Early diagnosis and outcome prediction of neonatal hypoxic-ischemic encephalopathy with color Doppler ultrasound

Main features and disease outcome of congenital myotonic dystrophy - experience from a single tertiary center

Congenital myotonic dystrophy type 1 (CDM1) is a rare neuromuscular disease. The aim of our study was to evaluate clinical variability of CDM1 and factors that may influence survival in CDM1. Research included 24 pediatric patients with CDM1. Most of our patients had some form of hypoxic ischemic encephalopathy (HIE) (74 %), from mild to severe. Prolonged and complicated deliveries (75 %), high percentage of children resuscitated at birth (57 %) and respiratory insufficiency (46 %) with consequent hypoxia were the main reasons that could explain high percentage of HIE. Therapeutic hypothermia was applied in three children with poor outcome. Median survival of all CDM1 was 14.2 ± 1.5 years. Six patients had a fatal outcome (25 %). Their mean age of death was 3.0 ± 2.8 years. Poor prognostic factors for the survival of our CDM1 patients were: preterm delivery, resuscitation at birth, severe HIE, hypothermia treatment and permanent mechanical ventilation. Respiratory insufficiency was the main life-threatening factor. Our data clearly indicates the need to develop natural history studies in CDM1 in order to enhance the standards of care and to develop clinical trials investigating causative therapies in pediatric patients with CDM1.

Neonatal cerebral ultrasound: anatomical variants and age-related diseases

Cerebral ultrasound is a non-invasive imaging technique widely used for the assessment of brain anatomy and diseases in neonates and infants. Indeed, it allows a precise characterization of common variants such as cavum septum pellucidum or diseases like intraventricular hemorrhage. The aim of this pictorial review is to provide a comprehensive overview of the main ultrasound features of the most common cerebral anatomical variants and disorders detectable by cerebral ultrasound using an age-related approach which could support non-subspecialized radiologists.

Transcranial Doppler Ultrasonography detection on cerebrovascular flow for evaluating neonatal hypoxic-ischemic encephalopathy modeling

Objective

This study aimed to investigate the feasibility of Transcranial Doppler Ultrasonography (TCD) in evaluating neonatal hypoxic-ischemic encephalopathy (NHIE) modeling through monitoring the alteration of cerebrovascular flow in neonatal hypoxic-ischemic (HI) rats.

Methods

Postnatal 7-day-old Sprague Dawley (SD) rats were divided into the control group, HI group, and hypoxia (H) group. TCD was applied to assess the changes of cerebral blood vessels, cerebrovascular flow velocity, and heart rate (HR) in sagittal and coronal sections at 1, 2, 3, and 7 days after the operation. For accuracy, cerebral infarct of rats was examined by 2,3,5-Triphenyl tetrazolium chloride (TTC) staining and Nissl staining to simultaneously verify the establishment of NHIE modeling.

Results

Coronal and sagittal TCD scans revealed obvious alteration of cerebrovascular flow in main cerebral vessels. Obvious cerebrovascular back-flow was observed in anterior cerebral artery (ACA), basilar artery (BA), middle cerebral artery (MCA) of HI rats, along with accelerated cerebrovascular flows in the left internal carotid artery (ICA-L) and BA, decreased flows in right internal carotid artery (ICA-R) relative to those in the H and control groups. The alterations of cerebral blood flows in neonatal HI rats indicated successful ligation of right common carotid artery. Besides, TTC staining further validated the cerebral infarct was indeed caused due to ligation-induced insufficient blood supply. Damage to nervous tissues was also revealed by Nissl staining.

Conclusion

Cerebral blood flow assessment by TCD in neonatal HI rats contributed to cerebrovascular abnormalities observed in a real-time and non-invasive way. The present study elicits the potentials to utilize TCD as an effective means for monitoring the progression of injury as well as NHIE modeling. The abnormal appearance of cerebral blood flow is also beneficial to the early warning and effective detection in clinical practice.

