Perinatal Brain Injuries in Preterm Infants

Background

Preterm infants are vulnerable to brain injury because of immature white matter, vascular regulation, and neuroprotective mechanisms. White matter injury (WMI), formerly known as periventricular leukomalacia, is a major cause of cerebral palsy and neurocognitive impairment, while perinatal stroke is an important cerebrovascular cause of adverse outcomes. White matter injury: WMI is linked to hypoxia–ischemia, inflammation or infection, oxidative stress, and impaired oligodendrocyte maturation. It may be cystic or diffuse non-cystic, which is now the most common phenotype. Cystic lesions are strongly associated with motor impairment and spastic cerebral palsy, whereas diffuse injury is increasingly related to cognitive, behavioral, and language deficits. Diagnosis relies on cranial ultrasonography and MRI; prevention focuses on optimized perinatal care, infection control, respiratory stabilization, and neuroprotection. Perinatal stroke: Stroke in preterm infants may occur antenatally or neonatally and includes periventricular hemorrhagic infarction, perinatal arterial ischemic stroke, and cerebral sinovenous thrombosis. Periventricular hemorrhagic infarction is the most common subtype and is often associated with germinal matrix hemorrhage–intraventricular hemorrhage. Risk factors are multifactorial, including fetal, neonatal, placental, thrombotic, infectious, and hemodynamic contributors. Clinical signs may be subtle, making neuroimaging central to classification and prognosis.