Five things to know about microcephaly and Zika

microcephaly Zika
(Catherine Delphia)

The rapid spread of Zika virus and its association with cases of microcephaly have raised alarm across the Americas, such that the World Health Organization has declared a global public health emergency.

Notes spoke to Ganeshwaran Mochida, MD, of the Boston Children’s Hospital Department of Neurology, who specializes in in microcephaly care, about the virus and microcephaly. He raised five points about microcephaly for both providers and their patients to consider.


Number 1Microcephaly is not a single disease

Microcephaly literally means “small head.” Clinicians diagnose microcephaly by comparing a child’s head size measurement to a standard growth chart. Microcephaly itself is not a disease; rather, it is a physical sign indicating that a child’s brain is smaller than normal for his or her age and sex.


Number 2Microcephaly has genetic and non-genetic causes

Microcephaly and Zika virus have gained a great deal of attention. While there is increasing evidence linking the two, more research is needed to firmly establish a causal relationship between them.

Other important causes of microcephaly include other congenital (present at birth) infections with agents such as cytomegalovirus or Toxoplasma, and exposure of the unborn baby to certain medications, toxins (including alcohol) and radiation. In addition, researchers have linked hundreds of genetic conditions with microcephaly.


Number 3Microcephaly may be identified before or after birth

Depending on its underlying cause and severity, doctors may detect microcephaly before birth (usually by ultrasound), at birth, or during the first few years of life. Therefore, it is important to follow a child’s head growth early in life at every routine pediatrician visit, even if the child’s head is in the normal size range at birth.


Number 4Diagnosing the underlying cause of microcephaly is important

Each underlying cause of microcephaly carries a different prognosis, ranging from normal cognitive and intellectual outcome to severe impairment. Also, each disorder is associated with different complications. For example, some disorders are associated with seizures, while some affect organs outside the brain.

Every child in whom microcephaly has been detected or suspected should be thoroughly evaluated by a specialist who can diagnose the underlying cause and make a comprehensive follow-up and intervention plan. If the cause is genetic, a genetic counselor can discuss with the child’s family the likelihood that the same condition would appear again in future pregnancies.


Number 5Interventions can make a difference

Currently there is no cure for most conditions associated with microcephaly. However, interventions — such as Early Intervention Programs; special needs preschool classes; and physical, occupational and speech therapies — can make a huge difference and help children with microcephaly achieve their full developmental potential. The younger the child, the more impact intervention can have, so it is important to start intervention as early as possible.

Keep track of Zika virus and its spread on HealthMap, an online public health reporting and mapping tool from Boston Children’s Computational Health Informatics Program.