Is lennox gastraut sydrome is the same as petit mal.

LGS and petit mal: LGS and petit mal are not the same. The first is a kind of severe epilepsy, in which there are multiple types of seizures. Petit mal is a type of seizure, akin to a staring spell. It is an old term for absence seizure, although it is sometimes confused with complex partial seizure. see this for more details: http://www.neurocuro.com/absence-epilepsy/