Table 2:

Clinical and histologic data of patients with positive and negative findings on MRI

	Negative MRI Findings	Positive MRI Findings	Total
No. of patients	29	42	71
Sex ratio (M/F)	0.8	1.8	1.3
Age at onset (yr) (median) (range)	6 (1–20)	5.8 (1–20)	6 (1–20)
Age at surgery (yr) (median) (range)	17 (8–41)	22.5 (8–52)	20 (8–52)
Location of FCD
Left/right ratio	1.4	1.25	1.35
Frontal lobe	23	37	60
Parietal lobe	4	3	7
Temporal lobe	1	1	2
Occipital lobe	1	1	2
Type 2 FCD subtypes
Type 2a (no balloon cells)	6	2	8
Type 2b (balloon cells)	23	40	63