Arnold-Chiari Syndrome

(Arnold-Chiari Malformation; Type II Chiari Malformation; Cerebellomedullary Malformation Syndrome)

Definition

Arnold-Chiari syndrome is a series of nervous system symptoms.
This condition is often present at birth, but can also develop later in life. Some people with mild forms of this syndrome may never know they have the condition. For others it can be more severe. These severe forms will need treatment.

Causes

Arnold-Chiari syndrome is caused by a problem in the back of the skull. The skull should have an indented space in the back of the head. The rear lower part of the brain and the brainstem are in this space. In some people, this indented skull space does not develop well. This is called Chiari malformation. The space inside the skull is too small for the brain. As a result, the brain and brain stem are pushed downward. It blocks the flow of fluid from the brain to the spinal column.
The problem with the skull develops before birth. It is not clear why it happens. In some cases, it occurs with a myelomeningocele, which is a form of spina bifida .
Brain Stem and Lower Brain
GM00010 97870 brainstem.jpg
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Risk Factors

There are no known risk factors for Chiari malformation. There may be a genetic connection in some families.

Symptoms

Symptoms in infants may include:
  • Vomiting
  • Weakness
  • Paralysis of the limbs
  • Choking
  • Chronic cough or hoarseness
Symptoms in adolescents are usually milder and may include:
  • Lightheadedness
  • Fainting
  • Weakness in the legs
  • Headaches
  • Inability to hear or ringing in the ears
  • Eye problems such as difficulty seeing, eye pain, and rapid eye movement
  • Poor coordination
  • Uncontrolled shaking or trembling
  • Difficulty walking
  • Numbness or tingling in the arms or legs

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done. Detailed images of the brain and skull may be needed. The pictures may be taken with:
Special studies may also be done to evaluate the flow of fluid around your brain and spinal cord.

Treatment

Treatment will be based on individual symptoms. For example:
  • Physical or occupational therapy can help improve muscular coordination and trembling. Braces or a wheelchair may also be needed.
  • Speech therapy for speech or swallowing problems
  • Medication to help manage headaches and pain
The malformation may also block the flow of fluid in the brain and spine. Surgery may be needed to correct the flow of fluid. Surgery may also be done to release compression of the brain.
Talk with your doctor about the best treatment plan for you.

Prevention

There is no known way to prevent Arnold-Chiari syndrome. Genetic counseling may help parents of a child with this condition to determine the risk in future children.

RESOURCES

American Syringomyelia & Chiari Alliance Project http://www.asap.org

National Institute of Neurological Disorders and Stroke http://www.ninds.nih.gov

CANADIAN RESOURCES

Canadian Neurological Sciences Federation http://www.cnsfederation.org

Health Canada http://www.hc-sc.gc.ca

References

Chiari malformation. Comer Children’s Hospital website. Available at: http://www.uchicagokidshospital.org/online-library/content=P02592. Accessed February 12, 2014.

Chiari malformations. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated March 12, 2012. Accessed February 12, 2014.

Chiari malformation information page. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/chiari/chiari.htm. Updated December 30, 2013. Accessed February 12, 2014.

Hekman KE, Aliaga L, et al. Positive and negative predictors for good outcome after decompressive surgery for Chiari malformation type 1 as scored on the Chicago Chiari Outcome Scale. Nuerol Res. 2012;34(7):694-700.

Revision Information

  • Reviewer: Rimas Lukas, MD
  • Review Date: 02/2014 -
  • Update Date: 02/12/2014 -