Jeanie Cheong | University of Melbourne (original) (raw)
Papers by Jeanie Cheong
Seminars in Fetal and Neonatal Medicine, 2009
Perinatal arterial ischaemic stroke (PAIS) is increasingly recognised as an important cause of ne... more Perinatal arterial ischaemic stroke (PAIS) is increasingly recognised as an important cause of neurological morbidity in children. The aetiology remains unclear although perinatal risk factors have been identified from limited case series. Risk factors for PAIS in term infants are different from those in preterm infants. Maternal primiparity, infertility, cocaine use, prothrombotic disorders, prolonged rupture of membranes, abnormal cardiotocograph, instrumental deliveries and emergency caesarean sections are reported risk factors in term infants. Uncomplicated vaginal delivery and prelabour caesarean section are uncommon in cases of PAIS. The presence of multiple risk factors increases the odds of developing PAIS. For preterm babies, fetal heart abnormalities, twin-twin transfusion and hypoglycaemia are recognised risk factors. Larger cohort studies are required to elucidate further the multifactorial pathway to perinatal arterial stroke.
Journal of Pediatric Hematology/Oncology, 2007
Noonan syndrome (NS) is a multiple malformation syndrome where confirmation of diagnosis is diffi... more Noonan syndrome (NS) is a multiple malformation syndrome where confirmation of diagnosis is difficult in the newborn. We report a case of a dysmorphic neonate who presented with bilateral chylous effusions and juvenile myelomonocytic leukemia where NS was confirmed by the presence of PTPN11 mutation. Juvenile myelomonocytic leukemia in NS is uncommon. The leukemia is usually self-limiting but lethal cases have been reported. Decisions regarding need for the treatment are unclear and further understanding of the genotype-phenotype relationships in PTPN11 mutations may help direct this.
Archives of Disease in Childhood - Fetal and Neonatal Edition, 2004
Sixteen cases of postnatal cytomegalovirus (CMV) infection were identified in a neonatal intensiv... more Sixteen cases of postnatal cytomegalovirus (CMV) infection were identified in a neonatal intensive care unit population over a five year period. Eleven of these infants had gastrointestinal signs at the time of presentation. These ranged from minor and transient (abdominal distension and enteral feed intolerance) to severe and life threatening (protein losing enteropathy, diarrhoea, and hypernatraemic dehydration). An initial diagnosis of necrotising enterocolitis was common, but no infant showed intestinal or hepatic portal pneumatosis. The gestational age of the infants was 24-38 weeks. All had received fresh maternal breast milk. It is suggested that CMV enteritis is added to the spectrum of clinical manifestations of postnatal CMV infection. Signs suggestive of necrotising enterocolitis with atypical features should prompt investigations for CMV infection.
Human brain mapping, Jan 24, 2015
To determine: (1) whether corpus callosum (CC) size and microstructure at 7 years of age or their... more To determine: (1) whether corpus callosum (CC) size and microstructure at 7 years of age or their change from infancy to 7 years differed between very preterm (VP) and full-term (FT) children; (2) perinatal predictors of CC size and microstructure at 7 years; and (3) associations between CC measures at 7 years or trajectories from infancy to 7 years and neurodevelopmental outcomes. One hundred and thirty-six VP (gestational age [GA] <30 weeks and/or birth weight <1,250 g) and 33 FT children had usable magnetic resonance images at 7 years of age, and of these, 76 VP and 16 FT infants had usable data at term equivalent age. The CC was traced and divided into six sub-regions. Fractional anisotropy, mean, axial, radial diffusivity and volume were measured from tractography. Perinatal data were collected, and neurodevelopmental tests administered at 7 years' corrected age. VP children had smaller posterior CC regions, higher diffusivity and lower fractional anisotropy compared ...
