Lennox-Gastaut syndrome is a severe form of childhood epilepsy that causes frequent seizures. Several types of seizures are usually present at the same time, including drop attacks (atonic or tonic seizures), which can cause injury.

Lennox-Gastaut syndrome may be caused by a variety of brain injuries. Other problems, such as mental retardation, delays in physical and intellectual growth, and other mental and physical disabilities, may also be present.

The condition can be difficult to treat. Treatment with medications (such as valproic acid, felbamate, lamotrigine, or topiramate), the ketogenic diet, or a type of brain surgery called corpus callosotomy may help control some of the seizures that occur with this syndrome. Most children will continue to have seizures throughout life.