Ultrasonographic features and severity scoring of periventricular hemorrhagic infarction in relation to risk factors and outcome

Magnetic resonance imaging and tractography of sensorimotor tracts in fetuses with intraventricular hemorrhage: feasibility and added prognostic value

OBJECTIVES

To assess the feasibility, characteristics and prognostic value of prenatal visualization of the corticospinal tracts (CSTs) using diffusion-weighted magnetic resonance imaging (MRI)-based tractography in fetuses with intraventricular hemorrhage (IVH).

METHODS

This was a retrospective single-center cohort study of singleton fetuses diagnosed with IVH on MRI from January 2011 to December 2018. The left and right CSTs were reconstructed according to an in-utero diffusion tensor imaging sequence using a multi-region of interest (ROI) deterministic tractography approach. The CSTs were segmented by two polygonal ROI: at the level of the posterior limb of the internal capsule and the crus cerebri. The morphology and integrity of the CSTs were assessed visually. Internal capsule and crus cerebri apparent diffusion coefficient and fractional anisotropy values were measured. Postnatal motor function data were obtained from the parents using the functional status scale.

RESULTS

A total of 35 fetuses with IVH (mean ± SD gestational age, 29.1 ± 5.1 (range, 19.9-38.9) weeks) were included in the analysis. Parenchymal involvement on T2-weighted sequences was demonstrated in 19 (54%) of the cohort. CST involvement correlated significantly with the presence of parenchymal damage on T2-weighted imaging (P = 0.02). Among liveborn cases, the rate of motor impairment was 14% (1/7) in children with intact CSTs compared with 100% (5/5) in cases in which the CSTs were impaired (P = 0.015).

CONCLUSIONS

Fetal corticospinal tractography is feasible technically and offers valuable prognostic information. It enhances parental counseling by providing insights into potential motor outcome, underscoring its utility in complementing fetal neurosonography in cases of prenatal IVH. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Risk factors associated with intraventricular hemorrhage in very-low-birth-weight premature infants

PURPOSE

To analyze the association between risk factors and severe intraventricular hemorrhage (grade II-IV) in PNB under 1500 g.

METHODS

Multicenter, retrospective, analytical, case-control study in PNB under 34 weeks and under 1500 g admitted to the NICU.

CASE

PNB with severe intraventricular hemorrhage (grade II-IV). Logistic regression analysis was used to adjust for IVH-associated variables and odds ratios (OR).

RESULTS

A total of 90 PNB files were analyzed, 45 cases and 45 controls. The highest risk factors for severe IVH were lower gestational age (OR 1.3, p < 0.001), perinatal asphyxia (OR 12, p < 0.001), Apgar < 6 at minute 1 and 5 (OR 6.3, p < 0.001).

CONCLUSION

Lower gestational age, birth asphyxia, Apgar score lower of 6, and respiratory-type factors are associated with increased risk for severe IVH.

Optimizing trajectories of social adaptive competencies after extreme prematurity during the first 1000 days

Over 75% of surviving extremely preterm infants do not have major neurodevelopmental disabilities; however, more than half face difficulties with communication, coordination, attention, learning, social, and executive function abilities. These "minor" challenges can have a negative impact on educational and social outcomes, resulting in physical, behavioral, and social health problems in adulthood. We will review assessment tools for social-emotional and adaptive functional skills in early childhood as these determine family and early childhood supports. We highlight bronchopulmonary dysplasia as an example of the critical intersections of parental wellbeing, medical and developmental adaptive trajectories in infancy and early childhood, and partnerships between child neurologists and community medical and developmental professionals. We examine studies of engaging parents to promote developmental trajectories, with a focus on supporting parent-child interactions that underlie communication, social-adaptive behaviors, and learning in the first 1000 days of life. Recommendations for neurodevelopmental surveillance and screening of extremely preterm infants can also be applied to infants with other risk factors for altered neurodevelopment.

Periventricular hemorrhagic infarction in preterm neonates: Etiology and time of development

BACKGROUND

To find the obstetrical and delivery associated risk factors of antenatal and postnatal grade III intraventricular hemorrhage (IVH) or periventricular hemorrhagic infarction (PVHI) in preterm neonates.

METHODS

A retrospective study of obstetric and delivery associated risk factors included neonates (<35 gestational weeks) with severe IVH/PVHI (n = 120) and a prospectively collected control group (n = 50). The children were divided into: (1) antenatal onset group (n = 27) with insult visible on cerebral ultrasonography within the first 12 hours of birth or periventricular cystic changes visible in PVHI within the first 3 days; (2) neonatal onset group (n = 70) with insult diagnosed after initial normal findings or I-II grade IVH, and (3) unknown time-onset group (n = 23) with insult visible at > 12 h of age.

RESULTS

The mothers of the antenatal onset group had significantly more bacterial infections before delivery compared to the neonatal onset group: 20/27 (74.1%) versus 23/69 (33.3%), (odds ratio (OR) 5.7 [95% confidence interval 2.1-16]; p = 0.0008) or compared to the control group (11/50 (22%); OR 11 [2.8-42]; p = 0.0005). Placental histology revealed chorioamnionitis more often in the antenatal compared to the neonatal onset group (14/21 (66.7%) versus 16/42 (38.1%), respectively; OR 3.7 [1.18-11]; p = 0.025). Neonates with neonatal development of severe IVH/PVHI had significantly more complications during delivery or intensive care.

CONCLUSIONS

Bacterial infection during pregnancy is an important risk factor for development of antenatal onset severe IVH or PVHI. In neonates born to mothers with severe bacterial infection during pregnancy, cerebral ultrasonography is indicated for early detection of severe IVH or PVHI.

Trends in Outcomes of Major Intracerebral Haemorrhage in a National Cohort of Very Preterm Born Infants in Switzerland

BACKGROUND

Major brain lesions, such as grade 3 intraventricular haemorrhage (G3-IVH) and periventricular haemorrhagic infarction (PVHI) are among the main predictors for poor neurodevelopment in preterm infants. In the last decades advancements in neonatal care have led to a general decrease in adverse outcomes.

AIM

To assess trends of mortality and neurodevelopmental impairment (NDI) in a recent Swiss cohort of very preterm infants with grade 3 intraventricular haemorrhage (G3-IVH) and periventricular haemorrhagic infarction (PVHI).

METHODS

In this retrospective population-based cohort study, rates of mortality, and NDI at 2 years corrected age were reported in infants born at 24-29 weeks gestational age (GA) in Switzerland in 2002-2014, with G3-IVH and/or PVHI.

RESULTS

Out of 4956 eligible infants, 462 (9%) developed G3-IVH (n = 172) or PVHI (n = 290). The average mortality rates for the two pathologies were 33% (56/172) and 60% (175/290), respectively. In 2002-2014, no change in rates of mortality (G3-IVH, p = 0.845; PVHI, p = 0.386) or NDI in survivors (G3-IVH, p = 0.756; PVHI, p = 0.588) were observed, while mean GA decreased (G3-IVH, p = 0.020; PVHI, p = 0.004). Multivariable regression analysis showed a strong association of G3-IVH and PVHI for both mortality and NDI. Death occurred after withdrawal of care in 81% of cases.

CONCLUSION

In 2002-2014, rates of mortality and NDI in very preterm born infants with major brain lesions did not change. The significant decrease in mean GA and changing hospital policies over this time span may factor into the interpretation of these results.

