Landau Kleffner Syndrome

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Landau Kleffner Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • LKS
  • acquired aphasia with convulsive disorder
  • acquired epileptiform aphasia

Disorder Subdivisions

  • None

General Discussion

Landau Kleffner syndrome (LKS) is a childhood disorder characterized by the loss of comprehension and expression of verbal language (aphasia) in association with severely abnormal electroencephalic (EEG) findings that often result in seizures.


The symptoms typically begin between the ages of three and seven years although it may rarely occur in children as young as 18 months of age. Affected children often appear to have acquired deafness since they fail to respond to verbal language and in some cases to nonverbal sounds. A significant minority of children develop serious behavioral dysfunction, including hyperactivity, temper outbursts, or withdrawn behaviors, but rarely the severe social impairments seen in autism.

Approximately 70% of affected children also have obvious seizures, most often simple or complex partial seizures and/or atypical absence in type.


The exact cause of Landau-Kleffner syndrome is not known. Many possible causes have been suggested including genetic factors, autoimmune disorders and other inflammatory processes.

Affected Populations

Landau-Kleffner syndrome is a rare disorder that affects twice as many males as females. Affected siblings have been reported rarely.

Standard Therapies


In additional to language regression, the diagnosis requires the presence of severely epileptiform activity on EEG, particularly during sleep. Additional testing may include magnetoencephalography. Brain imaging with magnetic resonance imaging (MRI) is recommended to exclude structural lesions. Other testing including behavioral and/or brainstem evoked audiometry and standardized psychometric and speech/language testing are helpful to exclude hearing loss and provide the basis for therapies to aide in recovery.


The standard therapeutic approach begins with antiepileptic drugs, particularly "spike-suppressing" medications such as divalproex, ethosuximide, levitiracetam, and benzodiazepines. Other antiepileptic drugs that may be beneficial are lamotrigine and felbamate.

A supportive team approach for children with Landau-Kleffner syndrome may help to reestablish some communication skills. Appropriate speech and language therapy is important for affected children. Sign language training may be useful for some affected children with little or no understanding of language. Special education classes for children with severe speech and language disorders may prove beneficial as well.

Investigational Therapies

When antiepileptic drugs are ineffective, other approaches include the ketogenic diet or immunosuppression with oral corticosteroids. Treatment with intravenous immunoglobulin and calcium-channel blocking drugs may also be beneficial. A neurosurgical procedure called multiple subpial transection (MST) has been used in some centers for children who fail to improve linguistically within two years and for those who develop steroid dependency or toxicity.

Information on current clinical trials is posted on the Internet at All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222

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For information about clinical trials sponsored by private sources, contact:



Mantovani JF. Developmental regression, autism and epilepsy. In: Shapiro BK, Accardo PJ, eds. Autism Frontiers: Clinical Issues and Innovations. Baltimore, MD: Paul H. Brookes; 2008:49-56.

Mantovani JF. Landau-Kleffner Syndrome. In: The NORD Guide to Rare Disorders, Philadelphia, PA: Lippincott, Williams and Wilkins; 2003:547-8.


Stefanatos G: Changing perspectives on Landau-Kleffner Syndrome. The Clinical Neuropsychologist. 2011;25(6):936-988.

Deonna T, Roulet-Perez E. Early-onset acquired epileptic aphasia (Landau-Kleffner Syndrome) and regressive autistic disorders with epileptic EEG abnormalities: The continuing debate. Brain & Development. 2010; 32:746-52.

Robinson RO, Baird G, Robinson G, et al. Landau-Kleffner Syndrome: course and correlates with outcome. Dev Med Child Neurol. 2001;43:243-247

Mantovani JF. Autistic regression and Landau-Kleffner syndrome: progress or confusion? Dev Med Child Neurol. 2000;42:349-353.

Lewine JD, Andrews R, Chez M, et al. Magnetencephalographic patterns of epileptiform activity in children with regressive autistic spectrum disorders. Pediatrics. 1999;104:405-418.

Grote CL, VanSlyke P, Hoeppner JAB. Language outcome following multiple subpial transections for Landau-Kleffner syndrome. Brain. 1999;122:561-566.

Kaga M. Language disorders in Landau-Kleffner syndrome. J Child Neurol. 1999;14:118-22.

Lagae LG, et al. Successful use of intravenous immunoglobulins in Landau-Kleffner syndrome. Pediatr Neurol. 1998;18:165-8.

Landau WM and Kleffner FR. Syndrome of acquired aphasia with convulsive disorder in children. Neurology. 1998;51:1241-9.

Fayad MN, et al. Landau-Kleffner syndrome: consistent response to repeated intravenous gamma-globulin doses: a case report. Epilepsia. 1997;38:489-94.

Tharpe AM, et al., Landau-Kleffner syndrome: acquired epileptic aphasia in children. J Am Acad Audiol. 1994;5:146-50.

Lerman P, et al. Effect of early corticosteroid therapy for Landau-Kleffner syndrome. Dev Med Child Neurol. 1991;33:257-60

Bishop DV, et al. Age of onset and outcome in 'acquired aphasia with convulsive disorder' (Landau-Kleffner syndrome). Dev Med Child Neurol. 1985;27:705-12.


Online Mendelian Inheritance in Man (OMIM). The Johns Hopkins University. Landau-Kleffner Syndrome; LKS. Entry No: 245570. Last Edited August 31, 2005. Available at: Accessed March 12, 2012.


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Epilepsy Canada

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FOLKS: Friends of Landau Kleffner Syndrome

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Genetic and Rare Diseases (GARD) Information Center

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Madisons Foundation

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For a Complete Report

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