Table 3: Analysis of surgery outcome at 1-year followup.

Variables of interest Favorable versus value unfavorable outcome Age of Onset: 40% versus 50% 0.54  <10 yrs  >10 yrs Scalp interictal EEG:  Group 1 (localized IED) 50% versus 40% 0.25  Group 2, 3, and 4 (other) Seizure semiology:  history of GTC 50% versus 49% 0.87  no history of GTC Duration of epilepsy:  >15 years 60% versus 40% 0.19  <15 years Pathology:  cortical dysplasia 50% versus 49% 0.51  gliosis Nonspecific MRI abnormality:  absent 50% versus 48% 0.9  present SISCOM perfusion abnormality:  localized 61% versus 45% 0.88  nonlocalized Postoperative scalp EEG 55% versus 50% 0.32 IED present versus negative

IED: interictal epileptiform discharge Group 1: localized IED; Group 2: lateralized but not localized IED; Group 3: generalized or bilateral IED; Group 4: no IED.