The impact of clinical seizures and adverse brain MRI patterns in neonates with hypoxic-ischemic encephalopathy and abnormal neurodevelopment.

Introduction: This study aimed to investigate the associations among seizures, clinical characteristics, and brain injury on Magnetic Resonance Imaging (MRI) in infants with Hypoxic Ischemic Encephalopathy (HIE), and to determine whether these findings can predict unfavorable neurodevelopmental outcomes.

Method: Clinical and electrographic seizures were assessed by amplitude-integrated electroencephalogram, and the extent of brain injury was evaluated by using MRI. At 12‒24 months of age, developmental impairment or death was assessed. Between 2012 and 2020, 143 newborns were admitted for HIE, and 8 infants were excluded from the study.

Results: Eighty-five infants were diagnosed with greater than moderate HIE and 65 infants underwent therapeutic hypothermia. In addition, 38 infants experienced clinical seizures (clinical seizure group, CSG), 49 infants had electrographic seizures (Electrographic Seizure Group, ESG), and 48 infants had no seizures (no seizure group, NSG). The proportion of infants with neurodevelopmental impairment or death was significantly higher in the CSG than in the NSG (57.7 % and 26.1 %, p = 0.026). A risk factor analysis indicated that cord blood pH (adjusted Odds Ratio [aOR = 0.01]; 95 % Confidence Interval [95 % CI 0.001‒0.38]; p = 0.015) and MRI findings (aOR = 4.37; 95 % CI 1.25‒15.30; p = 0.012) were independently associated with abnormal neurodevelopment, after adjustment.

Discussion: Clinical seizures in infants with HIE were independently associated with abnormal neurodevelopment. However, cord blood pH and abnormal brain MRI findings were consistently linked to long-term neurodevelopmental outcomes.