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:

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 is referred to as primary angiitis of the CNS (PACNS).

Is central nervous system vasculitis dangerous?

CNS vasculitis can be a serious condition. The inflamed vessel wall can block the flow of oxygen to the brain, causing a loss of brain function. In some cases, CNS vasculitis is life-threatening.

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)
  • Weakness
  • Fever
  • Joint pains
  • Abdominal (stomach) pain
  • Kidney problems (including dark or bloody urine)
  • Nerve problems (including numbness, weakness, and pain)

Other symptoms can occur, depending on the area of the body affected by vasculitis. If a blood vessel with vasculitis is small, the vessel may break and produce tiny areas of bleeding in the body. These areas will appear as small red or purple dots on the skin. If a larger vessel is inflamed, it may swell and produce a nodule (lump or mass of tissue), which may be felt if the blood vessel is close to the skin surface.

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)
  • Sensation abnormalities

Last reviewed by a Cleveland Clinic medical professional on 03/07/2016.


  • National Heart, Lung, and Blood Institute. What is vasculitis? Accessed 3/9/2016.
  • Hajj-Ali RA, Singhal A, Benseler S, Molloy E, Calabrese LH. Update on Primary Angiitis of the Central Nervous System. Lancet Neurol 2011 Jun;10(6):561-72.

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