Intrauterine Zika virus infection: review of the current findings with emphasis in the prenatal and postnatal brain imaging diagnostic methods.

Zika virus (ZIKV) is a widespread flavivirus transmitted to humans through the bite of Aedes mosquitoes. The number of ZIKV cases increased significantly between 2015 and 2016, and Brazil was the first to report autochthonous transmission of infection. The main neurological disorder related to ZIKV infection is microcephaly. Fetal magnetic resonance imaging (MRI) is the gold standard examination for the analysis of fetal brain infection, followed by obstetric ultrasonography. Cerebral atrophy, intracranial calcifications, ventriculomegaly, cerebellar, and brain gyrus abnormalities are some of the most common findings. Postnatal MRI shows high sensitivity and specificity. Corpus callosum abnormalities, cerebellar hypoplasia, and choroid plexus dilation can be also observed. We present a review of congenital ZIKV infection with emphasis on pre and postnatal brain findings using ultrasonography, MRI, computed tomography, and three-dimensional reconstruction models.

Performance of a local reference curve for predicting small for gestational age fetuses in pregnant women with HIV/AIDS.

PURPOSE: To compare the performance of a local estimated fetal weight curve with curves established for other populations to predict small for gestational age (SGA) fetuses. METHODS: A retrospective and cross-sectional study involving 231 fetuses in which the performance of a local curve (proposed model) was compared with the Hadlock and Intergrowth-21st curves in the prediction of SGA fetuses, by applying them to a population of high-risk pregnant woman with HIV/AIDS. For each model, a receiver operating characteristic curve was adjusted, considering the SGA classification by the neonatal Intergrowth method as the gold standard, and the area under the curve (AUC) was calculated. RESULTS: The models presented linear correlations with each other. The agreement of the proposed model with Hadlock was very good (kappa = 0.83), whereas the proposed model and Intergrowth-21st had moderate agreement (kappa = 0.44). The SGA fetus detection sensitivities of the proposed model and Hadlock were 61.9% and 57.1%, with specificity of 84.1% and 86.2% and accuracy of 80.1% and 81%, respectively, without statistical difference. The sensitivity of the Intergrowth-21st model was 33.3%, while the accuracy was 85.7% and the specificity was 97.4%. The AUC estimated values for the Hadlock, proposed, and Intergrowth-21st models were 0.834, 0.832, and 0.835, respectively. CONCLUSION: The proposed model and Hadlock were interchangeable in the prediction of SGA fetuses and superior to the Intergrowth-21st model.

Pregnant women infected by the Zika virus: Ultrasound findings and growth patterns of fetuses with and without microcephaly.

OBJECTIVE: To compare ultrasound growth measurements of fetuses with and without microcephaly in suspected Zika virus infection. METHODS: A retrospective cohort study included pregnant women with suspected Zika virus infection to evaluate 110 fetuses with and without microcephaly. The women had been admitted to the fetal medicine unit between October 2015 and August 2016. Cases of fetal microcephaly resulting from other causes were excluded. Variables evaluated were the ultrasound measurements taken at fetal biometry. The relation between each fetal biometry measurement and gestational age was analyzed using fractional polynomials in random-effects regression models. To evaluate fetal growth, curves of the mean fetal biometric parameters were constructed as a function of gestational age. RESULTS: Mean biparietal diameter and mean head circumference increased in both groups as a function of gestational age. In the group with fetal microcephaly, mean head circumference was significantly larger in the 13th and 14th weeks of pregnancy, becoming smaller compared with the group without microcephaly from the 20th week onwards, with the difference increasing with gestational age. CONCLUSION: Fetal head circumference continues to increase until birth, even after a diagnosis of microcephaly, with a reduction only in the pace of growth. Growth decelerates as the pregnancy approaches term.

Case Report: Multiorgan Involvement with Congenital Zika Syndrome.

We report the case of an infant born with congenital Zika syndrome (CZS). During the largest Zika virus (ZIKV) outbreak in Peru, the mother presented with fever and rash that were confirmed to be due to ZIKV by real-time PCR. The infant was born with severe microcephaly. Imaging revealed corpus callosum dysgenesis, lissencephaly, ventriculomegaly, and calcifications. Mild hypertrophic cardiomyopathy with diastolic dysfunction was reported in the echocardiogram. Valgus deviation of the lower extremities and a left clubfoot were diagnosed at birth. The hip ultrasound showed incipient signs of Graf type II dysplasia. The findings confirm that CZS is a multiorgan phenotype in which microcephaly is merely the tip of the iceberg. A multidisciplinary approach is needed for the evaluation of these children.

