EFFECTS OF A MULTICOMPONENT LIPID EMULSION ON BRAIN VOLUMES IN EXTREMELY LOW BIRTH WEIGHT INFANTS

Objective During the early weeks of life optimization of nutrition in extremely preterm infants presents a critical opportunity to attenuate the adverse neurologic consequences of prematurity and potentially improve neurodevelopmental outcome. We hypothesized that the use of multicomponent lipid emulsion (MLE) in PN would be related to larger volume of the cerebellum on brain magnetic resonance at term of equivalent age (TEA) in extremely low birthweight (ELBW) infants. Study Design We analyzed the brain Magnetic Resonance Imaging (MRI) at TEA of a cohort of preterm infants with gestational age (GA) ≤28 weeks and/or birthweight (BW) <1000 grams randomly assigned in our previous trial to receive a Multicomponent lipid emulsion (MLE) or Soybean-based lipid emulsion (SLE). The primary outcome of the study was the cerebellar volume (CeV) valued on MRI acquired at TEA. Secondary outcomes included total brain volume (TBV), Supratentorial Volume (SuV), Brainstem Volume (BsV) and Cerebellar volume corrected for TBV evaluated on MRI acquired at TEA. Results MRIs at TEA of 34 infants were then analyzed: 17 in the MLE group and17 in the SLE group. The postmenstrual age (PMA) at which MRIs were performed were comparable between the two study groups. The CeV, as well as the PMA-corrected CeV, were significantly higher in the MLE group than in the SLE group. No difference was found among the other brain volumes considered. Conclusion Our results suggest that the use of MLE in PN could promote CeV growth in ELBW infants, valued with MRI at TEA.

Fetal MRI of the heart and brain in congenital heart disease

Antenatal assessment of congenital heart disease and associated anomalies by ultrasound has improved perinatal care. Fetal cardiovascular MRI and fetal brain MRI are rapidly evolving for fetal diagnostic testing of congenital heart disease. We give an overview on the use of fetal cardiovascular MRI and fetal brain MRI in congenital heart disease, focusing on the current applications and diagnostic yield of structural and functional imaging during pregnancy. Fetal cardiovascular MRI in congenital heart disease is a promising supplementary imaging method to echocardiography for the diagnosis of antenatal congenital heart disease in weeks 30-40 of pregnancy. Concomitant fetal brain MRI is superior to brain ultrasound to show the complex relationship between fetal haemodynamics in congenital heart disease and brain development.

A Uniform Description of Perioperative Brain MRI Findings in Infants with Severe Congenital Heart Disease: Results of a European Collaboration

BACKGROUND AND PURPOSE

A uniform description of brain MR imaging findings in infants with severe congenital heart disease to assess risk factors, predict outcome, and compare centers is lacking. Our objective was to uniformly describe the spectrum of perioperative brain MR imaging findings in infants with congenital heart disease.

MATERIALS AND METHODS

Prospective observational studies were performed at 3 European centers between 2009 and 2019. Brain MR imaging was performed preoperatively and/or postoperatively in infants with transposition of the great arteries, single-ventricle physiology, or left ventricular outflow tract obstruction undergoing cardiac surgery within the first 6 weeks of life. Brain injury was assessed on T1, T2, DWI, SWI, and MRV. A subsample of images was assessed jointly to reach a consensus.

RESULTS

A total of 348 MR imaging scans (180 preoperatively, 168 postoperatively, 146 pre- and postoperatively) were obtained in 202 infants. Preoperative, new postoperative, and cumulative postoperative white matter injury was identified in 25%, 30%, and 36%; arterial ischemic stroke, in 6%, 10%, and 14%; hypoxic-ischemic watershed injury in 2%, 1%, and 1%; intraparenchymal cerebral hemorrhage, in 0%, 4%, and 5%; cerebellar hemorrhage, in 6%, 2%, and 6%; intraventricular hemorrhage, in 14%, 6%, and 13%; subdural hemorrhage, in 29%, 17%, and 29%; and cerebral sinovenous thrombosis, in 0%, 10%, and 10%, respectively.

CONCLUSIONS

A broad spectrum of perioperative brain MR imaging findings was found in infants with severe congenital heart disease. We propose an MR imaging protocol including T1-, T2-, diffusion-, and susceptibility-weighted imaging, and MRV to identify ischemic, hemorrhagic, and thrombotic lesions observed in this patient group.

