Acute and Chronic Kernicterus: MR Imaging Evolution of Globus Pallidus Signal Change during Childhood.

BACKGROUND AND PURPOSE: Despite its rarity in Western countries, kernicterus resulting from severe neonatal hyperbilirubinemia and its associated neurologic consequences still persists. Subtle MR imaging patterns may be overlooked, leading to diagnostic and prognostic uncertainties. The study systematically analyzes MR imaging pattern over time. MATERIALS AND METHODS: A retrospective MR imaging study was conducted in Departments of Pediatric Neurology at the University Children's Hospitals in Leipzig, Germany, or Tübingen, Germany, between 2012 and 2022 in patients who presented beyond the neonatal period suspected of having chronic kernicterus. RESULTS: Eight patients with a total of 15 MR images were identified. The clinical diagnosis of kernicterus was confirmed in all cases on the basis of typical MR imaging findings: Bilateral, diffuse hyperintensity of the globus pallidus was observed in the neonatal period on T1WI (1 MR imaging, at 2 weeks), in infancy on T2WI (4 MR images, at 9-26 months). In children 2 years of age and older, bilateral hyperintensity on T2WI was limited to the borders of the globus pallidus (8 MR images, at 20 months -13 years). Notably, 2 children exhibited normal initial MR imaging findings at 2 months of age. Hence, MR imaging depiction of kernicterus pathology evolves with time, first evident on T1WI, subsequently on T2WI, with a "blind window" during early infancy. The T2WI signal change initially involves the entire globus pallidus and later is limited to the borders. Kernicterus had not been diagnosed in any except 2 patients by previous investigators. CONCLUSIONS: All patients presented with a characteristic clinical history and signs and an evolving MR imaging pattern. Nonetheless, the diagnosis of kernicterus was frequently missed. Abnormalities on later MR images appear to be underrecognized.

Diagnostics Value of Quantitative Magnetic Resonance Imaging (MRI) in Neonatal Acute Bilirubin Encephalopathy.

Background: This study was designed to investigate the diagnostic value of relative signal intensity of globus pallidus on T1-weighted magnetic resonance imaging (MRI) in neonatal acute bilirubin encephalopathy (ABE). Methods: Participants who were recruited in hospital from April 2019 to May 2020 were grouped into mildly increased total serum bilirubin (TSB) group (n = 30), severely increased TSB group (n = 25), or extremely increased TSB group (n = 10) based on the total serum bilirubin level. Bilirubin-induced neurologic dysfunction scale score was used to determine if participants had acute bilirubin encephalopathy. All neonates underwent conventional brain MRI and the relative signal intensity of globus pallidus was measured on T1-weighted images. The diagnostic value of these 3 indices was assessed by receiver operating characteristic curve analysis. Results: There was a significant correlation between relative signal intensity of globus pallidus and total serum bilirubin level in neonates with hyperbilirubinemia (r = 0.551, P < .001). Relative signal intensity of globus pallidus in the extremely increased TSB group was significantly higher than that in severely increased TSB, mildly increased TSB, and healthy control groups. Relative signal intensity of globus pallidus in the acute bilirubin encephalopathy group was significantly higher than that in the non-acute bilirubin encephalopathy group (P < .01). The area under the receiver operating characteristic curve of the relative signal intensity of globus pallidus was 0.765 (P < .01), with sensitivity of 0.655 and specificity of 0.861. The area under the curve of the total serum bilirubin and visual inspection of globus pallidus signal was 0.621 and 0.579, respectively. The area under the curve of relative signal intensity was significantly greater than that of total serum bilirubin and visual inspection (P = .04 for both). Conclusion: Relative signal intensity of globus pallidus, which is an objective assessment, has the potential to be used as a diagnostic tool for acute bilirubin encephalopathy.

Detecting acute bilirubin encephalopathy in neonates based on multimodal MRI with deep learning.

