Arnold Chiari Malformations

Arnold-Chiari Malformation
Arnold-Chiari Malformation

Overview Of Arnold Chiari Malformations

Arnold Chiari malformations (CM’s) are structural defects of the brain in which the cerebellum, the area of the brain in charge of balance and movement coordination, extends into the spinal canal. This extension of brain tissue into areas it doesn’t belong can happen for a variety of reasons. One example of a cause is a specific section of the person’s skull being too small, which can then push the brain tissue down into the spinal canal area.

There are many types of Arnold chiari malformations. One well-known type often occurs in children also born with neural tube defects.

Causes Of Arnold Chiari Malformations 

Arnold chiari malformations can be caused by a variety of situations. The most common cause of this condition are various types of structural defects of the spinal cord and/or brain. These defects occur during fetal development, and are called primary or congenital chiari malformations.

These malformations can also occur later in life. When this occurs, they’re called secondary or acquired chiari malformations. One of the most common causes of this type is abnormal spinal fluid draining from the thoracic or lumbar areas of the spine. This draining typically comes about because of an injury, an infection, or some other disease.

Also, prevalence-wise, the secondary type is far rarer than the primary type.


Some types of Arnold chiari malformations have no symptoms whatsoever, and therefore do not require often require treatment. Other types, however, will have a variety of symptoms of varying severity.

These symptoms can include:

  • Poor coordination of fine motor skills
  • Difficulties eating and gaining weight
  • Tinnitus (a constant ringing or buzzing in the ears)
  • Neck pain
  • Problems with balance
  • Scoliosis (an abnormal spine curvature)
  • Numbness, weakness, or other abnormal sensations in the arms or legs
  • Vomiting
  • Vision problems
  • Difficulty swallowing or speaking
  • Excessive drooling or involuntary gagging
  • Dizziness
  • Headaches, especially after sudden sneezing, or coughing, or muscular strain
  • Hearing problems
  • Insomnia
  • Depression
  • Difficulties with breathing  

Exams & Tests

Health care providers will typically diagnose Arnold chiari malformations with imagining tests.

But, for those without symptoms, this condition is usually found accidentally, often appearing on scans that were taken to help diagnose some other problem. 

Treatment Of Arnold Chiari Malformations

Various medications can help with the symptoms of this condition, if any are present. However, the only permanent way to stop or slow the progression of nerve damage from this condition is surgery. 

The most commonly performed surgery for this condition is a posterior fossa decompression. This surgery creates more space for the cerebellum so it stops extending into the spinal cord space. The person’s cerebrospinal fluid will then be able to flow more normally after the decompression surgery, and their spinal cord should be far less compressed. Symptoms should improve with this surgery in most cases. However, this surgery isn’t the perfect solution for every case of this condition.

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