Is sequential cranial ultrasound reliable for detection of white matter injury in very preterm infants?

A Multiplanar Radiomics Model Based on Cranial Ultrasound to Predict the White Matter Injury in Premature Infants and an Analysis of its Correlation With Neurodevelopment

OBJECTIVES

To develop and evaluate a multiplanar radiomics model based on cranial ultrasound (CUS) to predict white matter injury (WMI) in premature infants and explore its correlation with neurodevelopment.

METHODS

We retrospectively reviewed 267 premature infants. The radiomics features were extracted from five standard sections of CUS. The Spearman's correlation coefficient combined with the least absolute shrinkage and selection operator (LASSO) was applied to select features and build radiomics signature, and a multiplanar radiomics model was constructed based on the radiomics signature of five planes. The performance of the model was evaluated using the area under the receiver operating characteristic curve (AUC). Infants with WMI were re-examined by ultrasound at 2 and 4 weeks after birth, and the recovery degree of WMI was evaluated using multiplanar radiomics. The relationship between WMI and the recovery degree and neurodevelopment was analyzed.

RESULTS

The AUC of the multiplanar radiomics in the training and validation sets were 0.94 and 0.91, respectively. The neurodevelopmental function scores in infants with WMI were significantly lower than those in healthy preterm infants and full-term newborns (P < .001). There were statistically significant differences in the neurodevelopmental function scores of infants between the 2- and 4-week lesion disappearance and 4-week lesion persistence (P < .001).

CONCLUSIONS

The multiplanar radiomics model showed a good performance in predicting the WMI of premature infants. It can not only provide objective and accurate results but also dynamically monitor the degree of recovery of WMI to predict the prognosis of premature infants.

Quantitative ultrasonographic examination of cerebral white matter by pixel brightness intensity as marker of middle-term neurodevelopment: a prospective observational study

Non-cystic white matter (WM) injury has become prevalent among preterm newborns and is associated with long-term neurodevelopmental impairment. Magnetic resonance is the gold-standard for diagnosis; however, cranial ultrasound (CUS) is more easily available but limited by subjective interpretation of images. To overcome this problem, we enrolled in a prospective observational study, patients with gestational age at birth < 32 weeks with normal CUS scans or grade 1 WM injury. Patients underwent CUS examinations at 0-7 days of life (T0), 14-35 days of life (T1), 370/7-416/7 weeks' postmenstrual age (T2), and 420/7-520/7 weeks' postmenstrual age (T3). The echogenicity of parieto-occipital periventricular WM relative to that of homolateral choroid plexus (RECP) was calculated on parasagittal scans by means of pixel brightness intensity and its relationship with Bayley-III assessment at 12 months' corrected age was evaluated. We demonstrated that: (1) Left RECP values at T1 negatively correlated with cognitive composite scores; (2) Right RECP values at T2 and T3 negatively correlated with language composite scores; (3) Left RECP values at T1 and T2 negatively correlated with motor composite scores. Thus, this technique may be used as screening method to early identify patients at risk of neurodevelopmental issues and promptly initiate preventive and therapeutic interventions.

White matter injury detection based on preterm infant cranial ultrasound images

Introduction

White matter injury (WMI) is now the major disease that seriously affects the quality of life of preterm infants and causes cerebral palsy of children, which also causes periventricular leuko-malacia (PVL) in severe cases. The study aimed to develop a method based on cranial ultrasound images to evaluate the risk of WMI.

Methods

This study proposed an ultrasound radiomics diagnostic system to predict the WMI risk. A multi-task deep learning model was used to segment white matter and predict the WMI risk simultaneously. In total, 158 preterm infants with 807 cranial ultrasound images were enrolled. WMI occurred in 32preterm infants (20.3%, 32/158).

Results

Ultrasound radiomics diagnostic system implemented a great result with AUC of 0.845 in the testing set. Meanwhile, multi-task deep learning model preformed a promising result both in segmentation of white matter with a Dice coefficient of 0.78 and prediction of WMI risk with AUC of 0.863 in the testing cohort.

Discussion

In this study, we presented a data-driven diagnostic system for white matter injury in preterm infants. The system combined multi-task deep learning and traditional radiomics features to achieve automatic detection of white matter regions on the one hand, and design a fusion strategy of deep learning features and manual radiomics features on the other hand to obtain stable and efficient diagnostic performance.

Posthemorrhagic ventricular dilatation late intervention threshold and associated brain injury

OBJECTIVE

To systematically assess white matter injury (WMI) in preterm infants with posthemorrhagic ventricular dilatation (PHVD) using a high-threshold intervention strategy.

STUDY DESIGN

This retrospective analysis included 85 preterm infants (≤34 weeks of gestation) with grade 2-3 germinal matrix-intraventricular hemorrhage. Cranial ultrasound (cUS) scans were assessed for WMI and ventricular width and shape. Forty-eight infants developed PHVD, 21 of whom (intervention group) underwent cerebrospinal fluid drainage according to a predefined threshold (ventricular index ≥p97+4 mm or anterior horn width >10 mm, and the presence of frontal horn ballooning). The other 27 infants underwent a conservative approach (non-intervention group). The two PHVD groups were compared regarding ventricular width at two stages: the worst cUS for the non-intervention group (scans showing the largest ventricular measurements) versus pre-intervention cUS in the intervention group, and at term equivalent age. WMI was classified as normal/mild, moderate and severe.

RESULTS

The intervention group showed significantly larger ventricular index, anterior horn width and thalamo-occipital diameter than the non-intervention group at the two timepoints. Moderate and severe WMI were more frequent in the infants with PHVD (p<0.001), regardless of management (intervention or conservative management). There was a linear relationship between the severity of PHVD and WMI (p<0.001).

CONCLUSIONS

Preterm infants with PHVD who undergo a high-threshold intervention strategy associate an increased risk of WMI.

Rate of head ultrasound abnormalities at one month in very premature and extremely premature infants with normal initial screening ultrasound

BACKGROUND

Premature infants are at risk for multiple types of intracranial injury with potentially significant long-term neurological impact. The number of screening head ultrasounds needed to detect such injuries remains controversial.

OBJECTIVE

To determine the rate of abnormal findings on routine follow-up head ultrasound (US) performed in infants born at ≤ 32 weeks' gestational age (GA) after initial normal screening US.

MATERIALS AND METHODS

A retrospective study was performed on infants born at ≤ 32 weeks' GA with a head US at 3-5 weeks following a normal US at 3-10 days at a tertiary care pediatric hospital from 2014 to 2020. Exclusion criteria included significant congenital anomalies, such as congenital cardiac defects necessitating surgery, congenital diaphragmatic hernia or spinal dysraphism, and clinical indications for US other than routine screening, such as sepsis, other risk factors for intracranial injury besides prematurity, or clinical neurological abnormalities. Ultrasounds were classified as normal or abnormal based on original radiology reports. Images from initial examinations with abnormal follow-up were reviewed.

RESULTS

Thirty-three (14.2%) of 233 infants had 34 total abnormal findings on follow-up head US after normal initial US. Twenty-seven infants had grade 1 germinal matrix hemorrhage, and four had grade 2 intraventricular hemorrhage. Two had periventricular echogenicity and one had a focus of cerebellar echogenicity that resolved and was determined to be artifactual.

