Neuroimaging shows abnormalities—both pre- and postnatal—caused by Zika

As a way to help radiologists understand and aid in recognizing the Zika virus and to take appropriate steps for counseling patients, researchers focused on prenatal and postnal imaging in patients with congenital infection of the Zika virus.

The authors studied patients seen at the Instituto de Pesquisa in Campina Grande State Paraiba (IPESQ) in northeastern Brazil, where the virus has hit the hardest.

From June 2015 to May 2016, 384 pregnant women were enrolled in the study in which they reported a rash or whose fetus had a history of abnormalities in the central nervous system. Results from 47 newborns with microcephaly were also included in the study, which was published in Radiology.

A large amount of patients who did not show up for follow-up imaging were excluded, as well as others who researchers could not find any characteristics of infection or diagnosis of a genetic syndrome.

Overall, researchers performed prenatal MR images and postnatal CT and MR images on 31 fetuses in 30 women, including one set of twins. An additional 14 newborns were enrolled after birth. Four radiologists with experience in fetal and/or neonatal neuroradiology subjectively described their neurological findings, which included:

• Most of fetuses (23 of 26) went through a series of prenatal ultrasounds, and had a head circumference under the fifth percentile until birth, ultimately leading to a diagnosis of microcephaly. Three fetuses had a normal head size at birth but showed signs of severe ventriculomegaly, which researches presume was due to the enlarged, obstructed ventricles.
• All neonatal images showed a reduction in the brains' parenchymal volume—16 of 17 confirmed infections and 28 of 28 presumed infections showed abnormalities of cortical development associated with the volume changes.
• The accumulation of calcium salts in body tissue was predominantly located in the gray matter-white matter junction. Researchers data suggests that calcifications were also found in the thalamus, basal ganglia, cortex and periventricular regions.

With these results and the epidemic of congenital Zika virus, researchers suggest these images of fetuses and neonates can help demonstrate the evolution of the infection.

“Prenatal sonograms may show normal or decreased head circumference and, rarely, increased head circumference. Almost all neonates will show intraparenchymal calcifications more severe than what are typically seen in TORCH infections and frequently occur at the gray matter–white matter junction, which is an unusual location for the calcifications of other congenital infections,” the authors wrote. 

Click here for the images from this study.