One study assessed the impact of hydroxyurea on secondary stroke prevention by enrolling 35 children who needed to discontinue their chronic transfusion protocol. The average hydroxyurea dose was 27 mg/kg/day, and the children were treated for a mean of 42 months. The rate of recurrent ischemic events was per 100 patient-years, which is better than was seen in another study in which children discontinued transfusions without starting hydroxyurea. One other study reported that brain images by magnetic resonance imaging (MRI) were stable during the course of treatment in 24 of 25 children. In the Belgian Registry, during 426.
