Engel class

Epilepsy surgery outcome

Class I

Free of disabling seizures
A: completely seizure-free since surgery
B: nondisabling simple partial seizures only since surgery
C: some disabling seizures after surgery, bur free of disabling seizures for at least 2 years

Class II

Rare disabling seizures ("almost seizure free")
A: initially free of disabling seizures but has rare seizures now
B: rare disabling seizures since surgery
C: more than rare disabling seizures since surgery, but rare seizures for the last 2 years
D: nocturnal seizures only

Class III

Worthwile improvement (requires additional data on seizure incidence and quality of life)
A: worthwile seizure reduction
B: prolonged seizure-free intervals amounting to greater than half the followed-up period, but not < 2 years

Class IV

No worthwile improvement
A: significant seizure reduction
B: no appreciable change
C: seizures worse


Wieser HG, Blume WT, Fish D, Goldensohn E, Hufnagel A, King D, et al. ILAE Commission Report. Proposal for a new classification of outcome with respect to epileptic seizures following epilepsy surgery. In: Epilepsia. 2001. p. 282–286.