Journal of Paediatrics and Child Health, 2015
Extremely preterm (EPT, born &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp... more Extremely preterm (EPT, born &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;28 weeks gestation) or extremely low birthweight (ELBW, birthweight &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1000 g) individuals are at increased risk of high blood pressure (BP) and cardiovascular disease. We compared office BP measurements with 24-h ambulatory BP measurement (ABP) in EPT/ELBW individuals at age 18 years and term controls, and determined the sensitivity and specificity of office BP in predicting masked hypertension (24-h ABP measurements &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 130/80). All EPT/ELBW individuals and matched term control adolescents born in Victoria, Australia, between 1991 and 1992 were recruited. A subset of this cohort was seen at 18 years, and researchers blinded to birth status measured office BP and ABP. We established the office BP thresholds that had the highest sensitivity and specificity in predicting masked hypertension. EPT/ELBW (N = 120) individuals had higher mean BP measurements at 18 years, compared with controls (N = 71). Although there were no significant differences in rates of high BP between groups, high proportions of both EPT/ELBW (43.3%) and term control (36.6%) participants met criteria for masked systolic hypertension. In EPT/ELBW individuals, office systolic BP measurement of ≥122.5 mmHg predicted masked systolic hypertension (sensitivity 79%, specificity 74%). Office diastolic BP measurement of ≥75.5 mmHg predicted masked diastolic hypertension (sensitivity 77%, specificity, 77%). At age 18 years, EPT/ELBW individuals have higher systolic and diastolic BP, compared with controls. Office BP may be an adequate screen for masked hypertension in EPT/ELBW survivors, but further research is needed to identify accurate ABP thresholds for masked hypertension for young Australians.
Imaging Decisions MRI, 2005
Magnetic resonance (MR) techniques have revolutionized the assessment of brain development and in... more Magnetic resonance (MR) techniques have revolutionized the assessment of brain development and injury in the newborn. MR studies at 3 T or above are becoming widespread; however, given the high cost and complexity of high-field MR systems, it is important to assess their benefits and limitations for clinical practice. MR spectroscopy (MRS) studies at high field carry potential benefits such as improved signal-to-noise ratio (SNR) and chemical shift dispersion compared with 1.5 T. However, safety is a very important consideration as radiofrequency (RF) tissue heating and acoustic noise also increase with field strength. Furthermore, increased chemical-shift dependence of the position of the volume of interest (VOI), shorter transverse and longer longitudinal relaxation times constitute additional challenges. We describe the first in-vivo, proton MRS studies of newborn human brain at 4.7 T. Nine infants with neonatal encephalopathy, all ventilated and with continuous physiological monitoring, were studied. We used L-FOCI localization, mostly with a VOI centred on the thalami. The absence of 4.7 T results from healthy infants made it impossible to interpret pathological metabolite peakarea ratios. However, concentration ratios and concentrations should be field-strength independent and interpretable using control values acquired at lower field. Of eight infants with concentration-ratio measurements, seven had low [N-acetylaspartate (NAA)]/[choline (Cho)] and three increased [lactate]/ [NAA]. Of the two infants with 'concentration' measurements both had low [NAA] and one reduced [creatine]. We used an adult coil and consequent RF power restrictions had repercussions for the minimum magnetization recovery time (TR). A smaller, neonatal coil should improve SNR and, with less RF power, relax TR constraints thereby enabling fuller exploitation of the potential of high-field MRS.
AJNR. American journal of neuroradiology, 2006
Results from cerebral proton (1)H-MR spectroscopy studies of neonates with perinatal hypoxic-isch... more Results from cerebral proton (1)H-MR spectroscopy studies of neonates with perinatal hypoxic-ischemic injury have generally been presented as metabolite peak-area ratios, which are T1- and T2-weighted, rather than absolute metabolite concentrations. We hypothesized that compared with (1)H-MR spectroscopy peak-area ratios, calculation of absolute metabolite concentrations and relaxation times measured within the first 4 days after birth (1) would improve prognostic accuracy and (2) enhance the understanding of underlying neurochemical changes in neonates with neonatal encephalopathy. Seventeen term infants with neonatal encephalopathy and 10 healthy controls were studied at 2.4T at 1 (1-3) and 2 (2-4) (median [interquartile range]) days after birth, respectively. Infants with neonatal encephalopathy were classified into 2 outcome groups (normal/mild and severe/fatal), according to neurodevelopmental assessments at 1 year. The MR spectroscopy peak-area ratios, relaxation times, absolu...
