We exist to improve the lives
of everyone affected by epilepsy


Landau Kleffner Syndrome

Landau-Kleffner syndrome (LKS) is a very rare epilepsy syndrome of childhood. Its main features are a loss of speech and language skills, with seizures and learning and behaviour problems. The speech and language skills may improve over time. LKS usually starts between 3 and 6 years and affects twice as many boys as girls. The underlying cause of LKS is not yet known.


The first symptoms are either epileptic seizures or problems with understanding and speaking words. The difficulty with language becomes obvious with the child not being able to recognise voices, or the content of conversations. This is called ‘verbal auditory agnosia’. Children with LKS are often mistakenly thought to have hearing loss.

Later on, children may have difficulty telling the difference between other, non-language based sounds such as the doorbell ringing, a dog barking or a car blowing its horn. The language difficulties may then worsen and speech may become affected. Children may have difficulties expressing themselves, may talk nonsense or in jargon, or even stop speaking altogether.

Behaviour problems such as hyperactivity and attention deficits are also common. Attention deficit hyperactivity disorder (ADHD), and attention deficit disorder (ADD) refer to a range of problem behaviours associated with poor attention span. These behaviours may include impulsiveness, restlessness and hyperactivity, as well as inattentiveness. They often prevent children from learning and socialising well.

The severity of the language and behavioural problems varies over time.

Epileptic seizures develop in about 6 or 7 out of every 10 children with LKS. The seizures are usually infrequent and respond well to treatment. A variety of seizure types can develop, including tonic-clonic seizures, focal seizures, prolonged absences and atonic seizures. The focal and tonic-clonic seizures happen most commonly during the night.


A routine EEG may show abnormalities over a part of the brain called the temporal lobe. The hospital doctor may want to organise a more prolonged EEG recording, particularly one during sleep. This is because the abnormalities seen on a routine recording become more obvious and even persistent during sleep. During the deeper stages of sleep the EEG may show a pattern called ‘continuous spike and waves in slow sleep’ (CSWSS). The EEG is sometimes used to monitor progress and response to treatment. Magnetic resonance imaging (MRI) and computed tomography (CT) brain scans are usually normal. A neuropsychology assessment (study of the central nervous system) and speech and language assessment are important to look at the particular pattern of language and learning difficulties a child may have. This is important to plan the best educational needs for the child and also to monitor progress and response to treatment.


Although the seizures of LKS usually respond well to treatment with epilepsy medicines, the speech and language difficulties can be much more of a problem. Response to treatment can be assessed in different ways, including an improvement in the child's language abilities, an improvement in the EEG abnormalities, and seizure control.

Commonly used medicines include sodium valproate (Epilim), ethosuximide (Zarontin) and clobazam (Frisium). A steroid called prednisolone and medicines called sulthiame (Ospolot) and levetiracetam (Keppra) may also be helpful. Sometimes 2 epilepsy medicines are given together, such as sodium valproate and prednisolone. A combination of 2 or 3 medicines may also be used. If these medicines fail, steroid medicines may be used, usually for short periods. There are 2 or 3 different preparations of steroids.

It is important to know that the epilepsy medicines, carbamazepine (Tegretol) and phenytoin (Epanutin) are not helpful and might worsen the seizures and learning difficulties in LKS.

The ketogenic diet has been used in only a few children with LKS, and it was only helpful for a couple of those children. However, the diet should be considered if the epilepsy medicines are not effective and certainly before epilepsy surgery.

If treatment with epilepsy medicines fails, there is an option to look into a highly specialised form of brain surgery called subpial transection. This procedure is only carried out in a few specialist centres, and may not be suitable for every child with LKS.

Children should also be seen and treated by a speech and language therapist and an educational psychologist to help with their speech and educational problems.

Information about treatments for children can be found on the Medicines for Children website.

There may be research studies open that are relevant to this epilepsy syndrome. Your child’s doctor will be able to discuss this with you.

If your child has this syndrome they may have prolonged or repeated seizures. Your child’s doctor will discuss a ‘rescue’ or emergency care plan with you to treat any prolonged or repeated seizures.


Although the outlook for seizures in children with LKS is good, many children will be left with significant language, learning and behavioural difficulties. The seizures usually stop by the age of 15, although a small number (about one in 10) continue to have infrequent seizures. Only 10-20 out of 100 children with Landau-Kleffner syndrome will have normal language and learning abilities in adulthood.


Freephone helpline (UK only): 0808 808 3555
Website: cafamily.org.uk
Email: info@cafamily.org.uk 

What is a syndrome?

A syndrome is a group of signs and symptoms that, added together, suggest a particular medical condition. In epilepsy, examples of these signs and symptoms would be things like the age at which seizures begin, the type of seizures, whether the child is male or female and whether they have physical or learning disabilities, or both. The results of an electroencephalogram (EEG) are also used to help identify epilepsy syndromes.

If you would like to know more about an epilepsy syndrome, please speak to your doctor. If you would like to know more about epilepsy in general, please contact Epilepsy Action.


Our thanks

Epilepsy Action would like to thank Dr Richard Appleton, consultant paediatric neurologist at Alder Hey Children’s Hospital, Liverpool, UK for preparing this information.

This information is exempt under the terms of The Information Standard.

  • Updated August 2017
    To be reviewed August 2020

There are no comments yet. Be the first to comment...

e-action newsletter

Subscribe to our e-action newsletter and stay informed

Subscribe to e-action newsletter feed