Lennox-Gastaut syndrome

What is Lennox-Gastaut syndrome?

LGS is a rare and severe form of epilepsy. It starts between the ages of 18 months and 8 years. The condition can start in older children but this is not common. Most children develop the syndrome between 3 and 5 years of age.

Children with this condition usually experience:

• Multiple seizure types that are often drug resistant
• Problems with thinking, learning, development and behaviour that may get worse over time
• Sleep problems
• LGS continues into adulthood for most people

About 1 to 3 in every 10 children develop LGS after having another type of epilepsy syndrome. This includes:

• Infantile epileptic spasms syndrome (West syndrome)
• Early infantile developmental and epileptic encephalopathy

LGS affects around 1 or 2 in every 100 children with epilepsy.

What causes Lennox-Gastaut syndrome?

LGS has several possible causes, including:

• Genetic conditions, such as Tuberous Sclerosis Complex
• Problems with the structure of the brain or how it’s formed during pregnancy
• Problems before or during a baby’s birth, which cause a lack of oxygen to their brain
• Having certain infections as a baby, such as meningitis
• Brain damage following a severe head injury
• Metabolic or mitochondrial disease, such as Leigh syndrome

For many children with LGS, there’s no clear cause.

What are the symptoms of Lennox-Gastaut syndrome?

Children with LGS usually have several types of seizures.

Most children with LGS syndrome have tonic seizures. These usually happen when they are asleep. But they can happen when they’re awake. They can also disrupt a child’s sleep.

Tonic seizures may be hard to notice. Sometimes a child’s eyes may widen, stare or roll upwards.

Tonic seizures can also cause the body, arms or legs to go stiff or tremble. A child may fall over if they are standing up when they have a seizure.

Children with LGS will also experience other types of seizures, including:

• Atypical absence seizures
• Atonic seizures
• Focal seizures
• Generalised tonic-clonic seizures
• Myoclonic seizures
• Myoclonic-atonic seizures
• Status epilepticus
• Epileptic spasms

Nearly all children with LGS also have learning disabilities and behavioural problems including:

• Hyperactivity
• Aggression
• Sleep disturbances

Some children with LGS also have autism.

There may or may not be signs of these when seizures start. These symptoms usually develop over time.

How is Lennox-Gastaut syndrome diagnosed?

Doctors diagnosing LGS will look at a person’s:

• Pregnancy and birth history
• Medical history
• Development and learning
• Behaviour
• Seizure history

They will also do some medical tests, which may include:

• An EEG (electroencephalogram)
• An MRI (magnetic resonance imaging)
• Genetic testing
• Blood tests
• Urine tests

Diagnosing LGS can take time. This is because everyone’s symptoms are different and can change over time. A healthcare professional may need to rule out other epilepsy syndromes before diagnosing LGS.

Your child may need regular medical appointments so their healthcare professional can:

• Reassess their condition
• Make sure their diagnosis is accurate
• Make sure their treatment is appropriate

People with LGS should have a neurologist who specialises in epilepsy as part of their care.

What is the treatment for Lennox-Gastaut syndrome?

There is no cure for LGS and the symptoms do not usually respond well to treatment. People with LGS may need to try a few different treatments to find something that works.

A doctor should talk to you about all the treatment options available and the pros and cons of treatment.

Medicines

The doctor will usually try sodium valproate first. This medicine can cause risks in pregnancy, so there are strict rules around prescribing it.

If this does not work, your healthcare professional may offer another medicine called lamotrigine. Your child may take lamotrigine on its own or together with sodium valproate. This may depend on how old they are.

If these medicines don’t control the seizures, other options include:

• Cannabidiol with clobazam
• Clobazam
• Fenfluramine
• Rufinamide
• Topiramate. This medicine can cause risks in pregnancy, so there are strict rules around prescribing it

There may be age restrictions for some of these medicines.

Your child’s doctor can tell you more about the treatments available and the pros and cons of each. Your child should be offered regular medication reviews with their doctor to find out if the medicine is working well.

Epilepsy medicines can have side effects. The doctor or pharmacist can explain the possible side effects of your child’s medicines and how to manage them.

Other treatment options

Your child’s doctor may suggest:

• A special diet called the ketogenic diet
• A medicine called felbamate

Your child’s doctor should refer them to a specialist centre if they do not respond to these treatments. They may offer other treatments, such as epilepsy brain surgery or vagus nerve stimulation (VNS).

What are the potential complications of Lennox-Gastaut syndrome?

Injuries caused by seizures

Seizures can put someone at risk of accidents and injury. These include head injuries, drowning, fractures and burns. Your healthcare professional can help you find ways to reduce the risks.

Find out more about safety advice for people with epilepsy.

Emergency treatment for prolonged or repeated seizures

Many children with LGS have seizures that last a long time or happen often. This includes status epilepticus, which is a medical emergency.

Your child may be prescribed emergency or rescue medicine. This is to stop the seizure before it causes any long-term complications. This treatment can only be given by someone trained to give it.

Sudden Unexpected death in epilepsy (SUDEP)

SUDEP stands for sudden unexpected death in epilepsy. This is when someone with epilepsy dies and no other cause of death can be found in the post–mortem.

LGS is associated with an increased risk of SUDEP. This may cause anxiety but SUDEP is rare and most people do not die because of epilepsy.

Overall, the risk of SUDEP in adults and children with epilepsy is about 1 in 1000 every year.

There are things that you can do to reduce the risk of SUDEP.

What is the long-term outlook for children with Lennox-Gastaut syndrome?

LSG is a severe epilepsy syndrome that usually continues throughout life. The symptoms of LGS can change over time. Some people develop a different type of epilepsy syndrome.

Most people with LSG have epilepsy that is difficult to control and lasts throughout their lives despite treatment. This is known as drug-resistant epilepsy.

Many children show improvements in learning, behaviour and development as they get older. But some need continued support with these problems.

Several health professionals may be involved in a child’s care. This may include:

• Epilepsy specialists
• Clinical psychologist or child psychiatrists that can help with behavioural problems
• Occupational therapists. They can tell you about personal equipment to reduce accidents and injuries
• Speech therapists
• Physical therapists

Many children need extra support at school. Some children may benefit from going to a specialist school that can better support their needs.

Transition

Transition is the move from children’s epilepsy care to adult epilepsy care. Transition should be a planned, gradual process. The aim is to:

• Prepare you and your child
• Help your child take more responsibility for their care
• Ensure continuity of epilepsy care and support

Find out more about transition.

Adults with LGS

LGS can be difficult to recognise later in life. If your healthcare professional thinks you have LGS, they may check your childhood medical records to see if it was missed.

The symptoms of LGS can change over time. Seizure types may look different in adulthood. An epilepsy specialist may arrange further tests to review a diagnosis and treatment.

Adults with LGS should remain under the care of a neurologist with expertise in epilepsy wherever possible.

Most adults with LGS can live into their 50s and beyond. But severe seizures and other health problems can mean that some people don’t live as long as this.

Living with LGS can affect education, relationships and daily living. Some people can live by themselves. But many need ongoing support from family members, carers or supported living services.

Caring for someone with LGS can be challenging. We have support available through our Helpline, Befriending service and Talk & Support groups.

More information and support

Lennox-Gastaut Foundation

Tuberous Sclerosis Association

Contact – for families with disabled children