A new guideline from the American Academy of Neurology, developed in full collaboration with the Child Neurology Society, finds that children with microcephaly, that is, children whose head size is smaller than that of 97 percent of childrenare at risk of neurologic and cognitive problems and should be screened for these problems. The guideline is published in the September 15, 2009, issue of Neurology®, the medical journal of the American Academy of Neurology.
Microcephaly is common, affecting more than 25,000 infants in the United States each year. If it is not present at birth, it usually has developed by the time a child is two years old. While microcephaly is not a disease, it is an important sign that may point to other conditions.
"The evidence suggests that children with microcephaly are more likely to have certain neurologic conditions, such as epilepsy and cerebral palsy, as well as mental retardation and eye and ear disorders," said lead guideline author Stephen Ashwal, MD, a child neurologist at Loma Linda University School of Medicine in Loma Linda, California, and a Fellow of the American Academy of Neurology. "In fact, the evidence shows that children with microcephaly are at risk for developmental delay and learning disorders. For these reasons, it is necessary for doctors to recognize microcephaly and check the child for these associated problems, which often require special treatments. This is an important recommendation, as it allows doctors to provide more accurate advice and counseling to families who have a child with microcephaly."
Doctors may also consider screening for coexisting conditions, such as epilepsy and cerebral palsy. "Forty percent of children with microcephaly also have epilepsy, 20 percent also have cerebral palsy, 50 percent also have mental retardation, and 20 to 50 percent also have eye and ear problems," said Ashwal.
Brain scans such as an MRI or CT scan as well as genetic testing may be useful in identifying the causes of microcephaly. Ashwal says even if a small head size runs in families, it is still important to see a doctor due to the risk of other conditions. He points out that it is also important to tell the doctor about any family history of neurologic disease. "It should be noted though, that some children with small head size have normal development and do not develop any related conditions or problems," Ashwal said.
The American Academy of Neurology has posted a video demonstrating how a doctor measures a child's head circumference for microcephaly. To view the video, visit the AAN's YouTube channel at www.youtube.com/AANChannel.