The Association of Dexamethasone and Hydrocortisone with Cerebellar Growth in Premature Infants

OBJECTIVES

Corticosteroids are used to prevent or treat lung disease of prematurity. While neurological side effects have been reported, detailed effects on cerebellar growth are unknown. This study aimed to compare cerebellar growth in premature infants who received dexamethasone or hydrocortisone to premature infants who did not receive postnatal corticosteroids.

STUDY DESIGN

Retrospective case-control study in infants born at a gestational age of <29 weeks and admitted to two level 3 neonatal intensive care units. Exclusion criteria were severe congenital anomalies and cerebellar or severe supratentorial lesions. Infants were treated with dexamethasone (unit 1) or hydrocortisone (unit 2) for chronic lung disease. Controls (unit 1) did not receive postnatal corticosteroids. Sequential head circumference (HC) and ultrasound measurements of transcerebellar diameter (TCD), biparietal diameter (BPD), and corpus callosum-fastigium length (CCFL) were performed until 40 weeks' postmenstrual age (PMA). Growth was assessed using linear mixed models correcting for PMA at measurement, sex, HC z-score at birth, and a propensity score indicating illness severity. Group differences before treatment were assessed using linear regression.

RESULTS

346 infants were included (68 dexamethasone, 37 hydrocortisone, 241 controls). Before starting corticosteroids, TCD, BPD, and HC measurements did not differ between patients and controls at a comparable PMA. After starting treatment, both types of corticosteroid had a negative association with TCD growth. BPD, CCFL, and HC growth were not negatively affected.

CONCLUSION

Administration of dexamethasone and hydrocortisone are both associated with impaired cerebellar growth in premature infants without evident negative associations with cerebral growth.

Neurological Surveillance in Moderate-Late Preterm Infants—Results from a Dutch–Canadian Survey

Preterm birth remains an important cause of abnormal neurodevelopment. While the majority of preterm infants are born moderate-late preterm (MLPT; 32–36 weeks), international and national recommendations on neurological surveillance in this population are lacking. We conducted an observational quantitative survey among Dutch and Canadian neonatal level I–III centres (June 2020–August 2021) to gain insight into local clinical practices on neurological surveillance in MLPT infants. All centres caring for MLPT infants designated one paediatrician/neonatologist to complete the survey. A total of 85 out of 174 (49%) qualifying neonatal centres completed the survey (60 level I–II and 25 level III centres). Admission of MLPT infants was based on infant-related criteria in 78/85 (92%) centres. Cranial ultrasonography to screen the infant’s brain for abnormalities was routinely performed in 16/85 (19%) centres, while only on indication in 39/85 (46%). In 57/85 (67%) centres, neurological examination was performed at least once during admission. Of 85 centres, 51 (60%) followed the infants’ development post-discharge, with follow-up duration ranging from 1–52 months of age. The survey showed a wide variety in neurological surveillance in MLPT infants among Dutch and Canadian neonatal centres. Given the risk for short-term morbidity and long-term neurodevelopmental disabilities, future studies are required to investigate best practices for in-hospital care and follow-up of MLPT infants.

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

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVES

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Neonatal care bundles are associated with a reduction in the incidence of intraventricular haemorrhage in preterm infants: a multicentre cohort study

OBJECTIVE

To investigate the effect of a nursing intervention bundle, applied during the first 72 hours of life, on the incidence of germinal matrix-intraventricular haemorrhage (GMH-IVH) in very preterm infants.

DESIGN

Multicentre cohort study.

SETTING

Two Dutch tertiary neonatal intensive care units.

PATIENTS

The intervention group consisted of 281 neonates, whereas 280 infants served as historical controls (gestational age for both groups <30 weeks).

INTERVENTIONS

After a training period, the nursing intervention bundle was implemented and applied during the first 72 hours after birth. The bundle consisted of maintaining the head in the midline, tilting the head of the incubator and avoidance of flushing/rapid withdrawal of blood and sudden elevation of the legs.

MAIN OUTCOME MEASURES

The incidence of GMH-IVH occurring and/or increasing after the first ultrasound (but within 72 hours), cystic periventricular leukomalacia and/or in-hospital death was the primary composite outcome measure. Logistic regression analysis was used to explore differences between groups.

