

Other tests may include X-rays, tissue biopsies (taking a sample of tissue to study under a microscope) and blood vessel scans. A provider might also want to examine the spinal fluid to see what is causing the inflammation, through a procedure called lumbar puncture or spinal tap. This test is often performed in CNS vasculitis.

Other essential test include magnetic resonance imaging (MRI), computer tomography (CT) or angiogram of the brain. An angiogram can show which blood vessels are narrowed.

Because other conditions can cause some of the same brain vessel abnormalities as CNS vasculitis, a brain biopsy is the only way to make certain of a diagnosis. A brain biopsy can distinguish between CNS vasculitis and other diseases that may have similar features.

How is central nervous system vasculitis treated?

CNS vasculitis is usually treated in stages.

The initial stage is known as induction therapy. Here high-dose steroids are usually administrated, often intravenously, with or without other immunosuppressive medications such as cyclophosphamide or mycophenolate mofetil medication that decreases the immune system's response to autoimmune diseases. Then steroids are tapered off over six months.

When a person is in remission they enter in a maintenance phase where cyclophosphamide (if used in the induction phase) is switched to other immunosuppressive medication such as mycophenelate mofetil. Low dose steroid may be used in the maintenance phase. Treatment must be continued for a prolonged period, sometimes for life.

If the patient has another illness (such as lupus) or systemic vasculitis, then treatment should also include guidelines for the specific condition.