Introduction of Ultra-High-Field MR Imaging in Infants: Preparations and Feasibility

BACKGROUND AND PURPOSE

Cerebral MR imaging in infants is usually performed with a field strength of up to 3T. In adults, a growing number of studies have shown added diagnostic value of 7T MR imaging. 7T MR imaging might be of additional value in infants with unexplained seizures, for example. The aim of this study was to investigate the feasibility of 7T MR imaging in infants. We provide information about the safety preparations and show the first MR images of infants at 7T.

MATERIALS AND METHODS

Specific absorption rate levels during 7T were simulated in Sim4life using infant and adult models. A newly developed acoustic hood was used to guarantee hearing protection. Acoustic noise damping of this hood was measured and compared with the 3T Nordell hood and no hood. In this prospective pilot study, clinically stable infants, between term-equivalent age and the corrected age of 3 months, underwent 7T MR imaging immediately after their standard 3T MR imaging. The 7T scan protocols were developed and optimized while scanning this cohort.

RESULTS

Global and peak specific absorption rate levels in the infant model in the centered position and 50-mm feet direction did not exceed the levels in the adult model. Hearing protection was guaranteed with the new hood. Twelve infants were scanned. No MR imaging-related adverse events occurred. It was feasible to obtain good-quality imaging at 7T for MRA, MRV, SWI, single-shot T2WI, and MR spectroscopy. T1WI had lower quality at 7T.

CONCLUSIONS

7T MR imaging is feasible in infants, and good-quality scans could be obtained.

Morphine affects brain activity and volumes in preterms: An observational multi-center study

OBJECTIVE

We hypothesized that morphine has a depressing effect on early brain activity, assessed using quantitative aEEG/EEG parameter and depressed activity will be associated with brain volumes at term in extremely preterm infants.

STUDY DESIGN

174 preterm infants were enrolled in 3 European tertiary NICUs (mean GA:26 ± 1wks) and monitored during the first 72 h after birth with continuous 2 channel aEEG. Six epochs of aEEG recordings were selected and minimum amplitude of aEEG (min aEEG), percentage of time amplitude <5 μV (% of time < 5 μV), spontaneous activity transients (SATrate) and interSAT interval (ISI) were calculated. For infants receiving morphine, the cumulative morphine dosage was calculated. In a subgroup of 58 infants, good quality MRI at term equivalent age (TEA) and the cumulative morphine dose until TEA were available. The effects of morphine administration and cumulative dose on aEEG/EEG measures and on brain volumes were investigated.

RESULTS

Morphine administration had a significant effect on all quantitative aEEG/EEG measures, causing depression of early brain activity [longer ISI (β 2.900), reduced SAT rate (β -1.386), decreased min aEEG (β -0.782), and increased % of time < 5 μV (β 14.802)] in all epochs. A significant effect of GA and postnatal age on aEEG/EEG measures was observed. Cumulative morphine dose until TEA had a significant negative effect on total brain volume (TBV) (β -8.066) and cerebellar volume (β -1.080).

CONCLUSIONS

Administration of sedative drugs should be considered when interpreting aEEG/EEG together with the negative dose dependent morphine impact on brain development.

Automatic extraction of the intracranial volume in fetal and neonatal MR scans using convolutional neural networks

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Automatic intracranial volume segmentation.

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Fetal and neonatal MRI.

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Deep learning.

MR images of infants and fetuses allow non-invasive analysis of the brain. Quantitative analysis of brain development requires automatic brain tissue segmentation that is typically preceded by segmentation of the intracranial volume (ICV). Fast changes in the size and morphology of the developing brain, motion artifacts, and large variation in the field of view make ICV segmentation a challenging task.

We propose an automatic method for segmentation of the ICV in fetal and neonatal MRI scans. The method was developed and tested with a diverse set of scans regarding image acquisition parameters (i.e. field strength, image acquisition plane, image resolution), infant age (23–45 weeks post menstrual age), and pathology (posthaemorrhagic ventricular dilatation, stroke, asphyxia, and Down syndrome). The results demonstrate that the method achieves accurate segmentation with a Dice coefficient (DC) ranging from 0.98 to 0.99 in neonatal and fetal scans regardless of image acquisition parameters or patient characteristics. Hence, the algorithm provides a generic tool for segmentation of the ICV that may be used as a preprocessing step for brain tissue segmentation in fetal and neonatal brain MR scans.

