Scalp and Intracranial EEG in Medically Intractable Extratemporal Epilepsy with Normal MRI

Table 3

Analysis of surgery outcome at 1-year followup.

Variables of interest	Favorable versus	𝑃 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.