Understanding the impact of congenital infections and perinatal viral exposures on the developing brain using white matter magnetic resonance imaging: a scoping review.

BACKGROUND: Magnetic Resonance Imaging (MRI)-based imaging techniques are useful for assessing white matter (WM) structural and microstructural integrity in the context of infection and inflammation. The purpose of this scoping review was to assess the range of work on the use of WM neuroimaging approaches to understand the impact of congenital and perinatal viral infections or exposures on the developing brain. METHODS: This scoping review was conducted according to the Arksey and O' Malley framework. A literature search was performed in Web of Science, Scopus and PubMed for primary research articles published from database conception up to January 2022. Studies evaluating the use of MRI-based WM imaging techniques in congenital and perinatal viral infections or exposures were included. Results were grouped by age and infection. RESULTS: A total of 826 articles were identified for screening and 28 final articles were included. Congenital and perinatal infections represented in the included studies were cytomegalovirus (CMV) infection (n = 12), human immunodeficiency virus (HIV) infection (n = 11) or exposure (n = 2) or combined (n = 2), and herpes simplex virus (HSV) infection (n = 1). The represented MRI-based WM imaging methods included structural MRI and diffusion-weighted and diffusion tensor MRI (DWI/ DTI). Regions with the most frequently reported diffusion metric group differences included the cerebellar region, corticospinal tract and association fibre WM tracts in both children with HIV infection and children who are HIV-exposed uninfected. In qualitative imaging studies, WM hyperintensities were the most frequently reported brain abnormality in children with CMV infection and children with HSV infection. CONCLUSION: There was evidence that WM imaging techniques can play a role as diagnostic and evaluation tools assessing the impact of congenital infections and perinatal viral exposures on the developing brain. The high sensitivity for identifying WM hyperintensities suggests structural brain MRI is a useful neurodiagnostic modality in assessing children with congenital CMV infection, while the DTI changes associated with HIV suggest metrics such as fractional anisotropy have the potential to be specific markers of subtle impairment or WM damage in neuroHIV.

Association of in utero HIV exposure with child brain structure and language development: a South African birth cohort study.

BACKGROUND: There is a growing population of children with in utero HIV exposure who are at risk of poor neurodevelopmental outcomes despite avoiding HIV infection. However, the underlying neurobiological pathways are not understood and neuroimaging studies are lacking. We aimed to investigate the cortical brain structure of children who are HIV-exposed and uninfected (HEU) compared to HIV-unexposed (HU) children and to examine the relationship with neurodevelopment. METHODS: The Drakenstein Child Health birth cohort study enrolled pregnant women from a high HIV prevalence area in South Africa with longitudinal follow-up of mother-child pairs. High-resolution magnetic resonance imaging scans from 162 children (70 HEU; 92 HU) were acquired at 2-3 years of age. All HEU children were born to mothers taking antiretroviral therapy. Measures of brain structure (cortical thickness and surface area) in the prefrontal cortex regions were extracted from T1-weighted images and compared between groups using multivariate analysis of variance and linear regression. Child development, assessed using the Bayley Scales of Infant and Toddler Development-III, was correlated with cortical structure, and mediation analyses were performed. RESULTS: Analyses demonstrated an association between HIV exposure and cortical thickness across the prefrontal cortex (p = 0.035). Children who were HEU had thicker cortices in prefrontal regions, with significantly greater cortical thickness in the medial orbitofrontal cortex (mOFC) bilaterally compared to HU children (3.21 mm versus 3.14 mm, p = 0.009, adjusted effect size 0.44 [95% CI 0.12 to 0.75]). Estimates held across multiple sensitivity analyses. There were no group differences in cortical surface area. Language scores, which were lower in HEU versus HU children (81.82 versus 86.25, p = 0.011, effect size - 0.44 [95% CI - 0.78 to - 0.09]), negatively correlated with prefrontal cortical thickness in both groups. Cortical thickness in the mOFC mediated the relationship between HIV exposure and poor language outcomes (Sobel test p = 0.032). CONCLUSIONS: In this cohort study, exposure to HIV during pregnancy was associated with altered cortical structure in early life. Our findings indicate that differences in cortical thickness development in the prefrontal region in children who are HEU may be a pathway leading to language impairment. Longitudinal studies are needed to determine the lasting impact.