Brain and CSF Volumes in Fetuses and Neonates with Antenatal Diagnosis of Critical Congenital Heart Disease: A Longitudinal MRI Study

BACKGROUND AND PURPOSE

Fetuses and neonates with critical congenital heart disease are at risk of delayed brain development and neurodevelopmental impairments. Our aim was to investigate the association between fetal and neonatal brain volumes and neonatal brain injury in a longitudinally scanned cohort with an antenatal diagnosis of critical congenital heart disease and to relate fetal and neonatal brain volumes to postmenstrual age and type of congenital heart disease.

MATERIALS AND METHODS

This was a prospective, longitudinal study including 61 neonates with critical congenital heart disease undergoing surgery with cardiopulmonary bypass <30 days after birth and MR imaging of the brain; antenatally (33 weeks postmenstrual age), neonatal preoperatively (first week), and postoperatively (7 days postoperatively). Twenty-six had 3 MR imaging scans; 61 had at least 1 fetal and/or neonatal MR imaging scan. Volumes (cubic centimeters) were calculated for total brain volume, unmyelinated white matter, cortical gray matter, cerebellum, extracerebral CSF, and ventricular CSF. MR images were reviewed for ischemic brain injury.

RESULTS

Total fetal brain volume, cortical gray matter, and unmyelinated white matter positively correlated with preoperative neonatal total brain volume, cortical gray matter, and unmyelinated white matter (r = 0.5-0.58); fetal ventricular CSF and extracerebral CSF correlated with neonatal ventricular CSF and extracerebral CSF (r = 0.64 and 0.82). Fetal cortical gray matter, unmyelinated white matter, and the cerebellum were negatively correlated with neonatal ischemic injury (r = -0.46 to -0.41); fetal extracerebral CSF and ventricular CSF were positively correlated with neonatal ischemic injury (r = 0.40 and 0.23). Unmyelinated white matter:total brain volume ratio decreased with increasing postmenstrual age, with a parallel increase of cortical gray matter:total brain volume and cerebellum:total brain volume. Fetal ventricular CSF:intracranial volume and extracerebral CSF:intracranial volume ratios decreased with increasing postmenstrual age; however, neonatal ventricular CSF:intracranial volume and extracerebral CSF:intracranial volume ratios increased with postmenstrual age.

CONCLUSIONS

This study reveals that fetal brain volumes relate to neonatal brain volumes in critical congenital heart disease, with a negative correlation between fetal brain volumes and neonatal ischemic injury. Fetal brain imaging has the potential to provide early neurologic biomarkers.

Neonatal stroke: a review of the current evidence on epidemiology, pathogenesis, diagnostics and therapeutic options

Neonatal stroke, including perinatal arterial ischaemic stroke and cerebral sinovenous thrombosis, remains a serious problem in the neonate. This article reviews the current evidence on epidemiology, pathogenesis, diagnostics and therapeutic options.

CONCLUSION

Although our understanding of the underlying mechanisms and possible risk factors has improved, little progress has been made towards therapeutic options. Considering the high incidence of neurological sequelae, the need for therapeutic options is high and should be the focus of future research.

Impact of neonate haematocrit variability on the longitudinal relaxation time of blood: Implications for arterial spin labelling MRI

BACKGROUND AND PURPOSE

The longitudinal relaxation time of blood (T 1b) is influenced by haematocrit (Hct) which is known to vary in neonates. The purpose of this study was threefold: to obtain T 1b values in neonates, to investigate how the T 1b influences quantitative arterial spin labelling (ASL), and to evaluate if known relationships between T 1b and haematocrit (Hct) hold true when Hct is measured by means of a point-of-care device.

MATERIALS AND METHODS

One hundred and four neonates with 120 MR scan sessions (3 T) were included. The T 1b was obtained from a T 1 inversion recovery sequence. T 1b-induced changes in ASL cerebral blood flow estimates were evaluated. The Hct was obtained by means of a point-of-care device. Linear regression analysis was used to investigate the relation between Hct and MRI-derived R1 of blood (the inverse of the T 1b).