RESULTS

The nursing intervention bundle was associated with a lower risk of developing a GMH-IVH (any degree), cystic periventricular leukomalacia and/or mortality (adjusted OR 0.42, 95% CI 0.27 to 0.65). In the group receiving the bundle, also severe GMH-IVH, cystic periventricular leukomalacia and/or death were less often observed (adjusted OR 0.54, 95% CI 0.33 to 0.91).

CONCLUSIONS

The application of a bundle of nursing interventions is associated with reduced risk of developing a new/progressive (severe) GMH-IVH, cystic periventricular leukomalacia and/or mortality in very preterm infants when applied during the first 72 hours postnatally.

Assessment of Brain Injury and Brain Volumes after Posthemorrhagic Ventricular Dilatation: A Nested Substudy of the Randomized Controlled ELVIS Trial

OBJECTIVE

To compare the effect of early and late intervention for posthemorrhagic ventricular dilatation on additional brain injury and ventricular volume using term-equivalent age-MRI.

STUDY DESIGN

In the Early vs Late Ventricular Intervention Study (ELVIS) trial, 126 preterm infants ≤34 weeks of gestation with posthemorrhagic ventricular dilatation were randomized to low-threshold (ventricular index >p97 and anterior horn width >6 mm) or high-threshold (ventricular index >p97 + 4 mm and anterior horn width >10 mm) groups. In 88 of those (80%) with a term-equivalent age-MRI, the Kidokoro Global Brain Abnormality Score and the frontal and occipital horn ratio were measured. Automatic segmentation was used for volumetric analysis.

RESULTS

The total Kidokoro score of the infants in the low-threshold group (n = 44) was lower than in the high-threshold group (n = 44; median, 8 [IQR, 5-12] vs median 12 [IQR, 9-17], respectively; P < .001). More infants in the low-threshold group had a normal or mildly increased score vs more infants in the high-threshold group with a moderately or severely increased score (46% vs 11% and 89% vs 54%, respectively; P = .002). The frontal and occipital horn ratio was lower in the low-threshold group (median, 0.42 [IQR, 0.34-0.63]) than the high-threshold group (median 0.48 [IQR, 0.37-0.68], respectively; P = .001). Ventricular cerebrospinal fluid volumes could be calculated in 47 infants and were smaller in the low-threshold group (P = .03).

CONCLUSIONS

More brain injury and larger ventricular volumes were demonstrated in the high vs the low-threshold group. These results support the positive effects of early intervention for posthemorrhagic ventricular dilatation.

TRIAL REGISTRATION

ISRCTN43171322.

Punctate white-matter lesions in the full-term newborn: Underlying aetiology and outcome

BACKGROUND

Punctate white matter lesions (PWMLs) are small focal patches of increased signal intensity (SI) on T1- and decreased SI on T2-weighted magnetic resonance imaging (MRI). To date, there have been few reports of PWMLs in term born infants.

OBJECTIVE

To identify associated diagnoses and factors predictive of clinical outcome in (near) term infants with PWMLs.

METHODS

MRI studies and clinical records of (near) term infants, with PWMLs on MRI scans performed in two institutions in the first 28 postnatal days were reviewed. The PWMLs were classified according to their number, pattern and distribution. The medical records were examined to assess the associated diagnoses and determine the neurodevelopmental outcome at >12 months of age. Infants with congenital heart defect(s), those who had neonatal surgery, or those with perinatal arterial ischemic stroke were not eligible for the study.

RESULTS

Forty-two (near) term infants with PWMLs were included. The major clinical association was perinatal asphyxia, present in 19/42 (45%). Ten (24%) had a history of seizures unrelated to asphyxia or a genetic diagnosis. Eleven (26%) had pathological genetic mutations. Other diagnoses, without seizures were identified in 2 (5%). The lesion load of PWMLs was high (>6) in 30/42 (71%). Evidence of irreversible white matter injury was present in 5 infants who had follow-up MRI performed between 18 and 24 months of age, because of clinical concerns. Five infants died and 37 had follow-up at a median age of 24 months. Neurodevelopmental outcome was poorest amongst 6 infants (16%) whose PWMLs occurred in the setting of a genetic disorder.

CONCLUSION

PWMLs in (near) term infants represent white matter injury that may evolve into gliosis and/or white matter loss. Infants with PWMLs in the setting of a genetic disorder appeared at most risk of a poor outcome.

