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PubMed This is a summary of 40 peer-reviewed journal articles Updated
Neurology

Landau-Kleffner Syndrome: A Patient Guide

At a Glance

Landau-Kleffner syndrome is a rare childhood condition that causes loss of previously learned language, often linked to abnormal brain activity during sleep. A sleep EEG helps identify it, while medical treatment, speech therapy, AAC, and school support address communication.

Landau-Kleffner Syndrome (LKS) is a rare neurological condition that can feel like a sudden or gradual, unexplained loss of connection with a child who was previously hitting every milestone. Primarily affecting children between the ages of 3 and 7, LKS is classified as an acquired epileptic aphasia [1][2]. This means that a child who has already learned to speak (acquired) begins to lose their language skills (aphasia) in association with abnormal electrical activity in the brain (epileptic) [3]. While the transition can be frighteningly rapid—sometimes unfolding over just a few days, or more gradually—it is a recognized medical condition that requires a prompt, specialist-led evaluation [4].

The hallmark of LKS is a struggle called auditory verbal agnosia, often described as “word deafness” [1]. To a child experiencing this, your voice hasn’t gone silent, but it has become a meaningless noise, much like a radio tuned to static or a foreign language they have never heard. It is important to understand that your child is not intentionally ignoring you; rather, their brain’s “processing center” for sound is malfunctioning [5][6]. Many children with LKS still react to non-speech sounds, such as music or a doorbell, which can make the diagnosis confusing for parents and doctors alike [7].

The abnormal electrical activity behind this language loss typically happens while your child is asleep. Even if you never see a physical seizure, the brain may experience a continuous pattern of electrical spikes during deep sleep, a state often associated with Electrical Status Epilepticus during Sleep (ESES) or Continuous Spike-Waves during Sleep (CSWS) [8][9]. Because these spikes may not appear while a child is awake, a sleep EEG is an essential tool for evaluation, as it allows doctors to see the brain’s activity during the non-REM (NREM) sleep stages where LKS is most active [10][11].

Management focuses on two simultaneous tracks: quieting the electrical activity and rebuilding communication. Medical treatments, including corticosteroids and specialized anti-seizure medications, are considered to reduce the abnormal brain activity and support the child’s developmental window [4][12]. At the same time, families use tools like Augmentative and Alternative Communication (AAC) or visual schedules to give the child a way to interact with the world while they work to regain their verbal skills [13][1].

The long-term outlook for LKS is a journey of persistence and variability. While the electrical abnormalities and seizures often resolve by the time a child reaches puberty, the degree of language recovery varies for each person [14][1]. Early and intensive intervention, including speech therapy and educational support, is important to preserve as much language as possible and help the brain adapt [15]. By focusing on a child’s strengths and providing a supportive, visual environment, families can help their children navigate these challenges toward an independent and meaningful adulthood [14].

In this guide

6 chapters

01

Understanding the Shock of Language Loss

Learn how Landau-Kleffner syndrome causes language loss, why sleep EEG testing matters, and how hearing and language evaluations help identify this rare condition.

02

The Diagnostic Roadmap: Essential Tests for LKS

Learn how Landau-Kleffner syndrome is evaluated with sleep EEG, SWI, hearing, speech-language and cognitive tests, plus MRI or genetic testing after regression.

03

Treatment Options: Stopping the Language Storm

Learn about Landau-Kleffner syndrome treatment, including steroids, anti-seizure medicines, EEG goals, side effects, and when surgery may be considered.

04

Daily Life: Navigating Communication and School

Learn how to support communication and school for children with Landau-Kleffner syndrome using AAC, IEP accommodations, and guidance on seizure warning signs.

05

The Long-Term Outlook: Beyond the Storm

Learn about the Landau-Kleffner syndrome long-term outlook, including EEG and seizure remission, language recovery, adult support, and mental health needs.

06

Building Your Care Team: Finding the Right Experts

Learn which specialists support children with Landau-Kleffner syndrome, what each expert does, and which records to bring for a second-opinion consultation.

Common questions in this guide

What is Landau-Kleffner syndrome?
Landau-Kleffner syndrome is a rare childhood condition in which a child who previously learned to speak begins to lose language skills. Abnormal electrical activity in the brain, often during sleep, can make spoken words difficult to recognize or understand.
Why does my child need a sleep EEG for suspected LKS?
Abnormal electrical activity in Landau-Kleffner syndrome is often strongest during sleep and may not be obvious when the child is awake. A sleep EEG records brain activity during sleep, helping clinicians look for these patterns and follow changes over time.
What treatments can help a child with Landau-Kleffner syndrome?
Doctors may use corticosteroids or anti-seizure medicines to reduce abnormal brain activity. Speech therapy, educational support, visual schedules, and augmentative and alternative communication tools can support communication and learning while language skills are impaired or recovering.
Will my child's language return after Landau-Kleffner syndrome?
Language recovery varies between children. Seizures and abnormal electrical activity often improve by puberty, but early, intensive speech therapy and educational support are important because language recovery may not be complete.
What should I do if my child stops responding to spoken words?
A prompt evaluation by a neurology specialist is important when a child loses previously acquired language or stops responding to speech. Note whether the child still reacts to non-speech sounds and record changes such as nighttime jerks, sweating, or difficulty waking to discuss with the care team.
How can AAC help a child with Landau-Kleffner syndrome?
Augmentative and alternative communication gives a child other ways to express needs while spoken language is difficult or recovering. A speech-language pathologist can evaluate the child and recommend communication tools and visual supports for home and school.

