Diagnosis of Bilirubin Encephalopathy in Preterm Infants with Dyskinetic Cerebral Palsy

Predictive and diagnostic measures for kernicterus spectrum disorder: a prospective cohort study

BACKGROUND

Kernicterus spectrum disorder (KSD) resulting from neonatal hyperbilirubinemia remains a common cause of cerebral palsy worldwide. This 12-month prospective cohort study followed neonates with hyperbilirubinemia to determine which clinical measures best predict KSD.

METHODS

The study enrolled neonates ≥35 weeks gestation with total serum bilirubin (TSB) ≥ 20 mg/dl admitted to Aminu Kano Hospital, Nigeria. Clinical measures included brain MRI, TSB, modified bilirubin-induced neurologic dysfunction (BIND-M), Barry-Albright Dystonia scale (BAD), auditory brainstem response (ABR), and the modified KSD toolkit. MRI signal alteration of the globus pallidus was scored using the Hyperbilirubinemia Imaging Rating Tool (HIRT).

RESULTS

Of 25 neonates enrolled, 13/25 completed 12-month follow-up and six developed KSD. Neonatal BIND-M ≥ 3 was 100% sensitive and 83% specific for KSD. Neonatal ABR was 83% specific and sensitive for KSD. Neonatal HIRT score of 2 was 67% sensitive and 75% specific for KSD; this increased to 100% specificity and sensitivity at 12 months. BAD ≥ 2 was 100% specific for KSD at 3-12 months, with 50-100% sensitivity.

CONCLUSIONS

Neonatal MRIs do not reliably predict KSD. BIND-M is an excellent screening tool for KSD, while the BAD or HIRT score at 3 or 12 months can confirm KSD, allowing for early diagnosis and intervention.

IMPACT

The first prospective study of children with acute bilirubin encephalopathy evaluating brain MRI findings over the first year of life. Neonatal MRI is not a reliable predictor of kernicterus spectrum disorders (KSD). Brain MRI at 3 or 12 months can confirm KSD. The modified BIND scale obtained at admission for neonatal hyperbilirubinemia is a valuable screening tool to assess risk for developing KSD. The Barry Albright Dystonia scale and brain MRI can be used to establish a diagnosis of KSD in at-risk infants as early as 3 months.

Second nationwide survey of bilirubin encephalopathy in preterm infants in Japan

OBJECTIVES

To determine the clinical features of bilirubin encephalopathy in preterm infants (pBE) in Japan.

METHODS

We performed a retrospective, nationwide questionnaire-based survey. The initial survey determined the number of children with pBE who were born after 2000. Using a structured questionnaire, the second survey clarified the clinical manifestations and characteristics of children with pBE, including demographic data, neurological symptoms, and MRI and auditory brainstem response (ABR) findings.

RESULTS

The initial survey identified 41 pBE infants from 18 institutions. After exclusion of patients included in previous studies, clinical information was collected from 30 patients (21 boys and 9 girls) during the secondary survey. The median gestational age was 26 weeks and the median birthweight was 846 g. Chronic lung disease and symptomatic patent ductus arteriosus were common neonatal complications. Head control was observed in 63% and functional gait in 17% of patients. Purposeful hand use was seen in 57% and verbal communication in 50% of patients. MRI showed T2 hyperintensities in the globus pallidus of 29 of 30 patients. ABR abnormalities were present in 11 of 15 patients. None of the variables were significantly different between the 2017 and 2021 surveys.

CONCLUSIONS

The pBE infants had severely impaired gross motor function and relatively preserved manual function and verbal communication. MRI and ABR findings aid in the diagnosis of pBE.

Reference intervals for end-tidal carbon monoxide of preterm neonates

OBJECTIVES

We constructed reference intervals for end-tidal carbon monoxide (ETCOc) levels of neonates 28 ^0/7 to 34 ^6/7 weeks gestation in order to assess hemolytic rate.

STUDY DESIGN

This is a prospective four-NICU study in Bangkok, Thailand, and Utah, USA.

RESULTS

Of 226 attempted measurements, 92% were successful. Values from day 1 through 28 were charted and upper (>95th percentile) reference interval limits calculated. During the entire 28 days, the ETCOc upper reference intervals from babies in Bangkok were higher than those in Utah (p < 0.01). No differences were found due to sex, or earliest vs. latest gestation at birth (both p > 0.1). Similar to term neonates, preterm neonates in Bangkok and Utah had higher ETCOc values during the first 48 h after birth than thereafter (p < 0.01).

CONCLUSIONS

Using this methodology, and the reference interval chart, the hemolytic rate of preterm infants ≥28 weeks can be assessed.

