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Chiari Malformation


My twenty month old girl and was diagnosed as having Chiari Malformation with Cerebellar Tonsils at C2 Level. This diagnosis was made 1 year ago and doctors are continuing to monitor her condition with MRI studies. Given her already small head size, we are concerned about the effects of the herniation. We are also concerned that the effects of this condition (possible paralysis, headaches, numbness in the extremities) might be present and causing developmental delays (such as walking) and account for some of her SIB, including "tearing" at skin, pulling out hair, biting and head banging. Developmentally she is standing, sitting and "scoots around on her bum." She is non-verbal. The only medication she is on is 20 mg of Prilosec for reflux. I would be interested in obtaining your impressions surrounding our concerns.

Answer of our experts

In general, the Chiari 1 malformation is painless. However, sometimes occipital headache is associated with it, in particular with certain head positions. Weakness, numbness, etc can be associated, usually when there is so called syrinx formation in the spinal cord (a long fluid-filled cavity running in the cord). Chiari 1 and syrinx are not infrequently associated with the syrinx causing the symptoms. The syrinx is easily seen on MRI scanning. The Chiari alone can also cause weakness if it really pushes on the upper cord/lower brainstem, it can then also cause difficulties swallowing. Such a "mass effect" can also be appreciated on the MR images. Most commonly, there are no symptoms associated with the Chiari 1 malformation, and it often is found by chance on images taken for another reason. It is not commonly seen in CdLS.

So I would agree that the current symptoms in this young child are likely not specifically associated with the Chiari 1 malformation, but rather with the underlying condition. This is much more difficult to follow in a nonverbal patient. Following by imaging and watching for changes in the child (in particular swallowing) seems very reasonable to me. There also is a very useful eye sign that one can follow to look for trouble in this region of the brainstem: nystagmus, or a beating downwards of the eyes, when the child is brought to look down and out.

The small head size most commonly in CdLS is associated with a proportionally smaller brain so that there are no real "crowding" issues. Whether there is any crowding around the lower brainstem can be readily assessed on the MR images independently of her overall small head size.

CB/ TK 7-13-10

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Growth in Childhood

The growth of every child with CdLS should be monitored by using CdLS-specific growth charts.


Paediatric Medical Care

The growth of every child with CdLS should be monitored by using CdLS-specific growth charts.

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