Decompression of Chiari Malformation

One type of Chiari malformation occurs when the posterior part of the brain, called the cerebellum, extends into the spinal canal (Figure 1). This issue occurs when the bony skull develops too small to fully contain the posterior part of the brain. The seriousness of this issue depends on the amount of brain that is extending into the spinal canal and on the symptoms that are occurring.

Figure 1 (Courtesy of Mayo Clinic) - Chiari malformation and decompression:
Figure 1

Signs of Chiari malformation may not occur until late childhood or adulthood. Common symptoms include severe headaches with coughing, sneezing, or straining, neck pain, imbalance, incoordination, choking, vomiting, double vision, numbness of the hands/feet, and/or dizziness.

Treatment will depend on the size and symptoms of the Chiari malformation. Chiari malformations with minimal brain tissue in the spinal canal and minimal symptoms may be observed without any active therapy. Chiari malformations with significant brain tissue in the spinal canal and major symptoms may need surgery. Surgical treatment for Chiari malformation involves creating a larger space for the posterior brain by removing a piece of skull from the back of the head (Figure 1), termed “decompression.”

In patients with a small Chiari malformation and headache as the only symptom, pain management for headache may be a better option than open brain surgery. Headaches often respond unreliably to surgical decompression, or worsen. Treatment decisions will be made after a comprehensive neurological evaluation.