Magnetic Resonance Imaging Findings in Preterm Infants With Bilirubin Encephalopathy Beyond Three Years Corrected Age

BACKGROUND

Magnetic resonance imaging (MRI) abnormalities in preterm infants with bilirubin encephalopathy (BE) become less clear as the infants age. We assessed MRI findings in children with preterm BE older than 36 months corrected age (CA).

METHODS

In a previous questionnaire survey, hospitals were asked to provide head MRI data of patients older than 36 months CA. MRI findings were reviewed by three pediatric neurology specialists and classified as no abnormalities, partial globus pallidus (GP) lesions, or diffuse GP lesions.

RESULTS

In total, 33 MRI scans were available from 28 patients. The median gestational age and birth weight were 26 weeks and 824 g, respectively. The prevalence of MRI abnormalities was 100% in patients at 37 to 48 months CA, 71% in those at 49 to 60 months CA, 50% in those at 61 to 72 months CA, 67% in those at 73 to 84 months CA, and 38% in those at 85 months CA or older. Partial GP lesions were more common than diffuse GP lesions at all ages. No significant differences in sex, gestational age, birth weight, or gross motor function impairment were observed among lesion groups.

CONCLUSIONS

GP lesions were detected on MRI in most children with preterm BE when studied after 36 months CA, although MRI abnormalities became less apparent along with age. Partial GP lesions may be a characteristic of older children with preterm BE.

Risk factors for hip dislocation in dyskinetic cerebral palsy

PURPOSE

To investigate the risk factors for hip displacement in patients with dyskinetic cerebral palsy (DCP).

METHODS

We evaluated 81 patients with DCP, 45 males and 36 females, aged 10-22 years, risk factors for hip displacement were evaluated using multivariate logistic regression analysis with primary brain lesions, Gross Motor Function Classification System (GMFCS) level, gestational age, birth weight, Cobb's angle, and complication of epilepsy as independent factors. Hip displacement was defined as migration percentage >30%. Primary brain lesions were classified into globus pallidus (GP), thalamus and putamen (TP), and others using brain magnetic resonance imaging (MRI). Perinatal and clinical features were compared between patients with GP lesions and those with TP lesions.

RESULTS

Hip displacement was observed in 53 patients (67%). Higher GMFCS levels (p = 0.013, odds ratio [OR] 2.6) and the presence of GP lesions (p = 0.04, OR 16.5) were independent risk factors for hip displacement. Patients with GP lesions showed significantly higher GMFCS levels, more frequent hip displacement, and lower gestational age and birth weight than those with TP lesions.

CONCLUSION

Primary brain lesion location may be an important factor in predicting hip displacement among patients with DCP. Appropriate risk assessment using brain MRI may contribute to the early detection and intervention of hip displacement because brain lesion location can be assessed during infancy before GMFCS level is decided.

Hyperbilirubinemia and Asphyxia in Children With Dyskinetic Cerebral Palsy

BACKGROUND

We aimed to study the clinical, etiologic, and radiological characteristics in children with dyskinetic cerebral palsy (DCP) and to compare the etiologic subtypes of hyperbilirubinemia and perinatal asphyxia.

METHODS

This is a cross-sectional, observational study that enrolled consecutive children with DCP, aged one to 14 years.

RESULTS

Sixty-five children with DCP were evaluated. Most children were boys (77%, n = 50), and term gestation (80%, n = 52). Presenting concerns were global developmental delay (97%, n = 63) and involuntary movements (60%, n = 39). Hyperbilirubinemia (66%, n = 43) and perinatal asphyxia (29%, n = 19) were the most important causes. The majority (83%, n = 54) of children were severely disabled (level V and IV). The hyperbilirubinemia group had significant motor delay (63% vs 37%, P = 0.03) and upward gaze palsy (69.7% vs 31.5%, P = 0.005) when compared with the perinatal asphyxia group. Hyperbilirubinemia significantly involved pallidi (86% vs 10% P = 0.0001) and subthalamic nucleus (26% vs none, P = 0.01), whereas asphyxia significantly involved the putamen (58% vs none, P = 0.0001), thalamus (63% vs none, P = 0.0001), and periventricular white matter (79% vs 19%, P = 0.0001).

CONCLUSIONS

DCP is the dominant type of cerebral palsy seen in term-born babies with severe dystonia, developmental delay, and motor impairment. Hyperbilirubinemia is the major cause of DCP in the study. Hyperbilirubinemia is associated with motor delay, upward gaze palsy, prominent dystonia, and involvement of globus pallidi and subthalamic nuclei.

Changes in amplitude-integrated electroencephalography, neuron-specific enolase, and S100B in neonates with brain injury induced by neonatal hyperbilirubinemia and their significance

OBJECTIVE

To explore the changes in amplitude-integrated electroencephalography (aEEG), neuron-specific enolase (NSE), and S100B in neonates with brain injury induced by neonatal hyperbilirubinemia (NHB).