PEDIATRICS, 2015
on behalf of the Victorian Infant Collaborative Study Group abstract BACKGROUND AND OBJECTIVES: E... more on behalf of the Victorian Infant Collaborative Study Group abstract BACKGROUND AND OBJECTIVES: Extremely preterm (EP; ,28 weeks) birth and extremely low birth weight (ELBW; ,1000 g) are risk factors for poor cognitive outcomes, including in executive function (EF; higher-order cognitive skills necessary for goal-directed, adaptive functioning and important for academic and behavioral-emotional outcomes). We aimed to (1) extend the limited data on EF in EP/ELBW survivors in adolescence compared with normal birth weight controls, and (2) determine changes in EF between ages 8 and 17 years in both groups.
Pediatric Research, 2004
Background: The electroencephalogram (EEG) provides a sensitive means of predicting outcome early... more Background: The electroencephalogram (EEG) provides a sensitive means of predicting outcome early after perinatal hypoxia-ischaemia (HI). The amplitude integrated EEG (aEEG), a compressed, rectified and filtered form of 1-channel EEG, is increasingly used clinically ...
Seminars in perinatology, Jan 24, 2015
Very preterm children are at a high risk for neurodevelopmental impairments, but there is variabi... more Very preterm children are at a high risk for neurodevelopmental impairments, but there is variability in the pattern and severity of outcome. Neonatal magnetic resonance imaging (MRI) enhances the capacity to detect brain injury and altered brain development and assists in the prediction of high-risk children who warrant surveillance and early intervention. This review describes the application of conventional and advanced MRI with very preterm neonates, specifically focusing on the relationship between neonatal MRI findings and later neurodevelopmental outcome. Research demonstrates that conventional MRI is strongly associated with neurodevelopmental outcome in childhood. Further studies are needed to examine the role of advanced MRI techniques in predicting outcome in very preterm children, but early research findings are promising. In conclusion, neonatal MRI is predictive of later neurodevelopment but is dependent on appropriately trained specialists and should be interpreted in...
BMC Pediatrics, 2014
Background: Most babies are born healthy and grow and develop normally through childhood. There a... more Background: Most babies are born healthy and grow and develop normally through childhood. There are, however, clearly identifiable high-risk groups of survivors, such as those born preterm or with ill-health, who are destined to have higher than expected rates of health or developmental problems, and for whom more structured and specialised follow-up programs are warranted. Discussion: This paper presents the results of a two-day workshop held in Melbourne, Australia, to discuss neonatal populations in need of more structured follow-up and why, in addition to how, such a follow-up programme might be structured. Issues discussed included the ages of follow-up, and the personnel and assessment tools that might be required. Challenges for translating results into both clinical practice and research were identified. Further issues covered included information sharing, best practice for families and research gaps. Summary: A substantial minority of high-risk children has long-term medical, developmental and psychological adverse outcomes and will consume extensive health and education services as they grow older. Early intervention to prevent adverse outcomes and the effective integration of services once problems are identified may reduce the prevalence and severity of certain outcomes, and will contribute to an efficient and effective use of health resources. The shared long-term goal for families and professionals is to work toward ensuring that high risk children maximise their potential and become productive and valued members of society.
Seminars in Fetal and Neonatal Medicine, 2014
Given the improving survival rates of extremely preterm (EP, gestational age <28 weeks) infants, ... more Given the improving survival rates of extremely preterm (EP, gestational age <28 weeks) infants, there is a need to understand their general growth and health outcomes not only in childhood, but also into adulthood. EP children are shorter and lighter compared with term children at term-equivalent age; with time, the weight disadvantage diminishes but the height disadvantage remains relatively unchanged. EP children and young adults also have higher rates of reported health concerns, medical conditions and visual impairment. Hospital readmissions are higher in early childhood, mostly attributed to respiratory illness. Individuals born EP have reduced bone health and are at increased risk for metabolic disorders. Increased rates of conditions such as diabetes or pathological fractures are not reported in the literature, although follow-up studies so far have only tracked EP individuals into young adulthood. Consequently, health care utilization and costs are increased in EP children and young adults. A thorough knowledge of the health risks related to EP birth is essential in planning surveillance and intervention strategies to optimize their health and wellbeing. Despite the increased risk of health problems, EP young adults generally report their quality of life to be similar to that reported in their term counterparts.
