Correlation of grading and duration of periventricular echodensities with neurodevelopmental outcome in preterm infants

Development and Validation of a Dynamic Nomogram to Predict the Risk of Neonatal White Matter Damage

Purpose

White matter damage (WMD) was defined as the appearance of rough and uneven echo enhancement in the white matter around the ventricle. The aim of this study was to develop and validate a risk prediction model for neonatal WMD.

Materials and Methods

We collected data for 1,733 infants hospitalized at the Department of Neonatology at The First Affiliated Hospital of Zhengzhou University from 2017 to 2020. Infants were randomly assigned to training (n = 1,216) or validation (n = 517) cohorts at a ratio of 7:3. Multivariate logistic regression and least absolute shrinkage and selection operator (LASSO) regression analyses were used to establish a risk prediction model and web-based risk calculator based on the training cohort data. The predictive accuracy of the model was verified in the validation cohort.

Results

We identified four variables as independent risk factors for brain WMD in neonates by multivariate logistic regression and LASSO analysis, including gestational age, fetal distress, prelabor rupture of membranes, and use of corticosteroids. These were used to establish a risk prediction nomogram and web-based calculator (https://caowenjun.shinyapps.io/dynnomapp/). The C-index of the training and validation sets was 0.898 (95% confidence interval: 0.8745-0.9215) and 0.887 (95% confidence interval: 0.8478-0.9262), respectively. Decision tree analysis showed that the model was highly effective in the threshold range of 1-61%. The sensitivity and specificity of the model were 82.5 and 81.7%, respectively, and the cutoff value was 0.099.

Conclusion

This is the first study describing the use of a nomogram and web-based calculator to predict the risk of WMD in neonates. The web-based calculator increases the applicability of the predictive model and is a convenient tool for doctors at primary hospitals and outpatient clinics, family doctors, and even parents to identify high-risk births early on and implementing appropriate interventions while avoiding excessive treatment of low-risk patients.

Spontaneous hypocarbia without mechanical ventilation in preterm infants with cystic periventricular leukomalacia

AIM

Hypocarbia induced by mechanical ventilation has been considered a main cause of cystic periventricular leukomalacia (cPVL). However, hypocarbia may occur spontaneously in response to intracellular metabolic acidosis. We aimed to assess whether hypocarbia is more common during mechanical respiratory support than during spontaneous ventilation in infants with cPVL.

METHOD

In this single-centre, retrospective chart analysis, we compared partial pressure of carbon dioxide (pCO₂ ) during the first 96 hours of life in infants with cPVL during endotracheal mechanical ventilation, non-invasive respiratory support, or without respiratory support.

RESULTS

Cystic periventricular leukomalacia was diagnosed in 23 infants born between 2006 and 2017. Gestational age was 24 weeks in two infants and ranged between 28 and 32 weeks in 21 infants. In these 21 infants, pCO₂ less than 35 mm Hg during the first 96 ours of life accounted for 9/60 (15%) measurements during endotracheal mechanical ventilation, 16/116 (14%) during non-invasive respiratory support and 14/42 (33%) in infants without respiratory support (P = .014).

CONCLUSION

In our series of infants with cPVL, hypocarbia was more common without respiratory support than during endotracheal mechanical ventilation and non-invasive respiratory support. This would suggest that hypocarbia is a symptom rather than a cause of cPVL in these infants.

The clinical characteristics and neurodevelopmental outcome of preterm infants with persistent periventricular echogenicity

PURPOSE

Periventricular echogenicity (PVE) presents as diffuse echo dense lesions of the periventricular white matter on cranial ultrasonography. Beyond two weeks of life, it is considered as prolonged or persistent PVE. The aim of our study was to investigate the clinical characteristics of preterm infants with persistent PVE beyond 2 weeks after birth and to determine whether these infants had an adverse neurodevelopmental outcome.

