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 very 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 is accompanied by a myelomeningocele, which is a form of spina bifida.

Brain Stem and Lower Brain

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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
• Deafness 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

Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor may also need detailed images of the brain and skull. The pictures may be taken with:

• MRI
• CT scan

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.