Fig. 1

Clinical, intraoperative and anatomopathological features. Preoperative magnetic resonance imaging (MRI) and electroencephalogram of patient 1 (A) and patient 2 (B). Arrows on MRI indicate the cortical area with dysplastic. In patient 1 (A), MRI showed blurring and signal alteration of the cortico-subcortical interface of the posterior segment of the right superior frontal gyrus. MRI of patient 2 (B) depicted an area of cortical thickening signal alteration and blurring of the cortical-subcortical interface in the left occipital lobe. C) Cerebral cortex during intraoperative electrocorticography with the indication of each electrode placed on the surface of the cortex before and after surgical resection for patient 1 and 2 respectively (D). Arrows focus on areas of epileptogenic activity. C) Histological section stained with hematoxylin and eosin of the lesion area showing the lack of the cortical lamination, dysmorphic and giants neurons, without presence of balloon cells, characterizing a Cortical Dysplasia Type IIa.