[Cerebral vasculopathy in pediatric sickle-cell anemia]

In children with sickle-cell anemia, cerebral vasculopathy is a frequent and severe complication. It is attributed not only to erythrocyte sickling but also to multiple physiological modifications associated with sickle-cell anemia: platelet and leukocyte activation, endothelial injury and remodeling, coagulation activation, hemolysis and subsequent chronic inflammation, impaired vasomotricity, etc. Intracranial large-vessel remodeling leads to clinical cerebral infarction, whereas microvascular injury and impaired vasoreactivity lead to so-called silent infarcts, which are actually associated with impaired cognitive development. Primary prevention strategies have been developed to screen children for cerebral vasculopathy and to further reduce stroke risk. Annual transcranial Doppler beginning at 2 years of age is recommended, allowing risk stratification. Patients at high risk are enrolled in a monthly transfusion exchange program, which reduces the risk of a first stroke by 90 %. Chronic transfusion therapy has also demonstrated efficacy in preventing a second stroke, as a secondary prevention strategy. Lifelong treatment is recommended, as recurrent stroke has been observed when transfusion is discontinued. The burden of chronic transfusion is heavy for patients. Furthermore, several studies have shown that, despite preventing clinically symptomatic stroke, chronic transfusion therapy may not be effective concerning silent infarct progression. Other therapeutic options are currently being explored to obtain better protection with reduced side effects.