Updated Imaging Findings in Congenital Zika Syndrome: A Disease Story That is Still Being Written.

In congenital Zika virus syndrome (CZS), the most frequent radiological findings are calcifications in the cortical-white matter junction and malformations of cortical development (pachygyria or polymicrogyria, which occur predominantly in the frontal lobes, or a simplified gyral pattern), ventriculomegaly, enlargement of the cisterna magna and the extra-axial subarachnoid space, corpus callosum abnormalities, and reduced brain volume. This syndrome can also result in a decrease in the brainstem and cerebellum volumes and delayed myelination. Infants with CZS may show venous thrombosis and lenticulostriate vasculopathies. Over a 3-year follow-up period, many infants with CZS showed hydrocephalus, reduction in brain calcifications, and greater reduction in brain thickness.

Congenital Zika Virus Infection with Normal Neurodevelopmental Outcome, Brazil.

We describe a case of a 20-month-old girl with probable congenital Zika virus infection and normal neurodevelopment, despite microcephaly and abnormal neuroimaging. This case raises questions about early prognostic markers and draws attention to the need for investigation in suspected Zika cases, even if the child's early neurodevelopment is normal.

Neuroimaging Findings of Zika Virus-Associated Neurologic Complications in Adults.

When the first suspected cases of neurologic disorders associated with the Zika virus were noticed in Brazil in late 2015, several studies had been conducted to understand the pathophysiology of the disease and its associated complications. In addition to its well-established association with microcephaly in neonates, the Zika virus infection has also been suggested to trigger other severe neurologic complications in adults, such as Guillain-Barré syndrome, radiculomyelitis, and meningoencephalitis. Hence, the Zika virus should be deemed a global threat that can cause devastating neurologic complications among individuals in all age ranges. The aim of this review was to further describe neuroimaging findings of Zika virus infection and associated neurologic complications found in adults.

Motor Abnormalities and Epilepsy in Infants and Children With Evidence of Congenital Zika Virus Infection.

Initial reports of congenital Zika virus (ZIKV) infection focused on microcephaly at birth with severe brain anomalies; the phenotype has broadened to include microcephaly that develops after birth and neurodevelopmental sequelae. In this narrative review, we summarize medical literature describing motor abnormalities and epilepsy in infants with evidence of congenital ZIKV infection and provide information on the impact of these conditions. Specific scenarios are used to illustrate the complex clinical course in infants with abnormalities that are consistent with congenital Zika syndrome. A search of the English-language medical literature was done to identify motor abnormalities and epilepsy in infants with evidence of congenital ZIKV infection by using Medline and PubMed, Embase, Scientific Electronic Library Online, Scopus, the OpenGrey Repository, and the Grey Literature Report in Public Health. Search terms included "Zika" only and "Zika" in combination with any of the following terms: "epilepsy," "seizure," "motor," and "cerebral palsy." Clinical features of motor abnormalities and epilepsy in these children were reviewed. Thirty-six publications were identified; 8 were selected for further review. Among infants with clinical findings that are consistent with congenital Zika syndrome, 54% had epilepsy and 100% had motor abnormalities. In these infants, impairments that are consistent with diagnoses of cerebral palsy and epilepsy occur frequently. Pyramidal and extrapyramidal motor abnormalities were notable for their early development and co-occurrence. Prompt identification of potential disabilities enables early intervention to improve the quality of life for affected children. Long-term studies of developmental outcomes and interventions in children with congenital ZIKV infection are needed.

Association of Prenatal Ultrasonographic Findings With Adverse Neonatal Outcomes Among Pregnant Women With Zika Virus Infection in Brazil.

