What is CNS vasculitis?
CNS vasculitis is an inflammation of blood vessels in the brain. Blood vessels are the veins and arteries that carry blood around the body. In CNS vasculitis, the immune system mistakes normal cells in the blood vessels for harmful intruders and attacks them. This makes the blood vessel walls swell and get thicker.
CNS vasculitis can harm the brain. When the blood vessels are inflamed, less blood can flow through them. This means that the brain tissue around the inflamed blood vessels may be damaged, or it may not get enough oxygen. If CNS vasculitis is not treated, it can cause permanent damage.
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
Your child will need to take different kinds of medicine for CNS vasculitis:
- Medicine to suppress the immune system and reduce the inflammation in the blood vessel walls. This includes prednisone, cyclophosphamide, azathioprine, and mycophenolate mofetil.
- Medicine to make the blood thinner and prevent blood clots. This includes low-dose ASA (acetylsalicylic acid or Aspirin) and heparin.
Your child will be taking these medicines for many months. You need to know about them and about the side effects that your child may have. These are described in more detail below.
If you are worried about any side effects, talk to your child's doctor.
Heparin
Children with large vessel CNS vasculitis often take intravenous (IV) heparin at first. "Intravenous" means your child will take this medicine through a needle or a tube that puts it directly into her bloodstream.
Later, your child may take low molecular weight heparin (LMWH). This medicine is given with a needle under your child's skin.
ASA (Aspirin)
If your child has large vessel CNS vasculitis, she will also take ASA (acetylsalicylic acid or Aspirin) for the whole time she is being treated. ASA makes your child's blood thinner. This helps your child's blood travel through the blood vessels.
Your child will take a very low dose of ASA, between 2 and 5 mg per kilogram of body weight per day. At this dose, ASA has no major side effects. Some children may have an upset stomach.
Prednisone
Prednisone is a drug that suppresses the immune system. This means that it lowers the number of immune cells that are attacking your child's blood vessels. When your child takes prednisone for a long time, the immune system is able to "reset" itself and make a new set of healthy immune cells. The new immune cells will not attack your child's body.
Your child will be taking a high dose of prednisone to start with. As the treatment goes on, the doctor will lower the dosage.
Your child needs to take the amount of prednisone that the doctor prescribes. This is very important. If your child is taking high doses of prednisone and then suddenly stops, your child's body will not be able to adjust to the change.
The side effects of prednisone are not pleasant, but there is no other way to treat CNS vasculitis. The effects are stronger at higher doses and with longer courses of treatment. The main side effects are:
- weight gain
- more risk of getting infections
- hair growth
- stretch marks
- acne
- mood swings
- upset stomach
- higher blood pressure
- higher blood sugar
- thinning bones (osteoporosis)
These side effects are all temporary. They will go away as soon as your child stops taking the prednisone.
Cyclophosphamide
Cyclophosphamide also suppresses the immune system. It slows down or stops the growth of immune system cells. Your child will take cyclophosphamide once a month through an IV tube.
Cyclophosphamide is also used to treat some kinds of cancer. But we use much lower doses for CNS vasculitis. This means that CNS vasculitis patients have fewer side effects than cancer patients.
For children with CNS vasculitis, cyclophosphamide has 3 main side effects:
- more risk of getting infections
- more risk of bleeding
- upset stomach and vomiting (throwing up)
A very large dose of cyclophosphamide can make it hard for girls or boys to have children later on. We will watch your child's treatment to make sure she does not reach this dose.
Azathioprine (Imuran)
Azathioprine also suppresses the immune system. It stops immune system cells from dividing.
Common side effects include:
- stomach upset
- diarrhea
- allergic reactions
- a flu-like illness
- liver irritation
To watch for problems, your child will need a blood test every month.
Some people cannot remove azathioprine from their bodies. Before your child starts taking this medicine, she will need a blood test to find out if she can take it safely.
Mycophenolate mofetil (Cellcept or MMF)
MMF also suppresses the immune system. It stops immune system cells from getting overactive.
The most common side effect is stomach upset. To prevent this, your child should take the medicine with food.