Decision-making for extremely preterm infants with severe hemorrhages on head ultrasound: Science, values, and communication skills

Severe intracranial hemorrhages are not rare in extremely preterm infants. They occur early, generally when babies require life-sustaining interventions. This may lead to ethical discussions and decision-making about levels of care. Prognosis is variable and depends on the extent, location, and laterality of the lesions, and, importantly also on the subsequent occurrence of other clinical complications or progressive ventricular dilatation. Decision-making should depend on prognosis and parental values. This article will review prognosis and the uncertainty of outcomes for different lesions and provide an outline of ways to conduct an ethically appropriate discussion on the decision of whether to continue life sustaining therapy. It is possible to communicate in a compassionate and honest way with parents and engage in decision-making, focussing on personalized information and decisions, and on function, as opposed to diagnosis.

High Prevalence of Collagenopathies in Preterm- and Term-Born Children With Periventricular Venous Hemorrhagic Infarction

INTRODUCTION

The aim of this study was to evaluate genetic risk factors in term-born children with antenatal periventricular hemorrhagic infarction (PVHI), presumed antenatal periventricular venous infarction and periventricular hemorrhagic infarction in preterm neonates.

METHODS

Genetic analysis and magnetic resonance imaging were performed in 85 children: term-born children (≥36 gestational weeks) with antenatal periventricular hemorrhagic infarction (n = 6) or presumed antenatal (n = 40) periventricular venous infarction and preterm children (<36 gestational weeks) with periventricular hemorrhagic infarction (n = 39). Genetic testing was performed using exome or large gene panel (n = 6700 genes) sequencing.

RESULTS

Pathogenic variants associated with stroke were found in 11 of 85 (12.9%) children with periventricular hemorrhagic infarction/periventricular venous infarction. Among the pathogenic variants, COL4A1/A2 and COL5A1 variants were found in 7 of 11 (63%) children. Additionally, 2 children had pathogenic variants associated with coagulopathy, whereas 2 other children had other variants associated with stroke. Children with collagenopathies had significantly more often bilateral multifocal stroke with severe white matter loss and diffuse hyperintensities in the white matter, moderate to severe hydrocephalus, moderate to severe decrease in size of the ipsilesional basal ganglia and thalamus compared to children with periventricular hemorrhagic infarction/periventricular venous infarction without genetic changes in the studied genes (P ≤ .01). Severe motor deficit and epilepsy developed more often in children with collagenopathies compared to children without genetic variants (P = .0013, odds ratio [OR] = 233, 95% confidence interval [CI]: 2.8-531; and P = .025, OR = 7.3, 95% CI: 1.3-41, respectively).

CONCLUSIONS

Children with periventricular hemorrhagic infarction/periventricular venous infarction have high prevalence of pathogenic variants in collagene genes (COL4A1/A2 and COL5A1). Genetic testing should be considered for all children with periventricular hemorrhagic infarction/periventricular venous infarction; COL4A1/A2 and COL5A1/A2 genes should be investigated first.

Neurodevelopmental Outcome at Two Years for Preterm Infants With Intraventricular Hemorrhage: A Case-Control Study

BACKGROUND

High-grade intraventricular hemorrhage (IVH), including grade III and grade IV IVH, is known to impact neurodevelopmental outcome of preterm infants, but prognosis remains difficult to establish due to confounding factors and significant variations in the reported outcomes. The aim of this study was to compare the neurodevelopmental outcome of preterm infants with or without severe IVH.

METHODS

A retrospective case-control study was conducted including preterm infants with gestational age <32 weeks hospitalized between 2009 and 2017 in a level III neonatal intensive care unit. This study included 73 cases with high-grade IVH and 73 controls who were matched to cases, based on the same gestational age, birth weight, sex, and year of birth. The neurodevelopmental outcome was compared at two years of age corrected for prematurity between cases and controls. Neurodevelopmental impairment was defined as cerebral palsy, hearing deficiency, visual impairment, or developmental delay. Multivariate analysis was used to identify whether high-grade IVH was an independent risk factor for neurodevelopmental impairment.

RESULTS

In univariate analysis, high-grade IVH was associated with death or poor neurodevelopmental outcome at two years of age corrected for prematurity (odds ratio [OR], 16.3; 95% confidence interval [CI], 5.93 to 57.8; P < 0.001), and this association remained significant after adjusting for confounding factors including neonatal infection and bronchopulmonary dysplasia in multivariate analysis (OR, 8.71; 95% CI, 2.48 to 38.09; P = 0.002).

CONCLUSIONS

This study highlights the impact of high-grade IVH as an independent risk factor of poor neurodevelopmental outcomes in very preterm infants and suggests that early interventions could improve the prognosis of these infants.

Grading of Intraventricular Hemorrhage and Neurodevelopment in Preterm <29 Weeks’ GA in Canada

Objective: The aim of this study was to evaluate the neurodevelopmental outcome at 18−24 months in surviving preterm infants with grades I−IV intraventricular hemorrhages (IVHs) compared to those with no IVH. Study Design: We included preterm survivors <29 weeks’ GA admitted to the Canadian Neonatal Network’s NICUs from April 2009 to September 2011 with follow-up data at 18−24 months in a retrospective cohort study. The neonates were grouped based on the severity of the IVH detected on a cranial ultrasound scan and recorded in the database: no IVH; subependymal hemorrhage or IVH without ventricular dilation (grades I−II); IVH with ventricular dilation (grade III); and persistent parenchymal echogenicity/lucency (grade IV). The primary outcomes of neurodevelopmental impairment (NDI), significant neurodevelopmental impairment (sNDI), and the effect modification by other short-term neonatal morbidities were assessed. Using multivariable regression analysis, the adjusted ORs (AOR) and 95% of the CIs were calculated. Results: 2327 infants were included. The odds of NDI were higher in infants with grades III and IV IVHs (AOR 2.58, 95% CI 1.56, 4.28 and AOR 2.61, 95% CI 1.80, 3.80, respectively) compared to those without IVH. Infants with an IVH grade ≤II had similar outcomes for NDI (AOR 1.08, 95% CI 0.86, 1.35) compared to those without an IVH, but the odds of sNDI were higher (AOR 1.58, 95% CI 1.16, 2.17). Conclusions: There were increased odds of sNDI in infants with grades I−II IVHs, and an increased risk of adverse NDI in infants with grades ≥III IVHs is corroborated with the current literature.

Routine Use of Cerebral Magnetic Resonance Imaging in Infants Born Extremely Preterm

OBJECTIVE

To describe cerebral abnormalities and their risk factors in a contemporary cohort of infants born extremely premature after the introduction of routine cerebral magnetic resonance imaging (cMRI) at term-equivalent age.

STUDY DESIGN

All cMRI examinations performed during November 2017 and November 2020, based on a standardized neonatal cMRI protocol, were included into analysis. Pathologies were retrospectively classified into 3 categories: intraventricular hemorrhage (IVH), white matter disease, and cerebellar injuries.

RESULTS

A total of 198 cMRI examinations were available for analyses; 93 (47%) showed abnormalities, most frequently IVH (n = 65, 33%), followed by cerebellar injuries (n = 41, 21%), and white matter disease (n = 28, 14%). Severe abnormalities were found in 18% of patients (n = 36). Significant clinical risk factors for abnormalities on cMRI were lower Apgar scores, lower umbilical artery and first neonatal pH, asphyxia, blood culture-proven sepsis (especially late-onset), and prolonged need of respiratory support and supplemental oxygen.

CONCLUSIONS

After routine cMRI, without preconfirmed pathology by cranial ultrasonography, low-grade IVH, noncystic white matter disease, and cerebellar injuries were the most frequently found abnormalities. The clinical value and long-term benefit of the detection of these low-grade pathologies have yet to be confirmed.