RESULTS

Mean T 1b was 1.85 s (sd 0.2 s). The mean T 1b in preterm neonates was 1.77 s, 1.89 s in preterm neonates scanned at term-equivalent age (TEA) and 1.81 s in diseased neonates. The T 1b in the TEA was significantly different from the T 1b in the preterm (p < 0.05). The change in perfusion induced by the T 1b was -11% (sd 9.1%, p < 0.001). The relation between arterial-drawn Hct and R1b was R1b = 0.80 × Hct + 0.22, which falls within the confidence interval of the previously established relationships, whereas capillary-drawn Hct did not correlate with R1b.

CONCLUSION

We demonstrated a wide variability of the T 1b in neonates and the implications it could have in methods relying on the actual T 1b as for instance ASL. It was concluded that arterial-drawn Hct values obtained from a point-of-care device can be used to infer the T 1b whereas our data did not support the use of capillary-drawn Hct for T 1b correction.

Rapid target allopurinol concentrations in the hypoxic fetus after maternal administration during labour

OBJECTIVE

Perinatal hypoxia-induced free radical formation is an important cause of hypoxic-ischaemic encephalopathy and subsequent neurodevelopmental disabilities. Allopurinol reduces the formation of free radicals, which potentially limits hypoxia-induced brain damage. We investigated placental transfer and safety of allopurinol after maternal allopurinol treatment during labour to evaluate its potential role as a neuroprotective agent in suspected fetal hypoxia.

DESIGN

We used data from a randomised, double-blind multicentre trial comparing maternal allopurinol versus placebo in case of imminent fetal hypoxia (NCT00189007).

PATIENTS

We studied 58 women in labour at term, with suspected fetal hypoxia prompting immediate delivery, in the intervention arm of the study.

SETTING

Delivery rooms of 11 Dutch hospitals.

INTERVENTION

500 mg allopurinol, intravenously to the mother, immediately prior to delivery.

MAIN OUTCOME MEASURES

Drug disposition (maternal plasma concentrations, cord blood concentrations) and drug safety (maternal and fetal adverse events).

RESULTS

Within 5 min after the end of maternal allopurinol infusion, target plasma concentrations of allopurinol of ≥2 mg/L were present in cord blood. Of all analysed cord blood samples, 95% (52/55) had a target allopurinol plasma concentration at the moment of delivery. No adverse events were observed in the neonates. Two mothers had a red and/or painful arm during infusion.

CONCLUSIONS

A dose of 500 mg intravenous allopurinol rapidly crosses the placenta and provides target concentrations in 95% of the fetuses at the moment of delivery, which makes it potentially useful as a neuroprotective agent in perinatology with very little side effects.

TRIAL REGISTRATION

The study is registered in the Dutch Trial Register (NTR1383) and the Clinical Trials protocol registration system (NCT00189007).

Brain tissue volumes in preterm infants: prematurity, perinatal risk factors and neurodevelopmental outcome: a systematic review

OBJECTIVE

To evaluate the clinical value of neonatal brain tissue segmentation in preterm infants according to the literature.

METHODS

A structured literature search was undertaken in MEDLINE/Pubmed. This included all publications on volumetric brain tissue assessment in preterm infants at term-equivalent age (TEA) compared to brain tissue volumes of term-born infants, related to perinatal risk factors or related to neurodevelopmental outcome.

RESULTS

Sixteen prospective cohort studies, described in 30 articles, fulfilled the criteria. Preterm infants displayed total and regional brain tissue alterations compared to healthy, term-born controls. These alterations seemed more prominent with decreasing gestational age. White matter injury, intraventricular haemorrhage, postnatal corticosteroid therapy, intra-uterine growth retardation and chronic lung disease were frequently associated with volume changes. Associations between volume alterations at TEA and neurodevelopmental outcome in early childhood were shown in a few studies.

CONCLUSIONS

Preterm birth is associated with brain tissue volume alterations that become more pronounced in the presence of perinatal risk factors and white matter injury. Moreover, associations between volumetric alterations as early as TEA and long-term neurodevelopmental impairments are scarce.

European perspective on the diagnosis and treatment of posthaemorrhagic ventricular dilatation

BACKGROUND

Posthaemorrhagic ventricular dilatation (PHVD) is a serious complication of prematurity with subsequent disabilities. The diagnostic and therapeutic approaches to PHVD vary among neonatal centres.

AIM

To gain more insight into the different diagnostic criteria and treatment policies on PHVD among neonatal intensive care units across Europe. Methods A PHVD questionnaire was designed and sent to neonatologists in 37 European centres.