Valoración del tromboembolismo pulmonar relacionado con infección SARS-CoV-2 activa en pacientes embarazadas / Assessment of pulmonary embolism related to active SARS-CoV-2 infection in pregnant women

Objetivo Analizar la muestra de pacientes embarazadas a las que se les realizó una gammagrafía de perfusión pulmonar para descartar la sospecha de tromboembolismo pulmonar (TEP) durante el ingreso en nuestro centro por infección aguda por COVID-19. Material y métodos A todas las pacientes (n=5) se les realizó una gammagrafía SPECT con dosis reducida (111MBq) de 99mTc-macroagregados de albúmina. Las imágenes obtenidas se interpretaron comparando los hallazgos con la imagen radiológica según criterios PISAPED. Resultados De las 5 pacientes, tan solo en una se diagnosticó TEP. En 2 pacientes los hallazgos patológicos de la gammagrafía fueron atribuibles a alteraciones radiológicas por neumonía COVID-19, y otras 2 mostraron una perfusión pulmonar normal. Conclusión Dado lo inespecífico de las manifestaciones clínicas y los valores del dímero D dentro de la COVID-19, así como su similitud con los de TEP, la gammagrafía de perfusión pulmonar, por su alta sensibilidad y menor irradiación que la TC, tiene un papel crucial en el despistaje de TEP en estas pacientes. Los resultados obtenidos son de especial relevancia, a pesar del número limitado de pacientes, dada la ausencia de publicaciones científicas en este grupo de pacientes dentro de la situación excepcional por la pandemia de COVID-19 (AU)

Aim To analyze the sample of pregnant patients who underwent pulmonary perfusion scintigraphy to rule out the pulmonary embolism (PE) suspicion during the acute COVID-19 infection hospitalization period in our hospital. Material and methods SPECT scintigraphy with a reduced dose (111MBq) of 99mTc-macroaggregated albumin was performed in all of the patients (n=5). The obtained images were interpreted by comparing the findings with the radiological images according to the PISAPED criteria. Results Only one of the 5 patients was diagnosed with PE. Two patients obtained pathological findings of the scintigraphy attributable to radiological alterations due to COVID-19 pneumonia, and the other 2 had normal pulmonary perfussion. Conclusion Given the non-specific features of the clinical manifestations and D-dimer values in COVID-19, as well as their similarity to those of PE, the pulmonary perfusion scintigraphy plays a crucial role in the screening of PE in these patients due to its high sensitivity and lower irradiation compared to CT. Despite the limited number of patients, the results obtained have special relevance related to the absence of scientific publications on this group of patients within the context of COVID-19 pandemic exceptional situation (AU)

Halo sign in fetal cytomegalovirus infection: cerebral imaging abnormalities and postmortem histopathology in 35 infected fetuses.

OBJECTIVE: To evaluate the correlation of periventricular echogenic halo (halo sign) with histopathological findings and its association with other brain imaging abnormalities in fetuses with cytomegalovirus (CMV) infection. METHODS: This was a retrospective study of fetuses diagnosed with severe CMV infection based on central nervous system (CNS) abnormalities seen on ultrasound, which had termination of pregnancy (TOP) or fetal demise at a single center from 2006 to 2021. All included cases had been evaluated by conventional complete fetal autopsy. A maternal-fetal medicine expert reanalyzed the images from the transabdominal and transvaginal neurosonography scans, blinded to the histological findings. The halo sign was defined as the presence of homogeneous periventricular echogenicity observed in all three fetal brain orthogonal planes (axial, parasagittal and coronal). Cases were classified according to whether the halo sign was the only CNS finding (isolated halo sign) or concomitant CNS anomalies were present (non-isolated halo sign). An expert fetal radiologist reanalyzed magnetic resonance imaging (MRI) examinations when available, blinded to the ultrasound and histological results. Hematoxylin-eosin-stained histologic slides were reviewed independently by two experienced pathologists blinded to the neuroimaging results. Ventriculitis was classified into four grades (Grades 0-3) according to the presence and extent of inflammation. Brain damage was categorized into two stages (Stage I, mild; Stage II, severe) according to the histopathological severity and progression of brain lesions. RESULTS: Thirty-five CMV-infected fetuses were included in the study, of which 25 were diagnosed in the second and 10 in the third trimester. One fetus underwent intrauterine demise and TOP was carried out in 34 cases. The halo sign was detected on ultrasound in 32 (91%) fetuses (23 in the second trimester and nine in the third), and it was an isolated sonographic finding in six of these cases, all in the second trimester. The median gestational age at ultrasound diagnosis of the halo sign was similar between fetuses in which this was an isolated and those in which it was a non-isolated CNS finding (22.6 vs 24.4 weeks; P = 0.10). In fetuses with a non-isolated halo sign, the severity of additional ultrasound findings was not associated with the trimester at diagnosis, except for microencephaly, which was more frequent in the second compared with the third trimester (10/18 (56%) vs 1/8 (13%); P = 0.04). With respect to histopathological findings, ventriculitis was observed in all fetuses with an isolated halo sign, but this was mild (Grade 1) in the majority of cases (4/6 (67%)). Extensive ventriculitis (Grade 2 or 3) was more frequent in fetuses with a non-isolated halo sign (21/26 (81%)) and those without a periventricular echogenic halo (2/3 (67%); P = 0.032). All fetuses with an isolated halo sign were classified as histopathological Stage I with no signs of brain calcifications, white-matter necrosis or cortical injury. On the other hand, 25/26 fetuses with a non-isolated halo sign and all three fetuses without a periventricular echogenic halo showed severe brain lesions and were categorized as histopathological Stage II. Among fetuses with a non-isolated halo, histological brain lesions did not progress with gestational age, although white-matter necrosis was more frequent, albeit non-significantly, in fetuses diagnosed in the second vs the third trimester (10/15 (67%) vs 3/11 (27%); P = 0.06). CONCLUSIONS: In CMV-infected fetuses, an isolated periventricular echogenic halo was observed only in the second trimester and was associated with mild ventriculitis without signs of white-matter calcifications or necrosis. When considering pregnancy continuation, detailed neurosonographic follow-up complemented by MRI examination in the early third trimester is indicated. The prognostic significance of the halo sign as an isolated finding is still to be determined. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Neurological and Neuroradiological Manifestations in Neonates Born to Mothers With Coronavirus Disease 2019.