METHODS

The medical records of preterm infants who were born at < 34 weeks of gestation and admitted to Pusan National University Hospital between 2009 and 2014 were reviewed. A total of 28 preterm infants with persistent PVE were enrolled. Sixty compatible infants closely matched for gestational age and birth weight to infants with PVE were selected as the control group. Clinical data, including maternal, perinatal and neonatal characteristics, were analyzed. We compared the Bayley Scales of Infant Development-III at 12 months' corrected age.

RESULTS

The mean gestational age and birth weight were 31 + 3 (range, 29 + 2-33 + 6) weeks and 1523 (range, 911-2210) g, respectively, in the persistent PVE group. In the control group, the mean gestational age was 31 + 4 (range, 29 + 2-33 + 6) weeks and the mean birth weight was 1537 (range, 840-2100) g. There was no significant difference between the persistent PVE group and the control group, except for a significantly higher incidence of late sepsis in the persistent PVE group (p = 0.001). The results of Bayley test at 12 months of corrected age were available for 24 infants in the persistent PVE group and for 26 infants in the control group. A motor score of 86 (range, 78-95) versus 88 (range, 79-100), a language composite score of 88 (range, 78-97) versus 89 (range, 80-105), and a cognitive score of 90 (range, 81-100) versus 92 (range, 85-105) were observed in the persistent PVE group and the control group, respectively. No difference was detected in any scores between the two groups.

CONCLUSION

The clinical characteristics and neurodevelopmental outcomes of preterm infants with persistent PVE were not different from those of infants with normal findings. Our study supports the concept that persistent PVE without cystic change may be a benign finding.

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.

Risk factors for periventricular echodensities and outcomes in preterm infants

OBJECTIVES

To determine the incidence, risk factors and outcomes associated with transient and/or persistent periventricular echodensities (PVED) among preterm infants.

METHODS

Medical records of preterm infants born at ≤ 32 weeks gestational age (GA) with PVED and no other brain pathology were reviewed and compared to matched control infants in a case-controlled retrospective study. Neurodevelopmental outcomes at 8-24 months corrected age were documented.

RESULTS

A 17.8% incidence of PVED was recorded, with the highest incidence of 30-40% recorded at 29-31 weeks GA. Study and control groups were similar for all maternal parameters and neonatal morbidities, except for a higher incidence of respiratory distress syndrome among the study group. PVED at one month of age was predicted by 5 min Apgar score < 7 [OR = 33.78 (CI 2.94-388.06, p = 0.005)]. PVED was not associated with long-term neurodevelopmental disability.

CONCLUSIONS

No risk factors or specific associated morbidities were identified among preterm infants with transient PVED. PVED at one month of age was predicted by low 5 min Apgar scores, possibly suggesting different pathogenesis or timing between the groups. Long-term outcome studies are needed to determine PVED impact.

Cinegraphic versus Combined Static and Cinegraphic Imaging for Initial Cranial Ultrasound Screening in Premature Infants

BACKGROUND

Cranial ultrasound is an essential screening and diagnostic tool in the care of neonates and is especially useful in the premature population for evaluation of potential germinal matrix/intraventricular hemorrhage (GM/IVH). There are typically two screening examinations, with the initial cranial sonography performed between 3 days and 14 days after birth, usually consisting of a series of static images plus several cinegraphic sweeps.

OBJECTIVE

Our primary goal was to assess whether cinegraphic sweeps alone are as accurate for diagnosing neurological abnormalities as combined static and cinegraphic imaging in the initial cranial US evaluation of premature infants. Our secondary goal was to establish the difference in time required to perform these two examinations.

MATERIALS AND METHODS

We retrospectively obtained 140 consecutive initial cranial US screening studies of premature infants. Three pediatric radiologists blinded to patient data read cinegraphic images alone and also combined (dual) imaging sets for a subset of subjects, recording findings for seven disease processes: germinal matrix/intraventricular hemorrhage (GM/IVH), right or left side; periventricular leukomalacia (PVL); choroid plexus cyst; subependymal cyst; cerebral and cerebellar infarction or hemorrhage; posterior fossa hemorrhage or infarction, and extra-axial hemorrhage. Separately, we compared retrospective dual imaging acquisition time against prospectively collected cinegraphic imaging time for premature infants undergoing initial cranial US evaluation.

