TABLE 2.

Characteristics of 41 craniotomies with subdural grid monitoring and depth electrode implantation for seizure localization^*

		Depth Electrode Placement
Characteristic	Total	Group A	Group B	p Value†
no. of patients	41	26	15
mean age in yrs (range)	33 ± 12 (8 –62)	35 ± 14	31 ± 8	NS
no. of children (≤18 yrs)	3 (7%)	2	1	NS
M/F	21:20	16:10	5:10	NS
electrode coverage
rt side	26 (63%)	16	10	NS
It side	15 (37%)	10	5	NS
lobe
frontal	23 (56%)	13	10	NS
temporal	41 (100%)	26	15	NS
subtemporal	39 (95%)	25	14	NS
parietal	11 (27%)	7	4	NS
implants
mean no. of grids (range)	1.1 ± 0.4 (1–2)	1.2 ± 0.5	1.1 ± 0.4	NS
mean no. of strips (range)	1.5 ± 1.8 (0–6)	0.7 ± 1.1	2.9 ± 2.1	<0.01
mean no. of cables (range)	8.2 ± 3.1 (4–18)	7.6 ± 2.8	9.3 ± 3.2	NS
mean no. of electrodes (range)	55 ± 23 (32–144)	51 ± 22	61 ± 25	NS
mean op time (min)	297 ± 18	327 ± 20	227 ± 28	<0.01
mean blood loss (ml)	253 ± 44	258 ± 62	248 ± 65	NS

^*Mean values are presented ± SDs.

Abbreviation: NS = nonsignificant.

^†Chi-square analysis.