Neurological

Landau-Kleffner Syndrome

Also known as LKS, acquired epileptic aphasia, verbal auditory agnosia, continuous spike-waves during slow sleep (CSWS)

Landau-Kleffner syndrome is a rare epileptic encephalopathy characterized by acquired verbal auditory agnosia (inability to understand spoken language) in children who had previously normal language development, associated with EEG abnormal

ORPHA:98818 ↗Gene GRIN2A (associated in some cases)Prevalence 1-9 per 1,000,000 (Orphanet)Onset ChildhoodUnknown (structural/immune mechanisms proposed)

0

studies recruiting now

as of 7 Sept 2026

3

studies registered in total

as of 7 Sept 2026

0

countries with a recruiting site

as of 7 Sept 2026

None

recruiting study posted to date

among recruiting studies

Recruiting trials

No recruiting trial found right now.

3 studies are registered for Landau-Kleffner Syndrome, but none was recruiting as of 7 Sept 2026. Here is what is still worth doing.

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About Landau-Kleffner Syndrome

Landau-Kleffner syndrome is a rare epileptic encephalopathy characterized by acquired verbal auditory agnosia (inability to understand spoken language) in children who had previously normal language development, associated with EEG abnormalities showing continuous spike-wave activity during slow-wave sleep (CSWS). Seizures are present in most but not all patients. The language regression may be partial or complete, and outcome is variable. Treatment with corticosteroids, IVIG, and antiseizure medications may partially restore language.

Common clinical features

Acquired verbal auditory agnosiaLanguage regressionCSWS on EEGSeizures (usually mild)Behavioral changesSleep disturbanceEducational difficulties

From Orphanet’s phenotype annotations (CC BY 4.0). Not a complete list.

Before you apply

Things trial teams commonly ask about for Landau-Kleffner Syndrome. Not eligibility rules; those are set by each study.

  • Prolonged overnight EEG documenting CSWS pattern is required for diagnosis and trial enrollment
  • Formal speech-language assessment documenting receptive language regression from normal baseline is required
  • Corticosteroid treatment history (response, duration, dosing) must be documented as it affects subsequent trial eligibility
  • Age at LKS onset and time from language regression to treatment affects language outcome and trial stratification

Related conditions

Information, not medical advice. Trial listings are shown as recorded on ClinicalTrials.gov; whether any study is right for you is a decision for you and your clinicians, and eligibility is decided by each research team. Disease information from Orphanet (CC BY 4.0).