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Second nationwide survey of bilirubin encephalopathy in preterm infants in Japan
Akihisa Okumura1, Ichiro Morioka2, Hiroshi Arai3
1Department of Pediatrics, Aichi Medical University, Japan.
Insights
Preterm infants with bilirubin encephalopathy (pBE) in Japan show severe motor deficits but preserved hand function and speech. Magnetic resonance imaging (MRI) and auditory brainstem response (ABR) tests help diagnose pBE.
Area of Science:
- Neonatology
- Pediatric Neurology
- Clinical Medicine
Background:
- Bilirubin encephalopathy (BE) is a significant concern in preterm infants.
- Understanding the clinical spectrum of pBE is crucial for early diagnosis and management.
- Previous data on pBE in Japan is limited.
Purpose of the Study:
- To determine the clinical features of bilirubin encephalopathy in preterm infants (pBE) in Japan.
- To characterize the neurological manifestations, MRI findings, and auditory brainstem response (ABR) in pBE patients.
- To assess the diagnostic utility of MRI and ABR in pBE.
Main Methods:
- A retrospective, nationwide questionnaire-based survey was conducted in Japan.
- The study involved two survey phases to identify and collect data on pBE infants born after 2000.
- Data collected included demographics, neurological symptoms, MRI, and ABR findings.
Main Results:
- 41 pBE infants were identified, with detailed information collected from 30 patients (median gestational age 26 weeks, birthweight 846g).
- Common neonatal complications included chronic lung disease and patent ductus arteriosus.
- Patients exhibited severely impaired gross motor function (e.g., gait 17%) but relatively preserved manual function (63% head control, 57% purposeful hand use) and verbal communication (50%).
- MRI revealed T2 hyperintensities in the globus pallidus in 29/30 patients.
- ABR abnormalities were present in 11/15 patients.
Conclusions:
- Preterm infants with bilirubin encephalopathy in Japan present with significant motor impairments but relatively preserved fine motor and communication skills.
- MRI and ABR findings are valuable tools in the diagnosis of pBE.
- These findings contribute to a better understanding of pBE clinical characteristics and diagnostic approaches.
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.
