Landau-Kleffner Syndrome

By:  Rahima Olatinwo

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What is Landau-Kleffner Syndrome?

Landau-Kleffner Syndrome (LKS) or Acquired Epileptic Aphasia is an age-related disorder that affects children with no prior developmental disorder. Only a few hundred cases have been reported, making it a very rare condition. Its defining characteristics are the regression of speech and language comprehension and seizures that occur during sleep.

Who Does It Affect?

It typically appears in males more often than females and occurs around 2-8 years old. The average age of onset is between 5-7 years old. However, LKS can develop in adolescence.

What Causes Landau-Kleffner Syndrome?

Landau-Kleffner Syndrome is idiopathic, so the causes are not known. However, research suggests that there is a correlation between genetic mutations and some cases of LKS. Around 20% of diagnosed children have a mutation of the GRIN2A gene. The GRIN2A gene codes for a specific protein receptor necessary for regulating the sending and receiving of nerve signals in the brain. A mutation in the gene results in an abnormal protein receptor, which can cause nerves to become overly excited. This leads to increased activity in parts of the brain, which is seen during seizures. The parts of the brain that appear to be affected are involved in language and speech. There is also a possibility that autoimmune factors play a part in certain cases.

What to Look For?

Children with Landau-Kleffner Syndrome usually show three main symptoms.

Impaired Language Development (defining symptom)

Children usually experience normal language development initially. However, as they get older, their language development regresses.

Children with a younger age of onset typically experience more severe language regression than children with an older age of onset.

Initially, children will begin to struggle with comprehending spoken language (receptive aphasia). This might result in the child losing the ability to make out or react to sounds, and they are often mistaken for being deaf.

Later, they have trouble producing speech (expressive aphasia). This might result in the child frequently mispronouncing words, speaking in flowing sentences that are incomprehensible, or becoming completely unable to speak (mutism).

Because of loss of speech, children might come up with other ways to communicate like through hand gestures.


Over two-thirds of children with Landau Kleffner Syndrome experience clinically apparent seizures. Focal motor seizures with awareness (formally known as simple partial seizures) are the most common seizure type seen in children with LKS.

Some children experience seizures that are not clinically apparent, such as electrographic status epilepticus of sleep (ESES). They cannot be physically observed. ESES is characterized by nighttime seizures that are only noticeable via an abnormal electroencephalogram (EEG).

Like ESES, most seizures in kids with LKS usually happen at night and occur infrequently, becoming less frequent as the child gets older. By age 15, most children no longer experience seizures.

Behavioral Problems

Behavioral problems are common in those with LKS.

Children may appear hyperactive with a reduced attention span, irritable, and impulsive.

Because seizures usually occur at night, children might also develop sleep disorders due to disrupted sleep.

Cognitive skills outside of language are usually unaffected. However, some children experience difficulties with short-term memory.

What Conditions Resemble LKS?

The symptoms of Landau Kleffner Syndrome can resemble those of…


Similarities: language regression and difficulties communicating

Differences: no seizures, difficulties with social interaction

Rett syndrome

Similarities: seizures; normal language development followed by regression of speech in early age

Differences: deterioration of motor functions; almost exclusively in females; younger age of onset (6-18 months); small head size


Similarities: inability to react to spoken language

Differences: no seizures; inability to hear sounds outside of spoken language; unable to pass an Auditory Brainstem Response test

Childhood apraxia of speech (CAS)

Similarities: difficulty producing speech

Differences: no seizures; no regression of language comprehension

Panayiotopoulos syndrome

Similarities: nighttime seizures; focal seizures that occur in children; infrequent seizures that do not continue into adulthood

Differences: no regression of language comprehension or speech

What Kind of Diagnostic Tests Will Be Ordered?

An EEG, or electroencephalogram is a test that measures electrical activity in parts of the brain, and a neurologist usually orders it. The EEG technician will place electrodes on the child’s scalp or on a cap that is on the child’s head. The electrodes are connected to wires that allow a computer to monitor the child’s brain activity. To diagnose LKS, an EEG taken while the child is asleep is needed. This process typically takes 2 hours and is usually conducted at a hospital or neurologist’s office.

To make sure that the inability to react to spoken language is not related to the inability to hear sound, an Auditory Brainstem Response test might also be conducted. It detects electrical activity from the inner ear to the brainstem, and children with LKS typically have normal results.

An MRI might also be done to check for brain abnormalities that might cause similar symptoms.

How is LKS Treated and Managed?

LKS requires management from a multidisciplinary team including a general pediatrician, a child neurologist, a speech therapist, and a clinical audiologist.

General pediatricians and child neurologists both perform evaluations, order diagnostic tests, and develop treatment plans for patients. They work together to develop a plan that best suits the patient. Treatment plans may include prescriptions for anti-epileptic drugs (AEDs) to manage clinical seizures and speech therapy to preserve, regain, or improve language capabilities.

Clinical audiologists perform hearing diagnostic tests to eliminate hearing-related conditions as possible diagnoses.

Speech therapists assess and manage communicative and speech disorders. Speech therapy is crucial for managing LKS. A child’s language capabilities are more likely to improve when the child begins speech therapy early. Speech therapists address the child’s needs and teach them how to improve their speech and language comprehension skills.

What Should Parents and Caregivers Know?

It can be difficult for children and caregivers when a child is diagnosed with Landau Kleffner syndrome. Parents and caregivers should reach out to healthcare professionals with any questions and concerns. They can ask about treatment/management options and what they should expect.

Children might experience outbursts and frustrations because they are no longer able to verbally communicate or understand. Therefore, understanding their frustrations and encouraging them to communicate in other ways like sign language or written language can help them to continue interacting with others. Children might also find enjoyment in expressive art forms like art or music. These art forms can help build confidence in their overall communication skills.

What are the Takeaways?

Landau Kleffner syndrome is a language disorder that affects speech and language comprehension in children and results in seizures.

The symptoms of Landau Kleffner syndrome include difficulties understanding spoken language, difficulties with speech, nighttime seizures, and behavioral disturbances. Children usually outgrow their seizures by age 15.

Early detection and intervention are very crucial to preserve and build upon as much of the child’s language capabilities as possible. AEDs can alleviate clinical seizures. Speech therapy can aid in regaining and preserving speech and language comprehension skills. Giving children alternative means to communicate via sign language or written language also allows them to interact with others.


Bhardwaj, P., Sharma, V. K., Sharma, R., & Gautam, P. (2009). Acquired epileptic aphasia: Landau-Kleffner syndrome. Journal of Pediatric Neurosciences, 4(1), 52.

Mayo Clinic. (2017). Childhood apraxia of speech – Symptoms and causes. Mayo Clinic.

Mikati, M. A., Kurdi, R. M., & Shamseddine, A. N. (2009). Landau-Kleffner Syndrome. Elsevier EBooks, 307–311.

Neiman, E. S. (2024). Acquired Epileptic Aphasia Treatment & Management: Approach Considerations, Anticonvulsant Drugs, Corticosteroid and Steroid Agents. EMedicine.

Pearl, P. L., Carrazana, E. J., & Holmes, G. L. (2001). The Landau-Kleffner Syndrome. Epilepsy Currents, 1(2), 39–45.

Plyler, E., & Harkrider, A. W. (2013). Serial Auditory-Evoked Potentials in the Diagnosis and Monitoring of a Child with Landau-Kleffner Syndrome. Journal of the American Academy of Audiology, 24(07), 564–571.

University of Rochester Medical Center. (n.d.). Landau-Kleffner Syndrome (LKS) in Children – Health Encyclopedia – University of Rochester Medical Center. Retrieved February 19, 2024, from

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