Neuroprotective effects of oxymatrine on hypoxic-ischemic brain damage in neonatal rats by activating the Wnt/β-catenin pathway

Neuronal apoptosis is a major pathological process associated with neurological dysfunction in neonates after hypoxic-ischemic brain damage (HIBD). Our previous study demonstrated that oxymatrine (OMT) exerts potential neuroprotective effects on neonatal rats subjected to hypoxic-ischemic insult. However, the underlying molecular mechanism remains unclear. In this study, we investigated the effects of OMT-mediated neuroprotection on neonatal HIBD by attempting to determine its effect on the Wnt/β-catenin signaling pathway and explored the underlying mechanism. Both 7-day-old rat pups and primary hippocampus neurons were used to establish the HIBD and oxygen-glucose deprivation (OGD) injury models, respectively. Our results demonstrated that OMT treatment significantly increased cerebral blood flow and reduced S100B concentration, infarct volume, and neuronal apoptosis in neonatal rats. In vitro, OMT markedly increased cell viability and MMP level and decreased DNA damage. Moreover, OMT improved the mRNA and protein levels of Wnt1 and β-catenin, inhibited the expression of DKK1 and GSK-3β, enhanced the nuclear transfer of β-catenin, and promoted the binding activity of β-catenin with Tcf-4; however, it downregulated the expression of cleaved caspase-3 and cleaved caspase-9. Notably, the introduction of XAV-939 (a Wnt/β-catenin signaling inhibitor) reversed the positive effects of OMT both in vivo and in vitro. Collectively, our findings demonstrated that OMT exerted a neuroprotective effect on neonatal HIBD by inhibiting neuronal apoptosis, which was partly via the activation of the Wnt/β-catenin signaling pathway.

Application of brain ultrasound in premature infants with brain injury

Brain injury is the main factor affecting the development and prognosis of the nervous system in premature infants. Early diagnosis and treatment are of great significance in reducing mortality and disability and improving the prognosis of premature infants. Craniocerebral ultrasound has become an important medical imaging method for evaluating the brain structure of premature infants due to its advantages of being non-invasive, cheap, simple, and bedside dynamic monitoring since it was applied to neonatal clinical practice. This article reviews the application of brain ultrasound to common brain injuries in premature infants.

Assessment of role of cranial ultrasound (CUS) in the evaluation of high-risk preterm and term neonates

Background

Cranial ultrasonography (CUS) has become an important tool to depict normal brain anatomy and to detect the ischemic and hemorrhagic brain injury patterns in high-risk neonates. The present study aimed to assess the utility of CUS to diagnose the spectrum of brain injury patterns in high-risk preterm and term neonates admitted to the neonatal intensive care unit (NICU) and to find the association of CUS findings in various adverse antenatal and perinatal feto-maternal factors.

Results

Out of the 200 neonates, 76 (38%) neonates had abnormal CUS findings and 124 (62%) had a normal CUS. Germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) (28/76; 36.8 %) was the commonest abnormality with GMH (grade 1) in 14/76 (18.4%), grade 2 in 7 (9.2%), grade 3 in 5 (6.5%), and grade 4 in 2 (2.63%). The other findings observed were cerebral edema (14/76; 18.4%), thalamic hyperechogenicity (10/76; 13.1%), periventricular leukomalacia (PVL) (4/76; 5.2%), and congenital anomalies (8; 10.5%). Abnormal CUS findings had a statistically significant association with birth weight <2000 g, prematurity, Apgar score <7, and adverse peri-natal fetal and maternal factors (all p-values <0.05). Abnormal CUS findings had a statistically significant association with poor cry, poor activity, abnormal tone, and presence of cyanosis (all p-values <0.05).

Conclusion

In this cohort study of high-risk preterm and term infants GMH-IVH, cerebral edema, thalamic hyperechogenicity, PVL, and congenital malformations were the commonest lesions detected on CUS. Abnormal CUS findings were found to have a statistically significant association with various adverse peri-natal fetal and maternal factors.

3D doppler ultrasound imaging of cerebral blood flow for assessment of neonatal hypoxic-ischemic brain injury in mice

