Landau-Kleffner Syndrome

What is Landau-Kleffner syndrome?
Landau-Kleffner syndrome (also called infantile acquired aphasia, acquired epileptic aphasia, or aphasia with convulsive disorder) is a language disorder. It frequently occurs in normally-developing children, usually between three and seven years of age, and is characterized by the gradual or sudden loss of the ability use or comprehend spoken language.

It is a rare disorder, with approximately 160 cases diagnosed between 1957, when the syndrome was first identified, and 1990.

What are the signs of Landau-Kleffner syndrome?
The following are the most common indicators of Landau-Kleffner syndrome, however, individuals may experience symptoms differently.

  • Early signs may be referred to as auditory agnosia, which includes the child:
  • suddenly having problems understanding what is said.
  • appearing to have problems with hearing -- deafness may be suspected.
  • appearing to be autistic or developmentally-delayed.
  • Spoken language is eventually affected, which may lead to complete loss of the ability to speak.
  • Some children develop their own method of communicating, such as with gestures or signs.



What is language?

Language is the expression of human communication. It allows a person to express, experience, explain, and share:

  • knowledge
  • thoughts
  • observations
  • questions
  • needs
  • values
  • beliefs
  • behaviors

It is a specific method, style, or form of communicating for individuals or groups of individuals. Most language is vocal, however, it may also be expressed by:

  • symbols, as in letters and numbers
  • gestures
  • sounds

When language is impaired, problems can occur in all areas of a person's life, including:

  • social development
  • academic performance
  • personal relationships
  • employment opportunities
  • self-sufficiency

Source: National
Institute on Deafness and Other Communication Disorders (NIDCD)


Approximately 80 percent of children with Landau-Kleffner syndrome have a history of one or more epileptic seizures that usually occur at night.

All children with Landau-Kleffner syndrome have abnormal electrical brain wave activity on both sides of the brain.


Hearing and intelligence usually are confirmed to be normal in children with Landau-Kleffner syndrome. However, the disorder may be accompanied by behavior or psychological problems such as:

  • hyperactivity
  • aggressiveness
  • depression

The symptoms of Landau-Kleffner syndrome may resemble other conditions or medical problems, such as deafness or learning disabilities. Consult a physician for diagnosis.

How is Landau-Kleffner syndrome diagnosed?
Landau-Kleffner syndrome is commonly diagnosed using an electroencephalogram (EEG), a scan that shows the brain's electrical waves, as well as other diagnostic tests.

Treatment for Landau-Kleffner syndrome:
Specific treatment will be determined by your physician(s) based on:

  • your age, overall health, and medical history
  • extent of the disease
  • your tolerance for specific medications, procedures, or therapies
  • expectations for the course of the disease
  • your opinion or preference

Treatment may include medication for seizures, convulsions, and language ability. Sign-language instruction may also be suggested.