Landau-Kleffner syndrome is a rare nervous system disorder. It causes loss of ability to understand and use language and causes seizures. It can happen in a child who has been developing normally. The symptoms may occur over time. Or they may happen suddenly. Treatment can be done to help prevent seizures. Speech therapy may help your child regain some language skills.

Researchers are still learning what causes LKS. It may be caused by changes (mutations) in genes, or by the effects of the environment on certain genes. In some cases, it may be caused by changes in a gene called GRIN2A. But most people with LKS don't have changes in the GRIN2A gene. They may have changes in other genes (RELN, BSN, EPHB2, NID2). Or the condition may be caused by the immune system attacking its own tissues. This is known as an autoimmune disorder.

A child is more at risk if they have a parent with LKS. The condition is more common in boys.

With LKS, the brain has problems processing speech and language. Symptoms can start from age 3 to age 8. They occur a bit differently in each child. They may happen slowly over time or occur suddenly. They can include:

• Not understanding what people say
• Seeming to have hearing loss
• Having trouble speaking words
• Total loss of ability to speak
• Using gestures or signs to communicate

LKS can also cause seizures. These are short periods of abnormal electrical activity in the brain. Seizures can cause episodes of uncontrolled physical motion or loss of attention.

Some children with LKS may also have:

• Behavior problems.
• Attention problems.
• Hyperactivity.
• Intellectual disability.

The symptoms of LKS may look like other health conditions. Have your child see their doctor for a diagnosis.

The doctor will ask about your child's symptoms and health history. They may also ask about your family's health history. The doctor will give your child a physical exam. Your child may also have tests, such as:

• Electroencephalogram (EEG). An EEG is a painless test that shows the electrical activity of the brain. The test looks for certain abnormal electrical activities while your child is asleep or awake.
• Genetic testing. This may be done to look for changes in the GRIN2A gene or other genes.
• Brain MRI. This test uses large magnets and a computer to create images of tissues in the body. It may be done to check for other problems in the brain that may cause symptoms like those of LKS.
• Hearing tests (audiometry). These may be done to check for hearing loss that may cause signs like those of LKS.

Treatment will depend on your child's symptoms, age, and general health. It will also depend on how severe the condition is. Treatment may include:

• Anticonvulsant medicine to help prevent seizures.
• Corticosteroid medicine to help prevent seizures.
• Speech therapy to regain some language skills.
• Sign-language instruction.
• Surgery called multiple subpial transection to reduce seizures.

Treatments for LKS are still being researched. Talk with your child's doctor about how to find a specialist to treat LKS. Talk with your child's health care providers about the risks, benefits, and possible side effects of all treatments.

Gene changes may be passed from a parent to a child. A child of someone with LKS has a high risk of inheriting a gene change that causes LKS. But not all people with LKS may have gene changes that have been passed down. And a gene passed from parent to child may not cause disease symptoms. Talk with your doctor about referring you to a genetic counselor before planning a pregnancy.

LKS is a lifelong condition. But you can help your child manage it by:

• Working with your child's health care team about a treatment plan.
• Making sure your child takes their medicines exactly as prescribed.
• Talking with the health care team about new treatments that may be available.
• Making sure your child has speech therapy and special education resources as needed.

Call the doctor if your child has:

• Symptoms that don't get better or get worse.
• New symptoms.

• Landau-Kleffner syndrome causes the loss of ability to understand and use language, and it can cause seizures.
• LKS may be caused by changes (mutations) in genes.
• Symptoms may start from age 2 to age 8. They may happen over time or happen suddenly.
• Symptoms can include not understanding what people say, seeming to have hearing loss, and having trouble speaking.
• Treatment can include medicines or surgery to help prevent seizures. Speech therapy may help your child regain some language skills.
• LKS is a lifelong condition. But you can help your child manage it by working with your child's health care team about a treatment plan.

Tips to help you get the most from a visit to your child's doctor:

• Know the reason for the visit and what you want to happen.
• Before your visit, write down questions you want answered.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you for your child.
• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are and when they should be reported.
• Ask if your child's condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if your child does not take the medicine or have the test or procedure.
• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your child's doctor after office hours and on weekends and holidays. This is important if your child becomes ill and you have questions or need advice.