Cerebral blood flow (CBF) acutely reduces in neonatal hypoxic-ischemic encephalopathy (HIE). Clinic studies have reported that severe CBF impairment can predict HIE outcomes in neonates. Herein, the present study uses a non-invasive 3D ultrasound imaging approach to evaluate the changes of CBF after HI insult, and explores the correlation between CBF alterations and HI-induced brain infarct in mouse pups. The neonatal HI brain injury was induced in postnatal day 7 mouse pups using the Rice-Vannucci model. Non-invasive 3D ultrasound imaging was conducted to image CBF changes with multiple frequencies on mouse pups before common carotid artery (CCA) ligation, immediately after ligation, and 0 or 24 hours after HI. Vascularity ratio of the ipsilateral hemisphere was acutely reduced after unilateral ligation of the CCA alone or in combination with hypoxia, and partially restored at 24 hours after HI. Moreover, regression analysis showed that the vascularity ratio of ipsilateral hemisphere was moderately correlated with brain infarct size 24 hours after HI, indicating that CBF reduction contributes to of HI brain injury. To further verify the association between CBF and HI-induced brain injury, a neuropeptide C-type natriuretic peptide (CNP) or PBS was intranasally administrated to the brain of mouse pups one hour after HI insult. Brain infarction, CBF imaging and long-term neurobehavioral tests were conducted. The result showed that intranasal administration of CNP preserved ipsilateral CBF, reduced the infarct size, and improved neurological function after HI brain injury. Our findings suggest that CBF alteration is an indicator for neonatal HI brain injury, and 3D ultrasound imaging is a useful non-invasive approach for assessment of HI brain injury in mouse model.

A 1-Tesla MRI system for dedicated brain imaging in the neonatal intensive care unit

Objective

To assess the feasibility of a point-of-care 1-Tesla MRI for identification of intracranial pathologies within neonatal intensive care units (NICUs).

Methods

Clinical findings and point-of-care 1-Tesla MRI imaging findings of NICU patients (1/2021 to 6/2022) were evaluated and compared with other imaging modalities when available.

Results

A total of 60 infants had point-of-care 1-Tesla MRI; one scan was incompletely terminated due to motion. The average gestational age at scan time was 38.5 ± 2.3 weeks. Transcranial ultrasound (n = 46), 3-Tesla MRI (n = 3), or both (n = 4) were available for comparison in 53 (88%) infants. The most common indications for point-of-care 1-Tesla MRI were term corrected age scan for extremely preterm neonates (born at greater than 28 weeks gestation age, 42%), intraventricular hemorrhage (IVH) follow-up (33%), and suspected hypoxic injury (18%). The point-of-care 1-Tesla scan could identify ischemic lesions in two infants with suspected hypoxic injury, confirmed by follow-up 3-Tesla MRI. Using 3-Tesla MRI, two lesions were identified that were not visualized on point-of-care 1-Tesla scan: (1) punctate parenchymal injury versus microhemorrhage; and (2) small layering IVH in an incomplete point-of-care 1-Tesla MRI with only DWI/ADC series, but detectable on the follow-up 3-Tesla ADC series. However, point-of-care 1-Tesla MRI could identify parenchymal microhemorrhages, which were not visualized on ultrasound.

Conclusion

Although limited by field strength, pulse sequences, and patient weight (4.5 kg)/head circumference (38 cm) restrictions, the Embrace^® point-of-care 1-Tesla MRI can identify clinically relevant intracranial pathologies in infants within a NICU setting.

Does abnormal Doppler on cranial ultrasound predict disability in infants with hypoxic-ischaemic encephalopathy? A systematic review

AIM

To evaluate whether abnormal resistive index or cerebral blood flow velocity (CBFV) on cranial ultrasound predicts disability (≥1 year) in infants with hypoxic-ischaemic encephalopathy (HIE).

METHOD

This was a systematic review and meta-analysis of studies comparing developmental outcomes of infants with HIE with normal versus abnormal resistive index or CBFV.

RESULTS

Twenty-six studies were included (pre-therapeutic hypothermia era, 20; therapeutic hypothermia era, six). Data from 15 studies (pre-therapeutic hypothermia, 10; therapeutic hypothermia, five) were available for meta-analysis. Pooled sensitivity and specificity, summary area under the receiver operating characteristic curve, and diagnostic odds ratio of resistive index or CBFV for predicting 'death or severe disability' were as follows. Pre-therapeutic hypothermia era: 0.83 (95% confidence interval [CI] 0.45-0.97) and 0.92 (95% CI 0.74-0.98), 0.94 (95% CI 0.92-0.96), 54 (95% CI 7-391). Therapeutic hypothermia era (measurements before therapeutic hypothermia): 0.62 (95% CI 0.41-0.80) and 0.96 (95% CI 0.88-0.99), 0.93 (95% CI 0.89-0.94), 23 (95% CI 6-91). Therapeutic hypothermia era (measurements during/after therapeutic hypothermia): 0.51 (95% CI 0.24-0.78) and 0.83 (95% CI 0.73-0.90), 0.81 (95% CI 0.78-0.85), 5 (95% CI 2-13). Overall Grading of Recommendations Assessment, Development and Evaluation (GRADE) rating of evidence was 'low' or 'very low'.