BACKGROUND: Differentiating acute bilirubin encephalopathy (ABE) from non-ABE in neonates with hyperbilirubinemia (HB) from routine magnetic resonance imaging (MRI) is extremely challenging since both conditions demonstrate similar T1 hyperintensities. To this end, we investigated whether the integration of multimodal MRI from routine clinical scans with deep-learning approaches could improve diagnostic performance. METHODS: A total of 75 neonates with ABE and 75 neonates with HB (non-ABE) were included in the study. Each patient had three types of multimodal images taken, i.e., a T1-weighted image (T1WI), a T2-weighted image (T2WI), and an apparent diffusion coefficient (ADC) map. The three types of MRI contrasts and their combination were fed into two deep convolutional neural networks (CNNs), i.e., ResNet18 and DenseNet201. The performance of CNNs was compared with a traditional statistical method named logistic regression. RESULTS: We demonstrated that diagnostic methods with the multimodal data were better than any of the single-modal data. Both CNN models outperformed the logistic regression method. The best performance was achieved by DenseNet201 with the combination of three modalities of T1WI, T2WI, and ADC, with an accuracy of 0.929 ± 0.042 and an area under the curve (AUC) of 0.991 ± 0.007. CONCLUSIONS: Our study demonstrated that CNN models with multimodal MRI significantly improve the accuracy of diagnosing ABE. IMPACT: We proposed an efficient strategy of detecting ABE in neonates based on multimodal MRI with deep learning, which achieved an accuracy of 0.929 ± 0.042 and an AUC of 0.991 ± 0.007. We demonstrated the advantage of integrating multimodal MRI in detecting ABE in neonates with HB, using deep-learning models. Our strategy of diagnosing ABE using deep-learning techniques with multimodal MRI from routine clinical scans is potentially applicable to clinical practice.

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.

Detecting neonatal acute bilirubin encephalopathy based on T1-weighted MRI images and learning-based approaches.

BACKGROUND: Neonatal hyperbilirubinemia is a common clinical condition that requires medical attention in newborns, which may develop into acute bilirubin encephalopathy with a significant risk of long-term neurological deficits. The current clinical challenge lies in the separation of acute bilirubin encephalopathy and non-acute bilirubin encephalopathy neonates both with hyperbilirubinemia condition since both of them demonstrated similar T1 hyperintensity and lead to difficulties in clinical diagnosis based on the conventional radiological reading. This study aims to investigate the utility of T1-weighted MRI images for differentiating acute bilirubin encephalopathy and non-acute bilirubin encephalopathy neonates with hyperbilirubinemia. METHODS: 3 diagnostic approaches, including a visual inspection, a semi-quantitative method based on normalized the T1-weighted intensities of the globus pallidus and subthalamic nuclei, and a deep learning method with ResNet18 framework were applied to classify 47 acute bilirubin encephalopathy neonates and 32 non-acute bilirubin encephalopathy neonates with hyperbilirubinemia based on T1-weighted images. Chi-squared test and t-test were used to test the significant difference of clinical features between the 2 groups. RESULTS: The visual inspection got a poor diagnostic accuracy of 53.58 ± 5.71% indicating the difficulty of the challenge in real clinical practice. However, the semi-quantitative approach and ResNet18 achieved a classification accuracy of 62.11 ± 8.03% and 72.15%, respectively, which outperformed visual inspection significantly. CONCLUSION: Our study indicates that it is not sufficient to only use T1-weighted MRI images to detect neonates with acute bilirubin encephalopathy. Other more MRI multimodal images combined with T1-weighted MRI images are expected to use to improve the accuracy in future work. However, this study demonstrates that the semi-quantitative measurement based on T1-weighted MRI images is a simple and compromised way to discriminate acute bilirubin encephalopathy and non-acute bilirubin encephalopathy neonates with hyperbilirubinemia, which may be helpful in improving the current manual diagnosis.

Early Amplitude-Integrated Electroencephalography Predicts Long-Term Outcomes in Term and Near-Term Newborns With Severe Hyperbilirubinemia.

