Perinatal arterial stroke: understanding mechanisms and outcomes.

Arterial ischemic infarction occurring around the time of birth is an increasingly recognized cause of neurological disability in children. The rate of arterial infarction in neonates is as high as the annual incidence of large-vessel ischemic stroke in adults. Factors contributing to this increased risk of stroke among neonates include complications that occur before, during, and after delivery. Maternal conditions that have been associated with perinatal stroke in the fetus include prothrombotic disorders, cocaine abuse, and placental complications such as chorioamnionitis and placental vasculopathy. In many cases, the placenta is suspected to be the underlying embolic source for perinatal stroke, although data on placental pathology is often lacking. During the delivery process, an infant may develop a cervical arterial dissection that leads to stroke. Several conditions in the neonatal period predispose to perinatal stroke including prothrombotic disorders, congenital heart disease, meningitis, and systemic infection. Perinatal stroke may present with neonatal seizures during the first weeks of life or may be asymptomatic until months later when the infant is first noted to have pathological handedness. The outcome of perinatal stroke is variable and depends on severity, anatomic localization, and other factors not yet well characterized. As many as 50% of infants with documented stroke recognized in the newborn period do not develop a hemiparesis. The incidence, clinical presentation, pathogenesis, risk factors, and outcome of this increasingly recognized disorder are reviewed.