INTERPRETATION

Low-level evidence suggests that abnormal resistive index or CBFV can predict death or disability with high sensitivity and specificity in infants with HIE who are not cooled. The specificity of these tests was high when performed before starting cooling in infants who received therapeutic hypothermia.

WHAT THIS PAPER ADDS

Cerebral doppler ultrasound may be useful in predicting death or disability in infants with hypoxic-ischaemic encephalopathy who are not cooled. Cerebral doppler ultrasound may also be useful in infants who are cooled, if done before starting cooling. Cerebral doppler ultrasound may not be useful when performed during or after completing cooling.

Surgical treatment of post-infectious hydrocephalus in infants

The management of post-infective hydrocephalus in infants remains a challenging task for the pediatric neurosurgeon. The decision-making curve is often complex in that appropriate temporizing measures need to be implemented to properly clear any infection within the CSF before any decision can be made regarding a permanent solution. The etiology differs at varying stages of neonatal development, and the weight of the child, skin fragility, and relevant surgical treatment options are often important limiting factors. Deciding on the optimal treatment option involves assessing the etiology, age, and clinical and radiological features of the individual case and selecting the most appropriate surgical option.

Early postnatal color Doppler changes in neonates receiving delivery room resuscitation with low 5 min Apgar score-a pilot study

AIMS AND OBJECTIVES

To evaluate the Doppler changes in the intracranial arteries of neonates exposed to perinatal hypoxic insult and compare it with normal neonates.

MATERIALS AND METHODS

Color Doppler of bilateral anterior and middle cerebral arteries was performed within 6 h of birth in 26 healthy neonates and 50 neonates who received delivery room resuscitation (DRR) for perinatal depression and had a 5 min Apgar score <7. Comparisons of resistive index (RI) and peak systolic velocity (PSV) were made between the (a) control group (b) patients with low 5 min Apgar score <7 who without clinical features of neonatal encephalopathy at 24 h (c) neonates with perinatal depression with a clinical evidence of disturbed neurological function at 24 h of birth and examination consistent with mild, moderate, or severe encephalopathy using modified Sarnat and Sarnat's classification.

RESULTS

Significantly higher RI was observed in the neonates with to perinatal depression compared to the normal neonates. Significantly higher RI was seen in the patients with clinical features of neonatal encephalopathy (Group C) compared to group B. RI <0.6 and >0.82 was associated with severe neonatal encephalopathy. Differences in PSV were not statistically significant in the various groups.

CONCLUSION

The study presents the changes in early cerebral Doppler parameters observed in neonates with low 5 min Apgar score following DRR compared to the normal neonates. We also present the relations of Doppler parameters with increasing severity of neonatal encephalopathy according to Sarnat classification.

Progress in the Application of Ultrasound Elastography for Brain Diseases

Ultrasound (US) can be used to evaluate the brain structure and nervous system damage. Patients with neurologic symptoms need rapid, noninvasive imaging with high spatial resolution and tissue contrast. Magnetic resonance imaging is currently the most sensitive and specific imaging method for evaluating neuropathologic conditions. This approach does present some challenges, such as the need to transport patients who may be seriously ill to the magnetic resonance imaging suite and the need for patients to remain for a considerable time. Cranial US provides a very valuable imaging method for clinicians, which can make a rapid diagnosis and evaluation without ionizing radiation. The main disadvantage of cranial US is its low sensitivity and specificity for subtle/early lesions. In recent years, with the rapid development of anatomic and functional US technology, the practicability of US diagnosis and intervention has been greatly improved. Ultrasound elastography may have the potential to improve the sensitivity and specificity of various cranial nerve conditions. Ultrasound elastography has received considerable critical attention, and an increasing number of studies have recognized its critical role in evaluating brain diseases. At present, US elastography has been applied to the evaluation of traumatic brain injury, ischemic stroke, intraoperative brain tumors, and hypoxic ischemic encephalopathy. The latest animal experiments and human clinical trial developments in the applications of US elastography for brain diseases are summarized in this review.

