Lennox-Gastaut Syndrome is diagnosed based on clinical and EEG findings. Identifying a possible cause can aid management and avoid unnecessary testing.

Conditions associated with LGS:

(1) genetic mutation

(2) structural damage to brain


In a quarter to a third no specific cause is identified.


Genetic causes may include mutations in:

(1) SCN1A (generalized epilepsy with febrile seizures plus, Dravet Syndrome)

(2) SLC2A1 (GLUT1-deficiency syndrome)

(3) STXBP1(associated with infantile spasms)

(4) SNM1 (associated with infantile spasms)

(5) GABRB3 (associated with infantile spasms)

(6) trisomy 21

(7) DNM1

(8) ALG13

(9) CDKL5

(10) SCN2A


Conditions with structural damage:

(1) CNS infection

(2) brain tumor

(3) developmental malformation of the brain

(4) other brain injury

(5) infantile spasms (West Syndrome) not associated with genetic mutation

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