Neonatal cranial ultrasound interpretation: a clinical audit

The value of magnetic resonance imaging in congenital cytomegalovirus infection: a systematic review

Congenital cytomegalovirus (cCMV) infection can lead to severe neurodevelopmental and hearing impairments. Imaging techniques can be used both pre- and postnatally to assess early signs of infection. The objective was to provide a systematic review of current literature regarding magnetic resonance imaging (MRI) and its value to predict clinical outcome in children with cCMV. PubMed, Embase, and Web of Science were searched for studies investigating MRI in cCMV between 2016-2024. Risk of bias was assessed using Newcastle-Ottawa quality assessment scales. Descriptive synthesis was performed. Twenty studies were included. MRI detected brain abnormalities in 5.0-53.0% of infected patients prenatally and 26.9-69.0% postnatally. The three most frequently detected abnormalities included white matter lesions, subependymal cysts, and ventricular dilatation. Symptoms at birth, first trimester seroconversion, and high viral load were associated with abnormal MRI; however, brain abnormalities were still found in 33-37% of clinically asymptomatic patients. Prenatal MRI had a negative predictive value of 94-100% and a positive predictive value of 12-60% for predicting adverse clinical outcome. Five in six studies found an association between MRI abnormalities and neurodevelopmental impairments, five in eight with (congenital) hearing loss. MRI detected additional abnormalities in 5.6-19.4% of children with normal ultrasound. In conclusion, MRI can detect a wide range of brain abnormalities, both pre- and postnatally, in symptomatic and asymptomatic patients. MRI can be a helpful tool in the prediction of clinical impairments and seems complementary to ultrasound. Therefore, both fetal and neonatal MRI should be considered in the standard work-up of all cCMV-infected children.

‘State-of-the-Art’ Neonatal Cranial Ultrasound

Cranial ultrasound (cUS) provides bedside imaging access to the neonatal brain. Modern scanners and the use of various acoustic windows give detail not only of the well known pathologies met in the preterm infant, but also allow assessment of more subtle aspects of normal and abnormal brain growth and development. cUS is also very helpful in the early diagnosis of the many aetiologies of neonatal encephalopathy and seizures in the term infant and the subsequent monitoring of progress of hypoxic-ischaemic brain injury. Training issues in cUS need to be addressed.

Serial cranial ultrasonography or early MRI for detecting preterm brain injury?

OBJECTIVE

To investigate detection ability and feasibility of serial cranial ultrasonography (CUS) and early MRI in preterm brain injury.

DESIGN

Prospective cohort study.

SETTING

Level III neonatal intensive care unit.

PATIENTS

307 infants, born below 29 weeks of gestation.

METHODS

Serial CUS and MRI were performed according to standard clinical protocol. In case of instability, MRI was postponed or cancelled. Brain images were assessed by independent experts and compared between modalities.

MAIN OUTCOME MEASURES

Presence of preterm brain injury on either CUS or MRI and discrepant imaging findings on CUS and MRI.

RESULTS

Serial CUS was performed in all infants; early MRI was often postponed (n=59) or cancelled (n=126). Injury was found in 146 infants (47.6%). Clinical characteristics differed significantly between groups that were subdivided according to timing of MRI. 61 discrepant imaging findings were found. MRI was superior in identifying cerebellar haemorrhage; CUS in detection of acute intraventricular haemorrhage, perforator stroke and cerebral sinovenous thrombosis.

CONCLUSIONS

Advanced serial CUS seems highly effective in diagnosing preterm brain injury, but may miss cerebellar abnormalities. Although MRI does identify these lesions, feasibility is limited. Improved safety, better availability and tailored procedures are essential for MRI to increase its value in clinical care.

