Malformations of cortical development

Malformations of cortical development are important causes of developmental delay and epilepsy. They are classified by the presumed stage during which normal development is interrupted: neuronal proliferation and differentiation; neuronal migration; and late migration/cortical organization. The important malformations in each of these groups are discussed in this article, along with a discussion of how and why the malformations develop, and their imaging findings. A better understanding of these disorders helps in genetic counseling and may help in the treatment of associated epilepsy.