RESULTS

Equivalence testing demonstrated no difference in equivalency between initial cranial US screening using cinegraphic evaluation alone and dual imaging for GM/IVH, cerebral and cerebellar infarct or hemorrhage, and subependymal cyst (all P < 0.05). For PVL and choroid plexus cyst, cinegraphic imaging and dual imaging did not demonstrate equivalence (P > 0.05). Cinegraphic images were obtained in less than one-third of the time required for dual imaging.

CONCLUSION

For the diagnoses that are critical to establish at initial screening (GM/IVH, cerebral and cerebellar infarct or hemorrhage) initial cranial US screening using cinegraphic sweeps was equivalent to dual imaging. Cinegraphic imaging required significantly less time to perform than dual imaging. We suggest that performance of cranial US screening using cinegraphic imaging alone is a potentially advantageous option in the initial evaluation of the premature neonate.

Isolated mild white matter signal changes in preterm infants: a regional approach for comparison of cranial ultrasound and MRI findings

OBJECTIVE

To compare echogenicity detected using cranial ultrasound (cUS) and diffuse excessive high signal intensity (DEHSI) detected using magnetic resonance imaging (MRI) by identical region-based scoring criteria in preterm infants. To explore the association between these white matter (WM) signal changes with early neurobehavior.

STUDY DESIGN

Forty-nine pre-selected premature infants with only echogenicity on a first routine cUS1 underwent MRI and a repeated cUS2 at term equivalent age. Echogenicity and DEHSI were graded in various brain areas and diffusivity values were calculated. Neurobehavior was assessed using the Rapid Neonatal Neurobehavioral Assessment Procedure.

RESULT

WM signal changes were significantly higher on cUS1 than cUS2; and higher in MRI than cUS2 in posterior regions. Infants with DEHSI demonstrated reduced tissue integrity. Imaging findings were not correlated with early neurobehavior.

CONCLUSION

Echogenicity and DEHSI likely represent the same phenomenon. Reduction of over-interpretation of WM signal changes may help define criteria for the judicious use of imaging in routine follow-up of premature infants.

Serious periventricular white matter injury has a significant effect on the voiding pattern of preterm infants

AIM

To evaluate the effect of serious periventricular white matter injury (PWMI) on the voiding patterns of preterm infants.

METHODS

Free voiding was continuously observed for eight hours in 19 preterm infants with serious PWMI and 16 infants without PWMI. The infants had a gestational age of 32-35 weeks and a postnatal age of 9-15 days. Voiding frequency, voided volume, postvoid residual volume, empty voiding, awake voiding and interrupted voiding were recorded and compared between the two groups of infants.

RESULTS

The voiding frequency ((5.1 ± 1.0) vs. (7.0 ± 1.1)), awake voiding percentage ((23 ± 11)% vs. (42 ± 7)%) and empty voiding percentage (lower quartile = 16% vs. 28%, median = 20% vs. 33%, upper quartile = 28% vs. 40%) were significantly lower, while the voided volume ((19.9 ± 6.6) mL vs.(15.9 ± 5.3) mL)and postvoid residual volume (lower quartile = 1 mL. vs. 0 mL., median = 3 mL. vs. 2 mL., upper quartile = 3 mL. vs. 2 mL.) were significantly higher in the injured preterm infants, compared with the healthy infants (p < 0.05).

CONCLUSION

Serious PWMI has a significant effect on the voiding pattern of preterm infants, and the senior nerve centre plays a role in the voiding reflex of preterm infants.

Persistent periventricular echogenicities in preterms are not related to smaller brains at term-equivalent age

BACKGROUND

Periventricular white matter (PWM) is particularly vulnerable in very preterm infants. Non-cystic white matter injury, known as non-cystic periventricular leukomalacia (ncPVL), is the commonest 'lesion' affecting the preterm brain. There is no consensus about whether ncPVL can be reliably identified from cerebral ultrasound (cUS) or whether there is any reliable correlate of ncPVL on cUS at term-equivalent age (TEA).