RESULTS

A response was obtained from 32/37 (86%) centres located in 17 European countries. An overall estimated incidence of 7% was reported for severe intraventricular haemorrhages (grades III or IV according to Papile) among premature neonates born below 30 weeks' gestation. Approximately half of these infants developed PHVD, of whom three-quarters required intervention. Ultrasound measurements of ventricular size were most commonly used to diagnose PHVD (94%). No consensus existed on which ventricular parameters needed to be enlarged and when to start treatment of PHVD. Early intervention (ie, initiated after the ventricular index (VI) exceeded the 97th percentile (p97) according to Levene) was provided in 8/32 centres (25%), whereas 23/32 centres (72%) first started therapy once the VI had crossed the p97+4 mm line and/or when neonates presented with a progressive increase in head circumference or with clinical symptoms of raised intracranial pressure. Wide variation was seen with respect to the applied therapy modalities for cerebrospinal fluid drainage.

CONCLUSION

This survey shows that diagnostic and therapeutic approaches to neonates with PHVD vary considerably. Uniform diagnostic criteria would facilitate studies to assess optimal timing and mode of intervention.

Cardiac biomarkers as indicators of hemodynamic adaptation during postasphyxial hypothermia treatment

BACKGROUND

Little is known about the effects of hypothermia on the cardiovascular system in term newborns with neonatal encephalopathy.

OBJECTIVES

To evaluate whether mild hypothermia for neonatal encephalopathy is cardioprotective as indicated by the cardiac biomarkers cardiac troponin I (cTnI) and B-type natriuretic peptide (BNP).

METHODS

This was an observational cohort study of infants treated for perinatal asphyxia. In infants, mild total body hypothermia treatment of 33.5°C during 72 h was initiated (n = 20). Samples of cTnI and BNP were collected before the start of hypothermia, at 24 and 48 h after birth, and after rewarming (84 h). BNP and cTnI values were then compared with BNP and cTnI values of asphyxiated infants not treated with hypothermia (n = 28).

RESULTS

No differences were found between the groups in clinical patient characteristics or inotropic support. The hypothermia-treated patients seemed to be clinically more affected (5-min Apgar score, p < 0.05; umbilical artery pH, p = 0.08), but showed similar encephalopathy scores. Significantly lower values for BNP were found in hypothermia- compared to nonhypothermia-treated infants at 48 h and at normothermia after rewarming [144 pmol/l (95-286) vs. 75 pmol/l (45-143), 182 pmol/l (73-341) vs. 43 pmol/l (24-163)]. No differences were found for cTnI concentrations between both groups.

CONCLUSIONS

The raised, but similar, cTnI values between hypothermia- and nonhypothermia-treated infants indicate similar myocardial damage in both groups. The lower BNP levels during hypothermia treatment suggest that hypothermia after perinatal asphyxia exerts a beneficial effect on cardiac function.

Quantitative fiber tracking in the corpus callosum and internal capsule reveals microstructural abnormalities in preterm infants at term-equivalent age

BACKGROUND AND PURPOSE

Signal-intensity abnormalities in the PLIC and thinning of the CC are often seen in preterm infants and associated with poor outcome. DTI is able to detect subtle abnormalities. We used FT to select bundles of interest (CC and PLIC) to acquire additional information on the WMI.

MATERIALS AND METHODS

One hundred twenty preterm infants born at <31 weeks' gestation with 3T DTI at TEA entered this prospective study. Quantitative information (ie, volume, length, anisotropy, and MD) was obtained from fiber bundles passing through the PLIC and CC. A general linear model was used to assess the effects of factor (sex) and variables (GA, BW, HC, PMA, and WMI) on FT-segmented parameters.

RESULTS

Seventy-two CC and 85 PLIC fiber bundles were assessed. For the CC, increasing WMI and decreasing FA (P = .038), bundle volume (P < .001), and length (P = .001) were observed, whereas MD increased (P = .001). For PLIC, MD increased with increasing WMI (P = .002). Higher anisotropy and larger bundle length were observed in the left PLIC compared with the right (P = .003, P = .018).

CONCLUSIONS

We have shown that in the CC bundle, anisotropy was decreased and diffusivity was increased in infants with high WMI scores. A relation of PLIC with WMI was also shown but was less pronounced. Brain maturation is affected more if birth was more premature.

The spectrum of associated brain lesions in cerebral sinovenous thrombosis: relation to gestational age and outcome

OBJECTIVE

To describe different patterns of associated brain lesions in preterm and full-term infants with cerebral sinovenous thrombosis (CSVT) and to assess whether these different patterns are related to gestational age at onset.