Maternal Pyelonephritis as a Potential Cause of Perinatal Periventricular Venous Infarction in Term-Born Children

Introduction: The study was designed to assess the prevalence of pregnancy and delivery associated risk factors in children suffering from neonatal or presumed periventricular venous infarction. Methods: Antenatal records and pregnancy outcome data were retrospectively assessed in children with presumed periventricular venous infarction (n = 43, born ≥36 gestational weeks) or neonatal periventricular venous infarction (n = 86, born <36 gestational weeks) and compared to a matched control group (n = 2168, ≥36 gestational weeks) from a prospective study. Results: Children with presumed periventricular venous infarction had significantly more maternal bacterial infections compared to the control group (47% vs 20%, respectively, P < .001), whereas no difference was found compared to the neonatal periventricular venous infarction group (49%, P = .80). Mothers with bacterial infection in the presumed periventricular venous infarction group had significantly more often pyelonephritis compared to the control group (50% vs 3.4%, respectively, P < .001). Conclusions: Our data show an increased risk for developing periventricular venous infarction in the case of maternal bacterial infections, especially between gestational weeks 21 and 31.

A study on neurosonography in neonates with hypoxic–ischemic encephalopathy and its correlation with neurodevelopmental outcome

Background:

Hypoxic–ischemic encephalopathy (HIE) is a devastating condition causing severe neurologic deficits and deaths in children, occurring in about 1.5 out of 1000 live births. The pattern of brain injury depends on the severity and duration of hypoxia as well as the degree of brain maturation at the time of insult. The prognosis can depend largely on diagnosing the early screening of suspected cases, assessment of severity of the injury, and timely intervention.

Aims and Objectives:

This study is aimed at signifying the importance of neurosonography in neonates with HIE as a diagnostic tool and screening modality in the neonatal intensive care unit (NICU) and at establishing the role of neurosonography and Doppler sonography as an investigatory modality for predicting the neurological damage and influencing their neurodevelopmental outcome.

Design:

This is a prospective longitudinal-type study.

Materials and Methods:

A total of 50 neonates admitted in the NICU were included in the study from January 2017 to August 2018 with FUJIFILM SONOSITE (Bothell, Washington, USA) machine using a high-frequency linear probe (6–12 MHz) and convex probe (2–5 MHz). A total of 50 neonates admitted to the NICU were selected and enrolled in the study after fulfilling the selection criteria. The first scans were obtained within 72 h of birth, and subsequent follow-up scans were done between the 8th and 10th day and on the 30th day. The infants were then followed up after 6 to 12 months for a detailed neurological assessment.

Statistical Analysis Used:

All the statistical analyses were carried out using Fisher’s exact test.

Results:

Out of the eight neurosonographic (NSG) findings analyzed in our study that were found to be associated with hypoxemic brain changes, four of them showed a statistically significant correlation with high positive predictive value (PPV) with poor clinical outcome at 6 to 12 months of age. The PPV of neonates with ventriculomegaly, multicystic leukomalacia, abnormal Doppler indices, and intraventricular hemorrhage (IVH) was found to be 78%, 80%, 82%, and 87%, respectively.

Conclusions:

Neurosonography was found to be highly significant to predict the clinical outcome in neonates with HIE, and it should be used as the initial screening modality.

Usefulness of Neurosonogram in Critical Ill Neonates

The Cranial Neurosonogram is the preferred method for viewing the infant's brain. Ultrasound tools are portable and may be used at the NICU bedside. This corresponds to the concept of point-of-care testing. The difficulties associated with moving newborns to CT or MRI rooms are eliminated. Furthermore, ultrasound is less expensive than CT, has no radiation impact, and does not require sedation, which is required for MRI. Cranial sutures are still open in newborns, allowing us to glimpse within the brain using ultrasonography. A radiologist or neonatologist specializing in that profession should do the neurosonogram. The majority of the time, the course of therapy and subsequent care of the patient can be based on a Neurosonogram finding. Regardless of weight, height, or gestational age, any neonate who has a higher risk of morbidity or death due to fetal, placental, or maternal factors is classified as critically unwell. A sick neonate is defined as any neonate, regardless of birth weight, size, or gestational age, who has a greater than average risk of morbidity or mortality due to fetal, maternal, or placental anomalies or an otherwise compromised pregnancy within the first 28 days of life.

Neonatal stroke in premature neonates

There are many neuro-imaging studies on the presence of brain lesions in the preterm infant, using cranial ultrasound (cUS) and/or term equivalent age MRI (TEA-MRI). These studies however tend to focus on germinal matrix-intraventricular hemorrhage (GMH-IVH) and white matter injury. Data about perinatal arterial ischemic stroke (PAIS) or cerebral sinovenous thrombosis (CSVT) in the preterm infant are very limited. In fact, several large cohort studies on neuro-imaging in preterm infants do not even mention neonatal stroke.^1-4 Most studies about PAIS exclude preterm infants.⁵ The aim of this review was to provide an update on neonatal stroke in the preterm infant, with a focus on neuro-imaging findings.

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.

Survival of Ventilated Extremely Premature Neonates With Severe Intraventricular Hemorrhage

BACKGROUND

Severe intraventricular hemorrhage (IVH) is a leading mortality risk factor among extremely premature neonates. Because other life-threatening conditions also occur in this population, it is unclear whether severe IVH is independently associated with death. The existence and potential implications of regional variation in severe IVH-associated mortality are unknown.

METHODS

We performed a retrospective cohort study of mechanically ventilated neonates born at 22 to 29 weeks' gestation who received care in 242 American NICUs between 2000 and 2014. After building groups composed of propensity score-matched and center-matched pairs, we used the Cox proportional hazards analysis to test our hypothesis that severe IVH would be associated with greater all-cause in-hospital mortality, defined as death before transfer or discharge. We also performed propensity score-matched subgroup analyses, comparing severe IVH-associated mortality among 4 geographic regions of the United States.

RESULTS

In our analysis cohort, we identified 4679 patients with severe IVH. Among 2848 matched pairs, those with severe IVH were more likely to die compared with those without severe IVH (hazard ratio 2.79; 95% confidence interval 2.49-3.11). Among 1527 matched pairs still hospitalized at 30 days, severe IVH was associated with greater risk of death (hazard ratio 2.03; 95% confidence interval 1.47-2.80). Mortality associated with severe IVH varied substantially between geographic regions.

CONCLUSIONS

The early diagnosis of severe IVH is independently associated with all-cause in-hospital mortality in extremely premature neonates. Regional variation in severe IVH-associated mortality suggests that shared decision-making between parents and neonatologists is strongly influenced by ultrasound-based IVH assessment and classification.

White matter injury in infants with intraventricular haemorrhage: mechanisms and therapies

Intraventricular haemorrhage (IVH) continues to be a major complication of prematurity that can result in cerebral palsy and cognitive impairment in survivors. No optimal therapy exists to prevent IVH or to treat its consequences. IVH varies in severity and can present as a bleed confined to the germinal matrix, small-to-large IVH or periventricular haemorrhagic infarction. Moderate-to-severe haemorrhage dilates the ventricle and damages the periventricular white matter. This white matter injury results from a constellation of blood-induced pathological reactions, including oxidative stress, glutamate excitotoxicity, inflammation, perturbed signalling pathways and remodelling of the extracellular matrix. Potential therapies for IVH are currently undergoing investigation in preclinical models and evidence from clinical trials suggests that stem cell treatment and/or endoscopic removal of clots from the cerebral ventricles could transform the outcome of infants with IVH. This Review presents an integrated view of new insights into the mechanisms underlying white matter injury in premature infants with IVH and highlights the importance of early detection of disability and immediate intervention in optimizing the outcomes of IVH survivors.

Motor outcome after perinatal stroke and early prediction of unilateral spastic cerebral palsy

BACKGROUND

Unilateral spastic cerebral palsy (USCP) occurs in 30%-68% of infants with perinatal stroke. Early detection of USCP is essential for referring infants to early intervention. The aims of this study were to report motor outcomes after perinatal stroke, and to determine the predictive value of the General Movements Assessment (GMA) and Hand Assessment for Infants (HAI) for detection of USCP.

