Lennox-Gastaut syndrome (LGS) is a rare and often debilitating form of childhood-onset epilepsy. The syndrome is characterized by a triad of signs including multiple seizure types, moderate to severe cognitive impairment, and an abnormal EEG with slow spike- wave complexes. LGS constitutes between 1-4% of pediatric epilepsies and typically appears between the second and sixth year of life.
Some of the known causes of Lennox-Gastaut Syndrome include brain injury associated with pregnancy or birth (including asphyxia, low birth weight, and prematurity), severe brain infections (including encephalitis, meningitis and rubella), developmental malformations of the brain, or a history of infantile spasms. In 30-35 percent of cases, no cause can be found.
Most children are typically developing normal when first diagnosed, but then begin to lose skills, sometimes dramatically, in association with uncontrolled seizures. Young children with LGS may exhibit behavioral issues, personality disturbances, mood instability, and slowing of psychomotor development. Behavioral disturbances can include poor social skills and attention seeking behavior, which can be caused by the effects of the medication, difficulty interpreting information, or the electric disturbances in the brain. Some children with LGS 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.