BACKGROUND: To investigate the complications that occurred in neonates born to mothers with coronavirus disease 2019 (COVID-19), focusing on neurological and neuroradiological findings, and to compare differences associated with the presence of maternal symptoms. METHODS: Ninety neonates from 88 mothers diagnosed with coronavirus disease 2019 (COVID-19) during pregnancy were retrospectively reviewed. Neonates were divided into two groups: symptomatic (Sym-M-N, n = 34) and asymptomatic mothers (Asym-M-N, n = 56). The results of neurological physical examinations were compared between the groups. Data on electroencephalography, brain ultrasound, and magnetic resonance imaging abnormalities were collected for neonates with neurological abnormalities. RESULTS: Neurological abnormalities at birth were found in nine neonates (Sym-M-N, seven of 34, 20.6%). Decreased tone was the most common physical abnormality (n = 7). Preterm and very preterm birth (P < 0.01), very low birth weight (P < 0.01), or at least one neurological abnormality on physical examination (P = 0.049) was more frequent in Sym-M-N neonates. All infants with abnormalities on physical examination showed neuroradiological abnormalities. The most common neuroradiological abnormalities were intracranial hemorrhage (n = 5; germinal matrix, n = 2; parenchymal, n = 2; intraventricular, n = 1) and hypoxic brain injury (n = 3). CONCLUSIONS: Neonates born to mothers with symptomatic COVID-19 showed an increased incidence of neurological abnormalities. Most of the mothers (96.4%) were unvaccinated before the COVID-19 diagnosis. Our results highlight the importance of neurological and neuroradiological management in infants born to mothers with COVID-19 and the prevention of maternal COVID-19 infection.

Predicting Outcome of Congenital Cytomegalovirus Infection by Differentiating and Revisiting Severe versus Mild Prenatal Imaging Features.

INTRODUCTION: Our objective was to evaluate the outcome of fetuses with first- and second-trimester fetal cytomegalovirus infection (CMVi) according to prenatal imaging patterns, especially fetuses presenting with mild imaging features (MF), being currently of uncertain prognosis. MATERIAL AND METHODS: In a retrospective study of 415 suspected CMVi cases, 59 cases were confirmed. Among prenatal imaging features, microcephaly, cortical disorder, and cerebellar hypoplasia as well as severe IUGR and fetal hydrops were considered as severe imaging features (SF). Other imaging features were considered as MF. Postnatal outcome was classified as "normal outcome," "mild sequelae" characterized mainly by sensorineural disorder (SND) and "severe sequelae" characterized by cognitive impairment. RESULTS: Only first-trimester (T1) and second-trimester (T2) CMVi cases were included in our study (n = 49) since all third-trimester cases (n = 10) had normal imaging and outcome. Sixteen fetuses had normal prenatal imaging and normal outcome, except one showing SND. Abnormal ultrasound findings were present in 33 fetuses, including SF noted in 16 fetuses, related exclusively to first-trimester CMVi. Termination of pregnancy was performed in 18 cases. Twelve first-trimester infected fetuses presented SF, whereas 6 fetuses (T1: n = 5, T2: n = 1) presented isolated MF. Four fetal deaths were encountered. Live-born babies with abnormal imaging included 10 fetuses with MF and one with SF. Among the 10 live babies with isolated MF, SND was encountered in 5 cases, whereas 5 children demonstrated normal outcome. Overall, 50% of our babies showing MF suffered from SND. No case of cognitive disorders was reported in babies showing only MF. CONCLUSION: SF were encountered only in first-trimester CMVi and should be distinguished from MF. Among our 10 live babies with prenatal MF following first- or second-trimester infection, 50% showed SND, whereas none presented severe sequelae. In 16 fetuses displaying normal fetal imaging, SND was encountered in one first-trimester case (6%).