CONCLUSION

When initial screening head ultrasounds in premature infants are normal, follow-up screening ultrasounds are typically also normal. Abnormal findings are usually limited to grade 1 germinal matrix hemorrhage.

A novel magnetic resonance imaging-based scoring system to predict outcome in neonates born preterm with intraventricular haemorrhage

AIM

To create a magnetic resonance imaging (MRI)-based scoring system specific to neonates born preterm with intraventricular haemorrhage (IVH), which could serve as a reliable prognostic indicator for later development and might allow for improved outcome prediction, individually-tailored parental counselling, and clinical decision-making.

METHOD

This retrospective, two-center observational cohort study included 103 infants born preterm with IVH (61 males, 42 females; median gestational age 26wks 6d), born between 2000 and 2016. Term-equivalent MRI was evaluated using a novel scoring system consisting of 11 items. A total MRI score was calculated and correlated with neurodevelopment between 2 years and 3 years of age. Prediction models for outcome were defined.

RESULTS

The proposed MRI scoring system showed high correlation and strong predictive ability with regard to later cognitive and motor outcome. The prediction models were translated into easy-to-use tables, allowing developmental risk assessment.

INTERPRETATION

The proposed MRI-based scoring system was created especially for infants born preterm with IVH and enables a comprehensive assessment of important brain areas as well as potential additional abnormalities commonly associated with IVH. Thus, it better represents the severity of brain damage when compared with the conventional IVH classification. Our scoring system should provide clinicians with valuable information, to optimize parental counselling and clinical decision-making.

Association of Delivery Room and Neonatal Intensive Care Unit Intubation, and Number of Tracheal Intubation Attempts with Death or Severe Neurological Injury among Preterm Infants

OBJECTIVE

The study aimed to assess the association of tracheal intubation (TI) and where it is performed, and the number of TI attempts with death and/or severe neurological injury (SNI) among preterm infants.

STUDY DESIGN

Retrospective cohort study of infants born 23 to 32 weeks, admitted to a single level-3 neonatal intensive care unit (NICU) between 2015 and 2018. Exposures were location of TI (delivery room [DR] vs. NICU) and number of TI attempts (1 vs. >1). Primary outcome was death and/or SNI (intraventricular hemorrhage grade 3-4 and/or periventricular leukomalacia). Multivariable logistic regression analysis was used to assess association between exposures and outcomes and to adjust for confounders.

RESULTS

Rate of death and/or SNI was 2.5% (6/240) among infants never intubated, 12% (13/105) among NICU TI, 32% (31/97) among DR TI, 20% (17/85) among infants with one TI attempt and 23% (27/117) among infants with >1 TI attempt. Overall, median number of TI attempts was 1 (interquartile range [IQR]: 1-2). Compared with no TI, DR TI (adjusted odds ratio [AOR]: 9.04, 95% confidence interval [CI]: 3.21-28.84) and NICU TI (AOR: 3.42, 95% CI: 1.21-10.61) were associated with higher odds of death and/or SNI. The DR TI was associated with higher odds of death and/or SNI compared with NICU TI (AOR: 2.64, 95% CI: 1.17-6.22). The number of intubation attempts (1 vs. >1) was not associated with death and/or SNI (AOR: 0.95, 95% CI: 0.47-2.03).

CONCLUSION

The DR TI is associated with higher odds of death and/or SNI compared with NICU TI, and may help identify higher risk infants. There was no association between the number of TI attempts and death and/or SNI.

KEY POINTS

· Delivery room intubation correlates with morbidity.. · Less than 2 intubation attempts are not associated with IVH.. · Provider training reduces intubation attempts..

Advanced Brain Imaging in Preterm Infants: A Narrative Review of Microstructural and Connectomic Disruption

Preterm birth disrupts the in utero environment, preventing the brain from fully developing, thereby causing later cognitive and behavioral disorders. Such cerebral alteration occurs beneath an anatomical scale, and is therefore undetectable by conventional imagery. Prematurity impairs the microstructure and thus the histological process responsible for the maturation, including the myelination. Cerebral MRI diffusion tensor imaging sequences, based on water’s motion into the brain, allows a representation of this maturation process. Similarly, the brain’s connections become disorganized. The connectome gathers structural and anatomical white matter fibers, as well as functional networks referring to remote brain regions connected one over another. Structural and functional connectivity is illustrated by tractography and functional MRI, respectively. Their organizations consist of core nodes connected by edges. This basic distribution is already established in the fetal brain. It evolves greatly over time but is compromised by prematurity. Finally, cerebral plasticity is nurtured by a lifetime experience at microstructural and macrostructural scales. A preterm birth causes a negative and early disruption, though it can be partly mitigated by positive stimuli based on developmental neonatal care.

Cranial Ultrasound Screening Protocols for Very Preterm Infants

Cranial ultrasound examinations are routinely performed in very preterm neonates. There is no widespread agreement on the optimal timing of these examinations. This review examines screening protocols and recommendations available for the timing of cranial ultrasound examinations in preterm neonates born before 32 wk of gestation. A systematic search was performed to find published screening protocols, and 18 articles were included in the final review. The protocols varied in their recommendations on timing, although at least one examination in the first week of life was universally recommended. The recommended timing for a "late" or final ultrasound examination was variable, and included at 6 wks of postnatal age, term-equivalent age or hospital discharge. There was no agreement as to whether weekly or fortnightly sequential ultrasound imaging should be performed after the first week of life. Further studies are required to establish an optimal protocol for these very preterm neonates to improve detection and monitoring of brain injuries.

Associations between Neonatal Magnetic Resonance Imaging and Short- and Long-Term Neurodevelopmental Outcomes in a Longitudinal Cohort of Very Preterm Children

OBJECTIVE

To assess associations between neonatal brain injury assessed by magnetic resonance imaging and cognitive, motor, and behavioral outcomes at 2 and 10 years of age, in a longitudinal cohort of children born very preterm.

STUDY DESIGN

There were 112 children born at <32 weeks of gestation who participated in a longitudinal prospective study on brain injury and neurodevelopmental outcome. Using the Kidokoro score, neonatal brain injury and altered brain growth in white matter, cortical and deep gray matter, and the cerebellum were assessed. Cognitive, motor, and behavioral outcomes were assessed during follow-up visits at both 2 (corrected) and 10 years of age.

RESULTS

After adjusting for perinatal factors and level of maternal education, the global brain abnormality score was associated with cognition (B = -1.306; P = .005), motor skills (B = -3.176; P < .001), and behavior (B = 0.666; P = .005) at 2 years of age, but was not associated with cognition at 10 years of age. In the subgroup of children with a moderate-severe global brain abnormality score, magnetic resonance imaging was independently associated with cognitive impairment at 10 years of age. For children with milder forms of brain injury, only birth weight and level of maternal education were associated with cognitive outcomes.

CONCLUSIONS

Neonatal brain injury, assessed by a standardized scoring system, was associated with short-term neurodevelopmental outcomes, but only with motor skills and behavior in childhood. Environmental factors, such as level of maternal education, become more important for cognitive development as children grow older, especially for children with relatively mild neonatal brain injury.