PLoS ONE, 2013
Extremely preterm (EP) survivors have smaller brains, lower IQ, and worse educational achievement... more Extremely preterm (EP) survivors have smaller brains, lower IQ, and worse educational achievement than their term-born peers. The contribution of smaller brain size to the IQ and educational disadvantages of EP is unknown. This study aimed (i) to compare brain volumes from multiple brain tissues and structures between EP-born (<28weeks) and term-born (≥37weeks) control adolescents, (ii) to explore the relationships of brain tissue volumes with IQ and basic educational skills and whether this differed by group, and (iii) to explore how much total brain tissue volume explains the underperformance of EP adolescents compared with controls.
PLoS ONE, 2014
Adolescents born extremely preterm (EP; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;... more Adolescents born extremely preterm (EP; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;28 weeks&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; gestation) and/or extremely low birthweight (ELBW; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1000 g) experience high rates of visual impairments, however the potential neural correlates of visual impairments in EP/ELBW adolescents require further investigation. This study aimed to: 1) compare optic radiation and primary visual cortical structure between EP/ELBW adolescents and normal birthweight controls; 2) investigate associations between perinatal factors and optic radiation and primary visual cortical structure in EP/ELBW adolescents; 3) investigate associations between optic radiation and primary visual cortical structure in EP/ELBW adolescents and the odds of impaired vision. 196 EP/ELBW adolescents and 143 controls underwent magnetic resonance imaging at a mean age of 18 years. Optic radiations were delineated using constrained spherical deconvolution based probabilistic tractography. Primary visual cortices were segmented using FreeSurfer software. Diffusion tensor variables and tract volume of the optic radiations, as well as volume, surface area and thickness of the primary visual cortices, were estimated. Axial, radial and mean diffusivities within the optic radiations, and primary visual cortical thickness, were higher in the EP/ELBW adolescents than controls. Within EP/ELBW adolescents, postnatal corticosteroid exposure was associated with altered optic radiation diffusion values and lower tract volume, while decreasing gestational age at birth was associated with increased primary visual cortical volume, area and thickness. Furthermore, decreasing optic radiation fractional anisotropy and tract volume, and increasing optic radiation diffusivity in EP/ELBW adolescents were associated with increased odds of impaired vision, whereas primary visual cortical measures were not associated with the odds of impaired vision. Optic radiation and primary visual cortical structure are altered in EP/ELBW adolescents compared with controls, with the greatest alterations seen in those exposed to postnatal corticosteroids and those born earliest. Structural alterations to the optic radiations may increase the risk of impaired vision in EP/ELBW adolescents.
PLoS ONE, 2014
Background and Aim: High tidal volume (V T ) ventilation during resuscitation of preterm lambs re... more Background and Aim: High tidal volume (V T ) ventilation during resuscitation of preterm lambs results in brain injury evident histologically within hours after birth. We aimed to investigate whether magnetic resonance spectroscopy (MRS) and/or diffusion tensor imaging (DTI) can be used for early in vivo detection of ventilation-induced brain injury in preterm lambs.
PEDIATRICS, 2008
We examined the relationship between head growth and MRI and provide information about brain path... more We examined the relationship between head growth and MRI and provide information about brain pathology and cerebral structures that might contribute to poor head growth.
Pediatric Research, 2014
Background: Caffeine is widely used to treat apnea of prematurity, but the standard dosing regime... more Background: Caffeine is widely used to treat apnea of prematurity, but the standard dosing regimen is not always sufficient to prevent apnea. Before higher doses of caffeine can be used, their effects on the immature brain need to be carefully evaluated. Our aim was to determine the impact of daily highdose caffeine administration on the developing white matter of the immature ovine brain. Methods: High-dose caffeine (25 mg/kg caffeine base loading dose; 20 mg/kg daily maintenance dose; n = 9) or saline (n = 8) were administered to pregnant sheep from 0.7 to 0.8 of term, equivalent to approximately 27-34 wk in humans. At 0.8 of term, the white and gray matter were assessed histologically and immunohistochemically. results: Daily caffeine administration led to peak caffeine concentration of 32 mg/l in fetal plasma at 1 h, followed by a gradual decline, with no effects on mean arterial pressure and heart rate. Initial caffeine exposure led to transient, mild alkalosis in the fetus but did not alter oxygenation. At necropsy, there was no effect of daily high-dose caffeine on brain weight, oligodendrocyte density, myelination, axonal integrity, microgliosis, astrogliosis, apoptosis, or neuronal density. conclusion: Daily high-dose caffeine administration does not appear to adversely affect the developing white matter at the microstructural level.
