Long-term neurobiological consequences of early postnatal hCMV-infection in former preterms: a functional MRI study

Postnatally acquired cytomegalovirus infection among preterm infants

PURPOSE OF REVIEW

Although there are multiple benefits of mother's own milk feeding for very-low birth weight, low gestation infants, those born to cytomegalovirus (CMV)-seropositive mothers are at risk for acquiring postnatal CMV infection. This review will describe the risk and consequences of postnatal CMV infection among very preterm infants.

RECENT FINDINGS

Postnatal CMV may manifest as clinically silent infection or as mild to severe and occasionally fatal disease. The risk of disease is balanced by the health benefits of human milk feeding to preterm infants. Postnatal CMV infection has been associated with increased risks of multiple preterm morbidities such as bronchopulmonary dysplasia, necrotizing enterocolitis and neurodevelopmental impairment, but current evidence is limited by the selection bias inherent to reporting in case series and retrospective cohort studies.

SUMMARY

Knowledge gaps exist regarding the risk-benefit balance of pasteurization to inactivate CMV in fresh breast milk, as well as the optimal dosing, duration and efficacy of treating infected infants with antiviral medications. Multicenter, prospective studies are urgently needed to accurately determine the true burden that postnatal CMV infection presents to very preterm infants. Such studies will inform the need for preventive strategies and treatment guidance.

Human Cytomegalovirus Infection and Neurocognitive and Neuropsychiatric Health

A common infection, human cytomegalovirus (HCMV) has been associated with a variety of human diseases, including cardiovascular disease and possibly certain cancers. HCMV has also been associated with cognitive, psychiatric, and neurological conditions. Children with congenital or early-life HCMV are at risk for microcephaly, cerebral palsy, and sensorineural hearing loss, although in many cases sensorineural loss may resolve. In addition, HCMV can be associated with neurodevelopmental impairment, which may improve with time. In young, middle-aged, and older adults, HCMV has been adversely associated with cognitive function in some but not in all studies. Research has linked HCMV to Alzheimer's and vascular dementia, but again not all findings consistently support these associations. In addition, HCMV has been associated with depressive disorder, bipolar disorder, anxiety, and autism-spectrum disorder, although the available findings are likewise inconsistent. Given associations between HCMV and a variety of neurocognitive and neuropsychiatric disorders, additional research investigating reasons for the considerable inconsistencies in the currently available findings is needed. Additional meta-analyses and more longitudinal studies are needed as well. Research into the effects of antiviral medication on cognitive and neurological outcomes and continued efforts in vaccine development have potential to lower the neurocognitive, neuropsychiatric, and neurological burden of HCMV infection.

Clinical Characteristics of Infants with Symptomatic Congenital and Postnatal Cytomegalovirus Infection-An 11-Year Multicenter Cohort Study in Taiwan

(1) Background: Cytomegalovirus (CMV) infection is a prevalent viral disease among infants. The prevalence typically ranges from 0.2% to 2.4% among all newborns. There are limited data regarding the demographic characteristics of infants with symptomatic CMV infections. (2) Methods: In this retrospective cohort study using the Chang Gung Memorial Hospital multicenter database, infants with CMV infection determined by a positive urine culture, positive blood polymerase chain reaction assay or positive immunoglobulin M result for CMV from 2011 through 2021 were included. Clinical characteristics at initial diagnosis, management and outcomes were investigated. Congenital CMV (cCMV) infection is diagnosed within three weeks after birth; postnatal CMV (pCMV) is diagnosed when CMV is detected after the first 3 weeks of life. (3) Results: Among the 505 CMV-infected infants identified, 272 were included in the analysis. According to the age at initial presentation, 21 infants had cCMV infection and 251 had pCMV infection. Higher incidences of prematurity and being small for gestational age and a lower Z score for weight at diagnosis were observed in the cCMV group. While thrombocytopenia (61.9%) was the leading presentation in the cCMV group, hepatitis (59.8%) and prolonged jaundice (21.9%) were more common in the pCMV group. (4) Conclusions: Utilizing an 11-year multicenter database, we demonstrated the characteristics of infants with CMV infection in Taiwan and highlighted the demographic disparities and differing symptoms between the cCMV and pCMV groups. These findings emphasize the necessity for future research to refine screening policies, explore treatment options, and establish follow-up protocols for affected infants.

Reduced structural connectivity in non-motor networks in children born preterm and the influence of early postnatal human cytomegalovirus infection

Introduction

Preterm birth is increasingly recognized to cause lifelong functional deficits, which often show no correlate in conventional MRI. In addition, early postnatal infection with human cytomegalovirus (hCMV) is being discussed as a possible cause for further impairments. In the present work, we used fixel-based analysis of diffusion-weighted MRI to assess long-term white matter alterations associated with preterm birth and/or early postnatal hCMV infection.