Comparative performance of head ultrasound and MRI in detecting preterm brain injury and predicting outcomes: A systematic review

AIM

To systematically review the literature to compare the performance of head ultrasound (HUS) and magnetic resonance imaging (MRI) in their ability to detect brain injury and their predictive value for neurodevelopmental outcomes.

METHODS

This was a systematic review based on literature search in three electronic databases (MEDLINE, EMBASE, Cochrane Library) and additional sources for studies on routine brain injury screening in preterm neonates published during 2000-May 2020. Studies were included if they reported on the comparative performance of HUS and MRI in detecting preterm brain injury and/or their predictive value for neurodevelopmental outcomes. Findings from the included studies underwent narrative synthesis.

RESULTS

Forty-six studies were included. In comparison with HUS, MRI detected more anomalies and provided more details on the severity and the extent of preterm brain injury, particularly for white matter injury and cerebellar haemorrhage. Neonatal neuroimaging predicted outcomes with high negative predictive value but relatively low positive predictive value. The prognostic value of neonatal neuroimaging varied according to several factors including modality and timing of imaging, and tools used for grading brain injury.

CONCLUSION

Compared with HUS, MRI offers a better characterisation of preterm brain injury and may enhance the ability to predict neurodevelopmental outcomes.

Consensus Approach for Standardizing the Screening and Classification of Preterm Brain Injury Diagnosed With Cranial Ultrasound: A Canadian Perspective

Acquired brain injury remains common in very preterm infants and is associated with significant risks for short- and long-term morbidities. Cranial ultrasound has been widely adopted as the first-line neuroimaging modality to study the neonatal brain. It can reliably detect clinically significant abnormalities that include germinal matrix and intraventricular hemorrhage, periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, cerebellar hemorrhage, and white matter injury. The purpose of this article is to provide a consensus approach for detecting and classifying preterm brain injury to reduce variability in diagnosis and classification between neonatologists and radiologists. Our overarching goal with this work was to achieve homogeneity between different neonatal intensive care units across a large country (Canada) with regards to classification, timing of brain injury screening and frequency of follow up imaging. We propose an algorithmic approach that can help stratify different grades of germinal matrix-intraventricular hemorrhage, white matter injury, and ventricular dilatation in very preterm infants.

Incidence of brain lesions in moderate-late preterm infants assessed by cranial ultrasound and MRI: The BIMP-study

PURPOSE

To evaluate the incidence and characteristics of brain lesions in moderate-late preterm (MLPT) infants, born at 32-36 weeks' gestation using cranial ultrasound (cUS) and magnetic resonance imaging (MRI).

METHODS

Prospective cohort study carried out at Isala Women and Children's Hospital between August 2017 and November 2019. cUS was performed at postnatal day 3-4 (early-cUS), before discharge and repeated at term equivalent age (TEA) in MLPT infants born between 32⁺⁰ and 35⁺⁶ weeks' gestation. At TEA, MRI was also performed. Several brain lesions were assessed e.g. hemorrhages, white matter and deep gray matter injury. Brain maturation was visually evaluated. Lesions were classified as mild or moderate-severe. Incidences and confidence intervals were calculated.

RESULTS

166 MLPT infants were included of whom 127 underwent MRI. One or more mild lesions were present in 119/166 (71.7 %) and moderate-severe lesions in 6/166 (3.6 %) infants on cUS and/or MRI. The most frequent lesions were signs suggestive of white matter injury: inhomogeneous echogenicity in 50/164 infants (30.5 %) at early-cUS, in 12/148 infants (8.1 %) at TEA-cUS and diffuse white matter signal changes (MRI) in 27/127 (23.5 %) infants. Cerebellar hemorrhage (MRI) was observed in 16/127 infants (12.6 %). Delayed maturation (MRI) was seen in 17/117 (13.4 %) infants. Small hemorrhages and punctate white matter lesions were more frequently detected on MRI than on cUS.

CONCLUSIONS

In MLPT infants mild brain lesions were frequently encountered, especially signs suggestive of white matter injury and small hemorrhages. Moderate-severe lesions were less frequently seen.

A systematic review on brain injury and altered brain development in moderate-late preterm infants

OBJECTIVES

To provide a systematic review of brain injury and altered brain development in moderate-late preterm (MLPT) infants as compared to very preterm and term infants.

STUDY DESIGN

A systematic search in five databases was performed in January 2020. Original research papers on incidence of brain injury and papers using quantitative data on brain development in MLPT infants were selected. The Johanna Briggs Institute 'Critical Appraisal Checklist for Studies Reporting Prevalence Data' was used for quality appraisal. Data extraction included: imaging modality, incidences of brain injury, brain volumes, 2D-measurements and diffusivity values.

RESULTS

In total, 24 studies were eligible. Most studies had a moderate quality. Twenty studies reported on the incidence of brain injury in MLPT infants. The incidence of intraventricular hemorrhage (IVH) ranged from 0.0% to 23.5% and of white matter injury (WMI) from 0.5% to 10.8%. One study reported the incidence of arterial infarction (0.3%) and none of cerebellar hemorrhage. Eleven studies compared incidences of brain injury between MLPT infants and very preterm or term infants. Five studies reported signs of altered brain development in MLPT infants.

CONCLUSIONS

The incidences of IVH and WMI in MLPT infants varied widely between studies. Other abnormalities were sparsely reported. Evidence regarding a higher or lower incidence of brain injury in MLPT infants compared to very preterm or term infants is weak due to moderate methodological quality of reported studies. There is limited evidence suggesting a difference in brain development between MLPT and term infants.

L’imagerie cérébrale systématique du nouveau-né prématuré

L’imagerie cérébrale systématique pour déceler les lésions touchant les nouveau-nés prématurés est utilisée pour prédire le pronostic à long terme et déterminer les complications susceptibles de nécessiter une intervention. Même si l’imagerie par résonance magnétique peut être indiquée dans des situations particulières, l’échographie cérébrale est la technique la plus utilisée et demeure la meilleure modalité d’imagerie systématique en raison de sa portabilité et de sa facilité d’accès. L’échographie cérébrale systématique est recommandée pour tous les nouveau-nés venus au monde à 31+6 semaines d’âge gestationnel ou auparavant. Chez les nouveau-nés prématurés venus au monde entre 32+0 et 36+6 semaines d’âge gestationnel l’échographie cérébrale systématique n’est recommandée qu’en présence de facteurs de risque d’hémorragie intracrânienne ou d’ischémie. Il est conseillé d’obtenir une imagerie cérébrale de quatre à sept jours après la naissance pour déceler la plupart des hémorragies de la matrice germinale et des hémorragies intraventriculaires. Il est recommandé de reprendre l’imagerie entre quatre et six semaines de vie pour déceler les lésions de la substance blanche. Chez les nouveau-nés prématurés venus au monde avant 26 semaines d’âge gestationnel, il est recommandé de reprendre l’échographie cérébrale à l’âge équivalant au terme.

Routine imaging of the preterm neonatal brain

Routine brain imaging to detect injuries affecting preterm infants is used to predict long-term outcomes and identify complications that might necessitate an intervention. Although magnetic resonance imaging may be indicated in some specific cases, head ultrasound is the most widely used technique and, because of portability and ease of access, is the best modality for routine imaging. Routine head ultrasound examination is recommended for all infants born at or before 31+6 weeks gestation. For preterm neonates born between 32+0 to 36+6 weeks gestation, routine head ultrasound is recommended only in presence of risk factors for intracranial hemorrhage or ischemia. Brain imaging in the first 7 to 14 days postbirth is advised to detect most germinal matrix and intraventricular hemorrhages. Repeat imaging at 4 to 6 weeks of age is recommended to detect white matter injury.