Seminars in Fetal and Neonatal Medicine, 2009
Perinatal arterial ischaemic stroke (PAIS) is increasingly recognised as an important cause of ne... more Perinatal arterial ischaemic stroke (PAIS) is increasingly recognised as an important cause of neurological morbidity in children. The aetiology remains unclear although perinatal risk factors have been identified from limited case series. Risk factors for PAIS in term infants are different from those in preterm infants. Maternal primiparity, infertility, cocaine use, prothrombotic disorders, prolonged rupture of membranes, abnormal cardiotocograph, instrumental deliveries and emergency caesarean sections are reported risk factors in term infants. Uncomplicated vaginal delivery and prelabour caesarean section are uncommon in cases of PAIS. The presence of multiple risk factors increases the odds of developing PAIS. For preterm babies, fetal heart abnormalities, twin-twin transfusion and hypoglycaemia are recognised risk factors. Larger cohort studies are required to elucidate further the multifactorial pathway to perinatal arterial stroke.
Journal of Pediatric Hematology/Oncology, 2007
Noonan syndrome (NS) is a multiple malformation syndrome where confirmation of diagnosis is diffi... more Noonan syndrome (NS) is a multiple malformation syndrome where confirmation of diagnosis is difficult in the newborn. We report a case of a dysmorphic neonate who presented with bilateral chylous effusions and juvenile myelomonocytic leukemia where NS was confirmed by the presence of PTPN11 mutation. Juvenile myelomonocytic leukemia in NS is uncommon. The leukemia is usually self-limiting but lethal cases have been reported. Decisions regarding need for the treatment are unclear and further understanding of the genotype-phenotype relationships in PTPN11 mutations may help direct this.
Archives of Disease in Childhood - Fetal and Neonatal Edition, 2004
Sixteen cases of postnatal cytomegalovirus (CMV) infection were identified in a neonatal intensiv... more Sixteen cases of postnatal cytomegalovirus (CMV) infection were identified in a neonatal intensive care unit population over a five year period. Eleven of these infants had gastrointestinal signs at the time of presentation. These ranged from minor and transient (abdominal distension and enteral feed intolerance) to severe and life threatening (protein losing enteropathy, diarrhoea, and hypernatraemic dehydration). An initial diagnosis of necrotising enterocolitis was common, but no infant showed intestinal or hepatic portal pneumatosis. The gestational age of the infants was 24-38 weeks. All had received fresh maternal breast milk. It is suggested that CMV enteritis is added to the spectrum of clinical manifestations of postnatal CMV infection. Signs suggestive of necrotising enterocolitis with atypical features should prompt investigations for CMV infection.
Human brain mapping, Jan 24, 2015
To determine: (1) whether corpus callosum (CC) size and microstructure at 7 years of age or their... more To determine: (1) whether corpus callosum (CC) size and microstructure at 7 years of age or their change from infancy to 7 years differed between very preterm (VP) and full-term (FT) children; (2) perinatal predictors of CC size and microstructure at 7 years; and (3) associations between CC measures at 7 years or trajectories from infancy to 7 years and neurodevelopmental outcomes. One hundred and thirty-six VP (gestational age [GA] <30 weeks and/or birth weight <1,250 g) and 33 FT children had usable magnetic resonance images at 7 years of age, and of these, 76 VP and 16 FT infants had usable data at term equivalent age. The CC was traced and divided into six sub-regions. Fractional anisotropy, mean, axial, radial diffusivity and volume were measured from tractography. Perinatal data were collected, and neurodevelopmental tests administered at 7 years' corrected age. VP children had smaller posterior CC regions, higher diffusivity and lower fractional anisotropy compared ...
