Cranial ultrasound and MRI: complementary or not in the diagnostic assessment of children with congenital CMV infection?

Isolated Brain Cysts in Children Afflicted with Congenital Cytomegalovirus

In our clinic, isolated brain cysts identified via early ultrasound are considered as central nervous system involvement in infants with children with congenital cytomegalovirus (cCMV). All infants were diagnosed with caudothalamic or subependymal cysts. When treated according to the cCMV protocol, these patients have an excellent prognosis and no neurological sequelae. Further data on the significance of different cysts in relation to cCMV is warranted.

Neuroimaging in infants with congenital cytomegalovirus infection and its correlation with outcome: emphasis on white matter abnormalities

OBJECTIVE

To evaluate the association between neuroimaging and outcome in infants with congenital cytomegalovirus (cCMV), focusing on qualitative MRI and quantitative diffusion-weighted imaging of white matter abnormalities (WMAs).

METHODS

Multicentre retrospective cohort study of 160 infants with cCMV (103 symptomatic). A four-grade neuroimaging scoring system was applied to cranial ultrasonography and MRI acquired at ≤3 months. WMAs were categorised as multifocal or diffuse. Temporal-pole WMAs (TPWMAs) consisted of swollen or cystic appearance. Apparent diffusion coefficient (ADC) values were obtained from frontal, parieto-occipital and temporal white matter regions. Available follow-up MRI at ≥6 months (N=14) was additionally reviewed. Neurodevelopmental assessment included motor function, cognition, behaviour, hearing, vision and epilepsy. Adverse outcome was defined as death or moderate/severe disability.

RESULTS

Neuroimaging scoring was associated with outcome (p<0.001, area under the curve 0.89±0.03). Isolated WMAs (IWMAs) were present in 61 infants, and WMAs associated with other lesions in 30. Although TPWMAs and diffuse pattern often coexisted in infants with IWMAs (p<0.001), only TPWMAs were associated with adverse outcomes (OR 7.8; 95% CI 1.4 to 42.8), including severe hearing loss in 20% and hearing loss combined with other moderate/severe disabilities in 15%. Increased ADC values were associated with higher neuroimaging scores, WMAs based on visual assessment and IWMAs with TPWMAs. ADC values were not associated with outcome in infants with IWMAs. Findings suggestive of progression of WMAs on follow-up MRI included gliosis and malacia.

CONCLUSIONS

Categorisation of neuroimaging severity correlates with outcome in cCMV. In infants with IWMAs, TPWMAs provide a guide to prognosis.

Apparent diffusion coefficient values of the white matter in magnetic resonance imaging of the neonatal brain may help predict outcome in congenital cytomegalovirus infection

BACKGROUND

White matter change is a well-known abnormality in congenital cytomegalovirus (cCMV) infection, but grading remains challenging and clinical relevance unclear.

OBJECTIVE

To investigate if quantitative measurement of white matter apparent diffusion coefficient (ADC) values in magnetic resonance imaging (MRI) of the neonatal brain can predict outcome in cCMV.

MATERIALS AND METHODS

A retrospective, single-center observational study, including patients with cCMV who had a neonatal brain MRI with diffusion-weighted imaging, was performed between 2007 and 2020. Regions of interest were systematically placed in the white matter on the ADC maps. Two pediatric radiologists independently scored additional brain abnormalities. Outcome measures were neonatal hearing and cognitive and motor development. Statistical analysis included simple and penalized elastic net regression.

RESULTS

Neonatal brain MRI was evaluated in 255 patients (median age 21 days, 25-75 percentiles: 14-28 days, 121 male). Gyral abnormalities were noted in nine patients (3.5%), ventriculomegaly in 24 (9.4%), and subependymal cysts in 58 (22.7%). General white matter ADC was significantly higher in patients with neonatal hearing loss and cognitive and motor impairment (P< 0.05). For neonatal hearing loss, simple logistic regression using only general white matter was the best prediction model, with a receiver operating characteristic area under the curve (AUC)=0.76. For cognitive impairment, interacting elastic net regression, including other brain abnormalities and frontoparietal white matter ADC, performed best, with AUC=0.89. For motor impairment, interacting elastic net regression, including other brain abnormalities and deep anterior frontal white matter performed best, with AUC=0.73.

CONCLUSION

Neonatal white matter ADC was significantly higher in patients with clinical impairments. Quantitative ADC measurement may be a useful tool for predicting clinical outcome in cCMV.

