Table 2.

Characteristics of patients: anatomical MRI features and EEG abnormalities

Pts	Anatomical MRI	Interictal events		Ictal events
		Types	Number	Types	Number	Duration (mean; range)
1	R TP nodular heterotopia (trigone, occipital horn and subcortical region). Thick overlying cortex	R T spike and waves	13	R FT sharp waves followed by polyspikes Electrical events during sleep	24	3.5 s; 2.1–6.2 s
2	R OT nodular heterotopia (occipital horn). Abnormal overlying cortex over the whole posterior quadrant with increase of thickness	R post. T spikes	30	R post. T sharp rhythmic activity Electrical event	1	22.3 s
3	Bil. nodular heterotopia (trigone). L anterior T resection	R T spikes L T spikes	41 40	R centroT 10Hz activity Clinical event	1	65 s
4	Bil. nodular heterotopia (trigones, temporal and occipital horns). Thick overlying occipital cortex	R T spikes L T spikes	23 8	L Trhythmic sharp waves Electrical events	3	2.5 s; 1.6–3.5 s
5	R ant. F focal cortical dysplasia	R F spike and waves	31	R F rhythmic spike and waves Clinical events	15	21.3 s; 7.2– 49.7 s
6	L centro P focal cortical dysplasia	L centro P spikes	42	Rhythmic L centro P sharp fast activity Clinical events	1	9.2 s
7	Band heterotopia predominating over parietal, occipital and temporal areas, R 4L	L TO polyspikes R TO polyspikes	100 74	R TPO discharges propagating to L homologous regions Electrical events during sleep	11	6.2; 3.8–13 s
8	Band heterotopia predominating over the frontal and parietal regions, bilaterally	Bil. TPO rhythmic slow waves	15	Rhythmic bil. occipital and R TPO discharges Electrical events during sleep	2	12 s; 10.5–13.5
Mean ± SD			38 ± 27.5		7.2 ± 8.6	17.7 ± 20.5 s

R = right; L = left; Bil = bilateral; T = temporal; F = frontal; C = central; P = parietal; O = occipital.