Journal of Paediatrics and Child Health, 2015
Extremely preterm (EPT, born &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp... more Extremely preterm (EPT, born &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;28 weeks gestation) or extremely low birthweight (ELBW, birthweight &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1000 g) individuals are at increased risk of high blood pressure (BP) and cardiovascular disease. We compared office BP measurements with 24-h ambulatory BP measurement (ABP) in EPT/ELBW individuals at age 18 years and term controls, and determined the sensitivity and specificity of office BP in predicting masked hypertension (24-h ABP measurements &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 130/80). All EPT/ELBW individuals and matched term control adolescents born in Victoria, Australia, between 1991 and 1992 were recruited. A subset of this cohort was seen at 18 years, and researchers blinded to birth status measured office BP and ABP. We established the office BP thresholds that had the highest sensitivity and specificity in predicting masked hypertension. EPT/ELBW (N = 120) individuals had higher mean BP measurements at 18 years, compared with controls (N = 71). Although there were no significant differences in rates of high BP between groups, high proportions of both EPT/ELBW (43.3%) and term control (36.6%) participants met criteria for masked systolic hypertension. In EPT/ELBW individuals, office systolic BP measurement of ≥122.5 mmHg predicted masked systolic hypertension (sensitivity 79%, specificity 74%). Office diastolic BP measurement of ≥75.5 mmHg predicted masked diastolic hypertension (sensitivity 77%, specificity, 77%). At age 18 years, EPT/ELBW individuals have higher systolic and diastolic BP, compared with controls. Office BP may be an adequate screen for masked hypertension in EPT/ELBW survivors, but further research is needed to identify accurate ABP thresholds for masked hypertension for young Australians.
Imaging Decisions MRI, 2005
Magnetic resonance (MR) techniques have revolutionized the assessment of brain development and in... more Magnetic resonance (MR) techniques have revolutionized the assessment of brain development and injury in the newborn. MR studies at 3 T or above are becoming widespread; however, given the high cost and complexity of high-field MR systems, it is important to assess their benefits and limitations for clinical practice. MR spectroscopy (MRS) studies at high field carry potential benefits such as improved signal-to-noise ratio (SNR) and chemical shift dispersion compared with 1.5 T. However, safety is a very important consideration as radiofrequency (RF) tissue heating and acoustic noise also increase with field strength. Furthermore, increased chemical-shift dependence of the position of the volume of interest (VOI), shorter transverse and longer longitudinal relaxation times constitute additional challenges. We describe the first in-vivo, proton MRS studies of newborn human brain at 4.7 T. Nine infants with neonatal encephalopathy, all ventilated and with continuous physiological monitoring, were studied. We used L-FOCI localization, mostly with a VOI centred on the thalami. The absence of 4.7 T results from healthy infants made it impossible to interpret pathological metabolite peakarea ratios. However, concentration ratios and concentrations should be field-strength independent and interpretable using control values acquired at lower field. Of eight infants with concentration-ratio measurements, seven had low [N-acetylaspartate (NAA)]/[choline (Cho)] and three increased [lactate]/ [NAA]. Of the two infants with 'concentration' measurements both had low [NAA] and one reduced [creatine]. We used an adult coil and consequent RF power restrictions had repercussions for the minimum magnetization recovery time (TR). A smaller, neonatal coil should improve SNR and, with less RF power, relax TR constraints thereby enabling fuller exploitation of the potential of high-field MRS.
AJNR. American journal of neuroradiology, 2006
Results from cerebral proton (1)H-MR spectroscopy studies of neonates with perinatal hypoxic-isch... more Results from cerebral proton (1)H-MR spectroscopy studies of neonates with perinatal hypoxic-ischemic injury have generally been presented as metabolite peak-area ratios, which are T1- and T2-weighted, rather than absolute metabolite concentrations. We hypothesized that compared with (1)H-MR spectroscopy peak-area ratios, calculation of absolute metabolite concentrations and relaxation times measured within the first 4 days after birth (1) would improve prognostic accuracy and (2) enhance the understanding of underlying neurochemical changes in neonates with neonatal encephalopathy. Seventeen term infants with neonatal encephalopathy and 10 healthy controls were studied at 2.4T at 1 (1-3) and 2 (2-4) (median [interquartile range]) days after birth, respectively. Infants with neonatal encephalopathy were classified into 2 outcome groups (normal/mild and severe/fatal), according to neurodevelopmental assessments at 1 year. The MR spectroscopy peak-area ratios, relaxation times, absolu...