Preterm white matter injury: ultrasound diagnosis and classification

White matter injury (WMI) is the most frequent form of preterm brain injury. Cranial ultrasound (CUS) remains the preferred modality for initial and sequential neuroimaging in preterm infants, and is reliable for the diagnosis of cystic periventricular leukomalacia. Although magnetic resonance imaging is superior to CUS in detecting the diffuse and more subtle forms of WMI that prevail in very premature infants surviving nowadays, recent improvement in the quality of neonatal CUS imaging has broadened the spectrum of preterm white matter abnormalities that can be detected with this technique. We propose a structured CUS assessment of WMI of prematurity that seeks to account for both cystic and non-cystic changes, as well as signs of white matter loss and impaired brain growth and maturation, at or near term equivalent age. This novel assessment system aims to improve disease description in both routine clinical practice and clinical research. Whether this systematic assessment will improve prediction of outcome in preterm infants with WMI still needs to be evaluated in prospective studies.

Comparison of cranial ultrasound and MRI for detecting BRAIN injury in extremely preterm infants and correlation with neurological outcomes at 1 and 3 years

This study aimed to investigate the accuracy of different grades of brain injuries on serial and term equivalent age (TEA)-cranial ultrasound imaging (cUS) as compared to TEA magnetic resonance imaging (MRI) in extremely preterm infants < 28 weeks, and determine the predictive value of imaging abnormalities on neurodevelopmental outcome at 1 and 3 years. Seventy-five infants were included in the study. Severe TEA-cUS injury had high positive predictive value-PPV (100%) for predicting severe MRI injury compared to mild to moderate TEA-cUS injury or severe injury on worst cranial ultrasound scan. Absence of moderate to severe injury on TEA cUS or worst serial cUS was a good predictor of a normal MRI (negative predictive values > 93%). Severe grade 3 injuries on TEA-US had high predictive values in predicting abnormal neurodevelopment at both 1 and 3 years of age (PPV 100%). All grades of MRI and worst serial cUS injuries poorly predicted abnormal neurodevelopment at 1 and 3 years. Absence of an injury either on a cranial ultrasound or an MRI did not predict a normal outcome. Multiple logistic regression did not show a significant correlation between imaging injury and neurodevelopmental outcomes.Conclusion: This study demonstrates that TEA cUS can reliably identify severe brain abnormalities that would be seen on MRI imaging and positively predict abnormal neurodevelopment at both 1 and 3 years. Although MRI can pick up more subtle abnormalities that may be missed on cUS, their predictive value on neurodevelopmental impairment is poor. Normal cUS and MRI scan may not exclude abnormal neurodevelopment. Routine TEA-MRI scan provides limited benefit in predicting abnormal neurodevelopment in extremely preterm infants. What is Known: • Preterm neonates are at increased risk of white matter and other brain injuries, which may be associated with adverse neurodevelopmental outcome. • MRI is the most accurate method in detecting white matter injuries. What is New: • TEA-cUS can reliably detect severe brain injuries on MRI, but not mild/moderate lesions as well as abnormal neurodevelopment at 1 and 3 years. • TEA-MRI brain injury is poor in predicting abnormal neurodevelopment at 1 and 3 years and normal cUS or MRI brain injury may not guarantee normal neurodevelopment.

Features of serial cranial ultrasound detected neuropathology in very preterm infants

BACKGROUND

The purpose of this study was to identify the pattern and factors associated with changes in cranial ultrasound (CUS) -detected findings in infants born at or less than 28 weeks of gestation.

METHODS

We compared readings of CUS performed at the end of the first week of life and at 4-5 weeks of age. Alteration of CUS findings was classified as: (i) unchanged, if no deviation was detected (Group 1); (ii) worsening, if there were new findings (Group 2); and (iii) improvement, if there was normalization or reduction in severity (Group 3). Descriptive statistics, multivariate controlled logistic regression, and kappa (k) statistics with 95% Confidence Interval (95% CI) were reported.

RESULTS

Among 510 studied infants, 82.3% (95% CI 78.8-85.4) were in Group 1, 10.0% (95% CI 7.7-12.9) in Group 2, and 7.7% (95% CI 5.7-10.3) in Group 3. Overall agreement between the two scans was moderate (k 0.62; 95% CI 0.55-0.69). Worsening of CUS findings was associated with neonatal morbidities independently from gestational age and birth weight. The probability for worsening of CUS findings was higher in infants with an initial diagnosis of intraventricular hemorrhage (IVH) grade 2, than in those reported as no pathology/IVH grade 1 (Odds Ratio 5.79; 95% CI 2.42-13.91) or IVH grade 3-4 (Odds Ratio 3.81; 95% CI 1.10-13.21).

CONCLUSIONS

In very preterm born infants, the initial CUS findings in combination with neonatal morbidities can help predict the brain lesions that are seen at the end of the first month of life and could be useful in their clinical management.

Postnatal Brain Growth Assessed by Sequential Cranial Ultrasonography in Infants Born <30 Weeks' Gestational Age

BACKGROUND AND PURPOSE

Brain growth in the early postnatal period following preterm birth has not been well described. This study of infants born at <30 weeks' gestational age and without major brain injury aimed to accomplish the following: 1) assess the reproducibility of linear measures made from cranial ultrasonography, 2) evaluate brain growth using sequential cranial ultrasonography linear measures from birth to term-equivalent age, and 3) explore perinatal predictors of postnatal brain growth.

MATERIALS AND METHODS

Participants comprised 144 infants born at <30 weeks' gestational age at a single center between January 2011 and December 2013. Infants with major brain injury seen on cranial ultrasonography or congenital or chromosomal abnormalities were excluded. Brain tissue and fluid spaces were measured from cranial ultrasonography performed as part of routine clinical care. Brain growth was assessed in 3 time intervals: <7, 7-27, and >27 days' postnatal age. Data were analyzed using intraclass correlation coefficients and mixed-effects regression.

RESULTS

A total of 429 scans were assessed for 144 infants. Several linear measures showed excellent reproducibility. All measures of brain tissue increased with postnatal age, except for the biparietal diameter, which decreased within the first postnatal week and increased thereafter. Gestational age of ≥28 weeks at birth was associated with slower growth of the biparietal diameter and ventricular width compared with gestational age of <28 weeks. Postnatal corticosteroid administration was associated with slower growth of the corpus callosum length, transcerebellar diameter, and vermis height. Sepsis and necrotizing enterocolitis were associated with slower growth of the transcerebellar diameter.

CONCLUSIONS

Postnatal brain growth in infants born at <30 weeks' gestational age can be evaluated using sequential linear measures made from routine cranial ultrasonography and is associated with perinatal predictors of long-term development.

Periventricular/Intraventricular Hemorrhage and Neurodevelopmental Outcomes: A Meta-analysis

CONTEXT

Periventricular/intraventricular hemorrhage (PIVH) is a common short-term morbidity in preterm infants, but its long-term neurodevelopmental impact, particularly with mild PIVH, remains unclear.