Early predictors of outcome in infants treated with hypothermia for hypoxic-ischaemic encephalopathy

Hypoxic-ischaemic encephalopathy (HIE) is a leading cause of acquired neonatal brain injury. Assessment of the severity of cerebral injury and likely neurological outcome in infants with HIE is important for determining management and prognosis, for counselling parents, and for selection for neuroprotective trials. The condition of the infant at birth, the severity of HIE, neurophysiological tests, including amplitude-integrated electroencephalography (aEEG), biochemical markers, and neuroimaging have been used to assess prognosis and predict long-term outcome. The predictive accuracy of these indicators in the early postnatal period is modest. Neurophysiological assessment seems to be most helpful during the first 24 to 48 hours after birth whilst magnetic resonance imaging (MRI) seems most informative later. Several biochemical markers, including serum S100β and neuron-specific enolase (NSE), are also associated with HIE but their levels depend on the timing of sampling and their prognostic value is uncertain. Comprehensive neurophysiological assessment and neuroimaging may be limited to specialist centres. Therapeutic hypothermia is now standard care in infants with moderate to severe HIE so it is important to examine the influence of hypothermia on the assessment of prognosis in these infants.

Mother's voice and heartbeat sounds elicit auditory plasticity in the human brain before full gestation

Brain development is largely shaped by early sensory experience. However, it is currently unknown whether, how early, and to what extent the newborn's brain is shaped by exposure to maternal sounds when the brain is most sensitive to early life programming. The present study examined this question in 40 infants born extremely prematurely (between 25- and 32-wk gestation) in the first month of life. Newborns were randomized to receive auditory enrichment in the form of audio recordings of maternal sounds (including their mother's voice and heartbeat) or routine exposure to hospital environmental noise. The groups were otherwise medically and demographically comparable. Cranial ultrasonography measurements were obtained at 30 ± 3 d of life. Results show that newborns exposed to maternal sounds had a significantly larger auditory cortex (AC) bilaterally compared with control newborns receiving standard care. The magnitude of the right and left AC thickness was significantly correlated with gestational age but not with the duration of sound exposure. Measurements of head circumference and the widths of the frontal horn (FH) and the corpus callosum (CC) were not significantly different between the two groups. This study provides evidence for experience-dependent plasticity in the primary AC before the brain has reached full-term maturation. Our results demonstrate that despite the immaturity of the auditory pathways, the AC is more adaptive to maternal sounds than environmental noise. Further studies are needed to better understand the neural processes underlying this early brain plasticity and its functional implications for future hearing and language development.

Magnesium sulphate given before very-preterm birth to protect infant brain: the randomised controlled PREMAG trial*

OBJECTIVE

To evaluate whether magnesium sulphate (MgSO(4)) given to women at risk of very-preterm birth would be neuroprotective in preterm newborns and would prevent neonatal mortality and severe white-matter injury (WMI).

DESIGN

A randomised study.

SETTING

Eighteen French tertiary hospitals. Population Women with fetuses of gestational age < 33 weeks whose birth was planned or expected within 24 hours were enrolled from July 1997 to July 2003 with follow up of infants until hospital discharge. METHODS Five hundred and seventy-three mothers were randomly assigned to receive a single 40-ml infusion of 0.1 g/ml of MgSO(4) (4 g) solution or isotonic 0.9% saline (placebo) over 30 minutes. This study is registered as an International Standard Randomised Controlled Trial, number 00120588.

MAIN OUTCOME MEASURES

The primary endpoints were rates of severe WMI or total mortality before hospital discharge, and their combined outcome. Analyses were based on intention to treat.

RESULTS

After 6 years of enrolment, the trial was stopped. Data from 688 infants were analysed. Comparing infants who received MgSO(4) or placebo, respectively, total mortality (9.4 versus 10.4%; OR: 0.79, 95% CI 0.44-1.44), severe WMI (10.0 versus 11.7%; OR: 0.78, 95% CI 0.47-1.31) and their combined outcomes (16.5 versus 17.9%; OR: 0.86, 95% CI 0.55-1.34) were less frequent for the former, but these differences were not statistically significant. No major maternal adverse effects were observed in the MgSO(4) group.

CONCLUSION

Although our results are inconclusive, improvements of neonatal outcome obtained with MgSO(4) are of potential clinical significance. More research is needed to assess the protective effect of MgSO(4) alone or in combination with other neuroprotective molecules.