Treatment thresholds for intervention in posthaemorrhagic ventricular dilation: a randomised controlled trial

OBJECTIVE

To compare a low versus a higher threshold for intervention in preterm infants with posthaemorrhagic ventricular dilatation.

DESIGN

Multicentre randomised controlled trial (ISRCTN43171322).

SETTING

14 neonatal intensive care units in six countries.

PATIENTS

126 preterm infants ≤34 weeks gestation with ventricular dilatation after grade III-IV haemorrhage were randomised to low threshold (LT) (ventricular index (VI) >p97 and anterior horn width (AHW) >6 mm) or higher threshold (HT) (VI>p97+4 mm and AHW >10 mm).

INTERVENTION

Cerebrospinal fluid tapping by lumbar punctures (LPs) (max 3), followed by taps from a ventricular reservoir, to reduce VI, and eventually a ventriculoperitoneal (VP) shunt if stabilisation of the VI below the p97+4 mm did not occur.

COMPOSITE MAIN OUTCOME MEASURE

VP shunt or death.

RESULTS

19 of 64 (30%) LT infants and 23 of 62 (37%) HT infants were shunted or died (P=0.45). A VP shunt was inserted in 12/64 (19%) in the LT and 14/62 (23%) infants in the HT group. 7/12 (58%) LT infants and 1/14 (7%) HT infants required shunt revision (P<0.01). 62 of 64 (97%) LT infants and 36 of 62 (58%) HT infants had LPs (P<0.001). Reservoirs were inserted in 40 of 64 (62%) LT infants and 27 of 62 (43%) HT infants (P<0.05).

CONCLUSIONS

There was no significant difference in the primary composite outcome of VP shunt placement or death in infants with posthaemorrhagic ventricular dilatation who were treated at a lower versus a higher threshold for intervention. Infants treated at the lower threshold received more invasive procedures. Assessment of neurodevelopmental outcomes will provide further important information in assessing the risks and benefits of the two treatment approaches.

Posthemorrhagic ventricular dilatation in preterm infants: When best to intervene?

OBJECTIVE

To compare neurodevelopmental outcomes of preterm infants with and without intervention for posthemorrhagic ventricular dilatation (PHVD) managed with an "early approach" (EA), based on ventricular measurements exceeding normal (ventricular index [VI] <+2 SD/anterior horn width <6 mm) with initial temporizing procedures, followed, if needed, by permanent shunt placement, and a "late approach" (LA), based on signs of increased intracranial pressure with mostly immediate permanent intervention.

METHODS

Observational cohort study of 127 preterm infants (gestation <30 weeks) with PHVD managed with EA (n = 78) or LA (n = 49). Ventricular size was measured on cranial ultrasound. Outcome was assessed at 18-24 months.

RESULTS

Forty-nine of 78 (63%) EA and 24 of 49 (49%) LA infants received intervention. LA infants were slightly younger at birth, but did not differ from EA infants for other clinical measures. Initial intervention in the EA group occurred at younger age (29.4/33.1 week postmenstrual age; p < 0.001) with smaller ventricles (VI 2.4/14 mm >+2 SD; p < 0.01), and consisted predominantly of lumbar punctures or reservoir taps. Maximum VI in infants with/without intervention was similar in EA (3/1.5 mm >+2 SD; p = 0.3) but differed in the LA group (14/2.1 mm >+2 SD; p < 0.001). Shunt rate (20/92%; p < 0.001) and complications were lower in EA than LA group. Most EA infants had normal outcomes (>-1 SD), despite intervention. LA infants with intervention had poorer outcomes than those without (p < 0.003), with scores <-2 SD in 81%.

CONCLUSION

In preterm infants with PHVD, those with early intervention, even when eventually requiring a shunt, had outcomes indistinguishable from those without intervention, all being within the normal range. In contrast, in infants managed with LA, need for intervention predicted worse outcomes. Benefits of EA appear to outweigh potential risks.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for preterm infants with PHVD, an EA to management results in better neurodevelopmental outcomes than a LA.