METHODS

67 neonates with brain injury induced by NHB admitted to our hospital from March 2016 to October 2018 were included in a brain injury group (BIG), and 82 neonates with NHB but without brain injury in our hospital during the same period were included in a non-BIG. The two groups were compared regarding the rates of normal and abnormal aEEG results.

RESULTS

The proportion of normal aEEG results in the BIG was significantly lower than that in the non-BIG, and the proportion of moderately and severely abnormal aEEG results in the BIG were both significantly higher than those in the non-BIG. The BIG showed significantly higher NSE and S100B levels than those of the non-BIG. The ROC curve for predicting prognosis showed that the AUC of aEEG, NSE, S100B, and the combined detection are 0.780, 0.754, 0.743, 0.788. The AUC > 0.700 indicated a good predictive value for the prognosis.

CONCLUSION

The combination of aEEG, NSE, and S100B has good value in diagnosing injury induced by NHB and can predict prognosis moderately well.

The application of magnetic resonance imaging and diffusion-weighted imaging in the diagnosis of hypoxic-ischemic encephalopathy and kernicterus in premature infants

BACKGROUND

To explore the application of magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in the diagnosis of hypoxic-ischemic encephalopathy and kernicterus in premature infants.

METHODS

Fifty-eight premature infants with hypoxic-ischemic encephalopathy and fifty-eight premature infants with kernicterus who were examined and treated in our hospital between January 2018 and January 2021 were assigned to the observation group or the control group. All patients were examined by MRI imaging and DWI imaging, and the examination results were compared between the two groups.

RESULTS

No significant differences were found in sensitivity, specificity, positive predictive value, or negative predictive value between the observation group and the control group (P>0.05). MRI could clearly visualize the signal changes of patients, whereas DWI did not show any signal changes. There was no significant difference between MRI and DWI in the diagnosis of hypoxic-ischemic encephalopathy in premature infants. Further, there was no significant difference in the diagnostic performance of MRI between the observation group and the control group (P>0.05). However, the diagnostic performance of DWI in the control group was better than that in the observation group, and the difference was statistically significant (P<0.05).

CONCLUSIONS

MRI and DWI imaging have high detection rates for the diagnosis of hypoxic-ischemic encephalopathy and kernicterus in premature infants. These imaging methods can benefit the treatment of premature infants and have important clinical application value.

Auditory brainstem response in preterm infants with bilirubin encephalopathy

AIM

To clarify auditory brainstem response (ABR) in preterm infants with bilirubin encephalopathy and the relationships between ABR and clinical variables.

METHOD

We retrospectively reviewed the ABR waveforms of 56 preterm infants with BE and graded them as "no response", "abnormal interwave separation", or "normal". Patient backgrounds, the peak total bilirubin level, the bilirubin/albumin ratio, verbal communication ability, and newborn hearing screening test results from an automated ABR evaluation had been collected during an earlier nationwide survey.

RESULTS

The frequency of abnormal ABR findings decreased with age. Verbal communication tended to be poorer in patients with more severe ABR abnormalities. ABR findings improved in 7 of 29 infants with available serial ABR data. Both gestational age and the peak total bilirubin level were relatively lower in patients with than in those without improved ABR findings. Newborn hearing screening using automated ABR evaluation yielded data consistent with manual ABR findings in 16 of 20 patients who underwent both examinations.

CONCLUSIONS

ABR abnormalities in preterm infants with bilirubin encephalopathy may improve over time, especially in those with a lower gestational age and peak total bilirubin level. Newborn hearing screening using automated ABR may fail to detect abnormalities in some infants.

Neonatal Jaundice in Preterm Infants with Bilirubin Encephalopathy

INTRODUCTION

The aim of this study is to clarify bilirubin parameters and its treatment in preterm infants with bilirubin encephalopathy (pBE).

METHODS

We asked the responders to an earlier nationwide Japanese survey on pBE to provide additional information. pBE was diagnosed based on the criteria used in the nationwide survey. We collected data on serum total bilirubin (TB), direct bilirubin (DB), albumin, and unbound bilirubin (UB) levels during the first 8 weeks of life, and on phototherapy and exchange transfusion treatments.

RESULTS

We obtained clinical data from 75 patients with pBE from 58 hospitals (response rate of 59%), who were born between 2002 and 2016. The average peak TB level was 12.6 mg/dL (215 μmol/L), and the average age at peak attainment was 19.7 days after birth. Albumin level was <2.5 g/dL in 44 patients, and the peak DB level was ≥2 mg/dL (34.2 μmol/L) in 20 patients. The average peak bilirubin/albumin (B/A) (mg/g) ratio was 3.8 (molar ratio of 0.475), and the average age at peak attainment was 18.6 days. The average peak UB level was 0.67 μg/dL (11.5 nmol/L). The median duration of phototherapy was 6 days, and the median day of the last session was 12. The peak TB level occurred after the last day of phototherapy in 30 of the 61 patients available for comparison.

