Microgyria brain disorder. Gross clinical specimen of a neonatal brain, showing numerous cerebral convolutions (polymicrogyria). This condition manifests at around 24 weeks of gestation and can be caused by a congenital herpes virus infection, as a result of exposure to carbon monoxide or due to a number of genetically inherited disorders. Children born with this condition have a poor prognosis, those that do survive have developmental delays, mental retardation and are prone to seizures.