This is in some areas claimed to be an extension of autism, and
in others claimed to possess many of the symptoms of autism but actually to be
different. I present the information and allow the reader to choose.
Basically, Landau-Kleffner Syndrome occurs in children between
the ages of 3 and 8 years old (some say 7). It manifests itself as a drop
or deterioration in spoken ability, together with an abnormal EEG pattern and
occasional seizures. The latter can be obvious or so insignificant that
even the parents may miss them.
And now to the information base, which I am presenting as a
series of extracts from the sources which I link to.
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 agnosia or "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
Syndrome - a description
Also known as Acquired Epileptic Aphasia
Most children first show signs of this syndrome somewhere between the age
of three and nine years old. Prior to this they have usually grown and
developed normally with no sign of a seizure.
The first sign of difficulty usually appears in the form
of difficulty with communicating with speech and language. They show not only
difficulty understanding what is said to them (a receptive dysphasia) but also
have difficulty in putting their thoughts into words (an expressive
dysphasia). Other aspects of learning are probably not affected.
Seizures will appear in the majority of these children
certainly within a few weeks of the first signs of the language difficulty.
They take the form either of tonic clonic seizures which are probably partial
in origin or complex partial seizures.
The EEG will show signs of a brain malfunction
involving both cerebral hemispheres but usually the spike and wave activity
seen on the EEG will be more prominent in the dominant cerebral hemisphere
which deals with language function. For most people this will be on the left
The cause of the syndrome is not known. Twice as
many boys than girls are affected which may mean that for many the problem
results from some of the computer networks within the brain falling short of
full development. In other children, the problem seems to be precipitated by a
viral infection and it may be that information within the computer networks is
the cause in those children.
Special investigations looking at the body’s
metabolism and scanning of the brain are usually all quite normal. At times
signs of a recent viral infection may be shown.
The long term outlook for most children with this
condition is good. In the vast majority, the seizures will disappear by the
time they are in their mid-teens. In half the children, the language
difficulties will disappear within a few months or certainly the first year or
two. In the remaining half, some improvement will occur in time. In perhaps 20
per cent, or one in five, of cases the children will keep their language
Most children in the early stages will need treatment
with anti-epileptic drugs for the partial seizures. There are reports that
steroid treatment may help recovery but as so many children do well anyway,
these reports are difficult to judge.
In children where there are persisting seizures
associated with persisting language difficulties, surgery has been shown to
help but this needs to follow a very careful selection process. The group of
nerve cells which are showing most signs of malfunction are isolated from the
rest of the brain by a process known as subpial resection.
A careful assessment of a child’s educational
strengths and weaknesses is just as important as medical treatment so that
appropriate help at school can be found. The doctors involved will probably
contact the Education Authority with this in mind. If a child is supported in
this way, the chances of them becoming frustrated and confused and showing
behavioural difficulty will be reduced.
Seizure Disorders and Landau-Kleffner Syndrome in the
A Review of Seizure Disorders and Landau-Kleffner Syndrome in the Autistic
Population: reprinted by kind permission Joanna S. Dalldorf, M.D. Developmental
Seizure Disorders and Landau-Kleffner Syndrome in the
and Frequency of Epilepsy in Autistic Population
Landau Kleffner Syndrome is a rare form of childhood epilepsy which results
in a severe language disorder. The cause of the condition is unknown.
What are the main symptoms?
All children with LKS have abnormal electrical activity in
one, sometimes both temporal lobes, the area of the brain
responsible among other functions for processing language. This epileptiform
activity shows up in an EEG test particularly when the child is asleep.
About two-thirds of LKS children have seizures. Seizures
during the night are common. Many children have very few seizures and these are
readily controlled by anti-epileptic drugs. Some children never
have obvious seizures: it is not necessary to have a seizure to have LKS. A few
children have many seizures which are harder to control.
The language disorder in most children affects comprehension
or understanding. Many LKS children become unable to understand their own name.
They are also likely to have difficulty recognising environmental sounds such as
the telephone ringing. These children may appear to be deaf.
Expressive language - the ability to speak is often
seriously affected; some children lose their speech completely. Rarely, a child
may be able to understand language, but have difficulty with speaking.
Landau-Kleffner syndrome (acquired epileptiform aphasia) is a disorder in
which young children with previously normal language development undergo a
deterioration in language skills in association with epileptiform (seizure-like)
abnormalities on EEG. Between 70 - 80% of children with acquired epileptic
aphasia have seizures, but these are not mandatory for diagnosis. Some of the
children may have associated behavioral abnormalities including hyperactivity,
decreased attention, distractibility, temper tantrums, aggressiveness and social
Written by Stephen M. Edelson, Ph.D.
Center for the Study of Autism, Salem, Oregon
Landau-Kleffner Syndrome is
manifested as a form of aphasia, (loss of language), which usually develops
between 3 and 7 years. It is twice as common in males than females. Initially,
these individuals have a healthy, problem-free development with normal speech
and vocabulary. These individuals first lose their ability to comprehend (i.e.,
receptive speech) and then their ability to speak (i.e., expressive speech).
These changes can occur gradually or suddenly.
People with Landau-Kleffner Syndrome have abnormal EEG patterns (i.e., brain
waves) in the temporal lobe (located on the sides of the brain) and in the
temporo-parieto-occipital regions during sleep. Diagnosis of this syndrome
usually involves examining the person's EEG patterns during sleep. Approximately
70% develop epilepsy; and these seizures are typically infrequent and can be
either with or without convulsions.
Speech Evaluation in Landau-KleffnerSyndrome
by Pat Van Slyke, MS
Language deterioration which occurs after a period of normal speech and
language acquisition with epileptiform activity in the speech cortex is a
primary characteristic of Landau-Kleffner Syndrome (LKS). Initially, children
with LKS may appear not to hear or have difficulty understanding even simple
directions. Although their hearing sensitivity is within normal limits, their
ability to process the verbal language input is seriously impaired (verbal
auditory agnosia). Subsequently, expressive language may become telegraphic and
contain multiple articulation errors, possibly deteriorating to the point of
mutism. Often these children are misdiagnosed as hearing impaired. However,
assessment of hearing sensitivity through Auditory Brainstem Response Testing is
always within normal limits.
quoted from a Rush Institute Newsletter. 1996
This syndrome was first described in 1957 and is also known as acquired
epileptic aphasia. By definition, this condition affects children, usually
between the ages of 3 and 7, who previously had no developmental, language, or
interactional difficulties. They usually experience a rather abrupt loss of
language comprehension and a diminution in their ability to express themselves.
They usually have clear-cut seizures- Their EEC, especially their sleep EEG, is
Children with Landau-Kleffner syndrome do not necessarily appear autistic,
although the quick loss of language comprehension and the resultant
communication handicap could certainly cause significant confusion and
frustration. Some affected children therefore might appear autistic.
with a complete site on LKS
No, they're not saying "Oh, isn't this lovely, let's have
some more... "; they have started a group who are friends to all
people who suffer from, directly or indirectly (eg parents and teachers)
LKS. I recommend getting in touch with them; a great pair of
hearts, and a loving cyber-smile for everyone.
Recently, new data arrived here about an email support group called
"FOLKS", and I have put the main gist of it below.
To visit the main FOLKS website go to
To download the FOLKS LKS Information Pack or FOLKS newsletters go to