Using cerebral ultrasound effectively in the newborn infant

Cranial ultrasound is the most available and easily repeatable technique for imaging the neonatal brain. Its quality and diagnostic accuracy depend on various factors; the suitability of the ultrasound machine for neonatal cranial work, the use of optimal settings and probes, appropriate scanning protocols, the use of a variety of acoustic windows and, not least, the scanning experience of the examiner. Knowledge of normal anatomy and the echogenicities of different tissues in normal and pathological situations as well as familiarity with the physiological and pathological processes likely to be encountered is vital. This paper assesses the value and appropriate use, safety and diagnostic accuracy of modern, high-quality ultrasound in evaluating the brain of the preterm and term born infant. Issues of concern regarding teaching, supervision and experience of the examiner are also addressed.

Cerebral palsy among very preterm children in relation to gestational age and neonatal ultrasound abnormalities: the EPIPAGE cohort study

OBJECTIVE

To estimate the prevalence of cerebral palsy at 2 years of age among children born very preterm, according to gestational age, infant gender, plurality, and neonatal cranial ultrasound abnormalities.

METHODS

All infants born between 22 and 32 weeks of gestation in 9 regions of France in 1997 were included in this prospective, population-based, cohort study. The main outcome measure was cerebral palsy prevalence at 2 years. Of the 2364 survivors eligible for follow-up evaluation, 1954 (83%) were assessed at 2 years of age.

RESULTS

Among the 1954 children assessed at 2 years, 8.2% had cerebral palsy. Bilateral spastic cerebral palsy, hemiplegia, and monoplegia accounted for 72%, 9%, and 10% of cases, respectively. Fifty percent of the children with cerebral palsy walked independently at the age of 2, 31% were unable to walk but could sit independently, and 19% could not sit (unable to maintain head and trunk control). The prevalence of cerebral palsy was 20% at 24 to 26 weeks of gestation, compared with 4% at 32 weeks. On the basis of ultrasound findings in the neonatal period, we found that 17% of children with isolated grade III intraventricular hemorrhage and 25% of children with white matter damage (ie, ventricular dilation, persistent echodensities, or cystic periventricular leukomalacia) had cerebral palsy, compared with 4% of children with normal ultrasound scans.

CONCLUSIONS

Despite recent improvements in survival rates, cerebral palsy remains highly prevalent among very preterm children. Severe cranial ultrasound abnormalities predict motor disability strongly, but one third of infants with cerebral palsy had no ultrasound abnormalities.

Variable interpretation of ultrasonograms may contribute to variation in the reported incidence of white matter damage between newborn intensive care units in New Zealand

BACKGROUND

The incidence of cerebral white matter damage reported to the Australian and New Zealand Neonatal Network (ANZNN) varies between neonatal intensive care units (NICUs).

HYPOTHESIS

Differences in the capture, storage, and interpretation of the cerebral ultrasound scans could account for some of this variation.

METHODS

A total of 255 infants of birth weight <1500 g and gestation <32 weeks born between 1997 and 2002 and drawn equally from each of the six NICUs in New Zealand were randomly selected from the ANZNN database. Half had early cerebral ultrasound scans previously reported to ANZNN as normal, and half had scans reported as abnormal. The original scans were copied, anonymised, and independently read by a panel of three experts using a standardised method of reviewing and reporting.

RESULTS

There was considerable variation between NICUs in methods of image capture, quality, and completeness of the scans. There was only moderate agreement between the reviewers' reports and the original reports to the ANZNN (kappa 0.45-0.51) and between the reviewers (kappa 0.54-0.64). The reviewers reported three to six times more white matter damage than had been reported to the ANZNN.

CONCLUSION

Some of the reported variation in white matter damage between NICUs may be due to differences in capture and interpretation of cerebral ultrasound scans.

Does variation in interpretation of ultrasonograms account for the variation in incidence of germinal matrix/intraventricular haemorrhage between newborn intensive care units in New Zealand?

BACKGROUND

The incidence of germinal matrix/intraventricular haemorrhage (GM/IVH) reported to the Australian and New Zealand Neonatal Network (ANZNN) varies between neonatal intensive care units (NICUs).

HYPOTHESIS

Differences in the capture, storage, and interpretation of the cerebral ultrasound scans may account for some of this variation.