The Effect of Head Positioning and Head Tilting on the Incidence of Intraventricular Hemorrhage in Very Preterm Infants: A Systematic Review

BACKGROUND

Despite advances in neonatal intensive care, germinal matrix-intraventricular hemorrhage (GMH-IVH) remains a frequent, serious complication of premature birth. Neutral head position and head tilting have been suggested to reduce the risk of GMH-IVH in preterm infants during the first 72 h of life.

OBJECTIVE

The aim of this study was to provide a systematic review of the effect of neutral head positioning and head tilting on the incidence of GMH-IVH in very preterm infants (gestational age ≤30 weeks). In addition, we reviewed their effect on cerebral hemodynamics and oxygenation.

METHODS

Literature was searched (June 2016) in the following electronic databases: CINAHL, Embase, Medline, SCOPUS, and several trial registers.

RESULTS

One underpowered trial studied the effect of head positioning on the incidence of GMH-IVH. This randomized controlled trial enrolled 48 preterm infants and found no effect on the occurrence of GMH-IVH. Three observational studies investigated the effect of head rotation and/or tilting on cerebral oxygenation in 68 preterm infants in total. Their results suggest that cerebral oxygenation is not significantly affected by changes in head positioning. The effect of head positioning and/or tilting on cerebral hemodynamics was described in 2 observational studies of 28 preterm infants and found no significant effect.

CONCLUSIONS

There is insufficient evidence regarding the effect of head positioning and tilting on the incidence of GMH-IVH and cerebral hemodynamics and oxygenation in preterm infants. We recommend further research in this field, especially in extremely preterm and clinically unstable infants during the first postnatal days.

Congenital Amegakaryocytic Thrombocytopenia Type II Presenting with Multiple Central Nervous System Anomalies

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare autosomal recessive bone marrow failure, caused by MPL gene mutations. The combination of CAMT and central nervous system abnormalities is uncommon. We describe a case with a homozygous missense MPL gene mutation and polymicrogyria, underdevelopment of the cerebellum, and multiple intracranial hemorrhages.

Prognostic value of gradient echo T2* sequences for brain MR imaging in preterm infants

BACKGROUND

Gradient echo T2*-W sequences are more sensitive than T2-W spin-echo sequences for detecting hemorrhages in the brain.

OBJECTIVE

The aim of this study is to correlate presence of hemosiderin deposits in the brain of very preterm infants (gestational age <32 weeks) detected by T2*-W gradient echo MRI to white matter injury and neurodevelopmental outcome at 2 years.

MATERIALS AND METHODS

In 101 preterm infants, presence and location of hemosiderin were assessed on T2*-W gradient echo MRI performed around term-equivalent age (range: 40-60 weeks). White matter injury was defined as the presence of >6 non-hemorrhagic punctate white matter lesions (PWML), cysts and/or ventricular dilatation. Six infants with post-hemorrhagic ventricular dilatation detected by US in the neonatal period were excluded. Infants were seen for follow-up at 2 years. Univariate and regression analysis assessed the relation between presence and location of hemosiderin, white matter injury and neurodevelopmental outcome.

RESULTS

In 38/95 (40%) of the infants, hemosiderin was detected. Twenty percent (19/95) of the infants were lost to follow-up. There was a correlation between hemosiderin in the ventricular wall with >6 PWML (P < 0.001) and cysts (P < 0.001) at term-equivalent age, and with a lower psychomotor development index (PDI) (P=0.02) at 2 years. After correcting for known confounders (gestational age, gender, intrauterine growth retardation and white matter injury), the correlation with PDI was no longer significant.

CONCLUSION

The clinical importance of detecting small hemosiderin deposits is limited as there is no independent association with neurodevelopmental outcome.

Cranial ultrasound - optimizing utility in the NICU

Cranial ultrasonography (cUS) is a reliable tool to detect the most frequently occurring congenital and acquired brain abnormalities in full-term and preterm neonates. Appropriate equipment, including a dedicated ultrasound machine and appropriately sized transducers with special settings for cUS of the newborn brain, and ample experience of the ultrasonographist are required to obtain optimal image quality. When, in addition, supplemental acoustic windows are used whenever indicated and cUS imaging is performed from admission throughout the neonatal period, the majority of the lesions will be diagnosed with information on timing and evolution of brain injury and on ongoing brain maturation. For exact determination of site and extent of lesions, for detection of lesions that (largely or partially) remain beyond the scope of cUS and for depiction of myelination, a single, well timed MRI examination is invaluable in many high risk neonates. However, as cUS enables bedside, serial imaging it should be used as the primary brain imaging modality in high risk neonates.