Importance: Congenital Zika virus infection causes a spectrum of adverse birth outcomes, including severe birth defects of the central nervous system. The association of prenatal ultrasonographic findings with adverse neonatal outcomes, beyond structural anomalies such as microcephaly, has not been described to date. Objective: To determine whether prenatal ultrasonographic examination results are associated with abnormal neonatal outcomes in Zika virus-affected pregnancies. Design, Setting, and Participants: A prospective cohort study conducted at a single regional referral center in Rio de Janeiro, Brazil, from September 1, 2015, to May 31, 2016, among 92 pregnant women diagnosed during pregnancy with Zika virus infection by reverse-transcription polymerase chain reaction, who underwent subsequent prenatal ultrasonographic and neonatal evaluation. Exposures: Prenatal ultrasonography. Main Outcomes and Measures: The primary outcome measure was composite adverse neonatal outcome (perinatal death, abnormal finding on neonatal examination, or abnormal finding on postnatal neuroimaging). Secondary outcomes include association of specific findings with neonatal outcomes. Results: Of 92 mother-neonate dyads (mean [SD] maternal age, 29.4 [6.3] years), 55 (60%) had normal results and 37 (40%) had abnormal results on prenatal ultrasonographic examinations. The median gestational age at delivery was 38.6 weeks (interquartile range, 37.9-39.3). Of the 45 neonates with composite adverse outcome, 23 (51%) had normal results on prenatal ultrasonography. Eleven pregnant women (12%) had a Zika virus-associated finding that was associated with an abnormal result on neonatal examination (adjusted odds ratio [aOR], 11.6; 95% CI, 1.8-72.8), abnormal result on postnatal neuroimaging (aOR, 6.7; 95% CI, 1.1-38.9), and composite adverse neonatal outcome (aOR, 27.2; 95% CI, 2.5-296.6). Abnormal results on middle cerebral artery Doppler ultrasonography were associated with neonatal examination abnormalities (aOR, 12.8; 95% CI, 2.6-63.2), postnatal neuroimaging abnormalities (aOR, 8.8; 95% CI, 1.7-45.9), and composite adverse neonatal outcome (aOR, 20.5; 95% CI, 3.2-132.6). There were 2 perinatal deaths. Abnormal findings on prenatal ultrasonography had a sensitivity of 48.9% (95% CI, 33.7%-64.2%) and a specificity of 68.1% (95% CI, 52.9%-80.1%) for association with composite adverse neonatal outcomes. For a Zika virus-associated abnormal result on prenatal ultrasonography, the sensitivity was lower (22.2%; 95% CI, 11.2%-37.1%) but the specificity was higher (97.9%; 95% CI, 88.7%-99.9%). Conclusions and Relevance: Abnormal results on prenatal ultrasonography were associated with adverse outcomes in congenital Zika infection. The absence of abnormal findings on prenatal ultrasonography was not associated with a normal neonatal outcome. Comprehensive evaluation is recommended for all neonates with prenatal Zika virus exposure.

Follow-up brain imaging of 37 children with congenital Zika syndrome: case series study.

Objective To compare initial brain computed tomography (CT) scans with follow-up CT scans at one year in children with congenital Zika syndrome, focusing on cerebral calcifications.Design Case series study.Setting Barão de Lucena Hospital, Pernambuco state, Brazil.Participants 37 children with probable or confirmed congenital Zika syndrome during the microcephaly outbreak in 2015 who underwent brain CT shortly after birth and at one year follow-up.Main outcome measure Differences in cerebral calcification patterns between initial and follow-up scans.Results 37 children were evaluated. All presented cerebral calcifications on the initial scan, predominantly at cortical-white matter junction. At follow-up the calcifications had diminished in number, size, or density, or a combination in 34 of the children (92%, 95% confidence interval 79% to 97%), were no longer visible in one child, and remained unchanged in two children. No child showed an increase in calcifications. The calcifications at the cortical-white matter junction which were no longer visible at follow-up occurred predominately in the parietal and occipital lobes. These imaging changes were not associated with any clear clinical improvements.Conclusion The detection of cerebral calcifications should not be considered a major criterion for late diagnosis of congenital Zika syndrome, nor should the absence of calcifications be used to exclude the diagnosis.

Ultrasonographic observations of the fetal brain in the first 100 pregnant women with Zika virus infection in Trinidad and Tobago.