MATERIALS AND METHODS

This was a prospective observational study involving infants with perinatal stroke. GMA was conducted between 10 and 15 weeks post term-age (PTA). The HAI was performed between 3 and 5 months PTA. Motor outcome was collected between 12 and 36 months PTA.

RESULTS

The sample consisted of 46 infants. Fifteen children (32.6%) were diagnosed with CP, two children with bilateral CP and 13 with USCP. Abnormal GMA had a sensitivity of 85% (95% confidence interval [CI] 55-98%) and a specificity of 52% (95% CI 33-71%) to predict USCP. When asymmetrically presented FMs were also considered as abnormal, sensitivity increased to 100%, hence the specificity declined to 43%. A HAI asymmetry index cut-off of 23, had both a sensitivity and a specificity of 100% to detect USCP.

CONCLUSION

Using GMA and HAI can enable prediction of USCP before the age of 5 months in infants with perinatal stroke. Nevertheless, GMA must be interpreted with caution in this particular population. The HAI was found to be a very accurate screening tool for early detection of asymmetry and prediction of USCP.

Cerebral palsy after very preterm birth - an imaging perspective

Neonatal brain imaging undoubtedly can provide the most accurate information from which to determine whether cerebral palsy is likely to affect an individual infant born preterm. The sensitivity and specificity of that information is different between cranial ultrasound and MRI, depending on what approaches and sequences are used and the timing of the examinations. In this chapter we highlight the changing incidence of different patterns of brain injury in the preterm newborn and present a comparison of cranial ultrasound and MRI for predicting cerebral palsy in preterm infants affected by the commoner intracranial pathologies.

Cranial ultrasound findings in preterm germinal matrix haemorrhage, sequelae and outcome

Germinal matrix-intraventricular haemorrhage (GMH-IVH), periventricular haemorrhagic infarction (PHI) and its complication, post-haemorrhagic ventricular dilatation (PHVD), are still common neonatal morbidities in preterm infants that are highly associated with adverse neurodevelopmental outcome. Typical cranial ultrasound (CUS) findings of GMH-IVH, PHI and PHVD, their anatomical substrates and underlying mechanisms are discussed in this paper. Furthermore, we propose a detailed descriptive classification of GMH-IVH and PHI that may improve quality of CUS reporting and prediction of outcome in infants suffering from GMH-IVH/PHI.

Periventricular Hemorrhagic Infarction in Very Preterm Infants: Characteristic Sonographic Findings and Association with Neurodevelopmental Outcome at Age 2 Years

OBJECTIVE

To describe the sonographic characteristics of periventricular hemorrhagic infarction (PVHI) and their association with mortality and neurodevelopmental disability in very preterm infants born in 2008-2013.

STUDY DESIGN

Retrospective multicenter observational cohort study. Diagonal PVHI size was measured and severity score assessed. PVHI characteristics were scored and temporal trends were assessed. Neurodevelopmental outcome at 2 years of corrected age was assessed using either the Bayley Scales of Infant and Toddler Development, Third Edition or the Griffiths Mental Development Scales. Multigroup analyses were applied as appropriate.

RESULTS

We enrolled 160 infants with median gestational age of 26.6 weeks. PVHI was mostly unilateral (90%), associated with an ipsilateral grade III intraventricular hemorrhage (84%), and located in the parietal lobe (51%). Sixty-four (40%) infants with PVHI died in the neonatal period. Of the survivors assessed at 2 years of corrected age, 65% had normal cognitive and 69% had normal motor outcomes. The cerebral palsy rate was 42%. The composite outcome of death or severe neurodevelopmental disability was observed in 58%, with no trends over the study period (P = .6). Increasing PVHI severity score was associated with death (P < .001). Increasing PVHI size and severity score were negatively associated with gross motor scores (P = .01 and .03, respectively). Trigone involvement was associated with cerebral palsy (41% vs 14%; P = .004). Associated posthemorrhagic ventricular dilation (36%) was an independent risk factor for poorer cognitive and motor outcomes (P < .001 for both).

CONCLUSIONS

Increasing PVHI size and severity score were predictive of less optimal gross motor outcome and death in very preterm infants.

rhIGF-1/rhIGFBP-3 in Preterm Infants: A Phase 2 Randomized Controlled Trial

OBJECTIVE

To investigate recombinant human insulin-like growth factor 1 complexed with its binding protein (rhIGF-1/rhIGFBP-3) for the prevention of retinopathy of prematurity (ROP) and other complications of prematurity among extremely preterm infants.

STUDY DESIGN

This phase 2 trial was conducted from September 2014 to March 2016. Infants born at a gestational age of 230/7 weeks to 276/7 weeks were randomly allocated to rhIGF-1/rhIGFBP-3 (250 µg/kg/ 24 hours, continuous intravenous infusion from <24 hours of birth to postmenstrual age 296/7 weeks) or standard neonatal care, with follow-up to a postmenstrual age of 404/7 weeks. Target exposure was ≥70% IGF-1 measurements within 28-109 µg/L and ≥70% intended therapy duration. The primary endpoint was maximum severity of ROP. Secondary endpoints included time to discharge from neonatal care, bronchopulmonary dysplasia, intraventricular hemorrhage, and growth measures.

RESULTS

Overall, 61 infants were allocated to rhIGF-1/rhIGFBP-3, 60 to standard care (full analysis set); 24 of 61 treated infants achieved target exposure (evaluable set). rhIGF-1/rhIGFBP-3 did not decrease ROP severity or ROP occurrence. There was, however, a 53% decrease in severe bronchopulmonary dysplasia in the full analysis set (21.3% treated vs 44.9% standard care), and an 89% decrease in the evaluable set (4.8% vs 44.9%; P = .04 and P = .02, respectively) for severity distribution between groups. There was also a nonsignificant trend toward decrease in grades 3-4 intraventricular hemorrhage in the full analysis set (13.1% vs 23.3%) and in the evaluable set (8.3% vs 23.3%). Fatal serious adverse events were reported in 19.7% of treated infants (12/61) and 11.7% of control infants (7/60). No effect was observed on time to discharge from neonatal care/growth measures.

CONCLUSIONS

rhIGF-1/rhIGFBP-3 did not affect development of ROP, but decreased the occurrence of severe bronchopulmonary dysplasia, with a nonsignificant decrease in grades 3-4 intraventricular hemorrhage.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01096784.

Neonatal brain injury and aberrant connectivity

Brain injury sustained during the neonatal period may disrupt development of critical structural and functional connectivity networks leading to subsequent neurodevelopmental impairment in affected children. These networks can be characterized using structural (via diffusion MRI) and functional (via resting state-functional MRI) neuroimaging techniques. Advances in neuroimaging have led to expanded application of these approaches to study term- and prematurely-born infants, providing improved understanding of cerebral development and the deleterious effects of early brain injury. Across both modalities, neuroimaging data are conducive to analyses ranging from characterization of individual white matter tracts and/or resting state networks through advanced 'connectome-style' approaches capable of identifying highly connected network hubs and investigating metrics of network topology such as modularity and small-worldness. We begin this review by summarizing the literature detailing structural and functional connectivity findings in healthy term and preterm infants without brain injury during the postnatal period, including discussion of early connectome development. We then detail common forms of brain injury in term- and prematurely-born infants. In this context, we next review the emerging body of literature detailing studies employing diffusion MRI, resting state-functional MRI and other complementary neuroimaging modalities to characterize structural and functional connectivity development in infants with brain injury. We conclude by reviewing technical challenges associated with neonatal neuroimaging, highlighting those most relevant to studying infants with brain injury and emphasizing the need for further targeted study in this high-risk population.