Placental calcifications after coronavirus disease 2019 in first trimester of pregnancy: ultrasound and pathology findings.

The effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on placental tissue is unclear. We present a case of symptomatic first trimester SARS-CoV-2 infection in which longitudinal ultrasound images demonstrated diffuse areas of echogenic foci. Her 39-week delivery, following an elective induction of labor, was uncomplicated, and placental pathol-ogy evaluation noted extensive calcifications. Such findings are sometimes seen in late and post-term pregnancies and those complicated by smoking, hypertensive disorders, diabetes, and viral infections. In this case, no other potential etiology was identified. Thus, we conclude that placental calcifications may be associated with SAR-CoV-2 infection in early pregnancy.

Parenchymal calcification is associated with the neurological prognosis in patients with congenital rubella syndrome.

Congenital rubella syndrome (CRS) results from maternal rubella virus infection in early pregnancy. Abnormal neuroimaging findings have been analyzed in a small number of CRS patients in the past; however, their clinical significance has been poorly addressed. Therefore, we have investigated the neuroimaging findings of 31 patients with CRS from previous studies. The most common finding was parenchymal calcification, which was observed in 18 of 31 patients (58.1%). A multivariable logistic regression model showed that it was associated with psychomotor or mental retardation (p = 0.018), suggesting that parenchymal calcification in CRS could be a prognostic factor.

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.

Influence of Covid-19 infection on fetal thymus size after recovery.

OBJECTIVES: To investigate the long-term effects of the SARS-CoV-2 infection on the fetal immune system by fetal thymus size measurements with ultrasound (USG). METHODS: This prospective study was conducted in the Turkish Ministry of Health Ankara City Hospital between November 1, 2020 and April 1, 2021, with recovered, pregnant women, four weeks after they had been confirmed for the SARS-CoV-2 infection by real-time polymerase-chain-reaction (RT-PCR). COVID-19 recovered (CR) pregnant women compared with age-matched pregnant controls in terms of demographic features, fetal thymic-thoracic ratio (TTR), and laboratory parameters. RESULTS: There was no difference in demographic features between the two groups. TTR found significantly lower in the CR group than the control group (p=0.001). The fetal TTR showed a significant and moderate correlation with maternal monocyte counts, monocyte to lymphocyte ratio (MLR), and red cell distribution width (RDW); while it did not correlate with lymphocyte counts, c-reactive protein (CRP), and procalcitonin levels. CONCLUSIONS: The 2019 novel coronavirus disease (COVID-19) reduces fetal thymus size in pregnant women with mild or moderate symptoms after recovery from the infection.

Atypical severe intrauterine growth retardation and affected placental function after COVID-19 infection.

This case report describes an atypical progression of pregnancy in a woman who was infected with COVID-19 in her second trimester and initially presented with signs of absent foetal movements. The foetus was diagnosed with severe intrauterine growth restriction and abnormal foetal Doppler flows. The condition slowly improved over months, and the pregnancy was terminated with an acute caesarean section in gestational week 35. Placenta was tested negative for SARS-CoV-2-nucleocapsid. Four days old, the child was found COVID-19-positive, but remained asymptomatic. This case is a rare example considering the improvement of placental function over time.

An Examination of the Long-Term Neurodevelopmental Impact of Prenatal Zika Virus Infection in a Rat Model Using a High Resolution, Longitudinal MRI Approach.