Materials and methods

36 former preterms (PT, median age 14.8 years, median gestational age 28 weeks) and 18 healthy term-born controls (HC, median age 11.1 years) underwent high angular resolution DWI scans (1.5 T, b = 2 000 s/mm2, 60 directions) as well as clinical assessment. All subjects showed normal conventional MRI and normal motor function. Early postnatal hCMV infection status (CMV+ and CMV-) had been determined from repeated screening, ruling out congenital infections. Whole-brain analysis was performed, yielding fixel-wise metrics for fiber density (FD), fiber cross-section (FC), and fiber density and cross-section (FDC). Group differences were identified in a whole-brain analysis, followed by an analysis of tract-averaged metrics within a priori selected tracts associated with cognitive function. Both analyses were repeated while differentiating for postnatal hCMV infection status.

Results

PT showed significant reductions of fixel metrics bilaterally in the cingulum, the genu corporis callosum and forceps minor, the capsula externa, and cerebellar and pontine structures. After including intracranial volume as a covariate, reductions remained significant in the cingulum. The tract-specific investigation revealed further reductions bilaterally in the superior longitudinal fasciculus and the uncinate fasciculus. When differentiating for hCMV infection status, no significant differences were found between CMV+ and CMV-. However, comparing CMV+ against HC, fixel metric reductions were of higher magnitude and of larger spatial extent than in CMV- against HC.

Conclusion

Preterm birth can lead to long-lasting alterations of WM micro- and macrostructure, not visible on conventional MRI. Alterations are located predominantly in WM structures associated with cognitive function, likely underlying the cognitive deficits observed in our cohort. These observed structural alterations were more pronounced in preterms who suffered from early postnatal hCMV infection, in line with previous studies suggesting an additive effect.

The Effect of Postnatal Cytomegalovirus Infection on (Micro)structural Cerebral Development in Very Preterm Infants at Term-Equivalent Age

INTRODUCTION

There are some data indicating a negative impact of postnatal cytomegalovirus (CMV) infection on long-term neurodevelopmental outcome of preterm infants. So far, there is only little knowledge about a cerebral imaging correlate of these neurodevelopmental alterations induced by postnatal CMV infection in preterm infants. The aim of the current study was to investigate the effect of postnatal CMV infection on the incidence of brain injury and on microstructural brain maturation in very preterm infants at term-equivalent age.

METHODS

Infants <32 gestational weeks (02/2011-11/2018) received cerebral MRI including axial diffusion-weighted images at term-equivalent age. All infants were screened for CMV infection using urine/saliva samples, and infection was regarded as acquired postnatal if a sample became positive >5 postnatal days. We compared brain injury as well as fractional anisotropy and apparent diffusion coefficient in 14 defined cerebral regions between infants with and without postnatal CMV infection.

RESULTS

401 infants were eligible, of whom 18 (4.5%) infants had a postnatal CMV infection. There were no significant differences in rates of brain injury or in microstructural brain development between both groups. This applied equally to the subgroup of infants <28 gestational weeks.

CONCLUSION

Although infants with postnatal CMV infection were born more immature and more frequently suffered from complications related to immaturity, we neither observed a higher rate of preterm brain injury nor disadvantageous alterations in microstructural brain maturation at term-equivalent age.

Postnatal CMV Infection and Antiviral Treatment in Extremely Premature Infants: A 12-Year Retrospective Analysis

BACKGROUND

The impact and outcomes of postnatal cytomegalovirus (CMV) infection are not entirely clear. We aimed to determine the associations between treatment outcomes of postnatal CMV infection and its antiviral treatment.

METHODS

Retrospective study in a tertiary center. Infants of < 29 weeks gestational age who were tested for postnatal CMV infection were included. CMV-infected infants were compared to uninfected infants (control group). CMV-infected infants were either treated with ganciclovir and/or valganciclovir (CMVPT group) or not (CMVPNT group). Demographic, clinical, laboratory, treatment, and outcome data were collected. Primary outcomes were the length of stay, death before discharge and hearing impairment, cognitive and motor development as assessed by the Denver Developmental Screening Test II, and neurologic impairment at the corrected age of 1.5-2 years.

RESULTS

We included 103 extremely premature infants. The Median (interquartile range [IQR]) length of stay was 94 (69-112) days in control, 85 (70-102) days in CMVPNT, and 100 (88-137) days in the CMVPT group. Mortality before discharge was 6% in control, 3.8% in CMVPNT, and 3.7% in the CMVPT group. Normal hearing at follow-up was found in 30/37 infants in control (81.1%), 13/13 infants in CMVPNT (100%), and 17/20 infants in the CMVPT group (85%). Denver Developmental Screening Test II results did not differ among the three groups. Neurologic impairment was found in 21/37 infants (56.8%) in control, 9/13 infants in CMVPNT (69.2%), and 14/20 infants in CMVPT group (70%).

