Polymicrogyria (PMG) is a rare brain disorder. PMG is a disorder of neuronal migration resulting in structurally abnormal cerebral hemispheres. The name Polymicrogyria broken down describes its characteristics "many small folds in the surface of the brain". It is also characterized by shallow sulci, a slightly thicker cortex, neuronal heterotopia and enlarged ventricles. When many of these small folds are packed tightly together, PMG may resemble pachygyria (a few "thick folds" - a mild form of lissencephaly) in parts of the brain.

The difference between PMG and pachygyria/lissencephaly can be difficult to see on an MRI or CT scan, even for an experienced radiologist. The diagnosis of PMG is merely descriptive and is not a disease in itself nor does it describe the underlying etiology or cause of the brain malformation

Most children with Polymicrogyria, but not all, have some degree of global developmental disabilities or delays, seizures, feeding difficulties, respiratory problems, motor dysfunction and mental retardation. It is difficult to make a predictable prognosis for children with the diagnosis of PMG because each child is very unique in their presentation of this disorder.

This listserv was established as a place to share medical information and emotional support. We are parents and relatives of children with PMG, not medical professionals. If you have a child or a relative diagnosed with Polymicrogyria (or a similar neuronal migration disorder) and are looking for information and support, please feel free to join this community.