OBJECTIVE

To systematically review and meta-analyze the neurodevelopmental outcomes of preterm infants ≤34 weeks' gestation with mild and severe PIVH, compared with no PIVH.

DATA SOURCES

Medline, Embase, CINAHL, and PsychINFO databases from January 2000 through June 2014.

STUDY SELECTION

Studies reporting long-term neurodevelopmental outcomes based on severity of PIVH were included.

DATA EXTRACTION

Study characteristics, inclusion/exclusion criteria, exposures, and outcome assessment data extracted independently by 2 coauthors.

RESULTS

The pooled unadjusted odds ratios of the primary outcome of death or moderate-severe neurodevelopmental impairment (NDI) were higher with both mild (1.48, 95% CI 1.26-1.73; 2 studies) and severe PIVH (4.72, 4.21-5.31; 3 studies); no studies reported adjusted odds ratios. Among survivors, odds of moderate-severe NDI were higher with mild and severe PIVH in both unadjusted (1.75, 1.40-2.20; 3 studies; 3.36, 3.06-3.68; 5 studies) and adjusted (1.39, 1.09-1.77; 3 studies; 2.44, 1.73-3.42; 2 studies) pooled analyses. Adjusted odds of cerebral palsy and cognitive delay were higher with severe but not mild PIVH.

LIMITATIONS

Only observational studies were included. Fifteen of 21 included studies had a moderate-high risk of bias.

CONCLUSIONS

Mild and severe PIVH are associated with progressively higher odds of death or moderate-severe NDI compared with no PIVH, but no studies adjusted for confounders. Among survivors, mild PIVH was associated with higher odds of moderate-severe NDI compared with no PIVH.

Anterior and posterior complexes: a step towards improving neurosonographic screening of midline and cortical anomalies

OBJECTIVE

To describe the anatomical structures that form the anterior (AC) and posterior (PC) complexes of the fetal brain and to categorize their anomalies in fetuses with cerebral abnormalities.

METHODS

We analyzed retrospectively volume datasets from 100 normal fetuses between 20 and 30 weeks' gestation. On the axial transventricular plane, our analysis of the AC included the interhemispheric fissure (IHF), the callosal sulcus (CS), the genu of the corpus callosum (CC), the cavum septi pellucidi (CSP) and the anterior horns (AH) of the lateral ventricles. The PC included the splenium of the CC, the medial wall of the lateral ventricles, the CS and the parieto-occipital fissure (POF). We then categorized AC/PC findings in 32 fetuses with agenesis of the septi pellucidi, schizencephaly, callosal dysgenesis, cortical malformation and hypoxic-ischemic brain injury.

RESULTS

The structures forming the AC and PC were visible in 100% and 92%, respectively, of normal cases. In the AC, the CSP was square-shaped in 73% of cases and it was triangular in 27%; the AH was comma-shaped in 92% of cases and triangular in the remainder. In the PC, the splenium of the CC interrupted and bridged the midline and was delimited posteriorly by the CS and the IHF. The POF was visible posteriorly. We categorized AC and PC abnormalities according to the main deviation from normality in their anatomical structures. The AC was abnormal in 30/32 cases and the PC was abnormal in 16/32 cases. In the two cases with normal AC, the PC was abnormal.

CONCLUSION

Normal appearance of AC and PC seems to be a strong indicator of fetal central nervous system normality. Morphological abnormalities in both complexes are robust markers of midline defects, but not exclusively so. The majority of fetuses with cortical malformations showed a defect in the AC.

Outcomes for extremely premature infants

Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for 7 years and is now approximately 11.39%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23 to 24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal estimated date of confinement. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (<1000 g) remain at high risk for death and disability with 30% to 50% mortality and, in survivors, at least 20% to 50% risk of morbidity. The introduction of continuous positive airway pressure, mechanical ventilation, and exogenous surfactant increased survival and spurred the development of neonatal intensive care in the 1970s through the early 1990s. Routine administration of antenatal steroids during premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91% and 95% (compared with 85%-89%) avoids excess mortality; however, final analyses of data from these trials have not been published, so definitive recommendations are still pending. The development of neonatal neurocritical intensive care units may improve neurocognitive outcomes in this high-risk group. Long-term follow-up to detect and address developmental, learning, behavioral, and social problems is critical for children born at these early gestational ages.The striking similarities in response to extreme prematurity in the lung and brain imply that agents and techniques that benefit one organ are likely to also benefit the other. Finally, because therapy and supportive care continue to change, the outcomes of extremely low birth weight infants are ever evolving. Efforts to minimize injury, preserve growth, and identify interventions focused on antioxidant and anti-inflammatory pathways are now being evaluated. Thus, treating and preventing long-term deficits must be developed in the context of a "moving target."

Prognosis of psychomotor and mental development in premature infants by early cranial ultrasound

Background

It is of high incidence of brain injuries in premature infants, so it is necessary to diagnose and treat the brain injury early for neonatal clinical practice. We are aimed to investigate the relationship between early postnatal cranial ultrasonography and psychomotor and mental development in prematrue infants at the age of 12 months.

Methods

Two-hundred and eight premature infants were selected and underwent follow-up from January, 2007 to November, 2012. Cranial ultrasonography was performed on them. The developmental outcomes of these premature infants at the age of 12 months were assessed by the psychomotor developmental index (PDI) scale and mental development index (MDI). The relationship between ultrasonic gray-scale value and PDI and MDI was analyzed.

Results

The worse prognosis for psychomotor and mental development was associated with the gestational age, Apgar score(1 min), gender, chorioamnionitis, duration of mechanical ventilation and duration of mechanic ventilation. The differences between the prognosis of psychomotor and mental development, and peri-intraventricular hemorrhage (PIVH) and periventricular white matter damage (PWMD), were statistically significant (P < 0.05). There were also significant differences between the early postnatal ultrasonic gray-scale value and prognoses of both psychomotor development and mental development (P < 0.05). There were negative correlations between ultrasonic gray-scale and both PDI and MDI (r = −0.753, P < 0.05; r = −0.764, P < 0.05).

Conclusions

The early postnatal cranial ultrasonography can assist to predict the prognosis of psychomotor and mental development for premature infants. The higher grade of PIVH and PWMD was associated with the worse prognosis of psychomotor and mental development.

Optimising nutrition to improve growth and reduce neurodisabilities in neonates at risk of neurological impairment, and children with suspected or confirmed cerebral palsy

Background

Neurological impairment is a common sequelae of perinatal brain injury. Plasticity of the developing brain is due to a rich substrate of developing neurones, synaptic elements and extracellular matrix. Interventions supporting this inherent capacity for plasticity may improve the developmental outcome of infants following brain injury. Nutritional supplementation with combination docosahexaenoic acid, uridine and choline has been shown to increase synaptic elements, dendritic density and neurotransmitter release in rodents, improving performance on cognitive tests. It remains elusive whether such specific ‘neurotrophic’ supplementation enhances brain plasticity and repair after perinatal brain injury.

Methods/Design

This is a two year double-blind, randomised placebo controlled study with two cohorts to investigate whether nutritional intervention with a neurotrophic dietary supplement improves growth and neurodevelopmental outcomes in neonates at significant risk of neurological impairment (the D1 cohort), and infants with suspected or confirmed cerebral palsy (the D2 cohort).