CONCLUSIONS

The associations between antiviral treatment of postnatal CMV infection and better treatment outcomes were nonsignificant.

Perinatal Cytomegalovirus Infection

PURPOSE OF REVIEW

There have been recent advances in the field of congenital CMV infection (cCMV) related to antiviral treatment of pregnant women and infants, the implementation of newborn CMV screening programs, and the frequency and diagnosis of complications among infected children. In addition, postnatal CMV infection (pCMV) is increasingly recognized as a potential cause of long-term sequelae in addition to acute complications among preterm infants, raising important questions related to treatment, and prevention.

RECENT FINDINGS

High-dose valacyclovir appears to be safe and effective for the prevention of cCMV among women with first-trimester primary CMV infection. New studies reveal high rates of vestibular dysfunction and neuropsychiatric manifestations among children with cCMV. Some studies report associations between pCMV and long-term consequences, including neurodevelopmental delay and bronchopulmonary dysplasia, among very low birth weight infants, in addition to high risk of sepsis and death acutely, which has motivated efforts to eliminate the virus from breast milk by different methods.

SUMMARY

More long-term complications of cCMV are increasingly recognized among children previously thought to be asymptomatic. Although a preventive CMV vaccine may be achievable, strategies to reduce the burden of cCMV disease include maternal education about risk-reduction behaviors, antiviral treatment of pregnant women with primary infection, and newborn screening to allow timely, appropriate care. Similarly, although it remains unclear if pCMV causes long-term problems, there is growing interest in identifying and preventing disease from CMV infections among preterm infants.

Postnatal Cytomegalovirus Infection: Is it Important? A 10-Year Retrospective Case-control Study of Characteristics and Outcomes in Very Preterm and Very Low Birth Weight Infants

BACKGROUND

To determine the characteristics and outcomes of postnatal cytomegalovirus (pCMV) infection in preterm infants in a neonatal intensive care unit (NICU).

METHODS

A retrospective, matched case-control study in a tertiary NICU. Infants born between January 2009 and December 2019, <32 weeks' gestational age (GA) and/or birth weight (BW) <1500 g with pCMV infection were matched 1:1 with cytomegalovirus-(CMV)-negative infants by year of admission, gender, GA and BW. Primary outcome was death ≤36 weeks' postmenstrual age or bronchopulmonary dysplasia (BPD). Secondary outcomes were length of ventilation (LOV), length of stay (LOS) and neurodevelopmental impairment (NDI) at corrected age 1 and 2 years.

RESULTS

Forty-eight pCMV-positive infants (median GA 25.3 weeks, BW 695 g, age 58 days) were identified from 1659 infants (incidence 2.9%). The most common symptoms of pCMV infection were abdominal distension (43.8%), sepsis-like syndrome (29.2%), thrombocytopenia (60.5%) and conjugated hyperbilirubinemia (60.9%). Compared with controls, there were no significant differences in the composite outcome of death or BPD (56.3% vs. 37.5%; P = 0.1) or NDI at 1 and 2 years (51.9% vs. 44%; P = 0.8; 71.4% vs. 50%; P = 0.4). pCMV-positive infants had a significantly longer median LOV (23.5 vs. 12 days)* and LOS (140 vs. 110.5 days)*. Eleven (22.9%) infants received antivirals. Ten improved and 1 died. Two untreated infants died (1 from pCMV infection).

CONCLUSIONS

Clinically identifiable pCMV infections are significant and associated with increased respiratory support and prolonged hospital stay in vulnerable infants. pCMV screening and preventive measures against transmission merit consideration.*P < 0.05.

How to Provide Breast Milk for the Preterm Infant and Avoid Symptomatic Cytomegalovirus Infection with Possible Long-Term Sequelae

Cytomegalovirus (CMV) is able to replicate in the breast milk of lactating mothers and thus the offspring might be affected by mild to severe symptoms of postnatal CMV disease in case of prematurity; not in term infants. Sepsis-like syndrome affects only very low birth infants; and few cases have been reported. The neurodevelopmental long-term outcome of those preterm infants revealed possible subtle deficiencies, but no major neurodevelopmental impairment. Neurodevelopmental sequelae are still in discussion and seem somewhat overestimated after careful evaluation of the published evidence. The main focus of postnatal CMV disease lies upon the extremely low birth weight of infants. Elimination of CMV is provided by short-term heating methods like the most widely used Holder pasteurization. Freezing and thawing methods leave a risk for CMV acquisition. The benefits of untreated breast milk have to be considered to outweigh the possible sequelae of postnatal CMV infection in the most vulnerable preterm infants.

