Lennox-Gastaut syndrome (also known as myoclonic-astatic epilepsy) is a combination of seizures usually including atypical absense seizures (starting with automatic behavior without conscious control); tonic seizures (stiffening) atonic or astatic seizures (drop attacks); mental retardation; a distinct slow spike-and-wave EEG; and onset between 1 and 5 years of age.
Some children are developmentally normal when the syndrome begins, but then lose skills, sometimes dramatically, in association with uncontrolled seizures. By age 6 most children with Lennox-Gastaut have some degree of mental retardation.
Children with Lennox-Gastaut syndrome typically have more than one type of seizure. The atonic-astatic (drop attack) seizures are most troubling because of the injuries caused by repeated falls. Many children wear protective helmets. The tonic (stiffening) seizures are most common during sleep, including nap time, whereas generalized tonic-clonic seizures (convulsions) occur most often on awakening.
Some of these children are prone to develop non-convulsive status epilepticus (a continuous seizure state that is associated with a change in the child's level of awareness. This requires medical intervention to bring it to an end).
As children with Lennox-Gastaut syndrome grow older, the types of seizures change. In most cases, the drop seizures abate. They are replaced by partial, complex partial, and secondarily generalized convulsions. Among teenagers with Lennox-Gastaut, complex partial seizures are the most common form.
This seizure syndrome is difficult to treat and often does not respond to the usual seizure medications. Other treatment choices may include the ketogenic diet, vagus nerve stimulation therapy or occasionally corpus callosotomy surgery.