120 children will be randomised to receive dietetic and nutritional intervention, and either active supplement or placebo. Eligible D1 neonates are those born <30⁺⁶ weeks gestation with weight <9^th centile, ≤30⁺⁶ weeks gestation and Grade II, III or IV Intra-Ventricular Haemorrhage or periventricular white matter injury, or those born at 31-40⁺²⁸ weeks gestation, with Sarnat grade I or II or III Hypoxic Ischaemic Encephalopathy or neuroimaging changes compatible with perinatal brain injury. Eligible D2 infants are those aged 1-18 months with a suspected or confirmed clinical diagnosis of cerebral palsy. The primary outcome measure is composite cognitive score on the Bayley Scales of Infant and Toddler Development III at 24 months. Secondary outcomes include visuobehavioural and visual neurophysiological assessments, and growth parameters including weight, height, and head circumference.

Discussion

This is the first study to supplement neonates and infants with perinatal brain injury with the combination of factors required for healthy brain development, throughout the period of maximal brain growth. A further study strength is the comprehensive range of outcome measures employed. If beneficial, supplementation with brain phosphatide precursors could improve the quality of life of thousands of children with perinatal brain injury.

Trial registration

Current Controlled trials: ISRCTN39264076 (registration assigned 09/11/2012), ISRCTN15239951 (registration assigned 23/04/2010).

Comparing 3T T1-weighted sequences in identifying hyperintense punctate lesions in preterm neonates

BACKGROUND AND PURPOSE

The loss of contrast on T1-weighted MR images at 3T may affect the detection of hyperintense punctate lesions indicative of periventricular leukomalacia in preterm neonates. The aim of the present study was to determine which 3T T1-weighted sequence identified the highest number of hyperintense punctate lesions and to explore the relationship between the number of hyperintense punctate lesions and clinical outcome.

MATERIALS AND METHODS

The presence of hyperintense punctate lesions was retrospectively evaluated in 200 consecutive preterm neonates on 4 axial T1-weighted sequences: 3-mm inversion recovery and spin-echo and 1- and 3-mm reformatted 3D-fast-field echo. Statistically significant differences in the number of hyperintense punctate lesions were evaluated by using a linear mixed-model analysis. Logistic regression analysis was used to assess the relation between the number of hyperintense punctate lesions and neuromotor outcome at 3 months.

RESULTS

Thirty-one neonates had at least 1 hyperintense punctate lesion indicative of periventricular leukomalacia in at least 1 of the 4 sequences. The 1-mm axial reformatted 3D-fast-field echo sequence identified the greatest number of hyperintense punctate lesions (P < .001). No statistically significant differences were found among the 3-mm T1-weighted sequences. The greater number of hyperintense punctate lesions detected by the 1-mm reformatted T1 3D-fast-field echo sequence in the central region of the brain was associated with a worse clinical outcome.

CONCLUSIONS

At 3T, the 1-mm axial reformatted T1 3D-fast-field echo sequence identified the greatest number of hyperintense punctate lesions in the central region of preterm neonate brains, and this number was associated with neuromotor outcome.

Coagulase-negative staphylococcus sepsis in preterm infants and long-term neurodevelopmental outcome

OBJECTIVE

The objective of this study was to examine the impact of Coagulase-negative staphylococcus (CoNS) sepsis in preterm infants on the neurodevelopmental outcomes at 30 to 42 months corrected age (CA).

STUDY DESIGN

This is a retrospective cohort study. All preterm infants born at <29 weeks gestational age between 1995 and 2008 and had a neurodevelopmetnal assessment at 30 to 42 months CA were eligible. The neurodevelopmetnal outcomes of infants exposed to CoNS sepsis were compared with infants unexposed to any type of neonatal sepsis.

RESULT

A total of 105 eligible infants who were exposed to CoNS sepsis were compared with 227 infants with no neonatal sepsis. In univariate analysis, infants with CoNS sepsis were more likely to have total major disability (odds ratio (OR)=1.9; 95% CI: 1.07 to 3.38) and cognitive delay (OR=2.53; 1.26 to 5.14).There was no significant difference in the incidence of cerebral palsy, blindness and deafness between the two groups. After correcting for potential confounders, CoNS sepsis was associated with increased risk of cognitive delay (adjusted odds ratio (aOR)= 2.23; 95% CI 1.01 to 4.9), but not with the total major disability (aOR=1.14; 95% CI: 0.55 to 2.34).

CONCLUSION

Our study suggests that CoNS sepsis in preterm infants might be associated with increased risk for cognitive delay at 36 months CA.

Magnetic resonance diffusion tractography of the preterm infant brain: a systematic review

AIM

Preterm birth is associated with an increased risk of adverse neurodevelopmental outcomes. Diffusion magnetic resonance imaging (dMRI) combined with tractography can be used to assess non-invasively white matter microstructure and brain development in preterm infants. Our aim was to conduct a systematic review of the current evidence obtained from tractography studies of preterm infants in whom MRI was performed up to term-equivalent age.

METHOD

Databases were searched for dMRI tractography studies of preterm infants.

RESULTS

Twenty-two studies were assessed. The most frequently assessed tracts included the corticospinal tract, the corpus callosum, and the optic radiations. The superior longitudinal fasciculus, and the anterior and superior thalamic radiations were investigated less frequently. A clear relationship exists between diffusion metrics and postmenstrual age at the time of scanning, although the evidence of an effect of gestational age at birth and white matter injury is conflicting. Sex and laterality may play an important role in the relationship between diffusion metrics, early clinical assessment, and outcomes.

INTERPRETATION

Studies involving infants of all gestational ages are required to elucidate the relationship between gestational age and diffusion metrics, and to establish the utility of tractography as a predictive tool. There is a need for more robust acquisition and analysis methods to improve the accuracy of assessing development of white matter pathways.

Persistent periventricular echogenicities in preterms are not related to smaller brains at term-equivalent age

BACKGROUND

Periventricular white matter (PWM) is particularly vulnerable in very preterm infants. Non-cystic white matter injury, known as non-cystic periventricular leukomalacia (ncPVL), is the commonest 'lesion' affecting the preterm brain. There is no consensus about whether ncPVL can be reliably identified from cerebral ultrasound (cUS) or whether there is any reliable correlate of ncPVL on cUS at term-equivalent age (TEA).

OBJECTIVE

To compare brain volumes and linear measures at TEA in infants with and without a diagnosis of ncPVL.

METHODS

Preterm infants of ≤32 weeks' gestation without major lesions were serially assessed using cUS. ncPVL was defined as PWM echogenicity comparable to the choroid plexus on two scans at least 2 weeks apart after the first postnatal week. At TEA, infants were scanned for the estimation of brain volume and ventricular and tissue dimensions. Head circumference was measured. The data were compared between those with/without ncPVL. Observer agreement was assessed using kappa statistic.

RESULTS

Of 63 eligible infants 29% had ncPVL. Significant differences were found between those with/without ncPVL for 5 min Apgar score, CRIB score, invasive ventilation rates and chronic lung disease but not for other relevant clinical data. No significant differences were found for estimated brain volume, ventricular size, corpus callosum length/thickness or central grey matter width. Intra-observer reliability was moderate (kappa = 0.51-0.56); inter-observer reliability was poor (kappa = 0.20-0.32).

