Sonographic brain patterns in neonates with hypoxic ischaemic encephalopathy undergoing therapeutic hypothermia in Moi Teaching And Referral Hospital, Eldoret

Abstract

Background: Hypoxic-ischemic encephalopathy (HIE) remains a major cause of neonatal mortality and neurodevelopmental disability. While magnetic resonance imaging (MRI) is considered the gold standard for brain injury assessment, cranial ultrasound (cUS) offers a practical, bedside alternative during therapeutic hypothermia (TH), particularly in resource-limited settings. This study aimed to assess the evolution of sonographic brain injury patterns during TH at Moi Teaching and Referral Hospital (MTRH), Eldoret, Kenya. Objective: To describe the evolution of sonographic brain patterns in neonates with HIE undergoing therapeutic hypothermia. Methods: This was a prospective, census study that recruited 37 neonates (≥36 weeks’ gestation) diagnosed with moderate or severe HIE and eligible for TH between August 2023 and February 2024. Approval to conduct the study was obtained from the Institutional Research and Ethics Committee (IREC). Permission to collect data was sought and granted by the Chief Executive Officer, Moi Teaching and Referral Hospital (M.T.R.H.) Further approval to conduct the study was obtained from the National Commission for Science Technology and Innovation (NACOSTI). Cranial ultrasound examinations were performed at the initiation of TH and on day seven of life. Brain regions assessed included periventricular and subcortical white matter, thalami, basal ganglia, and ventricles. Thompson clinical severity scores were recorded. Data were analyzed using STATA version 16, with findings presented as frequencies, medians, and proportions. Associations between cranial ultrasound findings and clinical severity were assessed. Results: Among the 37 neonates who were recruited, 89.2% had moderate and 10.8% had severe HIE. The median gestational age was 39 weeks, and the median birth weight was 3100 grams. Clinical seizures were present in 43.2%. Pre-treatment cUS findings included periventricular echogenicity (13.5%), subcortical echogenicity (13.5%), intraventricular hemorrhage (8.1%), thalamic hyper-echogenicity (8.1%), and basal ganglia echogenicity (2.8%). Significant associations were found between pre-treatment brain injury patterns and severe Thompson scores (p=0.0019). On day seven after TH, the brain abnormalities on cranial ultrasound scans included increased thalamic echogenicity (17.8%), increased subcortical echogenicity (7.1%), and intraventricular hemorrhage (7.1%). Clinical grading improved significantly post- treatment, with 89.3% of patients classified as having mild HIE. Conclusion: White matter injury was the predominant early sonographic pattern, whereas thalamic injury became more evident at day 7 of life. Therapeutic hypothermia was associated with substantial improvement in clinical severity scores. Recommendation: Routine serial cranial ultrasound should be incorporated into the management of neonates undergoing therapeutic hypothermia to identify and follow the evolution of brain injury in order to establish the sonographic biomarkers of HIE that determine prognosis.