Early Electroencephalogram as Predictor of Neuromotor Outcome in a Term Newborn with Hypoxic Ischaemia Encephalopathy- A Prospective Cohort Study

Abstract

Introduction: Birth asphyxia is the leading cause of neonatal morbidity and mortality globally. Early prediction of neuromotor problems in babies with Hypoxic Ischaemic Encephalopathy (HIE) allows parental counseling regarding treatment continuation, better utilisation of limited resources and prompt referral for early intervention services to so that the best possible outcomes can be achieved. Aim: To investigate the role of early Electroencephalogram (EEG) background activity in prediction of cerebral palsy, epilepsy and developmental delay in term newborn with HIE and also to check the association of EEG background activity with Hammersmith Neonatal Neurological Examination (HNNE), Hammersmith Infant Neurological Examination (HINE) score and various short-term and long-term outcome. Materials and Methods: This prospective clinical study was conducted in Neonatal Intensive Care Unit (NICU) of Department of Paediatrics, Shyam Shah Medical college and associated Gandhi Memorial Hospital, Rewa (MP) during April 2019 to June 2020. Total 81 term neonates with HIE underwent conventional EEG within six hours of birth using International 10-20 system, (modified for neonate) for electrode placement. At the time of discharge HNNE was performed. On follow-up (6 to 12 months), cerebral palsy was evaluated using HINE and modified Ashworth score, Developmental delay by Development Assessment Scale for Indian Infant (DASII) scale and for epilepsy by clinical history and EEG background activity. Association between EEG background activity, HNNE, HINE score and various short-term and long-term outcome was calculated using Chi-square test and Fisher’s-exact test. Results: In present study, out of 81 cases, 58 (71.6%) cases were male and 23 (28.4%) cases were female with mean Gestational Age (GA) of 39 weeks. A total of 57 neonates were discharged successfully after stay of mean duration 13.8 days in NICU. All neonates with normal/mildly abnormal EEG background activity had 100% survival rates whereas only 68.2% (15) and 37% (10) could be discharged from moderately abnormal and severely abnormal EEG background activity group. Out of discharged patients none with severely abnormal background had optimal HNNE whereas 75% (24) of mildly abnormal EEG had optimal HNNE score. Mean HNNE and HINE score was significantly lower in newborns with severely abnormal EEG (mean score 20.8) as compared to normal EEG group (mean score 30.3). Severely abnormal EEG at birth had significant association with cerebral palsy (p-value<0.0001), epilepsy (p-value= 0.003) and developmental delay (p-value<0.001) as compared to moderately and mildly abnormal EEG background activity in newborns with HIE. Conclusion: EEG within six hours of birth in term neonate with HIE has very high sensitivity and Negative Predictive Value (NPV) in predicting short-term outcome as death, poor neurological outcome and long-terms outcome as cerebral palsy, epilepsy and developmental delay.