Preterm brain injury: Germinal matrix-intraventricular hemorrhage and post-hemorrhagic ventricular dilatation

Germinal matrix hemorrhage and intraventricular hemorrhages (GMH-IVH) remain a common and clinically significant problem in preterm infants, particularly extremely preterm infants. A large GMH-IVH is often complicated by posthemorrhagic ventricular dilation (PHVD) or parenchymal hemorrhagic infarction and is associated with an increased risk of adverse neurologic sequelae. The widespread use of cranial ultrasonography since the early 1980s has shown a gradual decrease in the incidence of GMH-IVH and has helped with the identification of antenatal and perinatal risk factors and timing of the lesion. The increased use of magnetic resonance imaging (MRI) has contributed to more detailed visualization of the site and extent of the GMH-IVH. In addition, MRI has contributed to the awareness of associated white matter changes as well as associated cerebellar hemorrhages. Although GMH-IVH and PHVD still cannot be prevented, cerebrospinal fluid drainage initiated in the early stage of PHVD development seems to be associated with a better neurodevelopmental outcome. Further studies are underway to improve treatment strategies for PHVD and to potentially prevent and repair GMH-IVH and PHVD and associated brain injury. This chapter discusses the pathogenesis, incidence, risk factors, and management, including preventive measures, of GHM-IVH and PHVD.

Functional Connectivity Alterations in Children with Spastic and Dyskinetic Cerebral Palsy

Cerebral palsy (CP) has long been investigated to be associated with a range of motor and cognitive dysfunction. As the two most common CP subtypes, spastic cerebral palsy (SCP) and dyskinetic cerebral palsy (DCP) may share common and distinct elements in their pathophysiology. However, the common and distinct dysfunctional characteristics between SCP and DCP on the brain network level are less known. This study aims to detect the alteration of brain functional connectivity in children with SCP and DCP based on resting-state functional MRI (fMRI). Resting-state networks (RSNs) were established based on the independent component analysis (ICA), and the functional network connectivity (FNC) was performed on the fMRI data from 16 DCP, 18 bilateral SCP, and 18 healthy children. Compared with healthy controls, altered functional connectivity within the cerebellum network, sensorimotor network (SMN), left frontoparietal network (LFPN), and salience network (SN) were found in DCP and SCP groups. Furthermore, the disconnections of the FNC consistently focused on the visual pathway; covariance of the default mode network (DMN) with other networks was observed both in DCP and SCP groups, while the DCP group had a distinct connectivity abnormality in motor pathway and self-referential processing-related connections. Correlations between the functional disconnection and the motor-related clinical measurement in children with CP were also found. These findings indicate functional connectivity impairment and altered integration widely exist in children with CP, suggesting that the abnormal functional connectivity is a pathophysiological mechanism of motor and cognitive dysfunction of CP.

Feasibility trial of an early therapy in perinatal stroke (eTIPS)

BACKGROUND

Perinatal stroke (PS) affects up to 1/2300 infants and frequently leads to unilateral cerebral palsy (UCP). Preterm-born infants affected by unilateral haemorrhagic parenchymal infarction (HPI) are also at risk of UCP. To date no standardised early therapy approach exists, yet early intervention could be highly effective, by positively influencing processes of activity-dependent plasticity within the developing nervous system including the corticospinal tract. Our aim was to test feasibility and acceptability of an "early Therapy In Perinatal Stroke" (eTIPS) intervention, aiming ultimately to improve motor outcome.

METHODS

Design: Feasibility trial, North-East England, August 2015-September 2017. Participants were infants with PS or HPI, their carers and therapists. The intervention consisted of a parent-delivered lateralised therapy approach starting from term equivalent age and continuing until 6 months corrected age. The outcome measures were feasibility (recruitment and retention rates) and acceptability of the intervention (parental questionnaires including the Warwick-Edinburgh Mental Wellbeing Scale (WEBWMS), qualitative observations and in-depth interviews with parents and therapists). We also reviewed clinical imaging data and undertook assessments of motor function, including the Hand Assessment for Infants (HAI). Assessments were also piloted in typically developing (TD) infants, to provide further information on their ease of use and acceptability.

RESULTS

Over a period of 18 months we screened 20 infants referred as PS/HPI: 14 met the inclusion criteria and 13 took part. At 6 months, 11 (85%) of those enrolled had completed the final assessment. Parents valued the intervention and found it acceptable and workable. There were no adverse events related to the intervention. We recruited 14 TD infants, one of whom died prior to undertaking any assessments and one of whom was subsequently found to have a condition affecting neurodevelopmental progress: thus, data for 12 TD infants was analysed to 6 months. The HAI was well tolerated by infants and highly valued by parents. Completion rates for the WEBWMS were high and did not suggest any adverse effect of engagement in eTIPS on parental mental wellbeing.

CONCLUSION

The eTIPS intervention was feasible to deliver and acceptable to families. We plan to investigate efficacy in a multicentre randomised controlled trial.

TRIAL REGISTRATION

ISRCTN12547427 (registration request submitted 28/05/2015; retrospectively registered, 30/09/2015).

Severe intraventricular hemorrhage and withdrawal of support in preterm infants

OBJECTIVE

The objective of the study was to determine whether withdrawal of support in severe 'intraventricular hemorrhage' (IVH), that is, IVH grade 3 and periventricular hemorrhagic infarction (PVHI), has decreased after publication of studies that show improved prognosis and to examine cranial ultrasonograms, including PVHI territories defined by Bassan.

STUDY DESIGN

Retrospective cohort of preterm infants from 23 0/7 to 28 6/7 weeks' gestation in 1993 to 2013.

RESULTS

Among the 1755 infants, 1494 had no bleed, germinal matrix hemorrhage (GMH) or IVH grade 2, 137 had grade 3 IVH and 124 had PVHI. The odds of withdrawal of support, adjusted for severity of GMH-IVH and baseline variables, did not decrease after publications showing better prognosis. Among 82 patients who died with PVHI, 76 had life support withdrawn, including 34 without another contributing cause of death. The median number of PVHI territories involved was three.

CONCLUSION

Withdrawal of support adjusted for severity of GMH-IVH did not significantly change after publications showing better prognosis.

Early biomarkers of brain injury and cerebral hypo- and hyperoxia in the SafeBoosC II trial

BACKGROUND

The randomized clinical trial, SafeBoosC II, examined the effect of monitoring of cerebral oxygenation by near-infrared spectroscopy combined with a guideline on treatment when cerebral oxygenation was out of the target range. Data on cerebral oxygenation was collected in both the intervention and the control group. The primary outcome was the reduction in the burden of cerebral hypo- and hyperoxia between the two groups. In this study we describe the associations between the burden of cerebral hypo- and hyperoxia, regardless of allocation to intervention or control group, and the biomarkers of brain injury from birth till term equivalent age that was collected as secondary and explorative outcomes in the SafeBoosC II trial.

METHODS

Cerebral oxygenation was continuously monitored during the first 72h of life in 166 extremely preterm infants. Cranial ultrasound was performed at day 1,4,7,14, and 35 and at term. Electroencephalogram (EEG) was recorded at 64h. Blood-samples taken at 6 and 64 hours were analysed for the brain injury biomarkers; S100beta, brain-fatty-acid-binding-protein, and neuroketal. All analyses were conducted post hoc.

RESULTS

Significantly more infants with a cerebral burden of hypoxia within the 4th quartile versus infants within quartile 1-3 were diagnosed with severe intracranial haemorrhage (11/39 versus 11/117, p = 0.003), had low burst rate on EEG (12/28 versus 21/103, p = 0.015), or died (14/41 versus 18/123, p = 0.006), whereas none of these events were significantly associated with cerebral hyperoxia. The blood biomarkers were not significantly associated with the burden of cerebral hypo- or hyperoxia.