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

BACKGROUND

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

AIMS

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

AIM

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

METHOD

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

RESULTS

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

INTERPRETATION

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

Neonatal Cerebral Sinovenous Thrombosis From Symptom to Outcome

Background and Purpose— Cerebral sinovenous thrombosis is a rare disease with severe neurological sequelae. The aim of this retrospective multicenter study was to investigate the clinical course, possible risk factors, and outcome of a cohort of neonatal patients with sinovenous thrombosis and, second, to estimate the incidence in The Netherlands.

Methods— From January 1999 to March 2009, a review of all neonatal patients with sinovenous thrombosis from 6 tertiary neonatal intensive care units was performed. Population characteristics, clinical presentation, (prothrombotic) risk factors, neuroimaging, interventions, and neurodevelopment were evaluated. An estimated incidence was calculated based on the Netherlands Perinatal Registry.

Results— Fifty-two neonates were included (39 boys) with a median gestational age of 39 weeks (range, 30 to 42 weeks; 5 preterm). An assisted or complicated delivery occurred in 32 of 52. Presenting symptoms developed at a median postnatal age of 1.5 days (range, 0 to 28 days) and consisted mainly of seizures (29 of 52). All sinovenous thrombosis cases were confirmed with MRI/MR venography. Multisinus thrombosis was most common followed by superior sagittal sinus thrombosis. FII G20210A mutation was present in 2 of 18 tested neonates (11%). Anticoagulation therapy (in 22 of 52) did not result in hemorrhagic complications. At follow-up (median age, 19 months; range, 3 to 72 months), moderate to severe neurological sequelae were present in 38%. The mortality was 10 of 52 (19%). A variable, although high yearly incidence of 1.4 to 12 per 100 000 term newborns was found.

Conclusions— Neonatal sinovenous thrombosis is a multifactorial disease. The estimated incidence in The Netherlands seems higher than reported elsewhere.

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

Introduction

Cranial ultrasound (cUS) may not be reliable for detection of diffuse white matter (WM) injury. Our aim was to assess in very preterm infants the reliability of a classification system for WM injury on sequential cUS throughout the neonatal period, using magnetic resonance imaging (MRI) as reference standard.

Methods

In 110 very preterm infants (gestational age <32 weeks), serial cUS during admission (median 8, range 4–22) and again around term equivalent age (TEA) and a single MRI around TEA were performed. cUS during admission were assessed for presence of WM changes, and contemporaneous cUS and MRI around TEA additionally for abnormality of lateral ventricles. Sequential cUS (from birth up to TEA) and MRI were classified as normal/mildly abnormal, moderately abnormal, or severely abnormal, based on a combination of findings of the WM and lateral ventricles. Predictive values of the cUS classification were calculated.

Results

Sequential cUS were classified as normal/mildly abnormal, moderately abnormal, and severely abnormal in, respectively, 22%, 65%, and 13% of infants and MRI in, respectively, 30%, 52%, and 18%. The positive predictive value of the cUS classification for the MRI classification was high for severely abnormal WM (0.79) but lower for normal/mildly abnormal (0.67) and moderately abnormal (0.64) WM.

Conclusion

Sequential cUS during the neonatal period detects severely abnormal WM in very preterm infants but is less reliable for mildly and moderately abnormal WM. MRI around TEA seems needed to reliably detect WM injury in very preterm infants.