BACKGROUND: We aimed to determine the predictive neurological prognostic value of early amplitude-integrated electroencephalography (aEEG) in term and near-term neonates with severe hyperbilirubinemia compared with cranial magnetic resonance imaging (MRI) and auditory brainstem response (ABR). METHODS: Infants of ≥35 weeks of gestation with severe hyperbilirubinemia (total serum bilirubin [TSB] ≥340 µmol/L) or with hyperbilirubinemia (TSB ≥257 µmol/L) in association with bilirubin-induced neurological dysfunction were recruited. All the subjects had an aEEG after being admitted to the neonatal intensive care unit, whereas cranial MRI and ABR were performed when TSB had come down to the normal range. All the infants were followed up to 12 months. RESULTS: During the study period, 77 of 83 infants were eligible, of which 71 had severe hyperbilirubinemia and six had hyperbilirubinemia in association with bilirubin-induced neurological dysfunction. Thirty-three infants were diagnosed with acute bilirubin encephalopathy (ABE), two of whom died of ABE, and 62 completed the follow-up, of which 12 infants had adverse outcomes. Sixty-four infants underwent aEEG, 40 infants had cranial MRI, and 39 infants had ABR. Logistic regression and the receiver-operator characteristic curve analysis showed that the ability of severely abnormal aEEG to predict adverse neurological outcomes in severe hyperbilirubinemia was no better than abnormal ABR, with a sensitivity of 35.7% versus 83.3%, a specificity of 92.0% versus 74.1%, a positive predictive value of 55.6% versus 58.8%, and a negative predictive value of 83.6% versus 90.9%. CONCLUSIONS: Early aEEG could predict adverse neurodevelopmental outcomes in neonates with severe hyperbilirubinemia, although the sensitivity was lower than ABR.

Kernicterus with abnormal high-signal changes bilaterally in the globus pallidus: A case report.

Kernicterus is a relatively rare consequence of hyperbilirubinemia. There is an important role for MRI imaging for this entity in the appropriate clinical context as there are distinct signal changes in the globus pallidus. A case report and image findings are presented

Bilirubin-Induced Neurological Dysfunction: A Clinico-Radiological-Neurophysiological Correlation in 30 Consecutive Children.

The clinical expression of bilirubin-induced neurological dysfunction varies according to severity and location of the disease. Definitions have been proposed to describe different bilirubin-induced neurological dysfunction subtypes. Our objective was to describe the severity and clinico-radiological-neurophysiological correlation in 30 consecutive children with bilirubin-induced neurological dysfunction seen over a period of 5 years. Thirty children exposed to acute neonatal bilirubin encephalopathy were included in the study. The mean peak total serum bilirubin level was 625 µmol/L (range 480-900 µmol/L). Acoustic brainstem responses were abnormal in 73% (n = 22). Pallidal hyperintensity was observed on magnetic resonance imaging in 20 children. Peak total serum bilirubin levels correlated with motor severity (P = .03). Children with severe motor impairment were likely to manifest severe auditory neuropathy (P < .01). We found that in a resource-constrained setting, classical kernicterus was the most common bilirubin-induced neurological dysfunction subtype, and the majority of children had abnormal acoustic brainstem responses and magnetic resonance imaging.

Bilirubin-Induced Neurotoxicity in the Preterm Neonate.

Bilirubin-induced neurotoxicity in preterm neonates remains a clinical concern. Multiple cellular and molecular cascades likely underlie bilirubin-induced neuronal injury, including plasma membrane perturbations, excitotoxicity, neuroinflammation, oxidative stress, and cell cycle arrest. Preterm newborns are particularly vulnerable secondary to central nervous system immaturity and concurrent adverse clinical conditions that may potentiate bilirubin toxicity. Acute bilirubin encephalopathy in preterm neonates may be subtle and manifest primarily as recurrent symptomatic apneic events. Low-bilirubin kernicterus continues to be reported in preterm neonates, and although multifactorial in nature, is often associated with marked hypoalbuminemia.

The clinical outcomes of deep gray matter injury in children with cerebral palsy in relation with brain magnetic resonance imaging.

UNLABELLED: In the present study we investigated the nature and extent of clinical outcomes using various classifications and analyzed the relationship between brain magnetic resonance imaging (MRI) findings and the extent of clinical outcomes in children with cerebral palsy (CP) with deep gray matter injury. The deep gray matter injuries of 69 children were classified into hypoxic ischemic encephalopathy (HIE) and kernicterus patterns. HIE patterns were divided into four groups (I-IV) based on severity. Functional classification was investigated using the gross motor function classification system-expanded and revised, manual ability classification system, communication function classification system, and tests of cognitive function, and other associated problems. The severity of HIE pattern on brain MRI was strongly correlated with the severity of clinical outcomes in these various domains. Children with a kernicterus pattern showed a wide range of clinical outcomes in these areas. Children with severe HIE are at high risk of intellectual disability (ID) or epilepsy and children with a kernicterus pattern are at risk of hearing impairment and/or ID. Grading severity of HIE pattern on brain MRI is useful for predicting overall outcomes. The clinical outcomes of children with a kernicterus pattern range widely from mild to severe. WHAT THIS PAPER ADDS: Delineation of the clinical outcomes of children with deep gray matter injury, which are a common abnormal brain MRI finding in children with CP, is necessary. The present study provides clinical outcomes for various domains in children with deep gray matter injury on brain MRI. The deep gray matter injuries were divided into two major groups; HIE and kernicterus patterns. Our study showed that severity of HIE pattern on brain MRI was strongly associated with the severity of impairments in gross motor function, manual ability, communication function, and cognition. These findings suggest that severity of HIE pattern can be useful for predicting the severity of impairments. Conversely, children with a kernicterus pattern showed a wide range of clinical outcomes in various domains. Children with severe HIE pattern are at high risk of ID or epilepsy and children with kernicterus pattern are at risk of hearing impairment or ID. The strength of our study was the assessment of clinical outcomes after 3 years of age using standardized classification systems in various domains in children with deep gray matter injury.

