Children & families · Conditions
Chiari malformation
The lowest part of the brain sits lower than usual, through the opening at the base of the skull. Many children need no surgery.
What is it?
In a Chiari I malformation, the lowest part of the back of the brain (the cerebellar tonsils) sits lower than usual, through the opening at the base of the skull (foramen magnum). This can crowd the area and affect the flow of fluid around the brain and spinal cord. Some children also develop a fluid-filled cavity in the spinal cord (a syrinx). A different form, the Chiari II malformation, occurs in babies with open spina bifida.
What symptoms can it cause?
Many children have no symptoms and the finding is made on a scan done for another reason. When symptoms occur, the most typical is a headache at the back of the head or neck brought on by coughing, sneezing, laughing or straining. Others include neck pain, dizziness or balance problems, numbness or weakness in the arms or hands, scoliosis, and, less often, difficulty swallowing or breathing problems during sleep. Young children may show irritability or arching when crying.
How is it assessed?
Your child will be examined, and an MRI scan of the brain and spine shows the position of the tonsils and whether there is a syrinx. Some children need other tests, such as a sleep study or a swallowing assessment.
What are the treatment options?
Children without symptoms, and those with mild symptoms, are usually watched with regular review, with scans if needed. When surgery is recommended, it is usually a posterior fossa decompression: an operation at the back of the head and upper neck to make more room and improve the flow of fluid.
When might surgery be considered?
Surgery may be considered when symptoms are typical of Chiari and affect daily life, when there is a syrinx, or when there are signs of pressure on the brainstem or spinal cord. Not every headache in a child with a Chiari finding is caused by it, and this is discussed carefully.
What to expect from recovery and follow-up
Most children stay in hospital for a few days and have neck discomfort for a time afterwards. Follow-up checks symptoms and, where there was a syrinx, a repeat MRI after some months.
When to seek urgent help
If your child is very drowsy, difficult to wake, has a seizure, repeated vomiting or a severe headache, go to the nearest emergency unit or call 10177. If your child is under our care, also call the hospital switchboard and ask for Dr Labuschagne (Netcare Unitas Hospital 012 677 8000; Nelson Mandela Children's Hospital 010 133 0600). New weakness or numbness, difficulty swallowing or pauses in breathing during sleep also need prompt review.
This page is general information for parents and caregivers. Your child's doctor will advise on what applies to your child.