Lennox-Gastaut Syndrome

Lennox-Gastaut syndrome is a very rare and severe form of symptomatic generalized epilepsy ("symptomatic" meaning that the cause of the syndrome is known and "generalized" meaning that it affects the entire brain). Seizures usually begin to develop in children between the ages of 1 and 8 years. The Epilepsy Foundation of America^® estimates that anywhere from 20 to 60 percent of children have infantile spasms prior to being diagnosed with Lennox-Gastaut syndrome.

Diagnosis and treatment are extremely difficult because children with Lennox-Gastaut syndrome experience multiple types of seizures, especially tonic (body stiffening), atonic (drop attack) and absence (staring) seizures.

What Causes Lennox-Gastaut Syndrome?

Most children with Lennox-Gastaut syndrome have some sort of intellectual impairment. Several potential causes for the syndrome include:

Brain injury
Brain malformations
Degenerative conditions
Hearing loss and visual impairment
Infection of the central nervous system
Metabolic disorders
Neurological disorders (i.e. cerebral palsy)
Perinatal asphyxia (lack of oxygen)
Tuberous sclerosis (benign brain tumors resulting in a developmental delay).

According to the National Institute for Neurological Disorders and Stroke, in 30 to 35 percent of cases, there's no known cause for the child's seizures. Causes in such cases may be influenced by risk factors such as:

Family history (although inheritance patterns are unclear)
Gender (slightly higher incidence in males)
Previous infantile spasms.

What Does Lennox-Gastaut Syndrome Look Like?

While most epilepsy syndromes only exhibit one type of seizure, Lennox-Gastaut syndrome is characterized by multiple types of seizures in children, particularly absence, atonic and tonic seizures:

Absence seizures (petit mal) are very short lapses of consciousness. The individual may stare off into space.
Atonic seizures (or drop attacks) are the opposite of tonic seizures. Muscles suddenly go weak and the individual collapses.
Tonic seizures involve a stiffening of the arms, legs or the whole body. They last about 10 seconds and usually occur during sleep.

Tonic-clonic (convulsions) and myoclonic (sudden muscle contractions) seizures can also occur. Seizures in children may occur several times a day, although a child can experience occasional, brief seizure-free periods.

Other possible symptoms of Lennox-Gastaut syndrome include:

Behavioral problems (i.e. aggressiveness, autism, emotional instability, hyperactivity, hypersexuality)
Mental deterioration
Status epilepticus (a serious condition involving continuous seizures).

What's the Prognosis for Lennox-Gastaut Syndrome?

Although the prognosis varies among individuals, it's rare that an individual with this condition will develop a normal intellectual capacity or gain complete control over their seizures. Most children with Lennox-Gastaut syndrome have mental and behavioral disorders and few are able to function on their own as adults.