Hemorrhagic Transformation of Arterial Ischemic and Venous Stroke in Children

Hemorrhagic transformation can complicate both arterial ischemic stroke and cerebral sinus venous thrombosis. Risk factors for hemorrhagic transformation after adult arterial ischemic stroke include larger infarct volume, cardioembolic stroke, and anticoagulation in the acute period. Large hemorrhagic transformation in adults is associated with poor outcome. Therefore hemorrhagic transformation is used as a safety end point for most arterial ischemic stroke acute treatment and secondary prevention trials. Up to 30% of children with arterial ischemic stroke have hemorrhagic transformation, most of which are petechial. As in adults, large infarct size is the greatest predictor of hemorrhagic transformation, but in children, acute anticoagulation is not a clear predictor of hemorrhage. As use of acute endovascular interventions for arterial ischemic stroke has expanded in adults, these therapies have also been used in some teenagers and even younger children. More information, including safety data with end points like hemorrhagic transformation, is needed in the pediatric population. In adults with cerebral sinus venous thrombosis, including those with hemorrhagic transformation, acute anticoagulation is associated with better outcomes and is the standard of care. Some hemorrhagic transformation may be evident at baseline in over half of children and neonates with cerebral sinus venous thrombosis. Anticoagulation-associated hemorrhage in pediatric cerebral sinus venous thrombosis occurs in about 10% of children but is not clearly related to outcome, whereas lack of anticoagulation may be associated with clot propagation and worse outcomes. This review provides background on hemorrhagic transformation of ischemic stroke in adults and summarizes literature regarding hemorrhagic transformation of pediatric arterial ischemic stroke and cerebral sinus venous thrombosis, with a focus on implications for acute treatment and outcome.