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Landau Kleffner Syndrome


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.

Epilepsy Action has more information about seizure types, learning disabilities, and the EEG

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.

Landau-Kleffner syndrome

Landau-Kleffner syndrome (LKS) is an age-related epilepsy syndrome of childhood. Its main features are a loss of speech and language skills, with seizures. The speech and language skills may improve over time. LKS usually starts before the age of six 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 or a dog barking. 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 three quarters of 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 drop attacks. Seizures happen most commonly during the night.


A standard EEG may show abnormalities over a specific area of the brain called the temporal lobe. The 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 pronounced and persistent during sleep. The EEG can sometimes also be 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) is also useful to look at the particular pattern of difficulties a child may have. This is important in planning educational needs, for monitoring progress and response to treatment.

Epilepsy Action has more information about diagnosing epilepsy


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 a medicine called sulthiame (Ospolot) may also be helpful. Sometimes two epilepsy medicines are given together, such as sodium valproate and prednisolone. A combination of two or three medicines may also be used. If these medicines fail, steroid medicines may be used, usually for short periods. There are two or three different preparations of steroids.

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.
Epilepsy Action has more information about treating epilepsy

Prognosis (outlook)

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 a hundred children with Landau-Kleffner syndrome will have normal language and learning abilities in adulthood.

Advice and support organisations

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

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Our thanks

Epilepsy Action would like to thank
•Dr Richard Appleton, and Dr Rachel Kneen, consultant paediatric neurologists at Alder Hey Children’s Hospital, Liverpool, UK and
• Dr Stewart Macleod, consultant paediatric neurologist at Royal Hospital for Sick Children, Glasgow, UK.
 They have kindly prepared the information on this page. It is based on their own research, experience and expertise.

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

  • Updated May 2014
    To be reviewed May 2017

Comments: read the 2 comments or add yours


Hello im luke im 16 and i first got LKS when i was 9 and still currently got speech problems so is this condition permanent

Submitted by Luke Jenkinson on

Hi Luke

Thank you for contacting us.

For some children their seizures usually stop by the age of 15, although a small number (about one in 10) continue to have infrequent seizures. The speech problems that can happen due to LKS can improve in around 10-20 out of a hundred children. Maybe your epilepsy doctor or nurse, who knows you and your epilepsy, can explain if your speech problems will improve.

Luke, I wonder, as you are 16, if you may be interested in our online community, forum4e. This is for people with epilepsy and carers of people with epilepsy to share experience. You may be able to talk, online, to other people in a similar situation.


Advice and Information Team

Submitted by Diane-Epilepsy ... on

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