This information is for people affected by or concerned about Rasmussen encephalitis, including parents and carers.
On this page we talk about how Rasmussen encephalitis is diagnosed, what causes it, symptoms, treatment options and long-term outlook.
Use this page as a general guide and speak to a health professional for more information and support.
On this page
What is Rasmussen encephalitis?
Rasmussen encephalitis is a very rare condition that can occur at any time in childhood, but is most common in children between the ages of five and six years. It can also sometimes occur in adults. It is also known as Rasmussen syndrome.
In this condition, the brain cells in one part of one hemisphere (half) of the brain become inflamed and swollen. Very rarely, both hemispheres of the brain may be affected. It is linked to focal epilepsy that is difficult to control with treatment (drug-resistant), paralysis of one side of the body (progressive hemiplegia), and developmental delays (cognitive decline).
Rasmussen encephalitis is thought to affect a very small number of people – less than two in ten million people under the age of 16 years, in the UK, are diagnosed with it every year.
What causes Rasmussen encephalitis?
We do not know for sure what causes Rasmussen encephalitis. But there is some research which shows that an infection in the body, or an autoimmune disease, may cause inflammation in the brain and can lead to Rasmussen encephalitis.
What are the signs and symptoms of Rasmussen encephalitis?
Symptoms of Rasmussen encephalitis include seizures and hemiparesis (one-sided weakness of the body), as well as learning, behaviour and other developmental difficulties.
In people with Rasmussen encephalitis, inflammation of the brain can cause nerve cells to stop working well, which can lead to seizures.
In the beginning, seizures may not happen very often. But after a few weeks or months, they may start to happen several times a day.
People with Rasmussen encephalitis usually have focal onset seizures, which cause jerking on one side of the face or in their limbs. Seizures can last for many hours or even days. This is called ‘epilepsia partialis continua’.
Eventually, over a period of months or years, the child usually develops weakness in one side of their body. This is called a ‘hemiparesis’.
As the seizures continue, this weakness worsens and the child may lose movement in their arm or leg, or both.
Most children with Rasmussen encephalitis develop learning and behaviour difficulties as their condition progresses. This usually gets worse over time.
Learning and developmental problems can be a result of the following things:
- rasmussen encephalitis gets worse over time
- the number of seizures a child with Rasmussen encephalitis may have
- the side effects of anti-seizure medications
- a combination of all of these.
Children with Rasmussen encephalitis may also experience other difficulties, depending on which part of the brain is affected, including:
- using language incorrectly
- hemianopia (loss of vision in either the right or left side of both eyes)
- dysarthria (difficulty speaking clearly)
- swallowing difficulties.
How is Rasmussen encephalitis diagnosed?
If you think a child has epilepsy, including Rasmussen encephalitis, contact a doctor. Children and young people may be referred to a paediatrician (a doctor who specialises in child health). Or they may be referred to a doctor who specialises in diagnosing and treating very rare types of epilepsy, such as Rasmussen encephalitis. The child’s doctor may suggest doing the following tests:
- Brain scans and an EEG test (electroencephalogram) - a painless test that uses small sensors attached to the scalp to pick up the electrical signals produced by the brain. If a child has Rasmussen encephalitis, the EEG results will usually show a pattern called periodic lateralising epileptiform discharges (PLEDs).
- A magnetic resonance imaging (MRI) scan– a scan that uses magnetic fields and radio waves to produce images from inside the body. If a child has Rasmussen encephalitis, the MRI scan will usually show that inflammation has caused permanent damage to nerve cells.
Treatment for Rasmussen encephalitis
It is usually very hard to treat seizures in Rasmussen encephalitis. There isn’t one particular epilepsy treatment that seems to work better than any other.
The treatment that is available for people with Rasmussen’s encephalitis aims to reduce how serious the seizures are, how often they happen, and improve long-term outcomes.
Treatment for Rasmussen encephalitis usually includes:
- Anti-seizure medications to reduce and manage seizures.
- Immunosuppressive treatments, such as corticosteroids, to improve the long-term outcome of people with Rasmussen encephalitis.
- Surgery on the side of the brain affected by Rasmussen encephalitis.
Some of these medicines may help to control the seizures and slow down the rate at which the condition gets worse in some children, but not in all cases.
In the UK, surgery for Rasmussen encephalitis is only available in a few specialist centres, including The Children’s Epilepsy Surgery Service (CESS).
If you have a child with Rasmussen encephalitis, their specialist doctor will talk to you about the treatment options that are suitable for them. They will explain the risks and benefits of each, including any possible side effects from treatment or surgery. If your child has prolonged or repeated seizures, you should discuss an emergency care plan with your child’s paediatrician or paediatric neurologist.
Remember, if you’re not sure about something or you have questions, talk to the doctor. They are there to help and support you – it’s important you have all the information you need.
What’s the long-term outlook for people with Rasmussen encephalitis?
After several years, the inflammation may stop on its own and may not get any worse. However, the nerve cells in the brain may be permanently damaged and will continue to not work properly.
As a result, the epilepsy may continue. However, with the right treatment and support, it may be possible to manage and control the seizures and other symptoms.
Because most children with this condition also have one-sided weakness to their body, loss of vision and learning difficulties, they are likely to need additional support in education.
Living with Rasmussen encephalitis and getting support
Having a child with any form of epilepsy can be challenging and upsetting. But if the type of epilepsy that they have is very rare, it can be even harder to manage and come to terms with. Talk to the child’s doctor for help on how to support them well. And talk to your own doctor if you need support for yourself. If you’re caring for someone with Rasmussen encephalitis, it’s important that you look after yourself and get the support you need.
You may find it helpful joining an in-person or online support group, where you can listen to or share experiences with other people who understand what you’re going through.
Other useful organisations
Encephalitis International
Information, helpline, support groups and events
Children’s Epilepsy Surgery Service (CESS) centres