PEDIATRICS, 2015
on behalf of the Victorian Infant Collaborative Study Group abstract BACKGROUND AND OBJECTIVES: E... more on behalf of the Victorian Infant Collaborative Study Group abstract BACKGROUND AND OBJECTIVES: Extremely preterm (EP; ,28 weeks) birth and extremely low birth weight (ELBW; ,1000 g) are risk factors for poor cognitive outcomes, including in executive function (EF; higher-order cognitive skills necessary for goal-directed, adaptive functioning and important for academic and behavioral-emotional outcomes). We aimed to (1) extend the limited data on EF in EP/ELBW survivors in adolescence compared with normal birth weight controls, and (2) determine changes in EF between ages 8 and 17 years in both groups.
Pediatric Research, 2004
Background: The electroencephalogram (EEG) provides a sensitive means of predicting outcome early... more Background: The electroencephalogram (EEG) provides a sensitive means of predicting outcome early after perinatal hypoxia-ischaemia (HI). The amplitude integrated EEG (aEEG), a compressed, rectified and filtered form of 1-channel EEG, is increasingly used clinically ...
Seminars in perinatology, Jan 24, 2015
Very preterm children are at a high risk for neurodevelopmental impairments, but there is variabi... more Very preterm children are at a high risk for neurodevelopmental impairments, but there is variability in the pattern and severity of outcome. Neonatal magnetic resonance imaging (MRI) enhances the capacity to detect brain injury and altered brain development and assists in the prediction of high-risk children who warrant surveillance and early intervention. This review describes the application of conventional and advanced MRI with very preterm neonates, specifically focusing on the relationship between neonatal MRI findings and later neurodevelopmental outcome. Research demonstrates that conventional MRI is strongly associated with neurodevelopmental outcome in childhood. Further studies are needed to examine the role of advanced MRI techniques in predicting outcome in very preterm children, but early research findings are promising. In conclusion, neonatal MRI is predictive of later neurodevelopment but is dependent on appropriately trained specialists and should be interpreted in...
BMC Pediatrics, 2014
Background: Most babies are born healthy and grow and develop normally through childhood. There a... more Background: Most babies are born healthy and grow and develop normally through childhood. There are, however, clearly identifiable high-risk groups of survivors, such as those born preterm or with ill-health, who are destined to have higher than expected rates of health or developmental problems, and for whom more structured and specialised follow-up programs are warranted. Discussion: This paper presents the results of a two-day workshop held in Melbourne, Australia, to discuss neonatal populations in need of more structured follow-up and why, in addition to how, such a follow-up programme might be structured. Issues discussed included the ages of follow-up, and the personnel and assessment tools that might be required. Challenges for translating results into both clinical practice and research were identified. Further issues covered included information sharing, best practice for families and research gaps. Summary: A substantial minority of high-risk children has long-term medical, developmental and psychological adverse outcomes and will consume extensive health and education services as they grow older. Early intervention to prevent adverse outcomes and the effective integration of services once problems are identified may reduce the prevalence and severity of certain outcomes, and will contribute to an efficient and effective use of health resources. The shared long-term goal for families and professionals is to work toward ensuring that high risk children maximise their potential and become productive and valued members of society.
Seminars in Fetal and Neonatal Medicine, 2014
Given the improving survival rates of extremely preterm (EP, gestational age <28 weeks) infants, ... more Given the improving survival rates of extremely preterm (EP, gestational age <28 weeks) infants, there is a need to understand their general growth and health outcomes not only in childhood, but also into adulthood. EP children are shorter and lighter compared with term children at term-equivalent age; with time, the weight disadvantage diminishes but the height disadvantage remains relatively unchanged. EP children and young adults also have higher rates of reported health concerns, medical conditions and visual impairment. Hospital readmissions are higher in early childhood, mostly attributed to respiratory illness. Individuals born EP have reduced bone health and are at increased risk for metabolic disorders. Increased rates of conditions such as diabetes or pathological fractures are not reported in the literature, although follow-up studies so far have only tracked EP individuals into young adulthood. Consequently, health care utilization and costs are increased in EP children and young adults. A thorough knowledge of the health risks related to EP birth is essential in planning surveillance and intervention strategies to optimize their health and wellbeing. Despite the increased risk of health problems, EP young adults generally report their quality of life to be similar to that reported in their term counterparts.