DESIGN

Magnetic resonance scans of all neonates (six preterm, 24 full term) with suspected CSVT, collected over a 7-year period in two neonatal intensive care units, were evaluated to assess patterns of associated brain lesions. Comparisons between the two gestational age groups were made.

RESULTS

CSVT was confirmed on magnetic resonance venography in 26 of 30 neonates (six preterm, 20≥36 weeks' gestational age). The straight (85%) and superior sagittal (65%) sinus were most often affected. Several sinuses were involved in 81% of infants. White matter damage affecting the entire periventricular white matter was seen in five of six preterm infants. Intraventricular haemorrhage (IVH) was common in both groups (4/6 preterm, 16/20 full term). Frontal punctate white matter lesions with restricted diffusion (15/20) and thalamic haemorrhage associated with IVH (11/20) were the most frequent lesions in full-term infants. Focal arterial infarction was present in four of 20 full-term infants. Six infants died in the neonatal period (four preterm, two full term). Follow-up MRIs at 3 months in all survivors showed evolution of the lesions with frontal atrophy in 13 of 20 (12 full term) and delayed myelination in seven of 20 (six full term).

CONCLUSIONS

Preterm and full-term neonates show different patterns of associated brain lesions. Extensive white matter damage is the predominant pattern of injury in the preterm infant, while an IVH associated with a thalamic haemorrhage and punctate white matter lesions are more common in the full-term infant.

Neonatal tract-based spatial statistics findings and outcome in preterm infants

BACKGROUND AND PURPOSE

WM injury is associated with different disabilities that children born prematurely may experience during their lives. The aim of this study was to use TBSS to test the hypothesis that WM microstructure at TEA in preterm infants is correlated with cognitive and motor outcome at 2-year corrected age.

MATERIALS AND METHODS

Sixty-three preterm infants, born at a mean gestational age of 28.7 weeks, underwent MR imaging and DTI at TEA. Neurodevelopmental performance was assessed by using the BSITD-III. Voxelwise analysis of the DTI data was performed by using TBSS to assess the relationship among FA, AD, and RD at TEA, and cognitive, fine-motor, and gross-motor scores at 2-year corrected age.

RESULTS

Cognitive scores were correlated with FA values in the CC. Fine-motor scores were correlated with FA and RD throughout the WM. Gross-motor scores were associated with RD in the CC, fornix, and internal and external capsule.

CONCLUSIONS

WM microstructure in preterm infants at TEA was associated with cognitive, fine-motor, and gross-motor performance at 2-year corrected age. This study suggests that TBSS of DTI data at TEA has the potential to be used as a biomarker for subsequent neurodevelopment.

Anatomy of the circle of Willis and blood flow in the brain-feeding vasculature in prematurely born infants

BACKGROUND

Previous studies have shown a disrupted development of cerebral blood vessels at term-equivalent age in prematurely born infants.

OBJECTIVE

To assess the anatomy of the circle of Willis in preterm neonates (gestational age 25-31 weeks) at term-equivalent age and to evaluate the relation between anatomic variations and blood flow through the internal carotid arteries (ICAs) and basilar artery (BA).

METHODS

In 72 preterm neonates, flow measurements (ml/min) were obtained with 2-D phase-contrast magnetic resonance angiography (MRA) at term-equivalent age. Time-of-flight MRA was used to assess the circle of Willis for a dominant A1 segment of the anterior cerebral artery or a fetal-type posterior cerebral artery. Differences in flow were assessed with ANOVA.

RESULTS

In our cohort, 53/72 (74%) neonates showed a variant type of the circle of Willis. The flow in the ICA at the side of a dominant A1 segment (43.3 ml/min) was significantly increased compared to the flow in the contralateral ICA (33.0 ml/min; p = 0.009) and tended to be higher than in the ICA in children with a normal anterior anatomy (38.4 ml/min; p = 0.1). The flow in the BA was highest in neonates with a normal configuration of the posterior part of the circle of Willis (32.6 ml/min) compared to children with a unilateral (25.3 ml/min; p = 0.002) or bilateral fetal-type posterior cerebral artery (18.6 ml/min; p < 0.001).

