Aberrant morphogenesis of the central nervous system

Dysmorphogenesis of the central nervous system (CNS) can be broadly classified within a pathogenetic framework. Natural deformations result from aberrant mechanical forces, such as intrauterine constraint, and may result in craniosynostosis and abnormally shaped calvaria and brains. Dysplasia is reflected in altered gyral patterns and heterotopias, while disruptions in morphogenesis produce more serious consequences. Examples are early amnion rupture sequence, porencephaly, and atelencephaly/aproscencephaly. Malformations are diagnosed prenatally with increasing frequency and include such recognized entities as neural tube defects (anencephaly, encephalocele, myelomeningocele), holoprosencephaly, agenesis of the corpus callosum, and Dandy-Walker and Arnold-Chiari malformations. By maintaining a pathogenetic view of congenital anomalies of the CNS, the variability of anatomic features and role of etiologic factors may be better comprehended.