CONCLUSIONS

The explorative analysis showed that early burden of cerebral hypoxia, but not hyperoxia was significantly associated with low brain electrical activity and severe intracranial haemorrhage while none of the three blood biomarkers were associated with the burden of either cerebral hypo- or hyperoxia.

The effects of thyroid function on retinopathy of prematurity

OBJECTIVES

To assess whether TSH and fT4 have a role in the angiogenesis of vaso-obliteration and neovascularization which are the basic pathophysiology of ROP.

METHODS

In this retrospective case-control study, the control group (n = 56) included preterm newborns with risk for ROP while the laser group (n = 63) was recruited from cases who developed severe neovascularization and needed laser photocoagulation therapy. Considering the first (vaso-obliteration) and second (neovascularization) phases of the disease, in this study we researched the distribution of thyroid function tests between groups.

RESULTS

With regard to the first phase of the disease, TSH and fT4 showed no significant differences between the control and laser groups accordingly (P > 0.05). Likewise, in the second phase of ROP, there was no significant difference between the control and laser groups with respect to TSH and fT4 levels (P > 0.05).

CONCLUSION

We found that between the study groups, the levels of thyroid function tests did not have any significant differences, either in the first or the second phases of ROP which are the principal pathophysiology of the disease. Therefore, it was concluded that thyroid hormone values were not informative markers in the course of the disease in preterm babies at risk of developing ROP.

Findings and differential diagnosis of fetal intracranial haemorrhage and fetal ischaemic brain injury: what is the role of fetal MRI?

Ventriculomegaly (VM) is a non-specific finding on fetal imaging. Identification of the specific aetiology is important, as it affects prognosis and may even change the course of current or future pregnancies. In this review, we will focus on the application of fetal MRI to demonstrate intracranial haemorrhage and ischaemic brain injury as opposed to other causes of VM. MRI is able to identify the specific aetiology of VM with much more sensitivity and specificity than ultrasound and should be considered whenever VM is identified on obstetric ultrasound. Advances in both fetal and neonatal MRI have the potential to shed further light on mechanisms of brain injury and the impact of chronic hypoxia; such information may guide future interventions.

Quantitative analysis of cranial ultrasonographic periventricular echogenicity in relation to early neuromotor development in preterm infants

BACKGROUND

Periventricular white matter (WM) hyperechoic flares that do not evolve into cystic lesion(s) are frequently encountered on cranial ultrasonography (CUS) of preterm infants. Subjective interpretation of its presence, however, is challenging and its association with maturation and neurodevelopment remains undefined.

OBJECTIVES

To determine the relationship between quantitative WM echogenicity and postnatal and postmenstrual ages and the relationship between quantitative WM echogenicity and neuromotor development at term equivalent.

METHODS

We measured the mean pixel brightness intensity at the frontoparietal and parieto-occipital WM, choroid plexus and calvarium bone on sequential neonatal CUS scans of preterm infants born at <34 weeks gestation. The relative echogenicity (RE) was derived by dividing the mean WM echogenicity to that of the choroid plexus (RE(CP)) or bone (RE(BN)). The Lacey Assessment of the Preterm Infant was administered before discharge.

RESULTS

58 preterm infants (the mean gestational age 30.6±2.3 weeks and the mean birth weight 1211.9±224.7 g) were included. The RE(CP) of the frontoparietal WM decreased significantly with advancing postnatal and postmenstrual ages (r=-0.4, p<0.0001). The RE(BN) values of the frontoparietal and parieto-occipital WM during intermediate and late predischarge CUS studies, respectively, were significantly associated with neuromotor status at term (p<0.05). The RE(CP) and RE(BN) measured during the first week of life were not associated with neuromotor status at term.

CONCLUSIONS

Quantitative measurements of the periventricular WM echogenicity are feasible in neonatal CUSs of premature infants and may reflect microstructural developmental changes. An optimal echogenicity quantification technique and its correlation with long-term outcome remain to be determined.

Brain injury in the international multicenter randomized SafeBoosC phase II feasibility trial: cranial ultrasound and magnetic resonance imaging assessments

BACKGROUND

Abnormal cerebral perfusion during the first days of life in preterm infants is associated with higher grades of intraventricular hemorrhages and lower developmental score. In SafeBoosC II, we obtained a significant reduction of cerebral hypoxia by monitoring cerebral oxygenation in combination with a treatment guideline. Here, we describe (i) difference in brain injury between groups, (ii) feasibility of serial cranial ultrasound (cUS) and magnetic resonance imaging (MRI), (iii) local and central cUS assessment.

METHODS

Hundred and sixty-six extremely preterm infants were included. cUS was scheduled for day 1, 4, 7, 14, and 35 and at term-equivalent age (TEA). cUS was assessed locally (unblinded) and centrally (blinded). MRI at TEA was assessed centrally (blinded). Brain injury classification: no, mild/moderate, or severe.

RESULTS

Severe brain injury did not differ significantly between groups: cUS (experimental 10/80, control 18/77, P = 0.32) and MRI (5/46 vs. 3/38, P = 0.72). Kappa values for local and central readers were moderate-to-good for severe and poor-to-moderate for mild/moderate injuries. At TEA, cUS and MRI were assessed in 72 and 64%, respectively.

CONCLUSION

There was no difference in severe brain injury between groups. Acquiring cUS and MRI according the standard operating procedures must be improved for future trials. Whether monitoring cerebral oxygenation during the first 72 h of life prevents brain injury should be evaluated in larger multicenter trials.

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.

Risk Factors for Health Care-Associated Sepsis in Critically Ill Neonates Stratified by Birth Weight

BACKGROUND

Health care-associated bloodstream infection (HABSI) is a frequent complication in neonatal intensive care. Research on risk factors stratified by birth weight and adjusted for severity of illness and comorbidities is limited. Our objective is to describe independent risk factors for HABSI in critically ill neonates with emphasis on risk variation between birth weight groups.

METHODS

We performed a single-center historical cohort study in a tertiary referral center. A neonatal intensive care-audit system was used to identify eligible neonates admitted for ≥72 hours (2002-2011). HABSI is defined according to National Institute of Child Health and Human Development criteria. Risk factors for HABSI were assessed by univariate and logistic regression analysis for the total cohort and for birth weight subgroups, that is, neonates ≤1500 g and >1500 g.

RESULTS

A total of 342 neonates developed HABSI in 5134 admissions of ≥72 hours (6.7%). Very low birth weight, total parenteral nutrition (TPN), mechanical ventilation, gastrointestinal disease, surgery (cardiac and other type), and renal insufficiency are independent risk factors for the total cohort. Gastrointestinal disease and cardiac surgery are independent risk factors in both birth weight groups; mechanical ventilation (odds ratio [OR]: 2.6; confidence interval [CI]: 1.6-4.0) and other type of surgery (OR: 4.3; CI: 2.1-8.8) are solely independent risk factors in the ≤1500-g cohort; TPN is exclusively an independent risk factor (OR: 7.9; CI: 3.9-16.2) in the >1500-g cohort.

CONCLUSIONS

In our neonatal intensive care unit, risk stratification by birth weight revealed some difference. Special attention concerning infection control practices is for neonates receiving TPN, mechanical ventilation, cardiac surgery, and with a gastrointestinal disease.