METHODS

A total of 255 infants with birth weight <1500 g and gestation <32 weeks born between 1997 and 2002 were randomly selected from the ANZNN database, 44 from each of the six NICUs in New Zealand. Twenty two infants from each NICU had cerebral ultrasound scans previously reported to ANZNN as normal; another 22 had scans reported as abnormal. The original scans were copied using digital photography and anonymised and independently read by a panel of three experts using a standardised method of reviewing and reporting.

RESULTS

There was considerable variation between NICUs in methods of image capture and quality and completeness of the scans. However, there was little variation in the reporting of scans between the reviewers and the reports to ANZNN (weighted kappa 0.75-0.91). Grade 1 GM/IVH was generally over-reported and grade 4 under-reported to the ANZNN.

CONCLUSION

For all NICUs, a high level of agreement was found between the reviewers' reports and the reports to the ANZNN. Thus the variation between NICUs in the incidence of GM/IVH reported to the ANZNN is unlikely to be due to differences in capture, storage, and interpretation of the cerebral ultrasound scans. Further investigation is warranted into the reasons for the variation in incidence of GM/IVH between NICUs.

The EPICure study: associations and antecedents of neurological and developmental disability at 30 months of age following extremely preterm birth

AIMS

To describe perinatal factors associated with later morbidity among extremely preterm children at 30 months of age corrected for prematurity.

POPULATION

Of 308 surviving children born at <or=25 weeks gestation in the United Kingdom and Ireland from March to December 1995, 283 (92%) were evaluated at 30 months of age corrected for prematurity.

METHODS

Cerebral palsy, severe motor disability, and Bayley scores were used as dependent variables in sequential multiple regression analyses to identify factors associated with adverse outcomes.

RESULTS

Adverse outcomes were consistently more common in boys. Factors related to perinatal illness, ultrasound evidence of brain injury, and treatment (particularly postnatal steroids) were associated with adverse motor outcomes (cerebral palsy, disability or Bayley psychomotor development index). Increasing duration of postnatal steroid treatment was associated with poor motor outcomes. A score was developed for severe motor disability with good negative predictive value. In contrast, mental development was associated with a broader range of factors: ethnic group, maternal educational level, the use of antenatal steroids, and prolonged rupture of membranes in addition to chronic lung disease.

CONCLUSION

Male sex is a pervasive risk factor for poor outcome at extremely low gestations. Avoidable or effective treatment factors are identified, which may indicate the potential for improving outcome.

Training in neonatal cranial ultrasound: a questionnaire survey

A questionnaire was sent to every paediatric specialist registrar in the West Midlands to assess the training of paediatric specialist registrars in neonatal cranial ultrasound. 26% had never carried out supervised scans. 51% lacked confidence in performance and 57% in interpretation of scans. The current pattern of training in neonatal cranial ultrasound lacks structure, supervision and assessment of competency.

White matter damage and intraventricular hemorrhage in very preterm infants: the EPIPAGE study

OBJECTIVE

To evaluate the prevalence of cranial ultrasound abnormalities in very preterm infants as a function of gestational age, plurality, intrauterine growth restriction, and death before discharge.

STUDY DESIGN

A prospective, population-based cohort of 2667 infants born between 22 and 32 weeks of gestation in 1997 in nine regions of France, transferred to a neonatal intensive care unit, for whom at least one cranial ultrasound scan was available.

RESULTS

The frequencies of white matter damage (WMD), major WMD, cystic periventricular leukomalacia (PVL), periventricular parenchymal hemorrhagic involvement, and intraventricular hemorrhage with ventricular dilatation were 21%, 8%, 5%, 3%, and 3%, respectively. The risk of WMD increased with decreasing gestational age. Mean age at diagnosis of cystic PVL was older for the most premature infants. Intraventricular hemorrhage with ventricular dilatation was associated with a higher risk of cystic PVL. Intrauterine growth restriction was not associated with a lower prevalence of cystic PVL.

CONCLUSION

The frequency of WMD is high in very preterm babies and is strongly related to gestational age. The incidence of cystic PVL did not differ between babies with intrauterine growth restriction and babies who were appropriate for gestational age.