Cerebral blood flow velocity and oxygenation correlate predominantly with right ventricular function in cooled neonates with moderate-severe hypoxic-ischemic encephalopathy

The relationship between right ventricular (RV) function and cerebral blood flow (CBF) velocity and cerebral oxygenation was assessed in neonates with hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia (TH). Echocardiographic, transcranial Doppler, and hemodynamic data from 37 neonates with moderate-severe HIE + TH were reviewed. Twenty healthy newborns served as controls. Cardiac dysfunction in HIE + TH was characterized by a predominant RV dysfunction, with concomitantly reduced CBF velocity. A significant correlation was found between CBF velocity and tricuspid annular plane systolic excursion (TAPSE), RV output (RVO), and stroke volume (SV_RV), as well as with left ventricular output and stroke volume. Brain oxygenation (rSO2) correlated significantly with RVO, SV_RV, TAPSE, ejection fraction, and fractional shortening, whereas cerebral fractional tissue oxygen extraction (FTOEc) correlated with RVO, SV_RV, RV myocardial performance index, and superior vena cava flow. CBF velocity and cerebral NIRS correlations were stronger with parameters of right ventricular performance.Conclusion: CBF velocity and brain oxygenation correlate predominantly with RV function in HIE + TH. This suggests a preferential contribution of RV performance to cerebral hemodynamics in this context. What is Known: • Neonates with hypoxic ischemic encephalopathy frequently exhibit alterations of cardiac function and cerebral blood flow. • These are considered organ-specific consequences of perinatal asphyxia. What is New: • We show that cerebral blood flow velocity and brain oxygenation are correlated predominantly with right ventricular function during therapeutic hypothermia. • This suggests a potential direct contribution of right ventricular performance to cerebral hemodynamics in this context.

Predictions of Hypoxic-Ischemic Encephalopathy by Umbilical Cord Blood Lactate in Newborns with Birth Asphyxia

AIM:

The aim of the study was to investigate the role of umbilical cord blood lactate as early predictors of hypoxic ischemic encephalopathy in newborns with perinatal asphyxia and to evaluate their sensitivity and specificity for the early identification of hypoxic ischemic encephalopathy infants.

METHODS:

We performed a descriptive cross sectional study between April 2014 and April 2015 at Hue Central Hospital, Vietnam. 41 asphyxia newborns (Apgar score ≤ 7) were included in the study. Umbilical cord blood is sampled for lactate analysis.

RESULTS:

Umbilical cord blood lactate levels were significantly higher among infants born with HIE (mean 8.72 ± 1.75, range 5.12 – 11.96) compared to that with asphyxic infants without HIE (mean 6.86 ± 1.33, range 4.74 – 10.30), p = 0.00. With the optimal cutoff point for umbilical cord blood lactate level of 8.12 mmol/l to susspected of HIE (area under the curve 0.799) had a sensitivity 73.7% (95% CI 48.8-90.9), specificity 86.4% (95% CI 65.1-97.1).

CONCLUSION:

Umbilical cord blood lactate could be used as early predictors in diagnosis of hypoxic ischemic encephalopathy in newborns with asphyxia.

Monitoring and management of brain hemodynamics and oxygenation

While cardiorespiratory monitoring is standard for newborns in the NICU, monitoring of brain hemodynamics and oxygenation is usually sporadic and targeted to newborns with suspected or confirmed neurologic disorders. This is unfortunate, since critically ill newborns, both preterm and term-born, are at high risk of brain injury and would benefit from improved techniques for continuous monitoring of brain hemodynamics and oxygenation, in addition to monitoring of systemic hemodynamics and oxygenation. Near-infrared spectroscopy (NIRS) and, to a lesser extent, Doppler ultrasound are techniques that have been used in research and increasingly for clinical purposes to measure and monitor brain hemodynamics and oxygenation in newborns. NIRS monitoring can be useful for detection of diverse pathologic conditions that occur frequently in very preterm newborns and in selected populations of term newborns at risk for brain injury related to disturbances of systemic hemodynamics. This chapter reviews the current state of the art with regard to brain-monitoring techniques and the research directed at this important area, and it concludes with suggestions for the use of currently available tools to manage newborns at high risk of neurologic injury from disturbances in brain hemodynamics and oxygenation.