Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get StartedDefinition
By Mayo Clinic staffChiari malformation is a condition in which brain tissue protrudes into your spinal canal. It occurs when part of your skull is abnormally small or misshapen, pressing on your brain and forcing it downward. Chiari malformation is uncommon, but improved imaging tests have led to more frequent diagnoses.
The adult form, called Chiari malformation type I, develops as the skull and brain are growing. As a result, signs and symptoms may not occur until late childhood or adulthood. The most common pediatric form, called Chiari malformation type II, is present at birth (congenital).
Treatment of Chiari malformation depends on the form, severity and associated symptoms. Regular monitoring, medications and surgery are treatment options. In some cases, no treatment is needed.
Symptoms- NINDS Chiari malformation information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/chiari/chiari.htm. Accessed July 14, 2008.
- Chiari malformation. American Association of Neurological Surgeons. http://www.neurosurgerytoday.org/what/patient_e/chiari1.asp. Accessed July 14, 2008.
- What is the Chiari malformation? American Syringomyelia Alliance Project. http://www.asap.org/chiari-malformation.html. Accessed July 14, 2008.
- Ropper AH, et al. Chiari malformation. In: Ropper AH, et al. Adams and Victor's Principles of Neurology. 8th ed. New York, N.Y.: The McGraw-Hill Companies; 2005:28-32.