Cortical Dysplasia

This is a case of cortical dysplasia in a 9-year-old female with intractable seizures. Within the left orbitofrontal region and extending to involve the periventricular and deep white matter of the left frontal lobe, there is a focal region of polymicrogyria with cortical gray matter thickening and a dysplastic appearance. The degree of cortical thickening and disorganization is also demonstrated on the diffusion tensor and fractional anisotropic images. There is no suspicious postcontrast enhancement. Cortical dysplasia represents a malformation of cortical development secondary to grey matter disorganization. The four major subtypes of cortical dysplasia include polymicrogyria, as in this case, focal cortical dysplasia type 1, focal cortical dysplasia type 2 and grey matter heterotopia. Polymicrogyria is defined by excessively small gyri and prominent convolutions. The cortex may look normal or thick, as in this case.