What is Landau-Kleffner Syndrome

TL;DR: Landau-Kleffner Syndrome (LKS) is a rare childhood neurological disorder characterized by the sudden or gradual loss of the ability to understand and use spoken language, typically accompanied by abnormal electrical activity in the brain. Often presenting between the ages of 3 and 7, Landau-Kleffner Syndrome requires specialized multidisciplinary care to manage both the language regression and the associated seizure activity.

What is Landau-Kleffner Syndrome?

Landau-Kleffner Syndrome, also known as acquired epileptic aphasia, is a rare condition that primarily affects the language centers of the brain. A child who has previously developed normal language skills suddenly loses the ability to comprehend speech (auditory verbal agnosia) and eventually loses the ability to speak. While the child may retain their intelligence and hearing, the neurological disruption caused by Landau-Kleffner Syndrome prevents the brain from processing verbal information correctly.

Which body systems are affected by Landau-Kleffner Syndrome?

The primary system affected by Landau-Kleffner Syndrome is the central nervous system. The hallmark of the condition is a specific pattern of abnormal electrical activity in the brain, often observed during sleep via an electroencephalogram (EEG). This electrical disturbance is usually centered in the temporal lobes, which are responsible for language processing. Because of this, the condition impacts:

• Language and Communication: The most significant impact is the loss of receptive and expressive language.


• Behavioral Health: Many children with Landau-Kleffner Syndrome experience secondary behavioral challenges, including hyperactivity, attention deficits, or social withdrawal.


• Seizure Activity: While not present in every child, approximately 70-80% of individuals with Landau-Kleffner Syndrome experience clinical seizures, typically occurring at night.

Who is typically affected by Landau-Kleffner Syndrome?

Landau-Kleffner Syndrome is exceptionally rare, with the exact prevalence remaining unknown due to frequent underdiagnosis or misdiagnosis. It is most commonly diagnosed in children between the ages of 3 and 7 years old. Research indicates a slight male predominance, occurring in boys roughly 1.5 to 2 times more frequently than in girls. Currently, 127 families within the DiseaseMaps.org community have shared their experiences with Landau-Kleffner Syndrome, highlighting the importance of connecting with others who understand the diagnostic journey.

What differentiates Landau-Kleffner Syndrome from other conditions?

It is common to confuse Landau-Kleffner Syndrome with autism spectrum disorder or hearing impairment because of the sudden loss of communication. However, several key factors differentiate it:

1. Developmental History: Unlike many developmental disorders, children with LKS typically have a period of perfectly normal language development before the regression begins.


2. EEG Findings: The presence of continuous spike-and-wave discharges during slow-wave sleep (CSWS) is a diagnostic marker specific to this spectrum of epileptic aphasias.


3. Auditory Integrity: Clinical testing confirms that the child’s hearing mechanism is intact; the failure is in the brain's ability to interpret the sound, not the ear's ability to receive it.

Next steps

• Consult a specialist: Seek evaluation from a pediatric neurologist or an epileptologist familiar with childhood epileptic aphasias.


• Neuropsychological assessment: Work with a speech-language pathologist and a neuropsychologist to develop a communication strategy.


• Join our community: Connect with the 127 members on DiseaseMaps.org to share resources, coping strategies, and experiences with treatment protocols.


• Monitor sleep patterns: Keep a detailed log of nocturnal symptoms or behaviors to assist your physician in diagnosis and treatment planning.

Medical disclaimer: This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Landau-Kleffner Syndrome.


• Orphanet: Rare Disease Database, ORPHA: 2315.


• OMIM (Online Mendelian Inheritance in Man): Landau-Kleffner Syndrome (Entry #245570).


• Epilepsy Foundation: Information on Acquired Epileptic Aphasia.