Cranial Magnetic Resonance Imaging Findings in Neonates with Mild Hypoxic-Ischemic Encephalopathy (Sarnat Stage I): A Retrospective Cohort Study

Objective: Perinatal asphyxia is among the leading causes of morbidity in the newborn period and can give rise to hypoxic-ischemic encephalopathy (HIE).While therapeutic hypothermia is well established for moderate-to-severe HIE, the optimal management of infants with mild HIE-Sarnat stage I-remains controversial.What is becoming increasingly clear, however, is that a mild HIE may not always be a benign condition and that subtle brain injury may be present even with a mild clinical presentation.We aimed to evaluate cranial magnetic resonance imaging (MRI) findings in newborns with perinatal asphyxia classified as Sarnat stage I and to explore whether infants with normal versus abnormal imaging differ in their clinical presentation or laboratory markers. Methods:We conducted a retrospective cohort study of newborns admitted to our neonatal intensive care unit with perinatal asphyxia who met the criteria for Sarnat stage I HIE.Demographic data, Apgar scores, umbilical cord blood gas values, maternal risk factors, and neuroimaging results were recorded.Cranial MRI scans were classified as normal or abnormal, and the two groups were compared.Results: Sixty-six neonates were enrolled.MRI was normal in 54 (81.8%) patients and abnormal in 12 (18.2%)patients.Infants in the abnormal group tended to have lower Apgar scores and more pronounced metabolic acidosis, although neither difference reached statistical significance.The most common abnormal findings were hemorrhagic in nature-subdural, intraventricular, and parenchymal hemorrhages each accounted for a third of abnormal scans. Conclusion:Nearly one-fifth of neonates with mild HIE demonstrated abnormal cranial MRI findings.Closer follow-up may be considered, since mild HIE may be associated with subclinical brain injury.