Promoting Human Milk and Breastfeeding for the Very Low Birth Weight Infant

Provision of mother's own milk for hospitalized very low birth weight (VLBW) (≤1500 g) infants in the NICU provides short- and long-term health benefits. Mother's own milk, appropriately fortified, is the optimal nutrition source for VLBW infants. Every mother should receive information about the critical importance of mother's own milk to the health of a VLBW infant. Pasteurized human donor milk is recommended when mother's own milk is not available or sufficient. Neonatal health care providers can support lactation in the NICU and potentially reduce disparities in the provision of mother's own milk by providing institutional supports for early and frequent milk expression and by promoting skin-to-skin contact and direct breastfeeding, when appropriate. Promotion of human milk and breastfeeding for VLBW infants requires multidisciplinary and system-wide adoption of lactation support practices.

Optimizing Early Neonatal Nutrition and Dietary Pattern in Premature Infants

Providing adequate amounts of all essential macro- and micronutrients to preterm infants during the period of extraordinarily rapid growth from 24 to 34 weeks' postmenstrual age to achieve growth as in utero is challenging yet important, since early growth restriction and suboptimal neonatal nutrition have been identified as risk factors for adverse long-term development. Along with now well-established early parenteral nutrition, this review emphasizes enteral nutrition, which should be started early and rapidly increased. To minimize the side effects of parenteral nutrition and improve outcomes, early full enteral nutrition based on expressed mothers' own milk is an important goal. Although neonatal nutrition has improved in recent decades, existing knowledge about, for example, the optimal composition and duration of parenteral nutrition, practical aspects of the transition to full enteral nutrition or the need for breast milk fortification is limited and intensively discussed. Therefore, further prospective studies on various aspects of preterm infant feeding are needed, especially with regard to the effects on long-term outcomes. This narrative review will summarize currently available and still missing evidence regarding optimal preterm infant nutrition, with emphasis on enteral nutrition and early postnatal growth, and deduce a practical approach.

Early-childhood cytomegalovirus infection and children's neurocognitive development

BACKGROUND

Despite a clear association seen in congenitally infected children, the effect of postnatal cytomegalovirus (CMV) infection during early childhood on cognitive development has not yet been determined.

METHODS

CMV-infection status was obtained based on serological measurements when children were 7 years old. Using population-based longitudinal data, we employed multivariate Poisson regression with a robust variance estimator to characterize the relationship between childhood CMV infection and adverse neurocognitive outcomes in children. Suboptimal neurocognitive outcomes were compared between CMV-positive and CMV-negative children using various cognitive assessments from 8 to 15 years of age. Children were evaluated on the cognitive domains of language, reading, memory and general intelligence, with a suboptimal score being >2 standard deviations lower than the mean score. Approximate Bayes factor (ABF) analysis was used to determine the level of evidence for the observed associations.

RESULTS

With adjustment for potential confounders, we observed that early-childhood CMV infection was associated with suboptimal total intelligence quotient (IQ) at 8 years of age [incidence-rate ratio (IRR) = 2.50, 95% confidence interval (CI) 1.35-4.62, ABF = 0.08], but not with suboptimal total IQ at 15 years of age (IRR = 0.97, 95% CI 0.43-2.19, ABF = 1.68). Suboptimal attentional control at 8 years (IRR = 1.74, 95% CI 1.13-2.68, ABF = 0.18) and reading comprehension at 9 years (IRR = 1.93, 95% CI 1.12-3.33, ABF = 0.24) were also associated with CMV infection. ABF analysis provided strong evidence for the association between CMV infection and total IQ at 8 years, and only anecdotal evidence for attentional control at 8 years and reading comprehension at 9 years. All other cognitive measures assessed were not associated with CMV infection.

CONCLUSION

In this large-scale prospective cohort, we observed some evidence for adverse neurocognitive effects of postnatal CMV infection on general intelligence during early childhood, although not with lasting effect. If confirmed, these results could support the implementation of preventative measures to combat postnatal CMV infection.

Long-term Outcomes after Postnatal Cytomegalovirus Infection in Low Birthweight Preterm Infants: A Systematic Review

BACKGROUND

Cytomegalovirus (CMV) is the most common viral infection seen in newborns. Although postnatally acquired CMV (pCMV) infection rarely results in serious manifestations in term infants, preterm infants can develop severe clinical illness. However, the long-term implications of pCMV infection of preterm infants are unknown. Few robust studies on long-term outcomes of pCMV infection have been performed, and those reported often present conflicting results. Our objective was to assess the long-term outcomes for low birthweight (LBW) preterm infants after pCMV infection.

