Landau-Kleffner Syndrome

Landau-Kleffner syndrome is a rare epilepsy disorder that affects children between the ages of 3 and 7 years. The child begins to experience gradual or sudden loss of speaking and understanding words.

Children with Landau-Kleffner syndrome are known to also have abnormal electrical brain waves and seizures that occur primary during the night.

A normal developing child, gradually loses expressive and receptive skills. The syndrome affects the part of the brain that controls comprehension and speech. The Broca area which is a region located in the frontal lobe is responsible for speech. Damage to this part of the brain affects speaking. the Wernickle area is located in the left hemisphere of the brain and impacts receiving or understanding language.

Discovered by William M. Landau and Frank Kleffner in 1957 through 6 case histories. Landau and Kleffner findings show that after normal development speech, all children studied developed aphasia from a period ranging from 1 day to several months, studies also found that children also experience seizures and irregular EEG’s especial while sleeping.

Landau-Kleffner syndrome is also known as acquired aphasia with convulsive disorder, acquired epileptiform aphasia and LKS.


Laudau-Kleffer syndrome affects males more than females. It is a rare disease in which 200 cases have been recorded between 1957- 1980. Typically 100 cases are diagnosed every 10 years.


The cause of Laundau-Kleffner is unknown and likely occurs through a genetic mutation

Signs and Symptoms

Early signs of Landau-Kleffner syndrome includes children who were developing normally losing the ability to speak or understand spoken language. The appearance of hearing loss or deafness, and an epileptic seizure occurring at night. Seizures typically stop by the age of 15. Other signs include behavior issues such as hyperactivity, aggressiveness and depression.


Landau-Kleffner syndrome is often misdiagnosed as autism, pervasive developmental disorder and hearing impairment based on the gradual loss of language skills. EEG test are necessary in order to provide an accurate assessment since an abnormal EEG is common among children with Landau-Kleffner disorder. Testing often includes standardized speech language assessment in order to rule out deafness or hearing impairment


Antiepileptic drugs are often used including Keppra, diazepam at night, and depakote. Speech therapy is also given to help with the loss of language and a behavior treatment plan.


Landau-Kleffner Syndrome (1957). “Syndrome of acquired aphasia with convulsive disorder in children.” Neurology. 7(8): 523-30.

Epilepsy Foundation

John Hopkins Medicine

Medicine Net


National Organization for Rare Disorders




Updated 5/19/21

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