Fetal brain imaging provides valuable information in cCMV infected infants

BACKGROUND

Congenital CMV infection (cCMV) is the most common congenital infection with 10-15% of cases developing symptomatic disease. Early antiviral treatment is of essence when symptomatic disease is suspected. Recently, the use of neonatal imaging has been implicated as a prognostic tool for long term sequalae among asymptomatic newborns at high risk. Even though neonatal MRI is commonly used in neonatal symptomatic cCMV disease, it is less often used in asymptomatic newborns, mainly due to cost, access and difficulty to perform. We have therefore developed an interest in assessing the use of fetal imaging as an alternative. Our primary aim was to compare the fetal and neonatal MRIs in a small cohort 10 asymptomatic neonates with congenital CMV infection.

METHODS

We performed a single-center retrospective cohort study (case-series) on a convenience sample of children born from January 2014 to March 2021 with confirmed congenital CMV infection who had undergone both fetal and neonatal MRIs. We created a checklist of relevant cerebral abnormalities and asked 4 blinded radiologists to assess the MRIs (2 for each, namely fetal and neonatal) and then compared the findings between the fetal and neonatal imaging as well as the concordance in reporting of abnormalities within each category.

FINDINGS

Overall concordance between prenatal and postnatal scans was high (70%). When comparing the two blinded reports for each MRI, we found high levels of concordance: 90% concordance for fetal MRIs and 100% for neonatal MRIs. The most common abnormalities identified in both fetal and neonatal scans were "abnormal white matter hyperintensity" and "subependymal cysts."

INTERPRETATION

Even though this is a small descriptive study, it indicates that fetal MRI could potentially provide us with similar information as neonatal imaging. This study could form the basis for subsequent larger future studies.

Implications of isolated white matter abnormalities on neonatal MRI in congenital CMV infection: a prospective single-centre study

OBJECTIVE

Investigating the clinical implications of isolated white matter abnormalities on neonatal brain MRI in congenital cytomegalovirus (CMV).

DESIGN

Prospective, observational.

PATIENTS/INTERVENTIONS

Two paediatric radiologists, blinded to clinical data, independently scored the white matter in 286 newborns with congenital CMV. After assessing interobserver variability, mean score was used to categorise white matter (normal, doubtful or abnormal). Patients with other brain abnormalities were excluded.

MAIN OUTCOME MEASURES

Hearing and neuromotor evaluation.

RESULTS

Cohen's weighted kappa was 0.79 (95% CI 0.73 to 0.84). White matter was normal in 121 patients, doubtful in 62, abnormal in 28. Median clinical follow-up was 12.0 months (IQR 12.0-27.7 months). Neonatal hearing loss occurred in 4/27 patients (14.8%) with abnormal, 1/118 patients (0.8%) with normal and 1/62 patients (1.6%) with doubtful white matter (p<0.01). Impaired cognitive development was seen in 3/27 patients (11.1%) with abnormal, 3/114 patients (2.6%) with normal and 1/59 patients (1.7%) with doubtful white matter (p=0.104). Alberta Infant Motor Scale (AIMS) was below P75 in 21/26 patients (80.8%) with abnormal, 73/114 patients (64.0%) with normal and 36/57 patients (63.2%) with doubtful white matter (p=0.231). In a subgroup of patients with minimal clinical follow-up of 18 months, AIMS score was below P75 in 10/13 patients (76.9%) with abnormal, 13/34 patients (38.2%) with normal and 7/20 patients (35.0%) with doubtful white matter (p<0.05).

CONCLUSIONS

Abnormal white matter was associated with neonatal hearing loss and mild, lower motor scores. A tendency towards impaired cognitive development was seen. Patients with doubtful white matter did not show worse clinical outcome.

Discrepancies in Management of Congenital Cytomegalovirus in Preterm Infants: An International Survey

We performed an international survey regarding management of infants with congenital cytomegalovirus (cCMV) born at less than 32 weeks gestation or with birth weight under 1500 g. Replies from 51 level 3 neonatal intensive care units across 13 countries demonstrated striking discrepancies in screening practices, testing for cCMV, further investigations of confirmed cases, indications for initiation, and duration of treatment.