Magnetic Resonance Imaging Abnormalities in Advanced Acute Bilirubin Encephalopathy Highlight Dentato-Thalamo-Cortical Pathways.

A distinct pattern of acute restricted diffusion on magnetic resonance imaging localized to key regions within the dentato-thalamo-cortical pathway was observed early in a term newborn during advanced stages of acute bilirubin encephalopathy. These findings demonstrate that vulnerability to bilirubin toxicity extends across specific neuroanatomic tracts.

Serial brain MRI and ultrasound findings: relation to gestational age, bilirubin level, neonatal neurologic status and neurodevelopmental outcome in infants at risk of kernicterus.

AIMS: To describe cranial ultrasound (cUS) and magnetic resonance imaging (MRI) findings in neonates at risk of kernicterus, in relation to gestational age (GA), total serum bilirubin (TSB), age at imaging and neurodevelopmental outcome. PATIENTS AND METHODS: Neonates with peak TSB > 400 micromol/L and/or signs of bilirubin encephalopathy. Review of neonatal data, cUS, preterm, term and later MRI scans and neurodevelopmental outcome. RESULTS: 11 infants were studied, two < 31, four 34-36 and five 37-40 weeks GA. TSB levels: 235-583 micromol/L (preterms); 423-720 micromol/L (terms). Neonatal neurological examination was abnormal in 8/10. cUS showed increased basal ganglia (BG) in 4/9 infants and white matter (WM) echogenicity, lenticulostriate vasculopathy (LSV) and caudothalamic hyperechogencity/cysts (GLCs) in 5/9 infants. MRI showed abnormal signal intensity (SI) in the globus pallidum (GP) in 1/2 preterm, 8/9 term and 9/11 later scans. Abnormal WM SI occurred in 2 preterm, 7 term and 10/11 later scans. Seven infants developed athetoid/dystonic cerebral palsy (CP) and 6 hearing loss (HL). Adverse outcome was associated with abnormal BG on cUS (3/4 CP, 4/4 HL), with high SI in GP (7/9 CP, 6/9 HL) on late T2-weighted MRI (all GA) and on T1/T2-weighted term MRI, mainly in term-born infants. WM abnormalities, GLCs and LSV did not correlate with outcome. CONCLUSIONS: Severe CP occurred with relatively low TSB levels in preterms but only at high levels in full-terms; HL was difficult to predict. Early scans did not reliably predict motor deficits whilst all children with CP had abnormal central grey matter on later scans. Abnormal WM was seen early suggesting primary involvement rather than change secondary to grey matter damage. Why characteristic central grey matter MRI features of kernicterus are not seen early remains unexplained.

Single photon emission computed tomography and serial MRI in preterm infants with kernicterus.

Single photon emission computed tomography was performed in three preterm infants with athetoid cerebral palsy due to kernicterus. No clinical signs and symptoms of kernicterus, or ultrasonographic abnormalities were seen during the neonatal period in any patients. Although MRI during infancy revealed high intensity areas in bilateral globi pallidi in all of them, MRI abnormalities were mild in two of them. On later MRI, subtle high intensity areas in the globi pallidi were recognized in only one of them. Single photon emission computed tomography demonstrated hypoperfusion in the basal ganglia regions in all patients. Regions of interest analyses showed decreased blood flow in the basal ganglia related to the cortical areas. Single photon emission computed tomography will be useful for the diagnosis of kernicterus, whereas MRI abnormalities become less clear beyond infancy.