A more serious side effect is when MMF stops the body from making white blood cells, red blood cells, and platelets. To watch the levels of these blood cells, your child will need regular blood tests.
Preventing infection during treatment for CNS vasculitis
The medicines for CNS vasculitis make the immune system less active. This means your child is more likely to get sick if she comes in contact with germs. To help keep your child and family healthy:
- Wash hands often.
- Stay away from anyone with an illness that is catching.
- Keep all family members' immunizations up to date.
Remember, your child's immune system is still working. Your child does not need to "live in a bubble." Your child can still have a normal lifestyle and stay healthy.
Do not be afraid to ask your child's doctor if you have any questions.
Immunizations
While your child is being treated for CNS vasculitis, she should not take live vaccines. One common live vaccine is the MMR (measles, mumps, and rubella) vaccine.
Ask your doctor which immunizations are safe for your child to have.
Treatment for CNS vasculitis takes about 2 years
Treatment for CNS vasculitis is a slow process. The entire treatment plan takes at least 2 years.
Not all types of childhood CNS vasculitis are treated the same way. Different children will need different medicines for different amounts of time. If the CNS vasculitis symptoms flare up, the doctors may decide to treat your child for longer. If the treatment works fast, the doctors will give less medicine.
Progressive large vessel CNS vasculitis and small vessel CNS vasculitis
Children with small vessel or progressive large vessel CNS vasculitis are usually treated in 2 stages:
- In the first stage, your child will take high doses of strong medicine. This is called the induction stage. The goal is to rescue the brain by treating the severe inflammation in your child's blood vessels. Your child will start with high doses of prednisone. The doctor will slowly lower the dose over the next 9 months.
- Your child may also take cyclophosphamide. If so, she will take it every month for the first 6 months.
- In the second stage, your child will take a gentler combination of medicines for another 18 months. This is called the maintenance stage. The aim during this stage is to help stop CNS vasculitis from coming back while your child's brain is healing. The medicines are usually azathioprine or MMF, plus low doses of prednisone.
This type of treatment is called an induction-maintenance strategy.
At the same time, your child will take a blood thinner to prevent blood clots.
Non-progressive CNS vasculitis
Children with non-progressive CNS vasculitis are usually treated with a high dose of prednisone for 3 months. Then your child will take smaller and smaller doses of prednisone over the next months. Taking smaller and smaller doses is called tapering.
At the same time, your child will take a blood thinner to prevent blood clots.
Your child will be monitored during treatment
MRIs and angiograms
Your child will have MRI tests often during treatment. Your child may also have angiograms. These tests help doctors see how the blood vessels are healing. This lets them make sure your child is getting the right amount of medicine.
Blood tests
Your child will have regular blood tests to see how the medicine affects her immune system. The goal is to keep your child's immune system low enough to stop it attacking the blood vessels, but not so low that your child is at risk for serious infections.
Tests of thinking and learning
When your child is diagnosed with CNS vasculitis, a psychologist will test her thinking and learning skills. Your child will be tested again every year to see if there are any changes. If necessary, the psychologist will work out a plan so that your child's school can help her learn better.
Your observations
Probably the most important way to monitor CNS vasculitis is through what you notice about your child. Your child will come for regular clinic visits. At these visits, the doctor will ask you and your child about any changes in behaviour that you have noticed at home or at school.
Here are some examples of things to watch:
- mood
- attention span
- ability to perform daily tasks at home and at school
Remember, you know your child best. If anything seems unusual or important, mention it to your doctor.
What to expect from treatment
Every child is different, so we cannot say exactly what will happen to your child. The good news is that medicine can treat the blood vessel inflammation and stop it from coming back. But your doctor cannot know ahead of time whether your child's brain will fully recover from any damage.
We do know that children's brains have more ability than adults' brains to "rewire" themselves. This means they can sometimes find new pathways to replace a damaged area.
Key points
- CNS vasculitis is treated with medicine to suppress the immune system and prevent blood clots. Treatment takes about 2 years.
- While your child is being treated for CNS vasculitis, it is important to prevent infection and talk to your doctor about any side effects.
- You know your child best. Tell your child's doctor about any changes in behaviour or anything that seems unusual or important.