National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Polymicrogyria

Polymicrogyria is a condition characterized by abnormal development of the brain before birth. Specifically, the surface of the brain develops too many folds which are unusually small. The signs and symptoms associated with the condition vary based on how much of the brain and which areas of the brain are affected; however, affected people may experience recurrent seizures (epilepsy); delayed development; crossed eyes; problems with speech and swallowing; and muscle weakness or paralysis. Bilateral forms (affecting both sides of the brain) tend to cause more severe neurological problems. Polymicrogyria can result from both genetic and environmental causes. It may occur as an isolated finding or as part of a syndrome. Treatment is based on the signs and symptoms present in each person.[1][2]
Last updated: 10/12/2015
A wide variety of symptoms may be observed in people with polymicrogyria, depending on the areas of the brain implicated and whether or not it is part of a larger syndrome. Signs and symptoms may include:[3][4]
  • Developmental delay
  • Crossed eyes
  • Epilepsy
  • Paralysis of the face, throat, and tongue
  • Difficulty with speech and swallowing
  • Drooling
Last updated: 5/25/2016
The diagnosis of polymicrogyria is made by imaging brain structures using MRI. Typical findings include areas of the cerebral cortex with a complex set of small gyri that appear fused to each other and separated by shallow sulci. These findings may be isolated to one side of the brain (unilateral) or may involve both sides of the brain (bilateral).[3][4]
Last updated: 5/25/2016

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Polymicrogyria. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Polymicrogyria. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Polymicrogyria. Genetics Home Reference. June 2009; http://ghr.nlm.nih.gov/condition/polymicrogyria. Accessed 6/15/2015.
  2. Chang B, Walsh CA, Apse K, Bodell A. Polymicrogyria Overview. GeneReviews. August 6, 2007; http://www.ncbi.nlm.nih.gov/books/NBK1329/. Accessed 6/15/2015.
  3. Golden JA, Bonnemann CG. Developmental Structural Disorders. In: Goetz CG. Textbook of Clinical Neurology. Philadelphia, PA: Saunders; 2007;
  4. polymicrogyria. Genetics Home Reference. June 2009; https://ghr.nlm.nih.gov/condition/polymicrogyria. Accessed 5/25/2016.