Since Zika virus (ZIKV) first emerged as a public health concern in 2015, our ability to identify and track the long-term neurological sequelae of prenatal Zika virus (ZIKV) infection in humans has been limited. Our lab has developed a rat model of maternal ZIKV infection with associated vertical transmission to the fetus that results in significant brain malformations in the neonatal offspring. Here, we use this model in conjunction with longitudinal magnetic resonance imaging (MRI) to expand our understanding of the long-term neurological consequences of prenatal ZIKV infection in order to identify characteristic neurodevelopmental changes and track them across time. We exploited both manual and automated atlas-based segmentation of MR images in order to identify long-term structural changes within the developing rat brain following inoculation. The paradigm involved scanning three cohorts of male and female rats that were prenatally inoculated with 107 PFU ZIKV, 107 UV-inactivated ZIKV (iZIKV), or diluent medium (mock), at 4 different postnatal day (P) age points: P2, P16, P24, and P60. Analysis of tracked brain structures revealed significantly altered development in both the ZIKV and iZIKV rats. Moreover, we demonstrate that prenatal ZIKV infection alters the growth of brain regions throughout the neonatal and juvenile ages. Our findings also suggest that maternal immune activation caused by inactive viral proteins may play a role in altered brain growth throughout development. For the very first time, we introduce manual and automated atlas-based segmentation of neonatal and juvenile rat brains longitudinally. Experimental results demonstrate the effectiveness of our novel approach for detecting significant changes in neurodevelopment in models of early-life infections.

A Novel Radiologic Finding to Predict Ophthalmic Abnormalities in Children With Congenital Zika Syndrome.

BACKGROUND: The Zika virus (ZIKV) epidemic had devastating consequences in Brazil. We investigated whether a radiologic finding (ie, infratentorial abnormalities) was associated with sight-threatening defects in children born with congenital Zika syndrome (CZS). We also investigated whether ophthalmic abnormalities correlated with head circumference (HC) and gestational age of infection. METHODS: Cross-sectional evaluation based upon a previous cohort from March 2016 to December 2018, in Paraíba, Brazil. The study population was comprised of children born to mothers with laboratory-confirmed ZIKV infection during pregnancy (ZIKV reverse transcriptase polymerase chain reaction [RT-PCR]+) and children born with clinical and radiologic features of CZS. RESULTS: A total of 75 infants had complete data. All 75 had brain calcifications. Microcephaly was present in 53 (71%) of them. Infratentorial abnormalities were present in 17 infants (22.7%). Ophthalmic abnormalities were seen in 16 of the 17 children (94%) with infratentorial abnormalities, while 28% of children without infratentorial abnormalities had ophthalmic findings (odds ratio [OR]: 42.0; 95% confidence interval [CI]: 5.1-342.9). Similar associations were observed when macular chorioretinal atrophy and optic nerve abnormalities were analyzed individually (OR: 23.7; 95% CI: 6.0-93.3 and OR: 11.5; 95% CI: 3.3-40.0, respectively). Infratentorial abnormalities were more frequently associated with ophthalmic abnormalities (94%) than microcephaly (43.4%) (P < .001). Mean HC was statistically different between groups with and without ophthalmic abnormalities (P = .01). A statistically significant difference in gestational age between both groups was not noted (P = .12). CONCLUSIONS: In children with CZS, the presence of infratentorial abnormalities is a significant predictor of ophthalmic abnormalities. All neonates whose mothers had ZIKV exposure during pregnancy should have an ophthalmologic examination.

Diagnostic accuracy of magnetic resonance imaging for acute appendicitis during pregnancy: A systematic review.

BACKGROUND: The purpose of this study was to present a systematic review and meta-analysis of the diagnostic accuracy of magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis in pregnant women. METHODS: A literature search was conducted using the databases of PubMed, Ovid MEDLINE, EMBASE, and the Cochrane Library. The inclusion criteria were the use of MRI, as a diagnostic protocol for acute appendicitis in pregnant women, and the availability of diagnostic parameters, such as sensitivity and specificity. For each selected study, the basic demographic information and measures of diagnostic accuracy, such as sensitivity, specificity, and positive and negative predictive values, were extracted. Forest plots and summary receiver operating characteristic curves (SROC) were also obtained for diagnostic accuracy of MRI for acute appendicitis during pregnancy. RESULTS: A total of 22 studies and the data of 2392 patients were analyzed. Most studies had high sensitivity, with the exception of a few that had sensitivities of 0.18, 0.5, and 0.6. With respect to specificity, most results were close to 1.0, and the lowest result was 0.92. The SROC curves showed high levels of accuracy, as evidenced by an area under the curve value of 0.9922. CONCLUSION: MRI showed overall high accuracy for diagnosing acute appendicitis in pregnant women. Therefore, it is a good diagnostic tool as a first-line imaging method for suspected appendicitis in pregnant women.