Agyria pachygyria polymicrogyria


Polymicrogyria (PMG) is a developmental malformation of the human brain characterized by an excessive number of small convolutions (gyri) on the surface of the brain. Either the whole surface or parts of the surface can be affected.


  • Abnormal brain development
  • Agyria
  • Pachygyria
  • Polymicrogyria
  • Mental retardation
  • Refractory epilepsy


Causes are genetic, viral or due to nutritional deficits during gestation


With increased use of imaging techniques such as MRI and CT, polymicrogyria is becoming more widely diagnosed. However, polymicrogyria is often misdiagnosed as pachygyria or lissencephaly, even by experienced radiologists, since the differences between these conditions can be difficult to see on an MRI or CT scan