Neuroimaging in very preterm infants

Cranial ultrasonography (cUS) and MRI are the preferred modalities used to image the neonatal brain. Both have their specific contributions and advantages. A neuroimaging study, including sequential cUS and single MRI, was performed in a cohort of very preterm infants (gestational age <32 weeks). The major aims were: to study brain imaging findings and to assess the incidences of brain abnormalities and the relationship between brain abnormalities and perinatal clinical parameters; to compare cUS and MRI findings; to describe imaging findings of the thalami and basal ganglia; and to study the reliability of cUS for detection of (diffuse) white matter injury. Patients & methods: Very preterm infants, born during a 1.5-year period, were eligible if there were no exclusion criteria (i.e., metabolic and genetic disorders, or infections and/or congenital malformations of the CNS). Sequential cUS was performed from admission until discharge and on the day of the MRI following a standardized protocol. MRI (3 Tesla) was performed around or shortly after term equivalent age (TEA). Results: A total of 133 infants were included. The mean number of cUS scans per infant was 8.3 (range: 2–23). MRI was performed in 113 infants at a mean postmenstrual age of 44.7 weeks (range: 40.0–55.9). During admission we found periventricular echodensities and intraventricular hemorrhage in 80 and 30% of infants, respectively – both significantly associated with male gender. The incidence of lenticulo striate vasculopathy (LSV) was 19%. Around TEA, ventricular dilatation and widening of extracerebral spaces were frequent findings. In addition, MRI showed punctate white matter lesions and diffuse excessive high-signal intensity. MRI detected subtle white matter lesions more effectively, whereas cUS was better for the detection of LSV, calcifications and germinolytic and plexus cysts. Diffuse, subtle echogenicity of the basal ganglia and thalami was observed in the majority of infants with normal MRI findings in this area. Focal deep gray matter lesions were only rarely encountered. Conclusions: In very preterm infants, frequent, sequential cUS is an excellent tool to image and follow the brain throughout the neonatal period and detects some lesions and transient changes more effectively than MRI. Single MRI provides invaluable and detailed additional information on the growth and development of, and injury to, the brain. Sequential cUS throughout the neonatal period and a single MRI around TEA are therefore warranted. Bilateral, diffuse and subtle echogenicity in the deep gray matter on cUS probably reflects (normal) maturational processes in the immature brain. With the exception of LSV, focal lesions in the deep gray matter are rare and need to be distinguished from benign phenomena in the deep gray matter. Sequential high-quality cUS during the neonatal period predicts severe white matter injury, but is less predictive of mild-to-moderate white matter injury around TEA.

Cranial ultrasonography in neonates: role and limitations

In experienced hands, cranial ultrasonography (cUS) is an excellent tool to detect the most frequently occurring brain abnormalities in preterm and full-term neonates, to study the evolution of lesions, and to follow brain maturation. It enables screening of the brain and serial imaging in high-risk neonates. However, cUS also has limitations and magnetic resonance imaging is needed in most neonates with (suspected) parenchymal brain injury and/or neurological symptoms and in very preterm infants. In this review, we discuss the applications, possibilities, indications, predictive value, and limitations of neonatal cUS. We will pay attention to the standard cUS procedure and expand on optimizing the possibilities of cUS by using supplemental acoustic windows and changing transducers and focus points. For illustration numerous cUS images are provided.

Frequently encountered cranial ultrasound features in the white matter of preterm infants: correlation with MRI

BACKGROUND

Bilateral symmetrical echogenic and echolucent areas in the white matter are frequently seen on the cranial ultrasound scans of apparently well preterm infants without overt pathology.

AIM

To determine whether these features reflect maturational processes as seen on MRI.

METHODS

Preterm and term-born infants without overt pathology on contemporaneous brain ultrasound and MRI were studied. Ultrasound scans were compared with T(2)-weighted MRI to identify MR correlates for the bilateral and symmetrical echogenic and echolucent phenomena in the white matter seen on ultrasound.

RESULTS

Forty-four sets of scans (26 preterm, 8 term-born infants) were assessed. Echogenic features were better and more frequently seen on early ultrasound as compared to nearer term age. Echogenic blushes in the white matter correlated well with high signal intensity areas and echogenic lines with low signal intensity lines on MRI. Echolucent areas correlated with the site of the internal capsule and the myelinated posterior pons. The subplate was not reliably identified.

CONCLUSION

Many echogenic and echolucent features in the white matter of well preterm and some term-born infants correlated well with areas of differing signal intensity on MRI. They most likely reflect normal maturational processes but the echogenic hemispheric features may represent delayed or abnormal maturation.

Cerebellar injury in preterm infants: incidence and findings on US and MR images

PURPOSE

To investigate the incidence and characteristics of cerebellar injury in a cohort of very preterm infants by using the mastoid fontanelle (MF) and posterior fontanelle (PF) approach in addition to routine cranial ultrasonography (US) through the anterior fontanelle (AF), with magnetic resonance (MR) imaging as the reference standard.