A Cross-Sectional Survey of Pediatric Infectious Disease Physicians' Approach to Congenital Cytomegalovirus Infection

Congenital cytomegalovirus (cCMV) continues to be a major public health care issue due to its high prevalence throughout the world. However, there is a paucity of studies evaluating how providers manage this infection. This study surveyed North American Pediatric Infectious Disease (PID) physicians to elicit their approach towards the evaluation and treatment of this condition. Thirty-two PID physicians responded to this survey. Institutional testing and screening for cCMV were infrequently reported. The respondents in general agreed upon most laboratory and diagnostic testing except for neuroimaging. For those tests, there was a disparity in indications for head ultrasound versus brain MRI imaging. Most (68.8%) agreed with the clinical practice of starting valganciclovir in an infant less than 1 month of age with one sign or symptom of disease, and 62.5% would do so for an infant with isolated sensorineural hearing loss. However, only 28.1% would treat cCMV-infected infants older than 1 month of age. In conclusion, few healthcare institutions represented by PID physicians in this cohort had a cCMV screening or testing initiative, yet most respondents would test at a much higher level based on their clinical practice. While there is general consensus in evaluation and treatment of these children, there are disparities in practices regarding neuroimaging and indications for antiviral treatment with respect to age and severity of disease. There is a great need for an evidence based policy statement to standardize cCMV workup and treatment.

Risk Factors for Hearing Loss at Birth in Newborns With Congenital Cytomegalovirus Infection

Importance

With a prevalence between 0.2% and 6.1% of all live births, congenital cytomegalovirus (cCMV) infection is a major cause of congenital nonhereditary sensorineural hearing loss. Despite the large amount of research on cCMV-related hearing loss, it is still unclear which newborns are at risk of hearing loss.

Objective

To identify independent risk factors for cCMV-related congenital hearing loss and predictors of hearing loss severity at birth.

Design, Setting, and Participants

This cross-sectional study of newborns with cCMV infection used data included in the Flemish CMV registry that was collected from 6 secondary and tertiary hospitals in Flanders, Belgium, over 15 years (January 1, 2007, to February 7, 2022). Data were analyzed March 3 to October 19, 2022. Patients were included in the study after confirmed diagnosis of cCMV infection and known hearing status at birth. Patients who presented with other possible causes of sensorineural hearing loss were excluded.

Main Outcomes and Measures

Primary outcome was hearing status at birth. Clinical, neurological, and laboratory findings along with the timing of seroconversion and blood viral load were separately considered as risk factors. Binary logistic regression was performed to identify independent risk factors for congenital hearing loss in newborns with cCMV. Effect sizes were measured using Hedges g, odds ratio, or Cramer V.

Results

Of the 1033 newborns included in the study (553 of 1024 [54.0%] boys), 416 (40.3%) were diagnosed with symptomatic cCMV infection and 617 (59.7%) with asymptomatic cCMV infection. A total of 15.4% of the patients (n = 159) presented with congenital hearing loss; half of them (n = 80 [50.3%]) had isolated hearing loss. The regression model revealed 3 independent risk factors for congenital hearing loss: petechiae at birth (adjusted odds ratio [aOR], 6.7; 95% CI, 1.9-23.9), periventricular cysts on magnetic resonance imaging (MRI; aOR, 4.6; 95% CI, 1.5-14.1), and seroconversion in the first trimester (aOR, 3.1; 95% CI, 1.1-9.3). Lower viral loads were seen in patients with normal hearing compared with those with congenital hearing loss (median [IQR] viral load, 447.0 [39.3-2345.8] copies per milliliter of sample [copies/mL] vs 1349.5 [234.3-14 393.0] copies/mL; median difference, -397.0 [95% CI, -5058.0 to 174.0] copies/mL).

Conclusions and Relevance

Findings of this cross-sectional study suggest that newborns with cCMV infection and petechiae at birth, periventricular cysts on MRI, or a seroconversion in the first trimester had a higher risk of congenital hearing loss. Clinicians may use these risk factors to counsel parents in the prenatal and postnatal periods about the risk of congenital hearing loss. Moreover, linking clinical features to hearing loss may provide new insights into the pathogenesis of cCMV-related hearing loss. The importance of viral load as a risk factor for congenital hearing loss remains unclear.

Is CMV PCR of inner ear fluid during cochlear implantation a way to diagnose CMV-related hearing loss?

To evaluate the diagnostic performance of cytomegalovirus (CMV) polymerase chain reaction (PCR) on inner ear fluid collected during cochlear implantation and to assess its interest in current practice. This monocentric prospective study included consecutive children presenting with severe to profound sensorineural hearing loss (SNHL) who were candidates for unilateral and/or bilateral cochlear implantation. The etiology of the SNHL was determined before cochlear implantation when possible. During the surgery, drop-like samples of inner ear fluid and blood were collected. CMV PCR was then performed on both samples. Between January 2017 and September 2021, 113 children with severe to profound SNHL underwent cochlear implantation with inner ear fluid collection. Among these children, 77 of them presented with a known cause of SNHL (68%) and 36 of them had an unknown cause of SNHL at the time of surgery (32%). Sensitivity and specificity of the CMV PCR on inner ear fluid were 60% (95% CI: [49-71]) and 98% (95% CI: [96-100]), respectively. Positive and negative predictive values were 90% (95% CI: [83-97]) and 92% (95% CI: [86-98]), respectively. A sensitivity analysis according to age at cochlear implantation showed a decrease with age.