CONCLUSIONS

Most patients with pBE lacked marked elevations in serum TB levels and the B/A ratio, the peaks of which were sometimes delayed to >4 weeks after birth.

A nationwide survey of bilirubin encephalopathy in preterm infants in Japan

OBJECTIVES

To examine the clinical characteristics of bilirubin encephalopathy in preterm infants (pBE) in Japan.

METHODS

We performed a two-step nationwide questionnaire survey. The initial survey determined the number of children with pBE. Using a structured questionnaire, the second survey clarified the clinical manifestations and characteristics of children with pBE, including the perinatal history, neonatal complications, neurological features, verbal communication, diet, and magnetic resonance imaging (MRI) and auditory brainstem response (ABR) findings.

RESULTS

The initial survey included 190 pBE infants, indicating an incidence of approximately 10 per year. Clinical information was available for 142 of them. The median gestational age was 26 weeks and the median birthweight was 883 g. As to neonatal complications, 20% had none, 25% had one complication, 54% had two or more. Head control was observed in 45% and functional gait in 8%. Purposeful hand use was seen in 41% of patients and verbal communication in 40%. MRI showed T2 hyperintensities in the globi pallidi in 111 of 136 patients, especially between 7 and 18 months of corrected age. ABR abnormalities were present in 88 of 117 patients.

CONCLUSIONS

pBE was infrequent but constantly observed during the study period, especially in very preterm infants, even in those with no severe neonatal complications. Severely impaired gross motor function and relatively preserved manual function and verbal communication were characteristic. MRI and ABR abnormalities will facilitate diagnosis.

A Novel Method for Measuring Serum Unbound Bilirubin Levels Using Glucose Oxidase-Peroxidase and Bilirubin-Inducible Fluorescent Protein (UnaG): No Influence of Direct Bilirubin

The glucose oxidase–peroxidase (GOD–POD) method used to measure serum unbound bilirubin (UB) suffers from direct bilirubin (DB) interference. Using a bilirubin-inducible fluorescent protein from eel muscle (UnaG), a novel GOD–POD–UnaG method for measuring UB was developed. Newborn sera with an indirect bilirubin/albumin (iDB/A) molar ratio of <0.5 were classified into four groups of DB/total serum bilirubin (TB) ratios (<5%, 5–10%, 10–20%, and ≥20%), and the correlation between the UB levels and iDB/A ratio was examined. Linear regression analysis was performed to compare UB values from both methods with the iDB/A ratio from 38 sera samples with DB/TB ratio <5% and 11 samples with DB/TB ratio ≥5%. The correlation coefficient (r) between UB values and the iDB/A ratio for the GOD–POD method was 0.8096 (DB/TB ratio <5%, n = 239), 0.7265 (5–10%, n = 29), 0.7165 (10–20%, n = 17), and 0.4816 (≥20%, n = 16). UB values using the GOD–POD–UnaG method highly correlated with the iDB/A ratio in both <5% and ≥5% DB/TB ratio sera (r = 0.887 and 0.806, respectively), whereas a low correlation (r = 0.428) occurred for ≥5% DB/TB ratio sera using the GOD–POD method. Our GOD–POD–UnaG method can measure UB levels regardless of the presence of DB.

Increased Serum Expression of Inflammatory Cytokines may Serve as Potential Diagnostic Biomarker for Bilirubin Encephalopathy

OBJECTIVES

The present study was designed to explore the roles of inflammatory cytokines interleukin-1β (IL-1β) and Tumor growth factor-β (TGF-β) in the diagnosis and treatment of neonate bilirubin encephalopathy (BE).

METHODS

A total of 128 BE neonates and 128 normal neonates were included. The serum samples of the BE children and controls were collected, and the levels of IL-1β and TGF-β were examined. Moreover, the correlation between the level of bilirubin and serum expression of IL-1β or TGF-β in BE patients was analyzed. Finally, receiver operating characteristic (ROC) curves were generated to determine the diagnostic value of the cytokines.

RESULTS

IL-1β and TGF-β levels were higher in the serum of BE patients than those in non-BE patients, and the expression of either IL-1β or TGF-β showed a strong positive correlation with the serum expression of bilirubin in BE patients. Moreover, the results of ROC analysis showed that either IL-1β or TGF-β could distinguish BE patients from healthy controls.

CONCLUSION

IL-1β and TGF-β levels were upregulated in BE and might function as potential biomarkers or therapeutic targets for BE patients.