PLoS ONE, 2013
Extremely preterm (EP) survivors have smaller brains, lower IQ, and worse educational achievement... more Extremely preterm (EP) survivors have smaller brains, lower IQ, and worse educational achievement than their term-born peers. The contribution of smaller brain size to the IQ and educational disadvantages of EP is unknown. This study aimed (i) to compare brain volumes from multiple brain tissues and structures between EP-born (<28weeks) and term-born (≥37weeks) control adolescents, (ii) to explore the relationships of brain tissue volumes with IQ and basic educational skills and whether this differed by group, and (iii) to explore how much total brain tissue volume explains the underperformance of EP adolescents compared with controls.
PLoS ONE, 2014
Adolescents born extremely preterm (EP; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;... more Adolescents born extremely preterm (EP; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;28 weeks&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; gestation) and/or extremely low birthweight (ELBW; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1000 g) experience high rates of visual impairments, however the potential neural correlates of visual impairments in EP/ELBW adolescents require further investigation. This study aimed to: 1) compare optic radiation and primary visual cortical structure between EP/ELBW adolescents and normal birthweight controls; 2) investigate associations between perinatal factors and optic radiation and primary visual cortical structure in EP/ELBW adolescents; 3) investigate associations between optic radiation and primary visual cortical structure in EP/ELBW adolescents and the odds of impaired vision. 196 EP/ELBW adolescents and 143 controls underwent magnetic resonance imaging at a mean age of 18 years. Optic radiations were delineated using constrained spherical deconvolution based probabilistic tractography. Primary visual cortices were segmented using FreeSurfer software. Diffusion tensor variables and tract volume of the optic radiations, as well as volume, surface area and thickness of the primary visual cortices, were estimated. Axial, radial and mean diffusivities within the optic radiations, and primary visual cortical thickness, were higher in the EP/ELBW adolescents than controls. Within EP/ELBW adolescents, postnatal corticosteroid exposure was associated with altered optic radiation diffusion values and lower tract volume, while decreasing gestational age at birth was associated with increased primary visual cortical volume, area and thickness. Furthermore, decreasing optic radiation fractional anisotropy and tract volume, and increasing optic radiation diffusivity in EP/ELBW adolescents were associated with increased odds of impaired vision, whereas primary visual cortical measures were not associated with the odds of impaired vision. Optic radiation and primary visual cortical structure are altered in EP/ELBW adolescents compared with controls, with the greatest alterations seen in those exposed to postnatal corticosteroids and those born earliest. Structural alterations to the optic radiations may increase the risk of impaired vision in EP/ELBW adolescents.
PLoS ONE, 2014
Background and Aim: High tidal volume (V T ) ventilation during resuscitation of preterm lambs re... more Background and Aim: High tidal volume (V T ) ventilation during resuscitation of preterm lambs results in brain injury evident histologically within hours after birth. We aimed to investigate whether magnetic resonance spectroscopy (MRS) and/or diffusion tensor imaging (DTI) can be used for early in vivo detection of ventilation-induced brain injury in preterm lambs.
PEDIATRICS, 2008
We examined the relationship between head growth and MRI and provide information about brain path... more We examined the relationship between head growth and MRI and provide information about brain pathology and cerebral structures that might contribute to poor head growth.
Pediatric Research, 2014
Background: Caffeine is widely used to treat apnea of prematurity, but the standard dosing regime... more Background: Caffeine is widely used to treat apnea of prematurity, but the standard dosing regimen is not always sufficient to prevent apnea. Before higher doses of caffeine can be used, their effects on the immature brain need to be carefully evaluated. Our aim was to determine the impact of daily highdose caffeine administration on the developing white matter of the immature ovine brain. Methods: High-dose caffeine (25 mg/kg caffeine base loading dose; 20 mg/kg daily maintenance dose; n = 9) or saline (n = 8) were administered to pregnant sheep from 0.7 to 0.8 of term, equivalent to approximately 27-34 wk in humans. At 0.8 of term, the white and gray matter were assessed histologically and immunohistochemically. results: Daily caffeine administration led to peak caffeine concentration of 32 mg/l in fetal plasma at 1 h, followed by a gradual decline, with no effects on mean arterial pressure and heart rate. Initial caffeine exposure led to transient, mild alkalosis in the fetus but did not alter oxygenation. At necropsy, there was no effect of daily high-dose caffeine on brain weight, oligodendrocyte density, myelination, axonal integrity, microgliosis, astrogliosis, apoptosis, or neuronal density. conclusion: Daily high-dose caffeine administration does not appear to adversely affect the developing white matter at the microstructural level.