Q07.0: Arnold-Chiari syndrome

The brain is surrounded by a protective shell of bone, known as the skull or cranium. The cerebellum is part of the brain. The cerebellum is important for movement and balance. The cerebellum stores movement processes, for example, how one eats with cutlery or rides a bike. The brain stem is part of the brain. The brain stem is where breathing and heart rate are regulated.

While developing in the womb, many different types of tissue develop in the body. The organs and body parts develop out of the various types of tissue. If tissue fails to develop properly, defects can occur.

Part of your skull has not developed properly, causing there to be less room than normal for the brain inside the skull at the back. This pushes the cerebellum downwards towards the spine. It may also be that the brain stem has not developed properly. These changes can lead to different nerves not functioning normally.

This malformation can cause a range of symptoms. It may be that symptoms only appear in adolescence or adulthood, resulting in pain in the head, neck or arms, for example. Dizziness is also possible.

In some cases, the malformation can already be noticeable in newborns, and problems with breathing or swallowing, for example, may occur. Severe back muscle spasms may also occur. It is also possible that arms and legs are not able to move properly.