Relationship between characteristics on magnetic resonance imaging and motor outcomes in children with cerebral palsy and white matter injury

In a population cohort of children with white matter injury (WMI) and cerebral palsy (CP), we aimed to describe the magnetic resonance imaging (MRI) characteristics, identify key structure-function relationships, and classify the severity of WMI in a clinically relevant way. Stratified on MRI laterality/symmetry, variables indicating the extent and location of cerebral abnormalities for 272 children with CP and WMI on chronic-phase MRI were related to gross motor function and motor topography using univariable and multivariable approaches. We found that symmetrical involvement, severe WM loss in the hemispheres and corpus callosum, and cerebellar involvement were the strongest predictors of poor gross motor function, but the final model explained only a small proportion of the variability. Bilateral, extensive WM loss was more likely to result in quadriplegia, whereas volume loss in the posterior-mid WM more frequently resulted in diplegia. The extent and location of MRI abnormalities differed according to laterality/symmetry; asymmetry was associated with less extensive hemispheric involvement than symmetrical WMI, and unilateral lesions were more focal and located more anteriorly. In summary, laterality/symmetry of WMI, possibly reflecting different pathogenic mechanisms, together with extent of WM loss and cerebellar abnormality predicted gross motor function in CP, but to a limited extent.

Optical monitoring of stress-related changes in the brain tissues and vessels associated with hemorrhagic stroke in newborn rats

Stress is a major factor for a risk of cerebrovascular catastrophes. Studying of mechanisms underlying stress-related brain-injures in neonates is crucial for development of strategy to prevent of neonatal stroke. Here, using a model of sound-stress-induced intracranial hemorrhages in newborn rats and optical methods, we found that cerebral veins are more sensitive to the deleterious effect of stress than arteries and microvessels. The development of venous insufficiency with decreased blood outflow from the brain accompanied by hypoxia, reduction of complexity of venous blood flow and high production of beta-arrestin-1 are possible mechanisms responsible for a risk of neonatal hemorrhagic stroke.

Neonatal DTI early after birth predicts motor outcome in preterm infants with periventricular hemorrhagic infarction

BACKGROUND

To determine the association between early neonatal diffusion tensor imaging (DTI) and the development of unilateral spastic cerebral palsy (USCP) in preterm infants with periventricular hemorrhagic infarction (PVHI).

METHODS

Preterm infants with PVHI were assessed with early (≤4 wk after birth) and term-equivalent age MRI-DTI. Involvement of corticospinal tracts was assessed by visual assessment of the posterior limb of the internal capsule (PLIC) on DTI (classified asymmetrical, equivocal, or symmetrical) and by an atlas-based approach calculating fractional anisotropy asymmetry index in the PLIC. Motor outcome was assessed at ≥15 mo corrected age.

RESULTS

Seven out of 23 infants with PVHI developed USCP. Their PLIC was visually scored as asymmetrical in 6 and equivocal in 1 on the early DTI. Thirteen out of 16 infants with a symmetrical motor development had a symmetrical PLIC on early DTI, the remaining 3 were equivocal. All infants with USCP had a fractional anisotropy asymmetry index of >0.05 (optimal cut-off value) on early DTI. In infants with a symmetrical motor development (n = 16), 14 had an asymmetry index ≤0.05 while 2 had an index >0.05.

CONCLUSION

DTI in preterm infants with PVHI within a few weeks after birth is associated with later motor development.

The outcome of treatment limitation discussions in newborns with brain injury

BACKGROUND

Most deaths in severely brain-injured newborns in neonatal intensive care units (NICUs) follow discussions and explicit decisions to limit life-sustaining treatment. There is little published information on such discussions.

OBJECTIVE

To describe the prevalence, nature and outcome of treatment limitation discussions (TLDs) in critically ill newborns with severe brain injury.

DESIGN

A retrospective statewide cohort study.

SETTING

Two tertiary NICUs in South Australia.

PATIENTS

Ventilated newborns with severe hypoxic ischaemic encephalopathy and periventricular/intraventricular haemorrhage (P/IVH) admitted over a 6-year period from 2001 to 2006.

MAIN OUTCOME MEASURES

Short-term outcome (until hospital discharge) including presence and content of TLDs, early childhood mortality, school-age functional outcome.

RESULTS

We identified 145 infants with severe brain injury; 78/145 (54%) infants had documented TLDs. Discussions were more common in infants with severe P/IVH or hypoxic-ischaemic encephalopathy (p<0.01). Fifty-six infants (39%) died prior to discharge, all following treatment limitation. The majority of deaths (41/56; 73%) occurred in physiologically stable infants. Of 78 infants with at least one documented TLD, 22 (28%) survived to discharge, most in the setting of explicit or inferred decisions to continue treatment. Half of long-term survivors after TLD (8/16, 50%) were severely impaired at follow-up. However, two-thirds of surviving infants with TLD in the setting of unilateral P/IVH had mild or no disability.

CONCLUSIONS

Some critically ill newborn infants with brain injury survive following TLDs between their parents and physicians. Outcome in this group of infants provides valuable information about the integrity of prognostication in NICU, and should be incorporated into counselling.

Neonatal neurosonography

Neonatal neurosonography is used commonly to evaluate the central nervous system in the neonatal intensive care setting. The procedure can be performed at the bedside in these critically ill patients who may suffer from hemodynamic and thermoregulatory instability and often require mechanical ventilation. This article reviews current recommendations regarding neurosonography technique, pathophysiology, and imaging of intracranial insults including hemorrhage, white matter injury, infarction, and hypoxic-ischemic encephalopathy.

Neuroimaging and neurodevelopmental outcome of preterm infants with a periventricular haemorrhagic infarction located in the temporal or frontal lobe

AIM

The aim of the study was to compare clinical and neuroimaging characteristics and neurodevelopmental outcome in preterm infants with a periventricular haemorrhagic infarction (PVHI) located in the temporal or frontal periventricular white matter.

METHOD

The study was a retrospective hospital-based study of preterm infants with a frontal PVHI (n=21; 11 males, 10 females; mean birthweight 1527g; mean gestational age 30.3wks) or temporal PVHI (n=13; five males, eight females; mean birthweight 1205g; mean gestational age 30.2wks) admitted to the neonatal intensive care unit between 1990 and 2012. The clinical course, results of neuroimaging studies, and neurodevelopmental outcomes of preterm infants with a gestational age less than 34 weeks with a confirmed PVHI on early cranial ultrasonography and/or magnetic resonance imaging were reviewed. For assessment of neurodevelopmental outcome we used the Griffiths Mental Development Scales, the Movement Assessment Battery for Children, the Gross Motor Function Classification System, the Wechsler Preschool and Primary Scale of Intelligence, the Child Behavior Checklist, and ophthalmological assessment. An unfavourable neurodevelopmental outcome was defined as moderately or severely atypical neurological examination during the last visit: presence of cerebral palsy, epilepsy, a hearing or visual impairment, and/or atypical cognitive development (Griffiths Mental Development Scales developmental quotient or Wechsler Preschool and Primary Scale of Intelligence <85).

RESULTS

Unfavourable outcome was observed in 12 out of 13 children with a temporal PVHI compared with six out of 21 children with a frontal PVHI (p=0.002). Only one of the included infants with a PVHI in the temporal white matter developed cerebral palsy, which was due to a parietal PVHI in the contralateral hemisphere. Cognitive impairment was noted in seven infants with a frontal PVHI and five with a temporal PVHI. There were more infants with a temporal PVHI who developed visual impairment (n=5) or behavioural problems (n=7) compared with those with a frontal PVHI (visual impairment (n=2), behavioural problems (n=3).

INTERPRETATION

PVHI located in the temporal or frontal lobe is almost invariably related to a typical motor outcome, but carries a risk of cognitive, behavioural, and visual problems, especially in infants with a PVHI located in the temporal lobe.

Population-based studies of brain imaging patterns in cerebral palsy

AIM

The aim of this study was to review the distribution of neuroimaging findings from a contemporary population cohort of individuals with cerebral palsy (CP) and to facilitate standardization of imaging classification.