CONCLUSIONS

This study indicates that an ultrasound diagnosis of ncPVL should not be used as a sole predictor of lower brain growth detectable at TEA.

Systemic inflammation, intraventricular hemorrhage, and white matter injury

To see if the systemic inflammation profile of 123 infants born before the 28th week of gestation who had intraventricular hemorrhage without white matter injury differed from that of 68 peers who had both lesions, we compared both groups to 677 peers who had neither. Cranial ultrasound scans were read independently by multiple readers until concordance. The concentrations of 25 proteins were measured with multiplex arrays using an electrochemiluminescence system. Infants who had both hemorrhage and white matter injury were more likely than others to have elevated concentrations of C-reactive protein and interleukin 8 on days 1, 7, and 14, and elevated concentrations of serum amyloid A and tumor necrosis factor-α on 2 of these days. Intraventricular hemorrhage should probably be viewed as 2 entities: hemorrhage alone and hemorrhage with white matter injury. Each entity is associated with inflammation, but the combination has a stronger inflammatory signal than hemorrhage alone.

Accuracy of transcranial ultrasound in the detection of mild white matter lesions in newborns

Cranial Ultrasound (cUS) may not be sensitive enough to detect subtle white matter (WM) injuries. Our study compared serial cUS with MRI at term equivalent age (TEA) to determine if it is possible to identify an ultrasound representation of subtle diffuse WM injuries such as punctate lesions (PWMLs) and diffuse excessive high signal intensity (DEHSI). Fifty-six very preterm infants were scanned sequentially from birth to TEA, an MRI was performed at TEA. Each echodensity found on cUS was classified as absent, transient (≤7 days), or prolonged (>7 days). A transient periventricular echodensity was detected in seven infants (12.5%), and a prolonged echodensity in 15 (26.8%). MRI examinations were performed in all 56 infants. No altered signal intensity was found in 18 infants (32.1%). DEHSI was detected in 14 infants (25%), and PWMLs were detected in eight babies (14.3%). Both abnormalities were found in 16 infants (28.6%). The positive predictive values of the prolonged echodensity for DEHSI and PWMLs were 86.7% and 46.7% respectively. However, a significant statistical correspondence (p=0.002, Odds Ratio 11.9) was found comparing DEHSI with cUS abnormal echodensities. Serial cUS during the neonatal period in preterm infants is essential and cannot be replaced with MRI at TEA. MRI seems to be more reliable in detecting mild or moderate WM abnormalities. However, serial cUS performed by an experienced neonatologist can provide valuable information on early WM changes such as prolonged echodensities that could potentially lead to a diffuse injury.

Tractography of white-matter tracts in very preterm infants: a 2-year follow-up study

AIM

The aim of this study was to determine whether tractography of white-matter tracts can independently predict neurodevelopmental outcome in very preterm infants.

METHOD

Out of 84 very preterm infants admitted to a neonatal intensive care unit, 64 (41 males, 23 females; median gestational age 29.1 weeks [range 25.6-31.9]; birthweight 1163 g [range 585-1960]) underwent follow-up at 2 years. Diffusion tensor imaging (DTI) values obtained around term were associated with a neurological examination and mental and psychomotor developmental index scores at 2 years based on the Bayley Scales of Infant Development (version 3). Univariate and logistic regression analyses tested for associations between DTI values and follow-up parameters. Cut-off values predicting motor delay and cerebral palsy (CP) were determined for fractional anisotropy, apparent diffusion coefficient (ADC), and fibre lengths.

RESULTS

Infants with psychomotor delay and CP had significantly lower fractional anisotropy values (p=0.002, p=0.04 respectively) and shorter fibre lengths (p=0.02, p=0.02 respectively) of the posterior limb of the internal capsule. Infants with psychomotor delay also had significantly higher ADC values (p=0.03) and shorter fibre lengths (p=0.002) of the callosal splenium. Fractional anisotropy values of the posterior limb of the internal capsule independently predicted motor delay and CP, with sensitivity between 80 and 100% and specificity between 66 and 69%. ADC values of the splenium independently predicted motor delay with sensitivity of 100% and specificity of 65%.

INTERPRETATION

Diffusion tensor imaging tractography at term-equivalent age independently predicts psychomotor delay at 2 years of age in preterm infants.

Brain ultrasound findings in neonates treated with intrauterine transfusion for fetal anaemia

BACKGROUND

The main causes of severe fetal anaemia are red-cell allo-immunization, parvo B19 virus infection and feto-maternal haemorrhage. Treatment consists of intrauterine transfusion (IUT). Neuro-imaging studies in surviving neonates treated with IUT are scarce.

AIMS

To assess if neonates treated with IUT for fetal anaemia are at risk for cerebral injury, report the incidence and severity of brain ultrasound (US) abnormalities and explore the relation between brain US findings and perinatal parameters and neurological outcome.

PATIENTS AND METHODS

Brain US scans of neonates born alive between 2001 and 2008 with at least one IUT were retrospectively reviewed and classified as normal, mildly or moderately/severely abnormal. Incidences of abnormalities were calculated for full-term and preterm neonates. Presence and severity of abnormalities were related to clinical and IUT related parameters and to neurological outcome around 2 years of age (adverse: moderate or severe disability; favourable: normal or mild disability).

RESULTS

A total of 127 neonates (82 born preterm) were included. Median number of IUTs was 3 (range 1-6) and of brain US 2 (1-6). Median gestational age and weight at birth were 36.6 (26.0-41.1) weeks and 2870 (1040-3950)g. In 72/127 (57%) neonates ≥1 abnormality was seen on brain US, classified as moderate/severe in 30/127 (24%). Neurological outcome was adverse in 5 infants. Presence of brain US abnormalities was not significantly related to any of the perinatal parameters or to neurological outcome.

CONCLUSIONS

Neonates undergoing IUT for fetal anaemia are at high risk of brain injury.

Topography of maturational changes in EEG burst spectral power of the preterm infant with a normal follow-up at 2 years of age

OBJECTIVE

To quantify the electroencephalography (EEG) burst frequency spectrum of preterm infants by automated analysis and to describe the topography of maturational change in spectral parameters.

METHODS

Eighteen preterm infants <32weeks gestation and normal neurological follow-up at 2years underwent weekly 4-h EEG recordings (10-20 system). The recordings (n=77) represent a large variability in postmenstrual age (PMA, 28-36weeks). We applied an automated burst detection algorithm and performed spectral analysis. The frequency spectrum was divided into δ1 (0.5-1Hz), δ2 (1-4Hz), θ (4-8Hz), α (8-13Hz) and β (13-30Hz) bands. Spectral parameters were evaluated as a function of PMA by regression analysis. Results were interpolated and topographically visualised.

RESULTS

The majority of spectral parameters show significant change with PMA. Highest correlation is found for δ and θ band. Absolute band powers decrease with increasing PMA, while relative α and β powers increase. Maturational change is largest in frontal and temporal region.

CONCLUSIONS

Topographic distribution of maturational changes in spectral parameters corresponds with studies showing ongoing gyration and postnatal white matter maturation in frontal and temporal lobes.