METHODS

A systematic review of English and non-English articles using MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL, and Web of Science was conducted. Search strategies included a mix of keywords and database-specific subject headings for CMV and LBW infants. Editorials, comments, reviews and animal-only studies were excluded. Case reports, observational, experimental and randomized controlled trials that examined pCMV in preterm or VLBW infants and long-term (>1 month) impact of pCMV were included.

RESULTS

pCMV infection in preterm infants is associated with increased risk for pulmonary and neurologic complications and increases length of stay. There is less evidence to suggest that pCMV is associated with necrotizing enterocolitis, ophthalmologic, audiologic and anthropomorphic complications in preterm infants.

CONCLUSIONS

Preterm infants with pCMV, especially those with symptomatic infection, may have long-term pulmonary and neurodevelopmental morbidity compared with their pCMV negative counterparts. Our results highlight the importance of pCMV detection and prevention in preterm infants in the neonatal intensive care unit. Large prospective studies are needed to fully define outcomes and determine if treatment improves outcomes.

Functional Magnetic Resonance Imaging during Visual Perception Tasks in Adolescents Born Prematurely

OBJECTIVES

Impairments in visual perception are among the most common developmental difficulties related to being born prematurely, and they are often accompanied by problems in other developmental domains. Neural activation in participants born prematurely and full-term during tasks that assess several areas of visual perception has not been studied. To better understand the neural substrates of the visual perceptual impairments, we compared behavioral performance and brain activations during visual perception tasks in adolescents born very preterm (birth weight ≤1500 g or gestational age <32 weeks) and full-term.

METHODS

Tasks assessing visual closure, discrimination of a deviating figure, and discrimination of figure and ground from the Motor-Free Visual Perception Test, Third Edition were performed by participants born very preterm (n = 37) and full-term (n = 34) at 12 years of age during functional magnetic resonance imaging.

RESULTS

Behavioral performance in the visual perception tasks did not differ between the groups. However, during the visual closure task, brain activation was significantly stronger in the group born very preterm in a number of areas including the frontal, anterior cingulate, temporal, and posterior medial parietal/cingulate cortices, as well as in parts of the cerebellum, thalamus, and caudate nucleus.

CONCLUSIONS

Differing activations during the visual closure task potentially reflect a compensatory neural process related to premature birth or lesser neural efficiency or may be a result of the use of compensatory behavioral strategies in the study group born very preterm.

Literature Review and an Italian Hospital Experience about Post-Natal CMV Infection Acquired by Breast-Feeding in Very Low and/or Extremely Low Birth Weight Infants

Breastfeeding is recommended for all neonates due to a known variety of beneficial effects, but infants can be infected by cell-associated bacteria and viruses from breast milk, such as cytomegalovirus (CMV). The majority of CMV-seropositive breastfeeding women have a viral, self-restricted reactivation, can shed the virus in the milk for about 12 weeks after delivery, and can transmit the infection to their offspring. Post-natal CMV-infected term infants are mainly asymptomatic, while very low birth weight (VLBW, <1500 g) and extremely low birth weight (ELBW, <1000 g) infants may present with severe disease, short-term sequelae ranging from abnormalities in laboratory indexes to sepsis-like syndrome, and long-term sequelae such as developmental problems. Thus, the use of thermally treated maternal milk for VLBW/ELBW infants may be indicated to prevent/reduce the risk of CMV transmission. Different techniques, with varying efficacy in eradicating CMV and maintaining the activity of biological compounds in milk are available: long/short pasteurization, freeze-thawing, the use of microwaves, and ultraviolet-C irradiation. In our NICU, the use of maternal raw milk is always strongly recommended for term/preterm infants, but to reduce risk of CMV transmission, freeze-thawing mother's own milk is used in neonates with GA ≤ 30 weeks or/and weight ≤ 1000 g, usually regardless of serological maternal condition, as CMV screening is not routinely offered to pregnant women and the milk of seroimmune mothers is not evaluated for CMV reactivation, as its rate is similar to seroprevalence. Over the last 4 years, we had 10 VLBW/ELBW newborns in our NICU with late-onset sepsis and negative cultures. In these cases, the research of CMV DNA in neonatal urine or saliva, for the diagnosis of post-natal symptomatic infection (once congenital transmission has been excluded) may be useful and not invasive. The take-home message we would like to share is that acquired CMV infection should be considered in VLBW/ELBW infants breastfed by seropositive mothers and presenting severe symptoms-particularly sepsis with negative cultures. This could allow pediatricians to make better-quality diagnoses, perform supportive therapy, provide antiviral treatment if needed, or establish a "pre-emptive" therapy for these high-risk neonates.