METHOD

Publications from 1995 to 2012 reporting imaging findings in population cohorts were selected through a literature search, and review of the titles, abstracts, and content of studies. Relevant data were extracted, including unpublished data from Victoria, Australia. The proportions for each imaging pattern were tabulated, and heterogeneity was assessed for all individuals with CP, and for subgroups based on gestational age, CP subtype, and Gross Motor Function Classification System level.

RESULTS

Studies from three geographic regions met the inclusion criteria for individuals with CP, and two additional studies reported on specific CP subtypes. Brain abnormalities were observed in 86% of scans, but were observed least often in children with ataxia (24-57%). White matter injury was the most common imaging pattern (19-45%), although the proportions showed high heterogeneity. Additional patterns were grey matter injury (21%), focal vascular insults (10%), malformations (11%), and miscellaneous findings (4-22%).

INTERPRETATION

This review suggests areas where further dialogue will facilitate progress towards standardization of neuroimaging classification. Standardization will enable future collaborations aimed at exploring the relationships among magnetic resonance imaging patterns, risk factors, and clinical outcomes, and, ultimately, lead to better understanding of causal pathways and opportunities for prevention.

Outcomes of extremely preterm infants following severe intracranial hemorrhage

OBJECTIVE

Severe intracranial hemorrhage (ICH) is an important prognostic variable in extremely preterm (EPT) infants. We examined imaging and clinical variables that predict outcomes in EPT infants with severe ICH.

STUDY DESIGN

Retrospective analysis of 353 EPT infants with severe ICH. Outcomes were compared by examining: (i) unilateral vs bilateral ICH; and (ii) presence vs absence of hemorrhagic parenchymal infarction (HPI). Regression analyses identified variables associated with death or neurodevelopmental impairment (NDI).

RESULT

Bilateral ICH and HPI had higher rates of adverse outcomes and were independently associated with death/NDI. HPI was the most important variable for infants of lower birth weight, and bilateral ICH for larger infants. For infants surviving to 36 weeks, shunt placement was most associated with death/NDI.

CONCLUSION

Bilateral ICH and the presence of HPI in EPT infants with severe ICH are associated with death/NDI, though the importance depends on birth weight and survival to 36 weeks.

Early and late complications of germinal matrix-intraventricular haemorrhage in the preterm infant: what is new?

Germinal matrix-intraventricular haemorrhage (GMH-IVH) remains a serious problem in the very and extremely preterm infant. This article reviews current methods of diagnosis, treatment and neurodevelopmental outcome in preterm infants with low-grade and severe GMH-IVH. We conclude that there is still no consensus on timing of intervention and treatment of infants with GMH-IVH, whether or not complicated by post-haemorrhagic ventricular dilatation. The discrepancies between the studies underline the need for international collaboration to define the optimal strategy for these infants.

Treatment with thyroxine restores myelination and clinical recovery after intraventricular hemorrhage

Intraventricular hemorrhage (IVH) remains a major cause of white matter injury in preterm infants with no viable therapeutic strategy to restore myelination. Maturation of oligodendrocytes and myelination is influenced by thyroid hormone (TH) signaling, which is mediated by TH receptor α (TRα) and TRβ. In the brain, cellular levels of TH are regulated by deiodinases, with deiodinase-2 mediating TH activation and deiodinase-3 TH inactivation. Therefore, we hypothesized that IVH would decrease TH signaling via changes in the expression of deiodinases and/or TRs, and normalization of TH signaling would enhance maturation of oligodendrocytes and myelination in preterm infants with IVH. These hypotheses were tested using both autopsy materials from human preterm infants and a rabbit model of IVH. We found that deiodinase-2 levels were reduced, whereas deiodinase-3 levels were increased in brain samples of both humans and rabbits with IVH compared with controls without IVH. TRα expression was also increased in human infants with IVH. Importantly, treatment with TH accelerated the proliferation and maturation of oligodendrocytes, increased transcription of Olig2 and Sox10 genes, augmented myelination, and restored neurological function in pups with IVH. Consistent with these findings, the density of myelinating oligodendrocytes was almost doubled in TH-treated human preterm infants compared with controls. Thus, in infants with IVH the combined elevation in deiodinase-3 and reduction in deiodinase-2 decreases TH signaling that can be worsened by an increase in unliganded TRα. Given that TH promotes neurological recovery in IVH, TH treatment might improve the neurodevelopmental outcome of preterm infants with IVH.

Timing of external ventricular drainage and neurodevelopmental outcome in preterm infants with posthemorrhagic hydrocephalus

OBJECTIVE

To delineate the impact of early (≤ 25 days of life) versus late (> 25 days) external ventricular drainage (EVD) on the neurodevelopmental outcome of preterm infants with posthemorrhagic hydrocephalus (PHH) following intraventricular hemorrhage (IVH).

METHODS

We retrospectively categorized 32 premature infants with PHH into two groups according to whether they underwent early (n = 10) or late (n = 22) EVD. We administered the Battelle Developmental Inventory II and a neuromotor examination (median age, 73 months, range: 29-100).

RESULTS

In adjusted comparisons, early EVD was associated with better scores than late EVD in adaptive (79 ± 22.6 vs. 58.8 ± 8.1, P = .01), personal social (90.7 ± 26 vs. 67.3 ± 15.9, P = .02), communication (95.4 ± 27.5 vs. 69.6 ± 20.5, P = .04) and cognitive (78.9 ± 24.4 vs. 60.7 ± 11.5, P = .055) functions. Three (30%) early EVD infants had severe (<2.5 standard deviation) cognitive disability compared to 18 (82%) late EVD infants (P = .03). The incidences of cerebral palsy and neurosurgical complications were equal for the two groups. Subgroup analyses suggested that early EVD was beneficial in infants with original grade III IVH (n = 15, P < 0.05), but that it had no beneficial effects in infants with prior parenchymal injury (n = 17, P = NS).

CONCLUSION

In this small retrospective series, early EVD is associated with lower rates of cognitive, communication and social disabilities than later EVD in infants with PHH without prior parenchymal injury. A randomized prospective trial is warranted.

Cerebral oxygenation is highly sensitive to blood pressure variability in sick preterm infants

Objectives

The significance of blood pressure variability (BPV) for cerebral oxygenation in extremely preterm infants has not been explored, though BPV may well be associated with end organ injury. We hypothesized that increased BPV in sick preterm infants, by exceeding the cerebral autoregulatory capacity, is associated with cerebral oxygenation changes which closely follow the blood pressure fluctuations. We assessed the autoregulatory capacity in the early postnatal period, by determining the correlation between BPV (mmHg²) and coherence of mean arterial blood pressure (MABP mmHg) and cerebral oxygenation (tissue oxygenation index, TOI %).

Study Design

Thirty-two preterm infants of mean gestational age of 26.3 (±1.5) weeks were studied on the first 3 postnatal days. Spectral analysis (Coherence and transfer-function gain analysis) was used to calculate coherence of MABP and TOI; BPV was quantified using power spectral density of MABP.

Results

Overall, maximum Coherence showed a trend for positive correlation with BPV (n = 32, p = 0.06). Infants identified as clinically unstable with documented brain injury (n = 7) had high Coherence values at low BPV. Separate analysis of stable infants (excluding the 7 critically ill infants) revealed a significant association between maximum Coherence and BPV (n = 25, p = 0.006).

Conclusions

Fluctuation in cerebral oxygenation is closely associated with increased BPV in preterm infants undergoing intensive care. Moreover, in the critically sick preterm infant, blood pressure-dependent variations in cerebral oxygenation occur even with relatively lower BPV, suggesting they have severely impaired autoregulation, and placing them at greater vulnerability to cerebral injury arising from blood pressure fluctuations.