Lennox-Gastaut Syndrome is an epileptic encephalopathy that may have several causes.

Onset: usually between 3 and 7 years of age


Key features at initial presentation:

(1) multiple seizure types (see below)

(2) therapy resistance with incomplete seizure control

(3) EEG changes, with interictal bursts of slow spike-wave complexes (< 3 Hz) and/or generalized paroxysmal fast activity during sleep (10-20 Hz)


Additional key features that may present later:

(1) intellectual disability


Seizure types (types 1 to 3 typical, types 4 to 7 variable):

(1) tonic (predominantly occur at night)

(2) atonic

(3) atypical absence

(4) epileptic spasms

(5) nonconvulsive status epilepticus

(6) focal seizures

(7) myoclonic seizures



(1) poor social functioning

(2) disability

(3) fall injury

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