Microcephaly and Zika virus: neonatal neuroradiological aspects

Abstract

PurposeThe aim of this study is to describe some radiological features in the newborns with microcephaly caused by Zika virus infection during pregnancy.MethodsWe radiologically analyzed 13 cases of newborns with microcephaly born to mothers who were infected by the Zika virus in the early stage of pregnancy.ResultsThe most frequently observed radiological findings were microcephaly and decreased brain parenchymal volume associated with lissencephaly, ventriculomegaly secondary to the lack of brain tissue (not hypertensive), and coarse and anarchic calcifications mainly involving the subcortical cortical transition, and the basal ganglia.ConclusionsAlthough it cannot be concluded that there is a definitive pathognomonic radiographic pattern of microcephaly caused by Zika virus, gross calcifications and anarchic distribution involving the subcortical cortical transition and the basal ganglia, in association with lissencephaly and in the absence of hypertensive ventriculomegaly, are characteristic of this type of infection.

Neuroimaging findings of Zika virus infection: a review article

“…It is severe (i.e., agyria) in about 80 % of cases. Other malformations described in the literature include polymicrogyria, heterotopia, and schizencephaly; (4) cerebellar and brainstem hypoplasia may also be noted in approximately 75 % and 10 % of cases, respectively; (5) white-matter hypodensity is seen in almost all neonates and is diffuse in near 90 % of them; no further characterization of white matter changes is possible on CT, but MRI studies suggest that white matter changes seen on CT are due to dysmyelination or delayed myelination; (6) chronic encephalomalacia is reported in one case in the territory of the middle cerebral artery (MCA) which is most likely caused by sequelae of prenatal ischemic stroke in early intrauterine life; (7) skull molding with a pointed occiput and overriding of bones mainly in the frontal and occipital regions is another described feature in head CT scans of affected neonates [24][25][26][27].…”

“…Craniofacial disproportion and microcephaly (HC < 32 cm) are seen in almost all brain MRI studies [25][26][27].…”

“…Other findings that are seen in almost all cases include: (1) brain atrophy and reduced brain cortical thickness; (2) enlarged subarachnoid spaces; (3) lissencephaly; (4) ventriculomegaly which is non-hypertensive and secondary to (5) agenesis/hypoplasia of the corpus callosum; (6) coarse calcifications that are most commonly seen in subcortical-cortical transition and the basal ganglia [25][26][27].…”

“…Less common findings include: (1) a large choroid plexus; (2) intraventricular septations; (3) periventricular calcifications; (4) cerebellar and brainstem hypoplasia; (5) schizencephaly; (6) gray matter heterotopia [8,[25][26][27].…”

Placental Pathology of Zika Virus: Viral Infection of the Placenta Induces Villous Stromal Macrophage (Hofbauer Cell) Proliferation and Hyperplasia

“…The spectrum of disease caused by Zika virus among adults and children is still being investigated and defined, but it is clear in the most recent epidemic in South and Central America, Mexico, and the Caribbean islands that when infection occurs in pregnant women, fetuses appear to be at increased risk for a poor clinical outcome. [2][3][4][5][6][7][8][9] The most significant effect of the Zika virus on the fetus is the occurrence of neuronal necrosis and microcephaly-this has been demonstrated in neuroimaging studies performed both before delivery and following the birth of infected infants. 2,3,7 Pathology studies have been shown to be an important component of the public health investigation of emerging infections, contributing to the understanding of the mechanisms of tissue injury, for example, human immunodeficiency virus, Ebola virus, hantavirus, West Nile virus, and many others.…”