Microcephaly (my-kroh-SEF-uh-lee) is a rare neurological condition in which an infant's head is significantly smaller than the heads of other children of the same age and sex. Sometimes detected at birth, microcephaly usually is the result of the brain developing abnormally in the womb or not growing as it should after birth.
Microcephaly can be caused by a variety of genetic and environmental factors. Children with microcephaly often have developmental issues. Generally there's no treatment for microcephaly, but early intervention may help enhance your child's development and improve quality of life.
The primary sign of microcephaly is:
Head size is measured as the distance around the top of the child's head (circumference). Using standardized growth charts, the measurement is compared with other children's measurements in percentiles. Some children just have small heads, which may measure in the third, second or even first percentiles. In children with microcephaly, head size measures significantly below the first percentile.
These characteristics may accompany severe microcephaly:
When to see a doctor
Microcephaly usually is the result of abnormal brain development, which can occur in the womb (congenital) or in infancy. Microcephaly may be genetic. Other causes may include:
Some children with microcephaly will be of normal intelligence and development, even though their heads will always be small for their age and sex. But depending on the cause and severity of the microcephaly, complications may include:
Preparing for your appointment
If you've just learned your child has microcephaly or you suspect that your child's head is too small, you're likely to start by seeing your pediatrician. However, in some cases, your pediatrician may refer you to a pediatric neurologist.
It's a good idea to prepare for your appointment. Here's some information to help you.
What you can do
Preparing a list of questions for your doctor will help you make the most of your time together. List your questions from most important to least important. For microcephaly, some basic questions to ask your doctor include:
Don't hesitate to ask other questions during your appointment.
Tests and diagnosis
To determine whether your child has microcephaly, your doctor likely will take a thorough prenatal, birth and family history and do a physical exam. He or she will measure the circumference of your child's head, compare it with a growth chart, and remeasure and plot the growth at subsequent visits. Parents' head sizes also may be measured to determine whether small heads run in the family.
In some cases, particularly if your child's development is delayed, your doctor may request tests such as a head CT or MRI and blood tests to help determine the underlying cause of the delay.
Treatments and drugs
Generally, there's no treatment that will enlarge your child's head or reverse complications of microcephaly. Treatment focuses on ways to manage your child's condition. Early childhood intervention programs that include speech, physical and occupational therapy may help your child strengthen abilities.
Certain complications of microcephaly, such as seizures or hyperactivity, may be treated with medication.
Coping and support
When you learn your child has microcephaly, you may experience a range of emotions, including anger, fear, worry, sorrow and guilt. You may not know what to expect, and you may worry about your child's future. The best antidote for fear and worry is information and support. Prepare yourself:
Learning your child has microcephaly may raise questions about future pregnancies. Work with your doctor to determine the cause of the microcephaly. If the cause is genetic, you and your spouse may want to talk to a genetic counselor about risks for future pregnancies.
Last Updated: 2010-03-19
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