OBJECTIVE: To evaluate the fetal brain in pregnant women infected with Zika virus in a limited-resource setting. METHODS: In an observational study in Trinidad and Tobago, 100 pregnant women infected with Zika virus who were referred for fetal medicine services provided by a single clinician were enrolled from March 31 to September 2, 2016. Two-dimensional ultrasonography was undertaken. RESULTS: The women were aged 17-41 years (mean 27.5 ± 5.7). Six cases of fetal brain abnormalities consistent with Zika infection were detected before 26 gestational weeks. The gestational period at infection and time of presentation ranged, respectively, from 7+3 to 16+0  weeks and from 23+2 to 25+5  weeks. In all cases, centiles of the biparietal diameter and head circumference decreased progressively over time to below the third centile. The skull contour appeared irregular, owing to collapse or overlap of the fetal skull bones. In four cases, brain anomalies were not obvious on the transabdominal scan but were diagnosed on the transvaginal scan. In a further two cases, brain abnormalities presented after 26 weeks of gestation. CONCLUSION: Overall, 8.0% of women infected with Zika virus had fetuses with brain abnormalities suggestive of Zika congenital syndrome. Six cases were detected before 26 weeks and two cases after 26 weeks.

Nonmicrocephalic Infants with Congenital Zika Syndrome Suspected Only after Neuroimaging Evaluation Compared with Those with Microcephaly at Birth and Postnatally: How Large Is the Zika Virus "Iceberg"?

BACKGROUND AND PURPOSE: Although microcephaly is the most prominent feature of congenital Zika syndrome, a spectrum with less severe cases is starting to be recognized. Our aim was to review neuroimaging of infants to detect cases without microcephaly and compare them with those with microcephaly. MATERIALS AND METHODS: We retrospectively evaluated all neuroimaging (MR imaging/CT) of infants 1 year of age or younger. Patients with congenital Zika syndrome were divided into those with microcephaly at birth, postnatal microcephaly, and without microcephaly. Neuroimaging was compared among groups. RESULTS: Among 77 infants, 24.6% had congenital Zika syndrome (11.7% microcephaly at birth, 9.1% postnatal microcephaly, 3.9% without microcephaly). The postnatal microcephaly and without microcephaly groups showed statistically similar imaging findings. The microcephaly at birth compared with the group without microcephaly showed statistically significant differences for the following: reduced brain volume, calcifications outside the cortico-subcortical junctions, corpus callosum abnormalities, moderate-to-severe ventriculomegaly, an enlarged extra-axial space, an enlarged cisterna magna (all absent in those without microcephaly), and polymicrogyria (the only malformation present without microcephaly). There was a trend toward pachygyria (absent in groups without microcephaly). The group with microcephaly at birth compared with the group with postnatal microcephaly showed significant differences for simplified gyral pattern, calcifications outside the cortico-subcortical junctions, corpus callosum abnormalities, moderate-to-severe ventriculomegaly, and an enlarged extra-axial space. CONCLUSIONS: In microcephaly at birth, except for polymicrogyria, all patients showed abnormalities described in the literature. In postnatal microcephaly, the only abnormalities not seen were a simplified gyral pattern and calcifications outside the cortico-subcortical junction. Infants with normocephaly presented with asymmetric frontal polymicrogyria, calcifications in the cortico-subcortical junction, mild ventriculomegaly, and delayed myelination.

Zika Virus Infection Associated With Congenital Birth Defects in a HIV-infected Pregnant Woman.

We describe a case of Zika virus infection acquired during the first trimester in a HIV-infected pregnant woman that led to multiple fetal malformations and fetal demise in Rio de Janeiro, Brazil.

Prenatal imaging findings in fetal Zika virus infection.

PURPOSE OF REVIEW: The aim of this review is to report the most recent observations concerning intrauterine Zika virus (ZIKV) infection and associated neuroimaging. RECENT FINDINGS: ZIKV outbreak in Brazil in 2015 was associated with an impressive registration of cases of congenital microcephaly in women with symptoms suggestive of ZIKV infection. Clinical and laboratory testing for ZIKV and hypothetic etiopathogenetic mechanisms are described. Diagnostic tests on blood, urine and amniotic fluid should be performed in all mothers with symptoms suggestive of intrauterine ZIKV infection. ZIKV causes multiple teratogenic malformations, mainly affecting the developing brain. SUMMARY: Neuroimaging investigation contributes to the prenatal detection of microcephaly and other brain abnormalities in cases of intrauterine ZIKV infection. Neuroimaging is based antenatally on two-dimensional and three-dimensional ultrasound and fetal MRI, whereas computed tomography scan is performed postnatally. Although neuropathology associated with intrauterine ZIKV infection is characterized by nonspecific findings of brain disorder, reduced cortical gyration and white-matter hypomyelination or dysmyelination and cerebellar hypoplasia have been consistently observed in the majority of fetuses and newborns. Prenatal or postnatal genetic workup should be carried out to exclude cases of primary microcephaly. Follow-up should rely upon MRI and computed tomography scan as well as neuropediatrician to better define developmental outcome in survivors.