MATERIALS AND METHODS

The institutional review board approved this prospective study and informed consent was obtained. A cohort of 77 preterm infants (< 32 weeks) was examined with serial cranial US throughout the neonatal period by using the AF, PF, and MF views. MR imaging was performed around term-equivalent age in 59 of 77 infants. Sensitivity, specificity, positive predictive value, and negative predictive value of routine cranial US and cranial US with additional views were calculated.

RESULTS

At cranial US performed through the MF, seven (9%) of 77 infants were identified to have posterior fossa hemorrhage. In only two of seven infants, the lesions were seen on routine AF views. The PF approach did not increase the detection rate of posterior fossa hemorrhage. MR images confirmed cranial US findings in all cases. MR images showed punctate hemorrhage in the cerebellum in six infants with normal cranial US findings. Among the 59 infants examined with both cranial US and MR imaging, cerebellar injury was diagnosed in 11 (19%).

CONCLUSION

Cerebellar injury is a frequent finding in very preterm infants. Cranial US through the MF can demonstrate injury missed by using the routine AF approach. Punctate hemorrhagic lesions may remain undetected even when the MF approach is used; the prognostic implications of these smaller lesions need further attention.

Brain imaging findings in very preterm infants throughout the neonatal period: part II. Relation with perinatal clinical data

This study describes the relation between frequent and clinically relevant brain imaging findings in very preterm infants (GA<32 weeks), assessed with sequential cranial ultrasonography throughout the neonatal period and MRI around term age, and several potential perinatal risk factors. For ultrasound findings during admission the following independent risk factors were identified: male gender for periventricular echodensities and intraventricular haemorrhage, postnatal corticosteroid treatment for cystic white matter lesions, and lower gestational age for post-haemorrhagic ventricular dilatation. For MRI findings around term age, including punctate white matter lesions, ventricular dilatation, decreased cortical complexity, and diffuse and excessive high signal intensity, no independent risk factors were found. In very preterm infants, the risk factors for frequently found changes on cranial ultrasound have largely remained unchanged over the last decades, while no risk factors could be identified for subtle and diffuse white matter injury as seen on MRI around term age.

Brain imaging findings in very preterm infants throughout the neonatal period: part I. Incidences and evolution of lesions, comparison between ultrasound and MRI

This study describes the incidence and evolution of brain imaging findings in very preterm infants (GA<32 weeks), assessed with sequential cranial ultrasound (cUS) throughout the neonatal period and MRI around term age. The accuracy of both tools is compared for findings obtained around term. Periventricular echodensities and intraventricular haemorrhage were the most frequent cUS findings during admission. Frequent findings on both cUS and MRI around term included ventricular dilatation, widened extracerebral spaces, and decreased cortical complexity. MRI additionally showed punctate white matter lesions and diffuse and excessive high signal intensity, but did not depict lenticulostriate vasculopathy and calcifications, and was less reliable for germinolytic and plexus cysts. cUS detected most abnormalities that have been associated with abnormal neurodevelopmental outcome.

Neonatal cranial ultrasonography: how to optimize its performance

Cranial ultrasonography (CUS) is an excellent and non invasive tool for brain imaging during the neonatal period. It is traditionally performed through the anterior fontanel. Although the advantages of CUS are numerous, there are also diagnostic limitations. Alternative imaging techniques including the use of different transducer types and frequencies and of additional acoustic windows can improve image quality and the diagnostic accuracy of CUS. This review will focus on techniques to be applied for optimizing the performance of CUS in the newborn infant.

Fetal brain sonography and fetal heart rate patterns in the preterm fetus

OBJECTIVE

The objective of the study was to study whether peri- and intraventricular echodensities in the brain of fetuses at risk for preterm birth are associated with changes in fetal heart rate (FHR) parameters.

STUDY DESIGN

Twenty preterm fetuses with peri- and intraventricular echodensities detected by transvaginal ultrasonography were matched with 20 fetuses without echodensities for gestational age, growth parameters, clinical disease, and maternal medication. Baseline FHR, long- and short-term variability, and the presence of accelerations and decelerations were analyzed with a computerized system and compared with the Wilcoxon matched-pairs signed-rank test. Both cases and controls were compared with a normal population.

RESULTS

No statistical differences in FHR parameters were found between cases with and controls without peri- and intraventricular echodensities. Both cases and controls had lower long- and short-term variabilities than the normal population.

