[Skip to Content]
Find care at Nemours Children's HealthDoctorsLocations

Lennox-Gastaut Syndrome

Reviewed by: Amy W. Anzilotti, MD
  • Listen

What Is Lennox-Gastaut Syndrome?

Lennox-Gastaut syndrome is a rare type of epilepsy. Children with the condition will have:

  • several different kinds of seizures
  • some degree of intellectual disability
  • abnormal findings on an EEG (a test to see brain waves/electrical activity)

Lennox-Gastaut (LEN-eks gas-TOE) syndrome begins when kids are 3 to 5 years old. It's a lifelong condition that requires a high level of care.

What Kinds of Seizures Happen in Lennox-Gastaut Syndrome?

There are different seizure types in Lennox-Gastaut syndrome. They can cause a variety of symptoms.

Tonic seizures:

  • muscles suddenly become stiff
  • last about 20 seconds
  • usually involve both sides of the body
  • often happen during sleep

Atonic seizures:

  • muscles briefly and unexpectedly go weak or limp (called "drop attacks")
  • last less than 20 seconds
  • can involve the whole body or just certain parts
  • after the seizure, the child recovers quickly

Other types:

  • atypical absence seizures: staring spells with blinking, smacking or chewing, rubbing hands together (called automatisms)
  • myoclonic seizures: brief muscle twitches or jerks in the neck, shoulders, upper arms, and face
  • tonic-clonic seizures: convulsions with rhythmic jerks, rigid muscles, loss of consciousness, and eyes rolling back

What Causes Lennox-Gastaut Syndrome?

Lennox-Gastaut syndrome can be caused by multiple conditions. For example, early brain injury from infection or trauma, gene mutations, or problems with the way the brain was formed before birth all can lead to the condition. Sometimes, it has no clear cause.

How Is Lennox-Gastaut Syndrome Diagnosed?

A pediatric neurologist (a doctor who treats brain, spine, and nervous system problems) can diagnose the condition by doing tests such as:

  • EEG to look for a pattern called "generalized slow spike and wave"
  • VEEG, or video electroencephalography (EEG with video recording)
  • CAT scan and MRI to get very detailed images of the brain

How Is Lennox-Gastaut Syndrome Treated?

Seizures in Lennox-Gastaut syndrome don't usually respond well to medicines. Other treatments include:

  • neurostimulation (a device that stimulates nerves to stop seizures)
  • ketogenic diet (a strict high-fat, low-carbohydrate diet)
  • surgery, such as corpus callosotomy where the "bridge" that connects the two brain hemispheres is cut. This works best for tonic and atonic seizures, and might not help the other types of seizures.

How Can Parents Help?

Caring for a child with Lennox-Gastaut syndrome can be challenging. Work with your child's care team to set up needed medical visits and therapies.

Make sure that you and other adults and caregivers (family members, babysitters, teachers, coaches, etc.) know what to do during a seizure. Your child may need to wear a helmet to prevent head injury during seizures.

What Else Should I Know?

If your child has Lennox-Gastaut syndrome, your doctor and the care team can answer questions and offer support. They also might be able to recommend a local support group. Online organizations can help too, such as:

Reviewed by: Amy W. Anzilotti, MD
Date reviewed: February 2021