Impact of breast milk-acquired cytomegalovirus infection in premature infants: Pathogenesis, prevention, and clinical consequences?

Maternal-fetal transmission of cytomegalovirus (CMV) represents the most common infectious cause of long-term neurodevelopmental disability in children. Congenital CMV (cCMV) infection is associated with microcephaly, seizure disorders, cognitive disability, developmental delay, and sensorineural hearing loss (SNHL). Of these disabilities, SNHL is the most common, affecting approximately 10% of infants with cCMV. Although the sequelae of cCMV are well recognized, it is much less clear what long-term morbidities may occur in neonates that acquire post-natal CMV infection. Post-natal CMV (pCMV) infection is most commonly transmitted by breast-feeding, and in full-term infants is of little consequence. However, in preterm, very-low birthweight (VLBW) infants (<1500 g), pCMV can result in a severe sepsis-like syndrome, with wide-ranging end-organ disease manifestations. Although such short-term complications are well recognized among clinicians caring for premature infants, the long-term risks with respect to adverse neurodevelopmental outcomes remain controversial. In this review, we provide an overview of the clinical manifestations of breast milk-acquired pCMV infection. In particular, we summarize studies that have examined-sometimes with conflicting conclusions-the risks of long-term adverse neurodevelopmental outcome in VLBW infants that acquire pCMV from breast milk. We highlight proposed preventive strategies and antiviral interventions, and offer recommendations for high-priority areas for future basic science and clinical research.

Assessing motor, visual and language function using a single 5-minute fMRI paradigm: three birds with one stone

Clinical functional Magnetic Resonance Imaging (fMRI) requires inferences on localization of major brain functions at the individual subject level. We hypothesized that a single "triple use" task would satisfy sensitivity and reliability requirements for successfully assessing the motor, visual and language domain in this context. This was tested here by the application in a group of healthy adults, assessing sensitivity and reliability at the individual subject level, separately for each domain.Our "triple use" task consisted of 2 conditions (condition 1, assessing motor and visual domain, and condition 2, assessing the language domain), serving mutually as active/control. We included 20 healthy adult subjects. Random effect analyses showed activation in primary motor, visual and language regions, as expected. Less expected regions were activated both for the motor and visual domains. Further, reliability of primary activation patterns was very high across individual subjects, with activation seen in 70-100% of subjects in primary motor, visual, and left-lateralized language regions.These findings suggest the "triple use" task to be reliable at the individual subject's level to assess motor, visual and language domains in the clinical fMRI context. Benefits of such an approach include shortening of acquisition time, simplicity of the task for each domain, and using a visual stimulus. Following establishment of reliability in adults, the task may also be a valuable addition in the pediatric clinical fMRI context, where each of these factors is of high relevance.

Human Breast Milk-acquired Cytomegalovirus Infection: Certainties, Doubts and Perspectives

Breast Milk (BM) is the best source of nutrition for newborns, especially if premature. In fact, its beneficial impact on short- and the long-term neonatal outcome has was deeply described. Unfortunately, BM could not be always so safe, especially due to the possible presence of maternal viruses that can be shed and transferred to the breastfed neonate. Among these, Cytomegalovirus (CMV) can potentially lead to a serious and acute illness, mostly in case of low gestational age. Some studies also report the association of CMV-acquired infection to an increased risk of structural and functional brain modifications and neurological impairment. Due to these reasons, a strategy to remove CMV from BM with a minimal or absent impact on its beneficial components would be desirable. Up to now, pasteurization, freezing, ultraviolet- C or microwave irradiation are the available techniques; they show different levels of efficacy and variable effects on BM composition, even if many studies are still needed to fully clarify these implications. In this review, we provide an update of the current evidence about these topics. We focus on the factors promoting CMV shedding through BM; moreover, the possible occurrence of a severe disease in preterm neonates is also described. Finally, we investigate the potential effects showed on BM properties by the strategies that prevent or reduce viral transmission, therefore influencing newborns' health, and the new techniques which could show a relevant role in the next future, such as metabolomics.

Ablation of proliferating neural stem cells during early life is sufficient to reduce adult hippocampal neurogenesis