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References

References (15)
  1. 1

    Evidence for normal letter-sound integration, but altered language pathways in a case of recovered Landau-Kleffner Syndrome.

    Pullens P, Pullens W, Blau V, et al.

    Brain and cognition 2015; (99()):32-45.

    PMID: 26232266
  2. 2

    Landau-Kleffner Syndrome Can Herald the Diagnosis of GRIN2A Gene Mutation.

    Ebrahim AK, Makhlooq JJ, Busehail MY

    Case reports in pediatrics 2025; (2025()):8869587 doi:10.1155/crpe/8869587.

    PMID: 40727434
  3. 3

    Landau-Kleffner syndrome.

    Tuft M, Årva M, Bjørnvold M, et al.

    Tidsskrift for den Norske laegeforening : tidsskrift for praktisk medicin, ny raekke 2015; (135(22)):2061-4 doi:10.4045/tidsskr.15.0162.

    PMID: 26627294
  4. 4

    [Landau-Kleffner Syndrome and Continuous Spike-and-Wave During Sleep Syndrome: Comparison of Clinical, Neurophysiological, and Neuropsychological Characteristics].

    Benítez-Provedo C, González-Alguacil E, García-Fernández M, et al.

    Revista de neurologia 2025; (80(7)):33484 doi:10.31083/RN33484.

    PMID: 40916958
  5. 5

    Diagnostic challenges in Landau-Kleffner syndrome.

    Lamônica D, Rosa KG, da Rocha E, et al.

    BMJ case reports 2026; (19(1)) doi:10.1136/bcr-2025-268738.

    PMID: 41526063
  6. 6

    Landau-Kleffner syndrome (LKS) in an 8-year-old girl: a case report and review of the literature.

    Salahaldin MM, Shehadeh MH, Abu Keshek A, et al.

    Annals of medicine and surgery (2012) 2024; (86(7)):4202-4205 doi:10.1097/MS9.0000000000002156.

    PMID: 38989194
  7. 7

    Prominent auditory deficits in primary progressive aphasia: A case study.

    Utianski RL, Duffy JR, Clark HM, et al.

    Cortex; a journal devoted to the study of the nervous system and behavior 2019; (117()):396-406 doi:10.1016/j.cortex.2019.01.021.

    PMID: 30878181
  8. 8

    [Landau-Kleffner Syndrome: Current Etiopathogenesis and Management].

    Méndez-Álvarez AD, Meneses-León KP, Monsalvo-Soler DB, et al.

    Revista de neurologia 2025; (80(4)):42643 doi:10.31083/RN42643.

    PMID: 40464423
  9. 9

    Rebuilding the Tower of Babel: The Current Landscape and Emerging Opportunities in DEE-SWAS.

    Stowe RC, Kelley SA, Bhatia S, et al.

    Epilepsy currents 2025; (25(6)):369-377 doi:10.1177/15357597251344191.

    PMID: 40502808
  10. 10

    Sleep and epilepsy syndromes.

    Schmitt B

    Neuropediatrics 2015; (46(3)):171-80 doi:10.1055/s-0035-1551574.

    PMID: 25965811
  11. 11

    Cerebral dominance in an unusual case of Landau-Kleffner syndrome.

    Chowdhury N, Bansal AR, Goyal R, Nikhila G

    BMJ case reports 2021; (14(12)) doi:10.1136/bcr-2021-246696.

    PMID: 34887295
  12. 12

    Unmet needs in epileptic encephalopathy with spike-and-wave activation in sleep: A systematic review.

    Chapman KE, Haubenberger D, Jen E, et al.

    Epilepsy research 2024; (199()):107278 doi:10.1016/j.eplepsyres.2023.107278.

    PMID: 38157757
  13. 13

    Cognitive linguistic Treatment in Landau Kleffner Syndrome: Improvement in Daily Life Communication.

    van der Meulen I, Pangalila RF, van de Sandt-Koenderman WME

    Child neurology open 2021; (8()):2329048X211022196 doi:10.1177/2329048X211022196.

    PMID: 34124282
  14. 14

    Acquired epileptiform aphasia: 44 years after diagnosis.

    Jokel R, Meloff K

    Epilepsy & behavior reports 2020; (14()):100388 doi:10.1016/j.ebr.2020.100388.

    PMID: 33103104
  15. 15

    Clinical and Molecular Genetic Characterization of Landau Kleffner Syndrome: An Observational Cohort and Experimental Study.

    Ngoh A, Clark M, Greenaway R, et al.

    Annals of neurology 2025; (98(5)):951-966 doi:10.1002/ana.27306.

    PMID: 40944498

This page is for informational purposes only and does not constitute medical advice. A neurology specialist and your child's care team should interpret the sleep EEG and tailor treatment to your child's needs.