Seizures, mental retardation. Association with corpus callosum agenesis, Chiari malformations, Tuberous Sclerosis, septooptic dysplasia. Schizencephaly Gray matter extension from the ventricle to the cortex. Association with septooptic dysplasia and optic atrophy. Most severe form of neuronal migrational anomalies.
Patients often have small brains, mental retardation, spasticity, seizures.
More mild form than agyria. Polymicrogyria Neurons reach the cortex but are abnormally distributed into multiple small gyri like dimples on the surface of a basketball. The cortex of polymicrogyria have bumps of about 5-7 millimeters in size whereas those of pachygyria are over 8 millimeters in size. Clinically less severe than lissencephaly. Seizures, developmental delays.