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Landau Kleffner Syndrome

BrainLandau-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 Landau-Kleffner syndrome is not yet known. There is an overlap with a rare condition called ‘electrical status epilepticus of slow wave sleep’ (ESESS).


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 Landau-Kleffner 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 door-bell ringing or a dog barking. The language difficulties may then worsen and speech may become affected.

Children may have difficulties expressing themselves, may talk in jargon or nonsense, or even stop speaking altogether. Behaviour problems such as hyperactivity and attention deficits are also common. The severity of the language and behavioural problems varies over time.

Epileptic seizures develop in about three quarters of children with Landau-Kleffner syndrome. The seizures are usually infrequent and respond well to treatment.

A variety of seizure types can develop including tonic-clonic seizures, focal (complex partial) seizures, prolonged absences and drop attacks. Seizures happen most commonly during the night.


A standard electroencephalogram (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. The abnormalities seen on a routine recording become more pronounced and persistent during sleep. The EEG can also be used sometimes to monitor progress and response to treatment.

Magnetic resonance imaging (MRI) and computed tomography (CT) brain scans are usually normal.

A neuro-psychology 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.


Although the seizures of Landau-Kleffner syndrome usually respond well to treatment with anti-epileptic drugs (AEDs), 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 drugs include sodium valproate (Epilim), ethosuximide (Zarontin) and clobazam (Frisium). A steroid called prednisolone and a drug called sulthiame (Opsolot) may also be helpful.

Sometimes two AEDs are given together, such as sodium valproate and prednisolone. A combination of two or three drugs may also be used. If these drugs fail, steroid medications may be used, usually for short periods. There are two or three different preparations of steroids.

If treatment with anti-epileptic drugs 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 Landau-Kleffner syndrome.

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.

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 per cent of children with Landau-Kleffner syndrome will have normal language and learning abilities in adulthood.

Attention deficit hyperactivity disorder (ADHD) and attention deficit disorder (ADD) refer to a range of problem behaviours associated with poor attention span. These may include impulsiveness, restlessness and hyperactivity, as well as inattentiveness, and often prevent children from learning and socialising well. ADHD is sometimes referred to as ‘hyperkinetic disorder’.

Support organisation

  • F.O.L.K.S. (Friends of Landau-Kleffner Syndrome, 2 Stone Buildings, Lincoln’s Inn, London, WC2A 3XL, telephone 0870 847 0707, http://www.friendsoflks.com/

If you would like any more information about epilepsy, then please contact Epilepsy Action via the Email Helpline or, if you live in the UK, by phoning the Freephone Helpline on 0808 800 5050. More information about Landau Kleffner syndrome is available from FOLKS (Friends Of Landau Kleffner).

Because this page is written by an epilepsy healthcare professional and not by Epilepsy Action, it falls outside the requirements of the Information Standard.

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Our thanks

Epilepsy Action is indebted to Dr Richard Appleton, a Consultant Paediatric Neurologist who specialises in children’s epilepsy, and to Dr Rachel Kneen, Consultant Paediatric Neurologist and Dr Stewart Macleod, Specialist Registrar in paediatric neurology, at Alder Hey at Alder Hey Children’s Hospital, Liverpool, who have kindly prepared the information on this page.

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

  • Updated July 2007
    To be reviewed December 2013

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