CONCLUSION

Sampling of inner ear fluid during cochlear implant surgery is an interesting, simple and safe way to diagnose CMV-related hearing loss, especially when the diagnosis of congenital infection can no longer be confirmed. However, the sensitivity decreases with age.

TRIAL REGISTRATION

NCT04724265 What is Known: • Congenital cytomegalovirus infection is the leading infectious cause of neurological disabilities and sensorineural hearing loss in children. In the absence of systematic screening at birth, many cCMV infections go undetected and are often undiagnosed despite the development of sensorineural sequelae.  • Nearly 40% of indications for cochlear implantation are of unknown etiology.

WHAT IS NEW

• Performing CMV PCR on inner ear fluid at the time of cochlear implantation is a safe way with high diagnostic performance (PPV = 90%, NPV = 92%) to detect a CMV-related hearing loss. • This sample may be interesting in cases of unknown cause of hearing loss in order to identify undiagnosed cCMV infections.

Targeted screening for congenital cytomegalovirus infection: clinical, audiological and neuroimaging findings

OBJECTIVE

To evaluate clinical, audiological and neuroimaging findings in a cohort of infants diagnosed with congenital cytomegalovirus (cCMV) infection after failure at newborn hearing screening.

METHODS

A prospective observational study in the Netherlands, using the existing newborn hearing screening infrastructure for well babies. Between July 2012 and November 2016, cytomegalovirus (CMV) PCR testing of neonatally obtained dried blood spots (DBS) was offered to all infants who failed newborn hearing screening. Clinical, neuroimaging and audiological data were collected.

RESULTS

DBS of 1374 infants were successfully tested and 59 were positive for CMV (4.3%). Data of 54 infants were retrieved. Three were small for gestational age and six had microcephaly. Forty-eight (89%) had sensorineural hearing loss (SNHL), of whom half had unilateral SNHL. In both unilaterally and bilaterally affected children, the majority of the impaired ears had severe or profound hearing loss. Neuroimaging abnormalities were found in 40 of 48 (83%) children who had evaluable cranial ultrasound and/or cerebral MRI. The abnormalities were mild in 34, moderate in 3 and severe in 3 infants. The degree of SNHL and the severity of neuroimaging abnormalities were found to be correlated (p=0.002).

CONCLUSIONS

The yield of targeted cCMV screening following newborn hearing screening failure was eight times higher than the estimated national birth prevalence of cCMV. The majority of this cohort of infants with clinically unsuspected cCMV disease had confirmed SNHL, neuroimaging abnormalities and lower than average birth weights and head circumferences. Newborns who fail newborn hearing screening should be tested for CMV to ensure appropriate clinical, neurodevelopmental and audiological follow-up.

An Overview of Cytomegalovirus Infection in Pregnancy

The objective of this review was to bring to attention cytomegalovirus (CMV) infection during pregnancy, taking into consideration all relevant aspects, such as maternal diagnosis, fetal infection and prevention, prenatal diagnosis, and postnatal prognosis. A literature review was performed regarding adult and congenital infection. General information regarding this viral infection and potential related medical conditions was provided, considering the issues of maternal infection during pregnancy, transmission to the fetus, and associated congenital infection management. Prenatal diagnosis includes maternal serum testing and the confirmation of the infection in amniotic fluid or fetal blood. Additionally, prenatal diagnosis requires imaging techniques, ultrasound, and complementary magnetic resonance to assess cortical and extracortical anomalies. Imaging findings can predict both fetal involvement and the postnatal prognosis of the newborn, but they are difficult to assess, even for highly trained physicians. In regard to fetal sequelae, the early diagnosis of a potential fetal infection is crucial, and methods to decrease fetal involvement should be considered. Postnatal evaluation is also important, because many newborns may be asymptomatic and clinical anomalies can be diagnosed when sequelae are permanent.

