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CNS Vasculitis

What is CNS vasculitis?

The brain and the spinal column make up the central nervous system (CNS). Vasculitis is an inflammation of the blood vessels. Blood vessels are the veins and arteries that carry blood around the body including the brain. So CNS vasculitis is an inflammation of blood vessels in the brain.

Vessel Anatomy of the Brain
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There are many blood vessels in the brain. Some are large vessels and they can be seen on an angiogram. The brain has many small vessels that can only be seen with a microscope. A biopsy is needed to examine these smaller vessels.
Inflammation (irritation and swelling) is a normal process. It is how our immune systems protect our bodies from bacteria and viruses that cause infection. But in CNS vasculitis, there is no infection. Instead, the immune system wrongly attacks normal cells causing inflammation. This type of problem is called an autoimmune disease. So far, we do not understand what causes these problems.

CNS vasculitis can harm the brain

The inflammation caused by CNS vasculitis can harm the brain. When they are inflamed, the walls of the blood vessels get thicker and the space inside them gets smaller. This means that less blood can flow through them. Parts of the brain get less blood than they need. Sometimes they get no blood at all. When this happens, two major problems can result:

  • Brain tissue around the inflamed blood vessel becomes irritated or damaged. This is also called brain inflammation.
  • Brain tissue around inflamed blood vessels does not get enough oxygen. This can cause a stroke.

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Inflammation causes the blood vessel walls to swell, restricting the space inside, and reducing blood flow.
CNS vasculitis is treated with medicine. This helps to prevent new damage. It also gives blood vessels time to heal.

Signs and symptoms of CNS vasculitis

The first signs of CNS vasculitis are usually one or more of the following:

  • headaches
  • irritability
  • learning problems
  • eyesight (vision) problems
  • problems dealing with loud sounds or bright lights

Most children are not diagnosed with CNS vasculitis when these symptoms first appear. Usually, a child is diagnosed with CNS vasculitis after having one of these serious problems:

  • numbness, weakness, or paralysis of one side of the body (hemiplegia)
  • seizure
  • stroke

There are many different names for CNS vasculitis

The naming of CNS vasculitis is very confusing. When you look at pages on the Web, you may see many different names for the same disease, including:

  • isolated angiitis of the CNS (IACNS)
  • transient cerebral arteriopathy (TCA)
  • transient cerebral vasculopathy

In medical journals, you will most often see childhood CNS vasculitis referred to as cPACNS. This stands for "childhood primary angiitis of the CNS."

There are 3 types of CNS vasculitis

Different types of CNS vasculitis are described in these terms:

  • the size of the blood vessel that is affected: small vessel or large vessel CNS vasculitis
  • whether the CNS vasculitis is spreading (progressive) or not spreading (non-progressive)

CNS Vasculitis
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This view of brain tissue under a microscope shows inflammation around a small vessel.
Your doctor needs to find out which type your child has, because the different types are treated in different ways. In general, these are the 3 types:

  1. Small vessel CNS vasculitis: This type is severe and needs to be treated with strong medicine. Once it is found and treated, it heals very well.
  2. Progressive large vessel CNS vasculitis: This type will spread to other blood vessels if it is not treated.
  3. Non-progressive large vessel CNS vasculitis: This type does not spread, but it needs to be treated to prevent brain damage.

There are several steps to diagnosing CNS vasculitis

Medical history and physical exam

First, the doctor will ask about your child's symptoms and medical history. The doctor will do a physical exam to see if your child has any symptoms of brain inflammation.

Blood sample and spinal tap

Next, the doctor will take samples of your child's blood and cerebrospinal fluid (CSF). CSF is the fluid that surrounds the brain and spinal cord. To get a sample of CSF, your child will need to have a spinal tap (lumbar puncture).

Your child's blood and CSF will be tested to see if they contain certain substances that can show if your child has inflammation somewhere in the body.

MRI of CNS Vasculitis
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MRI scan

Next, the doctor will order an MRI scan. This test makes special pictures of the brain, using radio waves and a strong magnet. The doctor will look at these pictures to see if your child's brain has either of these:

  • areas of brain inflammation
  • areas where not enough blood is flowing (ischemia or stroke)


If the MRI shows problems, the doctor will order two kinds of angiogram. An angiogram is a test that gives pictures of the large blood vessels. The two types are as follows:

  • A magnetic resonance angiogram (MRA) uses the same machine as an MRI. It gives a 3-dimensional picture of the large blood vessels.
  • An X-ray angiogram gives a picture of the large blood vessels. Your child will have a special dye injected into his blood. This dye is called contrast fluid. It helps blood vessels show up on the X-ray.

Angiogram of CNS Vasculitis
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An angiogram shows what the large blood vessels look like.
Angiograms will show if your child has large vessel CNS vasculitis. But they do not show the small blood vessels. So even if these tests do not show any problems, your child could still have small vessel CNS vasculitis.

Brain biopsy

The only way to find small vessel CNS vasculitis is with a test called a brain biopsy. A neurosurgeon will take a tiny sample from your child's brain. The sample is only the size of a needle. Another doctor will look at it under a microscope.

This test will show if your child has small vessel vasculitis. It can also help tell CNS vasculitis apart from other diseases, such as infections or brain tumours.

CNS vasculitis is treated with medicine

The treatment of CNS vasculitis aims to do these things:

  • improve the blood supply to the brain
  • prevent further complications
  • prevent blood clots from forming

CNS vasculitis is treated with medicine that stops the immune system from working so hard. This stops the inflammation and protects the brain. Your child will also need to take medicine to prevent blood clots.

A full course of treatment takes about two years.

Key points

  • CNS vasculitis is a condition where the immune system attacks the blood vessels in the brain.
  • CNS vasculitis can cause headaches, irritability, learning problems, vision problems, weakness on one side of the body, seizures, or stroke.
  • If you think your child may have CNS vasculitis, contact your family doctor and ask her to examine your child.

Susanne Benseler, MD

Holly Convery, RNEC, BScN