CONCLUSION

Preterm neonates show a high prevalence of variant types of the circle of Willis at term-equivalent age. A relation could be demonstrated between variations in the circle of Willis and the flow in the ICA and BA.

Preterm arterial ischemic stroke

Most studies about perinatal arterial ischemic stroke (PAIS) exclude preterm infants. In a prospectively studied hospital-based population, 42% of our 73 newborn infants with PAIS had a gestational age (GA) < or =36 weeks. PAIS was present on the left in 61% of the preterm infants and bilateral in 7%. The middle cerebral artery (MCA) was most often affected. Involvement of the lenticulostriate branches was common among preterm infants with GA of 28-32 weeks, and involvement of the MCA main branch was seen in almost all with a GA>33 weeks. Twin-to-twin transfusion syndrome, fetal heart rate abnormality and hypoglycemia were independent risk factors. No maternal risk factors could be identified. Comparing neurodevelopmental outcome, infants with a main branch MCA infarct, irrespective of being preterm or full-term, were found to be most at risk of motor/cognitive impairment. Preterm infants with PAIS had more language problems at 2 years of age.

Primary cortical folding in the human newborn: an early marker of later functional development

In the human brain, the morphology of cortical gyri and sulci is complex and variable among individuals, and it may reflect pathological functioning with specific abnormalities observed in certain developmental and neuropsychiatric disorders. Since cortical folding occurs early during brain development, these structural abnormalities might be present long before the appearance of functional symptoms. So far, the precise mechanisms responsible for such alteration in the convolution pattern during intra-uterine or post-natal development are still poorly understood. Here we compared anatomical and functional brain development in vivo among 45 premature newborns who experienced different intra-uterine environments: 22 normal singletons, 12 twins and 11 newborns with intrauterine growth restriction (IUGR). Using magnetic resonance imaging (MRI) and dedicated post-processing tools, we investigated early disturbances in cortical formation at birth, over the developmental period critical for the emergence of convolutions (26-36 weeks of gestational age), and defined early 'endophenotypes' of sulcal development. We demonstrated that twins have a delayed but harmonious maturation, with reduced surface and sulcation index compared to singletons, whereas the gyrification of IUGR newborns is discordant to the normal developmental trajectory, with a more pronounced reduction of surface in relation to the sulcation index compared to normal newborns. Furthermore, we showed that these structural measurements of the brain at birth are predictors of infants' outcome at term equivalent age, for MRI-based cerebral volumes and neurobehavioural development evaluated with the assessment of preterm infant's behaviour (APIB).

Mapping the early cortical folding process in the preterm newborn brain

In the developing human brain, the cortical sulci formation is a complex process starting from 14 weeks of gestation onward. The potential influence of underlying mechanisms (genetic, epigenetic, mechanical or environmental) is still poorly understood, because reliable quantification in vivo of the early folding is lacking. In this study, we investigate the sulcal emergence noninvasively in 35 preterm newborns, by applying dedicated postprocessing tools to magnetic resonance images acquired shortly after birth over a developmental period critical for the human cortex maturation (26-36 weeks of age). Through the original three-dimensional reconstruction of the interface between developing cortex and white matter and correlation with volumetric measurements, we document early sulcation in vivo, and quantify changes with age, gender, and the presence of small white matter lesions. We observe a trend towards lower cortical surface, smaller cortex, and white matter volumes, but equivalent sulcation in females compared with males. By precisely mapping the sulci, we highlight interindividual variability in time appearance and interhemispherical asymmetries, with a larger right superior temporal sulcus than the left. Thus, such an approach, included in a longitudinal follow-up, may provide early indicators on the structural basis of cortical functional specialization and abnormalities induced by genetic and environmental factors.

Early postnatal allopurinol does not improve short term outcome after severe birth asphyxia

OBJECTIVE

To investigate whether postnatal allopurinol would reduce free radical induced reperfusion/reoxygenation injury of the brain in severely asphyxiated neonates.

METHOD

In an interim analysis of a randomised, double blind, placebo controlled study, 32 severely asphyxiated infants were given allopurinol or a vehicle within four hours of birth.

RESULTS

The analysis showed an unaltered (high) mortality and morbidity in the infants treated with allopurinol.

CONCLUSION

Allopurinol treatment started postnatally was too late to reduce the early reperfusion induced free radical surge. Allopurinol administration to the fetus with (imminent) hypoxia via the mother during labour may be more effective in reducing free radical induced post-asphyxial brain damage.