Progressive lesions of central nervous system in microcephalic fetuses with suspected congenital Zika virus syndrome.

OBJECTIVE: To describe the pattern and progression of central nervous system (CNS) lesions in microcephalic fetuses with suspected Zika virus (ZIKV) infection. METHODS: In this prospective study in Salvador, Brazil, we analyzed fetuses diagnosed with microcephaly and suspected ZIKV infection after a routine primary care ultrasound scan between July 2015 and February 2016 raised suspicion of fetal microcephaly. The pregnancies were followed with serial ultrasound scans until delivery at one of the three main referral centers for fetal abnormalities in Salvador, Brazil. Microcephaly was diagnosed when the head circumference was two or more SDs below the mean for gestational age and its relationship with ZIKV infection was defined according to the World Health Organization's criteria. All women were interviewed, to assess potential factors associated with fetal microcephaly. Serology test results for toxoplasmosis, cytomegalovirus, rubella, syphilis and human immunodeficiency virus (HIV) were recorded, as were previous routine ultrasound results. Signs/symptoms of infection during the pregnancy were noted. RESULTS: Of 60 cases of suspected ZIKV-related fetal microcephaly seen during the study period, eight were excluded due to serological evidence of other congenital infections or major ultrasound chromosomal markers. In the remaining 52 fetuses, microcephaly was diagnosed between 19 and 40 (median, 27.7; interquartile range, 23.4-32.0) weeks of gestation. The main ultrasound findings were: ventriculomegaly (65.4% of cases), cerebral calcifications (44.2%) and posterior fossa abnormalities (32.7%). 9.6% presented with arthrogryposis as an associated finding. Microcephaly was an isolated finding in four cases (7.7%). While ventriculomegaly was progressive in 41.2% of cases with this finding, the velocity of head circumference increase decreased progressively in almost all cases. Exanthematic disease was present in the majority (86.5%) of the women, 67.3% presenting in the first trimester of pregnancy. Additional lesions were detected after birth in 71.4% of the 35 cases with neonatal follow-up. CONCLUSIONS: The majority of cases of congenital ZIKV syndrome have other ultrasonographic findings in addition to microcephaly. ZIKV-related CNS anomalies present mainly as progressive CNS lesions and slowing rate of growth of the fetal head, and this seems to be evident only in the late second trimester, even when maternal infection occurs in the first trimester. Other ultrasound findings, such as ventriculomegaly, brain calcifications and posterior fossa destruction lesions, are also common in this congenital syndrome. Posterior fossa destruction lesions and arthrogryposis are an uncommon finding in other congenital infections, perhaps suggesting a novel severe congenital syndrome associated with fetal ZIKV. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Cerebral injuries associated with Zika virus in utero exposure in children without birth defects in French Guiana: Case report.

RATIONALE: A major epidemic of Zika virus (ZIKV) infection occurred in French Guiana and West Indies. French national epidemiological surveillance estimated that 1650 pregnant women contracted the ZIKV during epidemic period from January 2016 to October 2016 in French Guiana. PATIENT CONCERNS: ZIKV infection during pregnancy is a cause of microcephaly and birth defects. DIAGNOSES: In this report, we describe 2 children with proven in utero ZIKV exposure. Their mothers were both symptomatic and ZIKV infection occurred early in pregnancy. Ultrasonography monitoring in utero did not show any abnormality for both patient. They were born at full-term, healthy, without any birth defects and no sign of congenital ZIKV infection. INTERVENTIONS: ZIKV was neither found on placenta fragments nor children blood and urine at birth. Their neurodevelopment outcomes in early-life fitted the expectations. As recommended in national guidelines, we performed cerebral MRIs at 2 months old, showing severe brain abnormalities, especially of white matter areas. After a large screening, we did not find any differential diagnosis for their brain lesions. OUTCOMES: We concluded it was due to their in utero ZIKV exposure. LESSONS: In this report, pathogenicity of ZIKV may involve mother's immunological response or metabolic disorder during the infection.