Landau-Kleffner syndrome (LKS) is a childhood disorder. A major feature of LKS is the gradual or sudden loss of the ability to understand and use spoken language. All children with LKS have abnormal electrical brain waves that can be documented by an electroencephalogram (EEG), a recording of the electric activity of the brain.
Approximately 80 percent of the children with LKS have one or more epileptic seizures that usually occur at night.
Behavioral disorders such as hyperactivity, aggressiveness and depression can also accompany this disorder. LKS may also be called infantile acquired aphasia, acquired epileptic aphasia or aphasia with convulsive disorder.
This syndrome was first described in 1957 by Dr. William M. Landau and Dr. Frank R. Kleffner, who identified six children with the disorder.
What is it like?
In the typical case, a child between 3 and 7 years of age experiences language problems, with or without seizures. The language disorder may start suddenly or slowly.
It usually affects the child’s understanding of spoken language the most, but it may affect both understanding speech and speaking ability, or it may affect speaking only.
Seizures are usually few and often occur during sleep. Simple partial seizures involving movement are most common, but tonic-clonic seizures can also occur.
Who gets it?
The Landau-Kleffner syndrome is a rare disorder. It begins during childhood, with language disorders starting between ages 3 and 7 years.
What are the signs of Landau-Kleffner syndrome?
LKS occurs most frequently in normally developing children who are between 3 and 7 years of age. For no apparent reason, these children begin having trouble understanding what is said to them.
Doctors often refer to this problem as auditory agnosiaor “word deafness.” The auditory agnosia may occur slowly or very quickly.
Parents often think that the child is developing a hearing problem or has become suddenly deaf. Hearing tests, however, show normal hearing. Children may also appear to be autistic or developmentally delayed.
The inability to understand language eventually affects the child’s spoken language which may progress to a complete loss of the ability to speak (mutism).
Children who have learned to read and write before the onset of auditory agnosia can often continue communicating through written language.
Some children develop a type of gestural communication or sign-like language. The communication problems may lead to behavioral or psychological problems. Intelligence usually appears to be unaffected.
The loss of language may be preceded by an epileptic seizure that usually occurs at night. At some time, 80 percent of children with LKS have one or more seizures.
The seizures usually stop by the time the child becomes a teenager. All LKS children have abnormal electrical brain activity on both the right and left sides of their brains.
What causes Landau-Kleffner syndrome?
The cause of LKS is unknown. Some experts think there is more than one cause for this disorder. All of the children with LKS appear to be perfectly normal until their first seizure or the start of language problems.
There have been no reports of children who have a family history of LKS. Therefore, LKS is not likely to be an inherited disorder.
How is it treated?
Seizure control is rarely a problem, but standard seizure medications are not often effective against the language disorder. Drugs such as Lamictal (lamotrigine), Keppra (levetiracetam), and Depakote (valproate) sometimes help.
High dose diazepam given at bedtime has resulted in excellent improvement in some children. Steroids have also shown some efficacy, improving both the EEG and language.
A new form of epilepsy surgery, multiple subpial transections in which multiple small slices are made in brain cortex, may improve both the EEG abnormalities and the language disorder in a small number of children.
This procedure is still being studied in various epilepsy centers.
What’s the outlook?
After age 10, only 20% of patients still have seizures. The clinical course of the disorder fluctuates and it occasionally disappears on its own.
Some children are left with permanent language difficulties. Most commonly, these are children in whom medical or surgical therapy does not eliminate the epileptic patterns on the EEG.