What is Chiari Malformation?
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.
Is there any treatment?
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.
What is the prognosis?
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.
What research is being done?
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.
Organizations
March of Dimes Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
askus@marchofdimes.com
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
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
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
www.asap.org
Tel: 903.236.7079 800.ASAP.282 (272.7282)
Fax: 903.757.7456
Source: National Institutes of Health; National Institute of Neurological Disorders and Stroke
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 4/9/2009...#6008