Environmental exposures during early life, but not during adolescence or adulthood, lead to persistent reductions in neurogenesis in the adult hippocampal dentate gyrus (DG). The mechanisms by which early life exposures lead to long-term deficits in neurogenesis remain unclear. Here, we investigated whether targeted ablation of dividing neural stem cells during early life is sufficient to produce long-term decreases in DG neurogenesis. Having previously found that the stem cell lineage is resistant to long-term effects of transient ablation of dividing stem cells during adolescence or adulthood (Kirshenbaum, Lieberman, Briner, Leonardo, & Dranovsky, ), we used a similar pharmacogenetic approach to target dividing neural stem cells for elimination during early life periods sensitive to environmental insults. We then assessed the Nestin stem cell lineage in adulthood. We found that the adult neural stem cell reservoir was depleted following ablation during the first postnatal week, when stem cells were highly proliferative, but not during the third postnatal week, when stem cells were more quiescent. Remarkably, ablating proliferating stem cells during either the first or third postnatal week led to reduced adult neurogenesis out of proportion to the changes in the stem cell pool, indicating a disruption of the stem cell function or niche following stem cell ablation in early life. These results highlight the first three postnatal weeks as a series of sensitive periods during which elimination of dividing stem cells leads to lasting alterations in adult DG neurogenesis and stem cell function. These findings contribute to our understanding of the relationship between DG development and adult neurogenesis, as well as suggest a possible mechanism by which early life experiences may lead to lasting deficits in adult hippocampal neurogenesis.

Outcome of Preterm Infants With Postnatal Cytomegalovirus Infection

OBJECTIVES

To assess whether preterm infants with postnatal cytomegalovirus infection develop neurologic sequelae in early childhood.

METHODS

Infants <32 weeks' gestation were prospectively screened for cytomegalovirus (CMV) at term-equivalent age. Neurodevelopment was compared between CMV-positive and CMV-negative infants by using the Griffiths Mental Development Scales (GMDS) at 16 months' corrected age (CA); the Bayley Scales of Infant and Toddler Development, Third Edition or the GMDS at 24 to 30 months' CA; and the Wechsler Preschool and Primary Scale of Intelligence, Third Edition and Movement Assessment Battery for Children, Second Edition at 6 years of age. At 6 years old, hearing was assessed in CMV-positive children.

RESULTS

Neurodevelopment was assessed in 356 infants at 16 months' CA, of whom 49 (14%) were infected and 307 (86%) were noninfected. Infected infants performed significantly better on the GMDS locomotor scale. There were no differences at 24 to 30 months' CA on the Bayley Scales of Infant and Toddler Development, Third Edition or GMDS. At 6 years of age, infected children scored lower on the Wechsler Preschool and Primary Scale of Intelligence, Third Edition, but mean scores were within normal range, reaching significance only in verbal IQ (96 [SD 17] vs 103 [SD 15] points; P = .046). Multiple regression indicated no impact of CMV status but significant influence of maternal education and ethnicity on verbal IQ. No significant differences in motor development were found and none of the infected children developed sensorineural hearing loss.

CONCLUSIONS

In this cohort study, postnatal cytomegalovirus infection in preterm children did not have an adverse effect on neurodevelopment within the first 6 years of life.

Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage

Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development.

Postnatal Cytomegalovirus Infection Through Human Milk in Preterm Infants: Transmission, Clinical Presentation, and Prevention

Cytomegalovirus (CMV) is reactivated in the lactating breast in up to 96% of CMV seropositive mothers. There is a relevant entity of postnatally acquired symptomatic CMV infection and disease of preterm infants through raw breast milk (BM). Actual data support negative influence on long-term cognitive development. Concerning prevention, only heat inactivation eliminates virus infectivity, and short-term heat inactivation is most preservative; this can be applied effectively under routine conditions. Short-term heat inactivation for 5 minutes at 62°C maintains the benefits of feeding BM without the disadvantages of CMV transmission.

CerebroMatic: A Versatile Toolbox for Spline-Based MRI Template Creation

Brain image spatial normalization and tissue segmentation rely on prior tissue probability maps. Appropriately selecting these tissue maps becomes particularly important when investigating "unusual" populations, such as young children or elderly subjects. When creating such priors, the disadvantage of applying more deformation must be weighed against the benefit of achieving a crisper image. We have previously suggested that statistically modeling demographic variables, instead of simply averaging images, is advantageous. Both aspects (more vs. less deformation and modeling vs. averaging) were explored here. We used imaging data from 1914 subjects, aged 13 months to 75 years, and employed multivariate adaptive regression splines to model the effects of age, field strength, gender, and data quality. Within the spm/cat12 framework, we compared an affine-only with a low- and a high-dimensional warping approach. As expected, more deformation on the individual level results in lower group dissimilarity. Consequently, effects of age in particular are less apparent in the resulting tissue maps when using a more extensive deformation scheme. Using statistically-described parameters, high-quality tissue probability maps could be generated for the whole age range; they are consistently closer to a gold standard than conventionally-generated priors based on 25, 50, or 100 subjects. Distinct effects of field strength, gender, and data quality were seen. We conclude that an extensive matching for generating tissue priors may model much of the variability inherent in the dataset which is then not contained in the resulting priors. Further, the statistical description of relevant parameters (using regression splines) allows for the generation of high-quality tissue probability maps while controlling for known confounds. The resulting CerebroMatic toolbox is available for download at http://irc.cchmc.org/software/cerebromatic.php.