CONCLUSION

No association between the presence of peri- and intraventricular echodensities and specific FHR changes was demonstrated.

Differentiation between peritrigonal terminal zones and hypoxic-ischemic white matter injury on MRI

The differentiation between terminal zones and pathological signal intensity changes on MRI of children and young adults is of diagnostic importance. We assessed the diagnostic value of several morphological features on MRI to differentiate between terminal zones and hypoxic-ischemic white matter injury. We selected all brain MRI examinations performed in subjects up to 20 years of age showing increased signal intensity on T2-weighted images in the peritrigonal areas. 75 individuals were assigned to a patient group (n=28) if there was evidence of hypoxia-ischemia during the perinatal period or a control group (n=47). Aspect, location, extent, shape, and borders of signal intensity changes in the peritrigonal areas were studied. Signal intensity of the peritrigonal areas was related to signal intensity of surrounding white matter. Presence of Virchow Robin spaces, hypoxic-ischemic abnormalities, and local atrophy were also recorded. Chi-squared tests assessed whether presence or absence of morphological characteristics differed between patients and controls. Logistic regression analysis studied which characteristics were best to discriminate between the two groups. Very high signal intensity of the peritrigonal areas on FLAIR (Odds Ratio 25) and presence of local atrophy (Odds Ratio 14.3) were best predictors to discriminate between the two groups.

Incidence, origin, and character of cerebral injury in twin-to-twin transfusion syndrome treated with fetoscopic laser surgery

OBJECTIVE

The objective of the study was to determine the incidence, origin, and character of cerebral lesions in monochorionic twins with twin-to-twin transfusion syndrome treated with fetoscopic laser surgery.

STUDY DESIGN

This was a prospective study of monochorionic twins with twin-to-twin transfusion syndrome treated with fetoscopic laser surgery and monochorionic twins without twin-to-twin transfusion syndrome delivered at our center between June 2002 and September 2005, using cranial ultrasonography.

RESULTS

Incidence of antenatally acquired severe cerebral lesions in the twin-to-twin transfusion syndrome group was 10% (8/84) and 2% (2/108) in the non-twin-to-twin transfusion syndrome group (P = .02). Incidence of severe cerebral lesions at discharge was 14% (12/84) in the twin-to-twin transfusion syndrome group and 6% (6/108) in the non-twin-to-twin transfusion syndrome group (P = .04). Antenatal injury was responsible for severe cerebral lesions in 67% (8/12) of the twin-to-twin transfusion syndrome group.

CONCLUSION

Incidence of severe cerebral lesions in twin-to-twin transfusion syndrome treated with fetoscopic laser surgery is high and results mainly from antenatal injury.

Preoperative cranial ultrasound findings in infants with major congenital heart disease

BACKGROUND

Advances in diagnostic testing and surgical techniques have resulted in reduced mortality in neonates with congenital heart disease (CHD) and a major concern for neurological morbidity in the presence of preoperative neurological injury.

OBJECTIVES

To determine the incidence and nature of preoperative cerebral ultrasound abnormalities in neonates with major CHD and to examine the relationship between cerebral abnormalities and the type of CHD.

METHODS

Retrospective study; inclusion criteria: (1) neonates with major CHD admitted to the NICU over a 3-y period, (2) gestational age >35 wk, (3) documented preoperative cranial ultrasound available; exclusion criteria: (1) small for gestational age, (2) other congenital anomalies and/or chromosomal abnormalities, (3) a 5-min Apgar score <7, (4) congenital infection. Cranial ultrasounds (CUS) were reviewed without knowledge of the cardiac defect. CHDs were categorized.

RESULTS

Fifty of 108 neonates with CHD met the inclusion criteria. Twenty-one patients (42%) had abnormalities on CUS. Thirteen of these (26%) had widened ventricular and/or subarachnoid spaces, three (6%) lenticulostriate vasculopathy, one (2%) calcification in the basal nuclei, and four (8%) had acute ischaemic changes. Cerebral abnormalities occurred more frequently in patients with coarctation or hypoplastic left heart syndrome (HLHS) than transposition of the great arteries (TGA) (63% vs 14%; n.s.).

CONCLUSION

There is a high incidence of preoperative cerebral ultrasound abnormalities in this group of neonates with major CHD.