Polymicrogyria refers to a Congenital disorder that can be traced to a disruption of the structure of the developing brain during the fifth to sixth month of gestation. As a consequence of this disruption, the gyri fail to develop appropriately.
On inspection, the gyri are found to be small and crowded together. Learning disorders, mental retardation, epilepsy, and other neuropsychological anomalies are linked to the disorder.