Three new studies reporting on the effects of the Zika virus outbreak in Brazil will be presented this week at the annual meeting of the Radiological Society of North America (RSNA). The first study looks at CT findings of the central nervous system in 16 newborn babies with congenital Zika virus infection confirmed by tests in cerebral spinal fluid.
The researchers identified a pattern of CT brain findings in the babies, including decreased brain volume, simplified gyral pattern, calcifications, ventricular dilatation, and prominent occipital bone.
“We live in Pernambuco, a state in northeastern Brazil, which had the highest number of patients with microcephaly during the Zika outbreak in our country,” said study author Natacha Calheiros de Lima Petribu, MD, from the Department of Radiology at Barão de Lucena Hospital. “Our study proves that Zika virus infection can cause congenital brain damage in babies with and without microcephaly.”
Another study analyzed the imaging results of three target groups affected by Zika: adults who developed acute neurological syndrome, newborns with vertical infection with neurological disorders, and pregnant women with rash outbreaks suggestive of Zika
Many of the adults had symptoms of Guillain-Barré syndrome, a rare disorder in which the body’s immune system attacks the nervous system causing rapid onset muscle weakness. A few showed inflammation of the brain and spinal cord (Bickerstaff’s encephalitis) or brain stem and spinal cord lesions. Common MRI findings included enhancement of certain spinal and facial nerves. In the newborns, MRI showed orbital injuries and anatomical changes in brain tissue.
“It was alarming to find so many cases of neurological syndromes in adults, some very serious, related to Zika virus infection,” said study author Emerson de Melo Casagrande, MD, from the Department of Radiology at Antonio Pedro University Hospital-Federal Fluminense University. “We have also noticed a difference between these syndromes, even though the trigger was the same.”
In a third study, ultrasound and fetal MRI were performed on pregnant patients with Zika virus infection at different gestational ages. Once the babies were born, they underwent ultrasound, CT and MRI. The researchers then created 3D virtual and physical models of the skulls. More than half the babies had microcephaly, brain calcifications and loss of brain tissue volume, along with other structural changes.
“The emergence of Zika virus in the Americas has coincided with increased reports of babies born with microcephaly,” says study author Heron Werner Jr., MD, PhD, from the Department of Radiology at Clínica de Diagnóstico por Imagem. “An early diagnosis may help in treating these babies after birth.