Symptomatic Postnatal Cytomegalovirus Testing among Very Low-Birth-Weight Infants: Indications and Outcomes

Objective The objective of this study was to describe the indications for postnatal cytomegalovirus (CMV) testing among very low-birth-weight (VLBW, birth weight [BW] < 1,500 g) infants, clinical characteristics of infected infants, and adverse outcomes associated with CMV infection. Study Design This is a single-center, retrospective study of 2,132 VLBW infants from 1999 to 2013. Results In this study, 145 (6.8%) infants out of 2,132 were evaluated for postnatal CMV infection and 27 (18.6%) infants out of 145 were infected. CMV-tested infants were of significantly lower gestational age and BW compared with untested VLBW infants (p < 0.001). Respiratory decompensation and thrombocytopenia were the findings most commonly associated with infection. CMV-infected infants had significantly more exposure to mechanical ventilation and longer duration of hospitalization. Adjusting for multiple predictors of respiratory morbidity, the incidence of bronchopulmonary dysplasia (BPD) was significantly elevated among infants diagnosed with postnatal CMV infection (odds ratio, 4.0 [95% confidence interval, 1.3-12.4); p, 0.02.) Conclusion Symptomatic postnatal CMV infection was diagnosed in 1.3% of VLBW infants, most commonly among infants with BW < 1,000 g with respiratory instability and thrombocytopenia. Similar to late-onset bacterial infection, symptomatic postnatal CMV infection may be an independent contributor to the development of BPD. This possibility should be addressed in a prospective study of extremely low BW infants.

Postnatal human cytomegalovirus infection in preterm infants has long-term neuropsychological sequelae

OBJECTIVE

To evaluate whether an early postnatal infection poses a long-term risk for neuropsychological impairment to neonates born very prematurely.

STUDY DESIGN

Adolescents born very preterm (n = 42, 11.6-16.2 years, mean = 13.9; 15 girls; 19 with and 23 without an early postnatal human cytomegalovirus [CMV] infection) and typically developing, term born controls (n = 24, 11.3-16.6 years, mean = 13.6; 12 girls) were neuropsychologically assessed with the German version of the Wechsler Intelligence Scale and the Developmental Test for Visual Perception.

RESULTS

As expected, the full cohort of adolescents born preterm had significantly lower scores than term born controls on IQ (preterm: mean [SD] = 98.43 [14.83], control: 110.00 [8.10], P = .015) and on visuoperceptive abilities (95.64 [12.87] vs 106.24 [9.95], P = .016). Furthermore, adolescents born preterm with early postnatal CMV infection scored significantly lower than those without this infection regarding overall cognitive abilities (92.67 [14.71] vs 102.75 [13.67], P = .030), but not visuoperceptive abilities (91.22 [10.88] vs 98.96 [13.45], P > .05).

CONCLUSIONS

In our small but well-characterized group, our results provide evidence for adverse effects of early postnatal CMV infection on overall cognitive functions in adolescents born preterm. If confirmed, these results support the implementation of preventive measures.

Urine is superior to saliva when screening for postnatal CMV infections in preterm infants

BACKGROUND

Cytomegalovirus (CMV) is the most frequently contracted virus in preterm infants. Postnatal infection is mostly asymptomatic but is sometimes associated with severe disease. To diagnose an infection, urine or saliva samples can be tested for CMV-DNA by real-time polymerase chain reaction (rtPCR). Although the diagnostic accuracy of testing saliva samples has not been determined in preterm infants, saliva is widely used because it is easier to obtain than urine.

OBJECTIVES

To determine whether screening of saliva is equivalent to urine to detect a postnatal CMV infection in preterm infants.

STUDY DESIGN

Between 2010 and 2013 saliva and urine samples were collected from infants admitted to the Neonatal Intensive Care Unit of the University Medical Center Utrecht and born with a gestational age (GA) below 32 weeks. Urine samples were obtained within three weeks after birth and urine and saliva samples at term equivalent age (40 weeks GA) and tested for CMV-DNA by rtPCR. Infants with a congenital CMV infection were excluded.

RESULTS

Of 261 preterm infants included in the study, CMV-DNA was detected in urine of 47 and in saliva of 43 children. Of 47 infants with postnatal CMV infection, CMV was detected in 42 saliva samples (sensitivity 89.4%; CI 76.9-96.5). Of 214 children without postnatal CMV infection, one saliva sample tested positive for CMV (specificity 99.5%; CI 97.4-99.9).

CONCLUSIONS

Screening saliva for CMV-DNA by rtPCR is inferior to urine to diagnose postnatal CMV infections in preterm infants.