Landau Kleffner Syndrome

9th October 2019

Landau-Kleffner syndrome (LKS) is an extremely rare childhood epilepsy syndrome that affects boys twice as much as it affects girls and usually develops around the ages of 3 – 6. One of the key features of LKS is that it can affect speech and language skills in children and most likely result in behavioural problems. Unfortunately, despite research the cause of LKS is still unknown. 


Around 7 out of 10 children with LKS will develop seizures, however, these are often infrequent and are typically known to managed with treatment. The type of seizure can vary from person to person and may include tonic-clonic, focal, absence and atonic seizures. 

Problems understanding language and speaking are one of the first symptoms of LKS, which means the child is often unable to recognise voices or understand the context of a conversation. In fact, children with LKS are often mistaken for being deaf due to their unresponsive nature. This is known as ‘verbal auditory agnosia’. 

Language difficulties can worsen as the child gets older, which makes it difficult for them to differentiate between non-language sounds, such as a phone ringing. In addition, children with LKS can find it difficult to express themselves with many speaking in nonsensical ways or perhaps stopping speaking altogether. 

LKS often presents with behavioural issues too. Attention Deficit Hyperactivity Disorder (ADHD) and Attention Deficit Disorder (ADD) are both common problems associated with LKS. These behaviours may present in a number of ways, such as restlessness, impulsiveness and a lack of attention. 


An electroencephalogram (EEG) test may detect changes in the child’s brain brain activity, particularly in the temporal lobe. This is most commonly detected during the deeper stages of sleep, which may mean that an overnight EEG test is required.

Read more about the link between sleep and epilepsy here.

In addition, a Magnetic resonance imaging (MRI) and computed tomography (CT) scan may be used to confirm the diagnosis, alongside a neuropsychology assessment. 


LKS requires a wide range of treatments. Seizures usually respond well to epilepsy medications (AEDs), these include sodium valproate, ethosuximide and clobazam. In some cases a combination of AEDs may prove to be the most effective treatment to manage seizures. 

Behavioural, language and speech problems are much more challenging to treat and will likely require one to one care, as well as specialist input from speech, language and behavioural therapists. With these therapies things may improve over time. An educational psychologist may also be required. 


The outlook for a child with LKS is relatively good, although some will continue to have ongoing speech and behavioural problems. However, for the vast majority of individuals seizures cease at around age 15, however, some may continue to have infrequent seizures into adulthood. Around 50% of children who are diagnosed with LKS will mature to have their language and learning abilities restored. 

National Epilepsy Training can help

For more information on Landau-Kleffner Syndrome, please contact us on 01706 373075 or email