OBJECTIVE

To compare brain volumes and linear measures at TEA in infants with and without a diagnosis of ncPVL.

METHODS

Preterm infants of ≤32 weeks' gestation without major lesions were serially assessed using cUS. ncPVL was defined as PWM echogenicity comparable to the choroid plexus on two scans at least 2 weeks apart after the first postnatal week. At TEA, infants were scanned for the estimation of brain volume and ventricular and tissue dimensions. Head circumference was measured. The data were compared between those with/without ncPVL. Observer agreement was assessed using kappa statistic.

RESULTS

Of 63 eligible infants 29% had ncPVL. Significant differences were found between those with/without ncPVL for 5 min Apgar score, CRIB score, invasive ventilation rates and chronic lung disease but not for other relevant clinical data. No significant differences were found for estimated brain volume, ventricular size, corpus callosum length/thickness or central grey matter width. Intra-observer reliability was moderate (kappa = 0.51-0.56); inter-observer reliability was poor (kappa = 0.20-0.32).

CONCLUSIONS

This study indicates that an ultrasound diagnosis of ncPVL should not be used as a sole predictor of lower brain growth detectable at TEA.

Echogenicity changes in the fetal brain, a 6-year follow-up study

OBJECTIVE

To asses the relation between echogenicity changes in the fetal brain and neurodevelopmental outcome until 6 years of age.

METHODS

Fetuses (n = 124) from pregnancies affected by hypertensive disorders (n = 64) or preterm labor (n = 60) at risk for preterm birth (26-34 weeks gestation) were studied. Moderate echogenicity changes (periventricular grade IB, II; intraventricular grade II-III; local basal ganglia/thalami) in the fetal and neonatal brain were related to neurological outcome and Griffiths mental developmental scales quotients at 1, 2 and 6 years. Multiple regression analysis tested the influence of moderate echogenicity changes and perinatal clinical characteristics on composite outcome (death or abnormal neurodevelopment).

RESULTS

Moderate echogenicity changes were present in 37/124 (30%) fetuses. Median gestational age and weight at birth were respectively 31 weeks (range 26-43), 1314 g (range 550-4330), mortality was 19%, follow-up loss 10%. Composite outcome was abnormal in 47/124 (38%). Fetal and neonatal moderate intraventricular echodensities were related to cerebral palsy at 6 years (p < 0.04). In the multiple regression analysis only gestational age was related to composite outcome (p = 0.005).

CONCLUSIONS

Moderate intraventricular echodensities in the fetal brain related to cerebral palsy at 6 years of age. Gestational age at birth was the main predictor of abnormal composite outcome.

Myth: cerebral palsy cannot be predicted by neonatal brain imaging

There is controversy in the literature about the value of brain imaging in neonates regarding the prediction of cerebral palsy (CP). The aim of this review was to unravel the myth that CP cannot be predicted by neuroimaging in neonates. Major intracranial lesions in the preterm infant should be recognized with sequential cranial ultrasound and will predict those with non-ambulatory CP. Magnetic resonance imaging (MRI) at term-equivalent age will refine the prediction by assessment of myelination of the posterior limb of the internal capsule. Prediction of motor outcome in preterm infants with subtle white matter injury remains difficult, even with conventional MRI. MRI is a better tool to predict outcome in the term infant with hypoxic-ischaemic encephalopathy or neonatal stroke. The use of diffusion-weighted imaging as an additional sequence adds to the predictive value for motor outcome. Sequential and dedicated neuroimaging should enable us to predict motor outcome in high risk newborns infants.

