Chiari malformations (CMs) are structural defects in the cerebellum, the part of the brain that controls balance. When the indented bony space at the lower rear of the skull is smaller than normal, the cerebellum and brainstem can be pushed downward. The resulting pressure on the cerebellum can block the flow of cerebrospinal fluid (the liquid that surrounds and protects the brain and spinal cord) and can cause a range of symptoms including dizziness, muscle weakness, numbness, vision problems, headache, and problems with balance and coordination. There are three primary types of CM. The most common is Type I, which may not cause symptoms and is often found by accident during an examination for another condition. Type II (also called Arnold-Chiari malformation) is usually accompanied by a myelomeningocele-a form of spina bifida that occurs when the spinal canal and backbone do not close before birth, causing the spinal cord to protrude through an opening in the back. This can cause partial or complete paralysis below the spinal opening. Type III is the most serious form of CM, and causes severe neurological defects. Other conditions sometimes associated with CM include hydrocephalus, syringomyelia, and spinal curvature.
Medications may ease certain symptoms, such as pain. Surgery is the only treatment available to correct functional disturbances
or halt the progression of damage to the central nervous system. More than one surgery may be needed to treat the condition.
Many people with Type I CM are asymptomatic and do not know they have the condition. Many patients with the more severe types
of CM and have surgery see a reduction in their symptoms and/or prolonged periods of relative stability, although paralysis
is generally permanent.
The NINDS supports research on disorders of the brain and nervous system such as Chiari malformations. The goals of this research
are to increase scientific understanding of these disorders and to find ways to prevent, treat, and, ultimately, cure them.
March of Dimes Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 askus@marchofdimes.com http://www.marchofdimes.com Tel: 914-428-7100 888-MODIMES (663-4637) Fax: 914-428-8203 |
National Organization for Rare Disorders (NORD) P.O. Box 1968 (55 Kenosia Avenue) Danbury, CT 06813-1968 orphan@rarediseases.org http://www.rarediseases.org Tel: 203-744-0100 Voice Mail 800-999-NORD (6673) Fax: 203-798-2291 |
Spina Bifida Association of America 4590 MacArthur Blvd. NW Suite 250 Washington, DC 20007-4266 sbaa@sbaa.org http://www.spinabifidaassociation.org Tel: 202-944-3285 800-621-3141 Fax: 202-944-3295 |
American Syringomyelia Alliance Project (ASAP) P.O. Box 1586 Longview, TX 75606-1586 info@asap.org http://www.asap.org Tel: 903-236-7079 800-ASAP-282 (272-7282) Fax: 903-757-7456 |
Prepared by:
Office of Communications and Public Liaison
National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892
NINDS health-related material is provided for information purposes only and does not necessarily represent endorsement by or an official position of the National Institute of Neurological Disorders and Stroke or any other Federal agency. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient's medical history.
All NINDS-prepared information is in the public domain and may be freely copied. Credit to the NINDS or the NIH is appreciated.
Last updated December 11, 2007