Question:

My son is 18 months old, his weight is 24lbs, his head circumference is 49cm, the doctor expressed concern about his head growth, should I ask for a scan of his head

Answer:

This question is not easily answered as a yes or no. Large heads or familial macrocephaly (mack-row-cef-a-lee) is a common, nonproblematic variation in some families. This is likely to be the case of family members on your side of the family or his dad’s family have large heads reflected in large hat sizes. In this case, the child’s development is completely normal and head size has more than likely always been at the 90th percentile. If your child’s head size has suddenly increased compared to previous visits, it’s a good idea to start by asking for re-measurement to assure that the change in head growth rate is real and not a function of poor measurement technique.

If your child is a former preterm infant, concern is always present that a large head may be due to increased fluid in the ventricles. This condition is called hydrocephaly (hide-row-cef-a-lee) or water in the head and may also occur in children who are not preterm, but it is less common among them. All of us have fluid in our ventricles and bathing the brain and spinal cord. It helps in the management of waste removal from brain cells and provides cushioning to the brain tissue and spinal cord. A problem occurs for some children with an excessive build up of fluid in the brain, which if left untreated, will compress normal brain tissue, impairing both growth of and function in the brain. Treatment involves inserting a shunt or drain into the ventricles to divert the excess fluid from the ventricles through a tube into the abdomen where the blood vessels absorb it into the circulation. In this case, most children show some sign of increased pressure on the brain with vomiting, increase in crying and irritability, eye movement changes, and slowed development. This would also be true if there was a solid tumor mass causing the child’s head to enlarge too fast.

Certainly having a computed tomography scan (CT scan) of the brain or an MRI will quickly and definitively answer the question of whether or not there is a problem that requires treatment. The main drawbacks are cost, sedation of the child, and for CT scans, exposure to X-rays, which is not the case for an MRI. CT scans are faster and less expensive than MRIs, but an MRI will need to be done if a CT scan is positive for a problem, so you end up paying for two tests and two sedations.

If you are certain there are no concerns about your child’s development and there are large heads among family members who are entirely normal in their functioning, it would likely be fine to wait and see if there is a problem or not. Otherwise, it would be best to go ahead with testing.

I hope this information is helpful and that all is well with your child.

 

For more information:

Go to the Newborn and Infant Care health topic.