Predictability of cerebral palsy and its characteristics through neonatal cranial ultrasound in a high-risk NICU population

The aim of the study is to evaluate the predictive value of various types of brain injury detected by ultrasound in the neonatal period for the occurrence of cerebral palsy and its characteristics in a large cohort of high-risk infants. Thousand twenty-one consecutively NICU-admitted high-risk infants were assessed up to the corrected age of at least 2 years. Cerebral palsy (CP) was categorised into spastic or non-spastic, bilateral or unilateral and mild, moderate or severe CP. Different types of brain injury were identified by serial cranial ultrasound (US) during the NICU stay: white matter disease (WMD), haemorrhage, cerebral infarction, deep grey matter and parasagittal cerebral injury. There is a significant overall association between different types of brain injury and gestational age. Only 4% of the children with normal US develop CP. In the presence of any abnormal US image, the likeliness to develop CP is at least seven times higher. Within the group of infants with WMD and haemorrhage, the degree of brain involvement has a clear impact on the occurrence of CP. Concerning the characteristics of CP, deep grey matter lesion predict non-spastic CP versus spastic CP (OR = 31, P < 0.001). Cerebral infarction and haemorrhage grade IV are strong predictors of unilateral spastic CP versus bilateral spastic CP (OR = 49 and 24, respectively, P < 0.001). Deep grey matter lesion is a significant predictor for severe versus mild and moderate CP (OR = 6). In conclusion, neonatal cranial US is a useful tool in predicting CP and its characteristics.

Predictive values of cranial ultrasound and assessment of general movements for neurological development of preterm infants in the Maribor region of Slovenia

OBJECTIVE

The aim of the study was to assess the predictive values of cranial ultrasound (US) scans and assessment of general movements of fidgety character (GMs) for the later neurological development of preterm infants in the Maribor region of Slovenia.

METHODS

Results of cranial US scans done longitudinally from the day of birth until the end of three months of chronologic age and results of GMs at three months of corrected age were compared with traditional neurological examination and evaluation of psychomotor development of the same children at the corrected age of six years.

RESULTS

A total of 112 preterm infants (gestational age 37 weeks and below) were included in the study. The infants were classified as low-risk or high-risk for neurological impairment on the basis of cranial US scans. The scans classified as low-risk were followed by a normal neurological outcome in 74 (89%) of 83 infants; those classified as high-risk for neurological impairment were followed by abnormal neurological outcome in 21 (72%) of 29 infants. Of 77 infants with normal fidgety movements, 73 (95%) had a normal neurological outcome and 4 (5%) had an abnormal neurological outcome; of 35 infants with abnormal or absent fidgety movements, 26 (74%) had an abnormal neurological outcome and 9 (26%) had a normal neurological outcome. Of 30 children with abnormal outcome, cerebral palsy was diagnosed in 16, mental retardation in one, nine children had both of these, and four had complex minor neurological dysfunction. The validity of the scans was 85%, sensitivity 70%, specificity 90%, positive predictive value 72% and negative predictive value 89%; the validity of the GMs was 88%, sensitivity 87%, specificity 89%, positive predictive value 74% and negative predictive value 95%.

CONCLUSIONS

The sensitivity of the cranial US scans was clearly lower than that of assessment of general movements of a fidgety character. The specificities of the two methods were almost the same.

Prevalence of neonatal ultrasound brain lesions in premature infants with and without intrauterine growth restriction

AIM

To compare the prevalence of transient periventricular echodensities (TPE), periventricular leukomalacia (PVL) and haemorrhagic brain lesions (HBL) in singleton intrauterine growth-restricted (IUGR) infants and in those appropriate for gestational age (AGA).

METHODS

Thirty-five IUGR and 35 AGA singleton infants born between 24- and 34-week gestational age were studied. The presence of TPE, PVL and HBL was assessed with ultrasound (US) at day 3 (US-I), 2 weeks (US-II) after delivery and at term-equivalent age (US-III).

RESULTS

IUGR neonates had an increased prevalence of TPE at US-I (18/35 vs. 8/35, p= 0.02) and an increased prevalence of PVL at US-II (8/32 vs. 1/31, p = 0.03) and US-III (8/29 vs. 1/29, p = 0.02). No significant differences in the prevalence of HBL were found between the two groups.

CONCLUSIONS

IUGR is associated with an increased prevalence of white matter damage on US brain scans in preterm neonates.