From Fetal to Neonatal Neuroimaging in TORCH Infections: A Pictorial Review

Congenital infections represent a challenging and varied clinical scenario in which the brain is frequently involved. Therefore, fetal and neonatal neuro-imaging plays a pivotal role in reaching an accurate diagnosis and in predicting the clinical outcome. Congenital brain infections are characterized by various clinical manifestations, ranging from nearly asymptomatic diseases to syndromic disorders, often associated with severe neurological symptoms. Brain damage results from the complex interaction among the infectious agent, its specific cellular tropism, and the stage of development of the central nervous system at the time of the maternal infection. Therefore, neuroradiological findings vary widely and are the result of complex events. An early detection is essential to establishing a proper diagnosis and prognosis, and to guarantee an optimal and prompt therapeutic perinatal management. Recently, emerging infective agents (i.e., Zika virus and SARS-CoV2) have been related to possible pre- and perinatal brain damage, thus expanding the spectrum of congenital brain infections. The purpose of this pictorial review is to provide an overview of the current knowledge on fetal and neonatal brain neuroimaging patterns in congenital brain infections used in clinical practice.

Predictors of cochleovestibular dysfunction in children with congenital cytomegalovirus infection

The purpose of this study is to assess the predictive factors of both hearing and vestibular impairment in congenitally cytomegalovirus-infected children (cCMV) through a multivariate analysis of clinical and imaging characteristics collected during pregnancy and at birth. This retrospective study was conducted between March 2014 and March 2020, including confirmed congenitally CMV-infected children with a complete vestibular and hearing assessment. Data concerning pregnancy, date of infection, clinical characteristics, and symptomatology at birth were collected. In total, 130 children were included, with a median age of 21 months. Eighty-three children (64%) presented with an inner ear impairment (both cochlear and vestibular impairment). Sex, modality of maternal infection (seroconversion or reactivation), pregnancy term, weight and head circumference at birth, neonatal clinical signs of infection, and treatment were not significantly correlated with inner ear impairment. However, multivariate analysis confirmed that there are two independent predictive factors of inner ear impairment: antenatal imaging lesions (OR_a = 8.02 [1.74; 60.27], p-value = 0.01) and infection during the first trimester (OR_a = 4.47 [1.21; 19.22], p-value = 0.03). Conversely, infections occurring during the second trimester were rarely associated with inner ear impairment: 4/13 (31%) in our series, with vestibular impairment alone (4/4) and no hearing loss. None of the children infected during the third trimester developed inner ear dysfunction.

CONCLUSION

Besides the symptomatic status of the CMV infection at birth, we found that antenatal imaging brain damage and early infection (mainly during the first trimester) constitute the two best independent predictive factors of inner ear involvement in congenitally CMV-infected children.

WHAT IS KNOWN

• Congenital cytomegalovirus infection is the leading infectious cause of neurological disabilities and sensorineural hearing loss in children and responsible of vestibular disorders, which are probably underestimated. • No articles have yet defined the predictive factors of the entire inner ear impairment (vestibule and cochlea).

WHAT IS NEW

• The timing of the infection during pregnancy (first and second trimester, ORa=4.47) and antenatal imaging lesions (ORa=8.02) are independently predictive (in a multivariate analysis) of inner ear involvement. • The symptomatic status at birth is a poor predictor of inner ear impairment.

Emerging Concepts in Congenital Cytomegalovirus

Over a century of research has focused on improving our understanding of congenital cytomegalovirus (cCMV), yet it remains the most common congenital infection in the United States, affecting 3 to 6 per 1000 live born infants each year. Pregnancies affected by cCMV are at a heightened risk of spontaneous abortion and intrauterine fetal demise. Neonates born with cCMV are also at substantial risk for long-term neurodevelopmental sequelae and disability, including sensorineural hearing loss, even those born without clinically apparent disease. Considerable progress has been made in recent years in study of the epidemiology and transmission of cCMV, developing better diagnostic strategies, implementing newborn screening programs, improving therapeutics, and launching vaccine trials. In this article, we review recent developments in the understanding of the virology and immunobiology of cytomegalovirus. We further discuss how this knowledge informs our understanding of the pathophysiology of cCMV and directs strategies aimed at improving outcomes and quality of life for congenitally infected children. We also provide an update on the epidemiology of cCMV in the United States, evolving scientific understanding of maternal-fetal transmission, enhanced screening approaches, and recognition of neonatal and long-term sequelae. Finally, we review the current landscape of pediatric cCMV research and provide recommendations for novel and high-priority areas for future investigation.

Kongenitale Zytomegalievirusinfektion: Reicht die Schädelsonografie?

Eine vorgeburtliche Infektion mit dem Zytomegalievirus (CMV) kann unter anderem das zentrale Nervensystem schädigen. Alle betroffenen Neugeborenen sollten daher eine entsprechende Bildgebung erhalten. Üblicherweise wird zunächst eine Schädelsonografie durchgeführt. Ob in jedem Fall – oder nur bei sonografischen-Auffälligkeiten – zusätzlich eine Magnetresonanztomografie (MRT) erfolgen sollte, wird allerdings kontrovers diskutiert.