Hypoxic–ischemic Encephalopathy

Hypoxic–ischemic encephalopathy (HIE) is a type of brain injury caused by oxygen deprivation and/or impaired perfusion. Etiologies include perinatal asphyxia, cardiac arrest, or severe hypotension. Pathophysiology involves neuronal energy failure, excitotoxicity, oxidative stress, and cell death. Diagnosis is clinical, supported by neuroimaging and biomarkers of neuronal injury. Management includes supportive care, therapeutic hypothermia (in neonates), and neurorehabilitation; prognosis varies with severity, duration of hypoxia, and timing of interventions.