SIGNIFICANCE

Computer analysis of EEG may allow objective and reproducible analysis for long-term prognosis and/or stratification of clinical treatment.

Feasibility of cerebral MRI in non-sedated preterm-born infants at term-equivalent age: report of a single centre

AIM

MRI is gaining in importance as an imaging tool for brain development and injury in preterm infants. The aim of this study was to evaluate the feasibility of performing MRI in non-sedated preterm-born infants at term-equivalent age (TEA).

METHODS

A total of 89 infants born before 32 gestational weeks were recruited. Infants were scanned without sedation. Duration of the entire examination including scan repetition and interruptions was registered.

RESULTS

Of the 89 infants, 56 (63%) underwent MRI at TEA. Out-patients required a significantly shorter total MR examination time than did in-patients (32 ± 12 vs. 54 ± 10 min, p < 0.01). Of the 56 infants, 39 (69.6%) were examined without interruption. Only four (7.2%) of the 56 scans were unusable because of motion artefacts. Mean duration of all scans was 36 ± 14 min. In cases with no interruptions, sessions were completed within 32 ± 12 min; MR sessions with interruption lasted 45 ± 13 min.

CONCLUSION

A well-trained team is indispensable in obtaining best-quality images as a prerequisite for good counselling. From our experience, we worked out a guideline to ensure that scans in stable non-sedated preterm-born infants at TEA run smoothly and provide high-quality images.

Neurocritical care for neonates

OPINION STATEMENT

Neurocritical care is an emerging subspecialty that combines expertise in neurology, critical care medicine, neuroradiology, and neurosurgery. Increasing evidence from the adult literature suggests that specialized neurocritical care can lead to improved outcomes following acute brain injury. Critically ill neonates with neurologic conditions may also benefit from specialized neurocritical care. Adherence to guidelines and managing patients in intensive care nurseries with dedicated, multidisciplinary neurocritical care personnel may optimize outcomes. This goal may be achieved by more quickly recognizing neurologic impairment, preventing secondary brain injury by maintaining basic physiologic functions, and rapidly implementing therapies. Nurseries that care for neonates with suspected acute brain injury should be prepared to adequately support multiorgan involvement, monitor the brain to detect seizures, evaluate for brain injury using MRI, and follow development through school age.

Ultrasound detection of white matter injury in very preterm neonates: practical implications

AIM

Diffuse white matter injury is not well detected by cranial ultrasonography (CUS). The aim of this study was twofold: (1) to assess in very preterm neonates the predictive values of individual CUS abnormalities for white matter injury on MRI and neurological outcome; (2) to develop a strategy optimizing CUS detection of white matter injury.

METHOD

Very preterm neonates (n=67; 44 males, 23 females) underwent serial CUS and single MRI. Predictive values of CUS findings for a white matter classification on MRI, individual MRI findings, and neurological outcome at 2 years corrected age were calculated. The effects of timing and frequency of CUS were evaluated.

RESULTS

Periventricular echodensities (PVEs) predicted abnormal white matter on MRI, but absence of PVEs did not predict absence of white matter changes. Peri- and intraventricular haemorrhage (P/IVH) was highly predictive of abnormal white matter on MRI. Frequency and timing of CUS did not influence predictive values. P/IVH and abnormal ventricular size/shape were reasonably predictive of unfavourable outcome, whereas absence of CUS abnormalities predicted a favorable outcome.

INTERPRETATION

(1) If PVEs are present, there is a significant chance of abnormal white matter on MRI. (2) Increasing frequency of CUS does not increase its diagnostic performance for white matter injury. (3) P/IVH is highly predictive of abnormal white matter on MRI and reasonably predictive of unfavourable outcome. (4) Absence of PVEs and P/IVH on CUS does not guarantee normal white matter, but predicts a favourable outcome.

High plasma cytokine levels, white matter injury and neurodevelopment of high risk preterm infants: assessment at two years

BACKGROUND

Controversy exists regarding association of high levels of proinflammatory cytokines, neonatal morbidities and poor neurodevelopment outcome in very low birth weight infants.

OBJECTIVE

To determine association between severity of early inflammatory response and neurodevelopment outcome in high risk very low birth weight infants.

METHODS

Sixty-two very preterm infants with high risk for early-onset sepsis were followed up to 24 months corrected age. Blood sample was collected for IL-6, IL-8, IL-10, IL-1β, and TNF-α analysis. Neurodevelopment outcome by Bayley Scales of Infant Development II was assessed at 22 to 24 months. Magnetic Resonance Image was performed at least once during the first 12 months.

RESULTS

In 24 (38.7%) MDI was <85, and 16 (25.8%) had PDI<85. Low birth weight was significantly associated with low MDI, and birth weight and periventricular leukomalacia were significantly associated with low PDI by multiple regression analysis. After controlling for birth weight and gestational age, none of the studied variables was associated with low MDI, and only periventricular leukomalacia with low PDI. Each additional 100g in the birth weight reduced the probability of low MDI and PDI scores in 14%.

CONCLUSIONS

There was no association of high cytokines plasma levels with poor neurodevelopment outcome at 22 to 24 months' corrected age, suggesting that elevations of plasma proinflammatory cytokines early in life do not play an important role in pathophysiology of brain injury in high risk preterm infants.

Microstructural and functional connectivity in the developing preterm brain

Prematurely born children are at increased risk for cognitive deficits, but the neurobiological basis of these findings remains poorly understood. Because variations in neural circuitry may influence performance on cognitive tasks, recent investigations have explored the impact of preterm birth on connectivity in the developing brain. Diffusion tensor imaging studies demonstrate widespread alterations in fractional anisotropy, a measure of axonal integrity and microstructural connectivity, throughout the developing preterm brain. Functional connectivity studies report that preterm neonates, children and adolescents exhibit alterations in both resting state and task-based connectivity when compared with term control subjects. Taken together, these data suggest that neurodevelopmental impairment following preterm birth may represent a disease of neural connectivity.

Tractography of developing white matter of the internal capsule and corpus callosum in very preterm infants

OBJECTIVES

To investigate in preterm infants associations between Diffusion Tensor Imaging (DTI) parameters of the posterior limb of the internal capsule (PLIC) and corpus callosum (CC) and age, white matter (WM) injury and clinical factors.

METHODS

In 84 preterm infants DTI was performed between 40-62 weeks postmenstrual age on 3 T MR. Fractional anisotropy (FA), apparent diffusion coefficient (ADC) values and fibre lengths through the PLIC and the genu and splenium were determined. WM injury was categorised as normal/mildly, moderately and severely abnormal. Associations between DTI parameters and age, WM injury and clinical factors were analysed.

RESULTS

A positive association existed between FA and age at imaging for fibres through the PLIC (r = 0.48 p < 0.001) and splenium (r = 0.24 p < 0.01). A negative association existed between ADC and age at imaging for fibres through the PLIC (r = -0.65 p < 0.001), splenium (r = -0.35 p < 0.001) and genu (r = -0.53 p < 0.001). No association was found between DTI parameters and gestational age, degree of WM injury or categorical clinical factors.

CONCLUSIONS

These results indicate that in our cohort of very preterm infants, at this young age, the development of the PLIC and CC is ongoing and independent of the degree of prematurity or WM injury.