Seizures associated with LGS

The onset of Lennox-Gastaut syndrome (LGS) does not begin with a specific type of seizure. For young children when there is no known cause, LGS usually begins with a "drop attack" followed by other seizures.1 The names and specific signs of the different seizure types are listed below. Keep in mind that as your child grows from childhood to adulthood, the seizures he or she experiences may change.


Tonic seizures are also known as drop attacks because they can cause the patient who is standing to be thrown to the ground.1

Doctors don’t usually diagnose LGS unless the child is having tonic seizures.1 Generally, muscles tighten (this can happen to a specific set of muscles, or most muscle groups at once), the eyes roll back, and pupils dilate.2 Tonic seizures can cause faster heartbeats and a temporary stop in breathing.2 They occur most often during sleep and usually last 10 to 60 seconds.2


Atonic seizures are also considered drop attacks.1 Atonic seizures cause head nods, loss of posture, and sagging at the knees.2 They are usually very brief, lasting between 1 and 4 seconds.2

Atypical absence

This is the second most common seizure associated with LGS.1 Atypical absences are characterized by a gradual onset and termination1 as well as staring, pauses in activity, and a lack of response.2 They are generally 5 to 30 seconds long.2


A period of jerking movements.3


Myoclonic seizures consist of sporadic jerks.3 They usually happen in the same way on both sides of the body.3


During partial seizures, a specific part of the brain does not work properly. Certain movements, emotions, sensations, and feelings can be affected.4


In the first phase of tonic-clonic seizures, the stiffening associated with tonic seizures occurs.3 It then gradually changes to the clonic phase, in which the muscles quickly switch between contraction and relaxation.3

Remember that LGS, just like other epilepsies, is more than seizures. Often, children with epilepsy have behavioral problems as well.1 And just as you need to understand the different types of seizures, you’ll need to understand the causes of behavioral problems and ways to approach them.

A child who has LGS may experience a number of different types of seizures.1
NEXT: Behavioral Issues


  • 1. Arzimanoglou A, French J, Blume WT, et al. Lennox-Gastaut syndrome: a consensus approach on diagnosis, assessment, management, and trial methodology. Lancet Neurol. 2009;8:82-93.
  • 2. Crumrine PK. Lennox-Gastaut syndrome. J Child Neurol. 2002;17(suppl 1):S70-75.
  • 3. Benbadis SR. Epileptic seizures and syndromes. Neurol Clin. 2001;19(2):251-270.
  • 4. Schachter SC, Sirven JI. Simple partial seizures. Accessed April 21, 2014.

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