. Author manuscript; available in PMC: 2018 Dec 1.

Published in final edited form as: Epilepsia. 2017 Oct 10;58(12):2133–2142. doi: 10.1111/epi.13920

Table 2.

Postoperative seizure outcomes stratified by patient characteristics

			Engel I	Engel II–IV	P value

	Total		369 (47%)	413 (53%)
A) Demographics	Gender	Female	31 (56%)	24 (44%)	0.56
	Gender	Male	44 (52%)	41 (46%)
	Age of seizure onset, years (mean ± SEM)		7.1 ± 0.9	6.6 ± 0.9	0.64
	Age of seizure onset, years (mean ± SEM)		N = 78	N = 67
	Age at initial surgery, years (mean ± SEM)		15.9 ± 1.3	14.9 ± 1.3	0.57
	Age at initial surgery, years (mean ± SEM)		N = 105	N = 89
	Age at last surgery, years (mean ± SEM)		16.8 ± 1.4	15.4 ± 1.3	0.48
	Age at last surgery, years (mean ± SEM)		N = 87	N = 77
B) Epilepsy characteristics	Pathology	Lesional	95 (61%)	62 (39%)	< 0.01^*
	Pathology	Non-Lesional	145 (41%)	205 (59%)
	Secondary seizure generalization	Yes	22 (38%)	36 (62%)	< 0.08
	Secondary seizure generalization	No	46 (53%)	41 (47%)
	Predominant seizure type	FOIA	54 (51%)	51 (49%)	0.01^*
		FOA	38 (45%)	46 (55%)
		Other	2 (12%)	15 (88%)
	Duration of epilepsy, years (mean ± SEM)		12.3 ± 1.9	8.5 ± 1.9	0.18
	Duration of epilepsy, years (mean ± SEM)		N = 36	N = 24
C) Diagnostics	MRI findings prior to 1^st surgery	Normal	18 (35%)	34 (65%)	0.03^*
	MRI findings prior to 1^st surgery	Abnormal	76 (53%)	68 (47%)
	Electrophysiology	Congruent	87 (69%)	39 (31%)	< 0.01^*
	Electrophysiology	Incongruent	31 (47%)	35 (53%)
	Invasive Monitoring	Used	67 (52%)	61 (48%)	< 0.01^*
	Invasive Monitoring	Not used	62 (76%)	20 (24%)
D) Surgical factors	Time between resections, years (mean ± SEM)		3.1 ± 0.3	3.0 ± 0.3	0.83
	Time between resections, years (mean ± SEM)		N = 96	N = 92
	Resection location – initial surgery	Temporal	94 (49%)	99 (51%)	0.04^*
	Resection location – initial surgery	Extratemporal	99 (39%)	155 (61%)
	Resection location – last surgery	Temporal	129 (54%)	112 (47%)	< 0.01^*
	Resection location – last surgery	Extratemporal	95 (37%)	160 (63%)
	Side of initial surgery	Left	47 (48%)	50 (52%)	0.26
	Side of initial surgery	Right	68 (56%)	53 (48%)
	Side of last surgery	Left	46 (49%)	47 (51%)	0.34
	Side of last surgery	Right	65 (55%)	51 (45%)
	Reason for failure of initial surgery	Surgical limitation	100 (50%)	102 (50%)	< 0.01^*
	Reason for failure of initial surgery	Disease-related	23 (32%)	48 (68%)

Statistically significant value (p ≤ 0.05).

Data are reported as N values (with corresponding percent) unless otherwise indicated. SEM = standard error of the mean; FOIA = focal onset with impaired awareness (i.e. complex partial); FOA = focal onset aware (i.e. simple partial); MRI = magnetic resonance imaging.